Taking an Exposure History Case Study

Acknowledgements

We gratefully acknowledge the work of the medical writers, editors, and reviewers in producing this educational resource. Contributors to this version of the Case Study in Environmental Medicine are listed below.

Please Note: Each content expert for this case study has indicated that there is no conflict of interest that would bias the case study content.

ATSDR Authors: Dianyi Yu, MD

ATSDR Planners: Charlton Coles, PhD; Kimberly Gehle, MD, MPH; Sharon L. Hall, PhD; Delene Roberts MSMHC; Julia Smith, MPH, CHES; Germania Pinheiro MD, MSc, PhD; Dianyi Yu, MD

Peer Reviewers: Dan Middleton, MD; Mohammed S. Uddin, MD, MPH

Disclaimer and Disclosure

The state of knowledge regarding the treatment of patients potentially exposed to hazardous substances from both environmental and occupational sources is constantly evolving and is often uncertain. In developing its educational products, ATSDR has made a diligent effort to ensure the accuracy and the currency of the presented information. ATSDR, however, makes no claim that the environmental/occupational medicine and health education resources discussed in these products comprehensively address all possible situations related to various substances. The products are intended for educational use to build the knowledge of physicians and other health professionals in assessing the conditions and managing the treatment of patients potentially exposed to hazardous substances. The products are not a substitute for a health professional's judgment. Please interpret the environmental/occupational medicine and the health education resources in light of specific information regarding the patient and in conjunction with other medical authorities.

Use of trade names in ATSDR products is for identification purposes only and does not imply endorsement by the Agency for Toxic Substances and Disease Registry or the U.S. Department of Health and Human Services.

How to Use This Course

The goal of Case Studies in Environmental Medicine (CSEM) is to increase the primary care provider's knowledge of hazardous exposures and to help in evaluation and treatment of potentially exposed patients. This CSEM focuses on taking an exposure history.

To make the most effective use of this course:

• Take the Initial Check to assess your current knowledge about taking an exposure history.
• Read the title, learning objectives, text, and key points in each section.
• Complete the progress check exercises at the end of each section and check your answers.

Instructional Format

This course is designed to help you learn efficiently. Topics are clearly labeled so that you can skip sections or quickly scan sections with which you are already familiar. This labeling will also allow you to use this training material as a handy reference. To help you identify and absorb important content quickly, each section is structured as follows

Learning Objectives

Upon completion of the Taking an Exposure History CSEM, you should be able to perform the following learning objectives.

Initial Check

Instructions

This Initial Check will help you assess your current knowledge about taking an exposure history. To take the Initial Check, read the case below, and then answer the questions that follow.

Case Study

On Tuesday afternoon, a 52-year-old man with previously diagnosed coronary artery disease controlled by nitroglycerin describes episodes of recurring headache for the past 3 weeks. Mild nausea often accompanies the headache; there is no vomiting. He describes a dull frontal ache that is not relieved by aspirin. The patient states that the headaches are sometimes severe; at other times they are a nagging annoyance. The durations range from half an hour to a full day.

His visit was also prompted by a mild angina attack that he suffered this past weekend shortly after he awoke on Sunday morning. He has experienced no further cardiac symptoms since that episode.

History of previous illness indicates that the patient was diagnosed with angina pectoris 3 years ago. He has been taking 0.4 milligrams (mg) of sublingual nitroglycerin prophylactically before vigorous exercise. He also takes one aspirin every other day. He has been symptom-free for the past 2.5 years.

Sublingual nitroglycerin relieved the pain of the Sunday morning angina attack within several minutes.

The patient does not smoke and rarely drinks alcohol. He is a trim man with a slightly ruddy complexion.

At present, he is afebrile and his vital signs are

• Blood pressure 120/85,
• Pulse 80, and
• Respirations 20.

Physical exam is within normal limits.

The results of an electrocardiogram (ECG) with a rhythm strip performed in your office are unremarkable.

Subsequent laboratory testing reveals normal

• Blood lipids,
• Cardiac enzymes,
• Complete blood cell count (CBC),
• Sedimentation rate,
• Glucose,
• Creatinine, and
• Thyroid function.

Initial Check Questions

1. What would you include in the patient's problem list?
2. What would you include in the differential diagnosis?
3. What additional information would you seek to assist in the diagnosis?

Initial Check Answers

1. The patient's problem list includes recurrent headache and nausea, and unstable angina pectoris.
2. The patient's differential diagnosis of chest pain includes myocardial infarction. The differential diagnosis of headache and nausea includes tension headaches, migraine, brain tumor, tooth or sinus problems, psychogenic headache, medication reaction (nitroglycerin can cause headaches), viral syndrome, and exposure to toxicants (carbon monoxide, solvents).
3. The additional information sought to make a diagnosis would include all aspects of a work and environmental exposure history.

What is the Purpose of Taking an Exposure History?

Purpose

Most environmental and occupational diseases either manifest as common medical problems or have nonspecific symptoms. Unfortunately, hazardous exposures rarely enter into the clinician's differential diagnosis. As a result, clinicians may miss the opportunity to make correct diagnoses that might influence the course of disease. A correct diagnosis may help stop exposure and might prevent disease in others by avoiding exposure [Gehle et al. 2011; Goldman and Peters 1981].

What can a clinician do to improve recognition of disease related to current or past exposures?

• First, one must be suspicious and think about the possibility of environmental and occupational factors of disease.
• Next, one needs to incorporate an exposure history questionnaire into clinical practice.

This course illustrates the principles and practices involved in the development of a differential diagnosis that includes possible hazardous exposure related etiologies.

Benefits

Taking an exposure history may enable physicians to

• Make more accurate diagnoses,
• Influence the course of disease by stopping current exposure,
• Prevent disease in others by avoiding future exposure, and
• Prompt workplace evaluations and the protection of workers.

Goals

The goals of taking an exposure history are

• Identifying the hazard,
• Avoiding or stopping the exposure,
• Preventing disease,
• Identifying and treating disease early, and
• Arresting or reversing the progression of the patient's illness.

Exposure Factors and Etiology

The preceding case study describes a patient with angina. He has new, nonspecific symptoms of headache and nausea.

Suppose this patient lived near a hazardous waste site.

• Would your differential diagnosis change?
• If the patient refinished furniture as a hobby, would you consider this important?
• Is there a connection between his headaches and cardiac symptoms?
• How would you investigate the possible correlation?
• Could he be exposed to chemicals in his workplace?

Each of these factors could play a role in the etiology of this patient's illness; each exposure could cause disease.

Three Scenarios

The patient described in the case study – a 52-year-old male with angina – is portrayed in three scenarios throughout this document. An exposure history provides clues that prompt the clinician to investigate the possibility of toxic exposure.

• Scenario 1: This patient is an accountant who has had the same job and the same residence for many years.
• Scenario 2: This patient owns a commercial cleaning service and uses cleaning products at various industrial and commercial sites.
• Scenario 3: This patient is a retired advertising copywriter who lives in the vicinity of an abandoned industrial complex.

In each scenario, the clinician's pursuance of the exposure history led to discovery of toxic exposure in each of the three cases.

In each case, the diagnosis and treatment might have been inappropriate without an exposure history.

Etiology Denotes Environmental and Occupational Diseases

Most environmental and occupational diseases either manifest as common medical problems (e.g., rashes, asthma, angina, spontaneous abortion) or have nonspecific symptoms (e.g., headache, difficulty concentrating, behavioral problems, myalgias, difficulty conceiving) [Amdur MO 1991; Marshall et al. 2002; Wigle D 2000].

Establishing the etiology can distinguish a disorder as an environmental illness.

Unless an exposure history is pursued by the clinician, the etiologic diagnosis might be missed, treatment may be inappropriate, and exposure can continue.

Key Points

Most environmental and occupational diseases either manifest as common medical problems or have nonspecific symptoms. Unless an exposure history is pursued by the clinician, the etiologic diagnosis might be missed, treatment may be inappropriate, and exposure can continue.

The goals of taking an exposure history are

• Identifying the hazard,

• Avoiding or stopping the exposure,

• Preventing disease,

• Early identification and treatment of disease, and

• Arresting or reversing the progression of the patient's illness.

Progress Check

1. Which of the following statements about taking an exposure history is NOT TRUE?

A. Most environmental and occupational diseases have specific symptoms.

B. An exposure history provides clues that prompt the clinician to investigate the possibility of toxic exposure.

C. Etiology distinguishes a disorder as an environmental or occupational illness.

D. Taking an exposure history may enable physicians to influence the course of disease.

Answer

The best choice and false statement is A. Choice A is NOT TRUE because most environmental and occupational diseases either manifest as common medical problems or have nonspecific symptoms.

Choice B is true because an exposure history may provide clues that prompt the clinician to investigate the possibility of toxic exposure.

Choice C is true. Etiology distinguishes a disorder as an environmental or occupational illness.

Choice D is true. Taking an exposure history may enable physicians to influence the course of disease by avoiding or stopping exposure, thus preventing disease, identifying and treating disease early, and/or arresting or reversing progression of disease.

What Role Do Primary Health Care Providers Have in Detecting, Treating and Preventing Disease Resulting from Toxic Exposures?

Environmental and occupational factors contribute to more than 25% of all global disease [Smith et al. 1999; WHO 2007], and toxic agents ranked fifth in underlying causes of U.S. deaths in 2000 [Mokdad et al. 2004].

Many people with illness caused or exacerbated by exposure to hazardous substances obtain their medical care from clinicians who are not specialists in environmental or occupational medicine.

Consideration of environmental and occupational exposures rarely enters into the clinician's history taking or diagnosis [Marshall et al. 2002]. Environmental medicine education is largely omitted in the continuum of U.S. medical education, leaving future physicians and current practitioners without expertise in environmental medicine to provide or facilitate environmental preventive or curative patient care [Gehle et al. 2011].

What Happens in the Clinical Setting

A chart review of 2,922 histories taken by 137 third-year medical students showed that smoking status was documented in 91%, occupation in 70%, and specific occupational exposures in 8.4% of the total number of cases. Patients less than 40 years of age and women were significantly less likely than older patients or men to have their occupation and industry noted [Marshall et al. 2002; McCurdy et al. 1998].

Findings from another study showed that work-related issues might not be adequately addressed or documented in the provider's clinical notes and that opportunities for preventive care relating to work-related injuries and illnesses may not be realized in the primary care setting [Thompson et al. 2000].

A recent report about U.S. medical schools disclosed that graduating students received inadequate instruction in environmental health [AAMC 2010].

A recent national online survey of American Congress of Obstetricians and Gynecologists (ACOG) fellows showed that among 2,514 survey responses, 50% reported that they rarely take an environmental health history; less than 20% reported routinely asking about environmental exposures commonly found in pregnant women in the United States; and only 1 in 15 reported any training on the topic [Stotland et al. 2014].

Practicing primary care physicians report the need for environmental medicine education to better recognize, diagnose, and treat patients in their clinical practice with environmental related illness [Gehle et al. 2011].

What Clinicians Need to Do

The single most important aspect of the approach to patients with potential occupational or environmental disease is to have a high index of suspicion and to follow through on that suspicion [Frank AL 2000].

Although many clinicians recognize the importance of taking a work and exposure history to evaluate certain problems, most have had little training or practice in doing so [Becker 1982; Frank AL 2000; Gehle et al. 2011; Kilpatrick et al. 2002; Merritt 1999; Pope AM and Rall DP 1995; Stotland et al. 2014].

There are numerous resources available to practitioners who may want to spend the time and effort needed to better understand environmental and occupational issues.

Extensive knowledge of toxicology is not needed to diagnose environmental and occupational disease. The criteria employed are the same as those used for diagnosing other medical problems:

• History, including onset and temporal pattern of symptoms, noting palliative and provocative factors;
• Physical examination; and
• Laboratory results.

If necessary, consultation with other health professionals such as industrial hygienists or occupational health nurses may facilitate the gathering of useful information concerning exposures. See Additional Environmental Health Resources for additional information.

Industrial hygienists, who are often employed by state health departments or industry, are a source of information to the clinician investigating a possible toxic exposure. Industrial hygiene is the discipline devoted to the recognition, evaluation, and control of workplace-related factors or stresses that may cause illness, impaired health or well-being, or significant discomfort and inefficiency among workers or community members. They can be helpful in assessing whether a significant exposure has occurred.

Occupational health nurses, who often work at patients' work sites, also have expertise and experience that may be valuable to the clinician.

Medical specialists, such as board certified clinicians specializing in occupational and environmental medicine or medical toxicology can assist the primary health care provider in the evaluation and management of patients exposed or potentially exposed to hazardous substances.

For more information on clinical consultation resources, please see Additional Environmental Health Resources.

In addition to current exposures, the clinician must consider the long-term or latent effects of past exposures to agents such as asbestos, radiation, and chemical carcinogens.

Taking an exposure history creates the opportunity to counsel patients in appropriate preventive behaviors to mitigate or limit their exposure risk.

Exposure History Form

The exposure history form can be completed by the clinician, other office staff, or by the patient. This information will help guide the clinician through various aspects of the process. This form elicits many important points of an exposure history, including job descriptions and categories associated with hazardous substances, or physical and biologic agents. In addition, it may suggest temporal and activity patterns related to environmental and occupational disease.

The form explores past and current exposures and comes in several formats including an editable electronic version (see the Appendix I for more information on available formats).

Process Takes Just a Few Minutes

Taking an exposure history requires only a few minutes and can be

• Abbreviated,
• Expanded, or
• Focused according to the patient's signs and symptoms.

The exposure history form is designed for quick scanning of important details. Its contents can be added to the electronic health record as baseline information that may aid in the investigation of current or future problems.

An exposure history should be taken on every patient. It is of particular importance if the patient's illness occurs at an atypical age or is unresponsive to treatment.

Use Sound Judgement

The diagnosis of environmental and occupational disease cannot always be made with certainty. Sound clinical judgment must be used and common etiologies should be considered. The multi-factorial nature of many conditions, particularly chronic diseases, should not be overlooked.

The clinician must also keep in mind that many organ systems are affected by toxic exposures. Exposure and effects can be acute or chronic. The latency period from exposure to disease manifestation can vary, ranging from immediate to delayed (hours or days) or prolonged (decades).

Conclusion

With practice using the exposure history form and utilizing appropriate clinical resources when necessary, the primary care clinician can play an important role in the detection, treatment, and prevention of diseases that may result from toxic exposures.

Progress Check

2. Which of the following statements is true?

A. Taking an exposure history requires lots of the clinician's time.

B. Extensive knowledge of toxicology is needed to diagnose environmental and occupational diseases.

C. Many primary care clincians have had little training or practice in taking an exposure history.

D. Many people with illness caused or exacerbated by exposure to hazardous substances obtain their medical care from occupational and environmental medicine or medical toxicology specialists.

Answer

The best choice is C. Many primary care clinicians have had little training or practice in taking an exposure history. Although many clinicians recognize the importance of taking a work and exposure history to evaluate certain problems, many have had little training or practice doing so.

Choice A is NOT TRUE. Taking an exposure history requires only a few minutes of the clinician's time and can be abbreviated, expanded, or focused according to the patient's signs and symptoms.

Choice B is NOT TRUE. Extensive knowledge of toxicology is NOT generally needed to diagnose environmental and occupational disease. The same criteria are employed as those used in diagnosing other medical problems: history, including onset and temporal pattern of symptoms and palliative and provocative factors; physical examination; and laboratory results.

Choice D is NOT TRUE. Many people with illness caused or exacerbated by exposure to hazardous substances obtain their medical care from primary health care providers and NOT from clinicians with experience and expertise in evaluating and managing patients exposed or potentially exposed to hazardous substances (such as occupational and environmental medicine specialists or medical toxicologists).

3. Taking an exposure history is an important component in daily clinical settings because without it

A. An etiologic diagnosis might be missed.

B. Treatment may be inappropriate.

C. Exposure can continue.

D. All of the above.

Answers

The best choice is D, All of the above. In each clinical case, the diagnosis and treatment might have been inappropriate without an exposure history; and exposure may continue. Use of an exposure history to manage patient problems and guide patients toward appropriate preventive behaviors, demonstrates its value as an important preventive tool.

Which Organ Systems are Affected

All organ systems can be targets of toxic exposures. Different hazards affect various and differing organ systems [Nelson et al. 2011; Pope AM and Rall DP 1995]. Specific current information about the adverse effects of exposures to chemical and biological agents can be obtained from several publicly available resources mentioned in the Additional Environmental Health Resources section.

Respiratory

The respiratory system is both a target organ and a portal of entry for toxicants. Asthma morbidity and death from asthma are increasing. More than 100 toxicants cause asthma, and many more can exacerbate it [Rom 2007].

A large number of xenobiotics and occupations are associated with the development of work-aggravated and work-related asthma. Many high molecular weight xenobiotics, usually plant or animal derived, have been identified, such as

• Arthropod and mite related materials,
• Latex,
• Flour,
• Molds,
• Endotoxins, and
• Biological enzymes.

Lower molecular weight xenobiotics associated with work-related asthma include

• Isocyanates (used in spray paints and foam manufacturing),
• Cleaning agents,
• Anhydrides,
• Amines,
• Dyes, and
• Glues [Nelson et al. 2011].

Skin

Irritant and allergic contact dermatitis account for 90% of occupational skin disorders. Other skin disorders with occupational/environmental exposure etiologies include

• Pigment alterations,
• Chloracne,
• Urticaria, and
• Malignant neoplasms [Levy BS and Wegman DH 2011].

Children appear particularly at risk for toxicity from percutaneous absorption because their skin is more penetrable than an adult's, and specific anatomic sites, such as the face, often represent larger percentage of body surface areas than in the adult [Nelson et al. 2011].

Liver and Kidney

The liver is the primary site of biotransformation and detoxification of xenobiotics. Clinical presentations of toxic liver injury range from indolent, often asymptomatic progression of impairment of hepatic function to rapid development of hepatic failure [Nelson et al. 2011].

The kidneys are exposed to exogenous or endogenous xenobiotics in their role as primary defenders against harmful xenobiotics entering the bloodstream. The environment, the workplace, and, especially, the administration of medications, represent potential sources of nephrotoxicity. Organic solvents and heavy metals are two major classes of toxicants known to adversely affect renal function [Nelson et al. 2011; Pope AM and Rall DP 1995].

Nervous System

Neurotoxicants can cause

• Peripheral neuropathy,
• Ataxia,
• Parkinsonism,
• Seizures,
• Coma, and
• Death.

Many chemicals cause mild central nervous system depression that may be misdiagnosed as inebriation and, if undetected, can progress to psychoses or dementia. Sensory impairment can also be caused by exposure to toxicants (e.g., visual disturbances caused by methanol) and physical agents (e.g., hearing impairment caused by loud noise) [Nelson et al. 2011; Pope AM and Rall DP 1995; Rom 2007].

Reproductive

Toxicants that target the reproductive system can cause a variety of adverse effects. These effects may include

• Early or delayed puberty,
• Early pregnancy loss,
• Fetal death,
• Impaired fetal growth,
• Infertility,
• Low birth weight,
• Menstrual irregularities,
• Premature birth,
• Structural (e.g., cardiac defect) or functional (e.g., learning disability) birth defects, and
• Subfertility.

The impact of exposure to a reproductive toxicant may not be immediately evident. Instead, the effects may emerge at key life transitions. For example:

• When attempting conception,
• During pregnancy,
• During development of the embryo or fetus,
• in the newborn, and
• During the offspring's childhood, puberty, and eventual fertility as an adult [Association of Reproductive Health Professionals 2010; Sutton et al. 2012].

Cardiovascular and Hematologic

The cardiovascular and hematologic systems are frequent targets of toxicants. Chemical substances may produce adverse effects on the cardiovascular system by acting on the myocardial cells or the autonomic nervous system to affect the:

• Heart rate,
• Blood pressure, or
• Cardiac contractility.

Lead, carbon disulfide, arsenic, cadmium, ozone, and vinyl chloride have all been implicated in the etiology of cardiovascular disease. Benzene can cause bone marrow changes leading to

• Aplastic anemia,
• Acute leukemia, and
• Chronic myelogenous leukemia [Kim et al. 2012; Nelson et al. 2011; Patel et al. 2014; Pope AM and Rall DP 1995; Rom 2007; Zeliger 2013].

Key Points

All organ systems can be targets of toxic exposures.

Progress Check

4. Exposure to which of the following hazards are best known to target the renal system?

A. Asbestos and tobacco smoke.

B. Organic solvents and heavy metals.

C. Carbon monoxide and nitrates.

D. Noise and vinyl chloride.

Answers

The best choice is B. Organic solvents and heavy metals are two classes of hazards whose known target organs include the renal system.

Asbestos and tobacco smoke in choice A are two hazards whose known target organs include the respiratory system.

Carbon monoxide and nitrates in choice C are two hazards whose known target organs include the cardiovascular system.

Noise and vinyl chloride in choice D are two hazards whose known target organs include the central nervous system.

What are Possible Sources of Indoor Air Pollution?

Indoor air pollution can pose a serious health threat. EPA studies indicate that the levels of many air pollutants may be two to five times higher in indoor air than outdoor air. In some cases, indoor air pollutants may even be 100 times higher than outdoors. High levels of indoor pollutants are of particular concern because people may spend as much as 90% of their time indoors [American Lung Association 2010; U.S. Consumer Product Safety Commission (CPSC) 2012; US Environmental Protection Agency 2012a].

The clinician should consider the following possible sources of indoor air pollution when eliciting information on exposures. Possible indoor contaminants include

• Asbestos,
• Biologic agents,
• Building materials,
• Radon,
• Tobacco smoke, and
• Wood stoves, gas range, or other heating devices.

The content in this section focuses on the above potential sources of indoor air pollution. The next section discusses additional potential exposure sources and pathways to hazardous substances in the home and environment that may also contribute to poor indoor air quality and pose exposure and health risks.

Environmental Tobacco Smoke

Environmental tobacco smoke (ETS) is the mixture of smoke that comes from the burning end of a

• Cigarette,
• Pipe, or
• Cigar

as well as smoke exhaled by the smoker. It is a complex mixture of over 4,000 compounds, more than 40 of which are known to cause cancer in humans or animals and many of which are strong irritants. ETS is often referred to as secondhand smoke and exposure to ETS is often called passive smoking. In general, children's lungs are more susceptible to harmful effects from ETS than adults. In infants and young children up to 3 years, exposure to ETS causes an approximate doubling in the incidence of

• Pneumonia,
• Bronchitis, and
• Bronchiolitis [U.S. Consumer Product Safety Commission (CPSC) 2012; US Environmental Protection Agency 2012a].

ETS is an entirely preventable public health hazard and strongly linked to major respiratory diseases such as asthma and lung cancer [Dhala et al. 2006; DHHS 2014].

Gas Space Heaters, Wood Stoves, and Gas Ranges

In addition to environmental tobacco smoke, other sources of combustion products include

• Fireplaces,
• Gas stoves,
• Unvented kerosene and gas space heaters, and
• Woodstoves.

The major pollutants released include

• Carbon monoxide,
• Nitrogen dioxide,
• Radon, and
• Particulates.

Unvented kerosene heaters may also generate acid aerosols.

Combustion gases and particulates also come from chimneys and flues that are improperly installed or maintained and cracked furnace heat exchangers. Pollutants from fireplaces and woodstoves with no dedicated outdoor air supply can be back-drafted from the chimney into the living space, particularly in weatherized homes [US Environmental Protection Agency 2012a].

Wood stoves, when not properly maintained and vented, emit noxious substances including

• Carbon monoxide,
• Oxides of nitrogen,
• Particulates, and
• Hydrocarbons.

Studies have shown that children living in homes heated with wood stoves have a significant increase in respiratory symptoms compared with children living in homes without wood stoves [Belanger and Triche 2008].

Gas ranges, which may produce nitrogen oxide, a respiratory irritant, are used for cooking in more than half of the homes in the United States [Belanger and Triche 2008].

Building Materials

Building materials, home improvement products, and textiles used in the home can pose health risks. For example, formaldehyde volatilizes from pressed wood products made using adhesives that contain urea-formaldehyde (UF) resins. Pressed wood products made for indoor use include

• Particleboard (used as subflooring and shelving and in cabinetry and furniture),
• Hardwood plywood paneling (used for decorative wall covering and used in cabinets and furniture), and
• Medium density fiberboard (used for drawer fronts, cabinets, and furniture tops).

Formaldehyde exposure can cause

• Watery eyes,
• Burning sensations in the eyes and throat,
• Nausea, and
• Difficulty in breathing in some humans exposed to elevated levels (above 0.1 parts per million).

Higher environmental concentrations may trigger breathing problems in people with asthma that are exposed. There is evidence that some people can develop sensitivity to formaldehyde. It has also been shown to cause cancer in animals and possibly in humans [US Environmental Protection Agency 2012a].

Asbestos

Asbestos is most commonly found in older homes [US Environmental Protection Agency 2012a]) in

• Pipe and furnace insulation materials,
• Asbestos shingles,
• Millboard,
• Textured paints and other coating materials,
• Floor tiles, and
• Ceiling titles and panels.

Intact, undisturbed asbestos-containing materials generally do not pose a health risk. Elevated concentrations of airborne asbestos can occur after asbestos-containing materials are disturbed by

• Cutting,
• Sanding or
• Other remodeling activities.

Improper attempts to remove these materials can release asbestos fibers into the air in homes, increasing asbestos levels and endangering people living in those homes. Exposure to these fibers has been associated with

• Lung cancer,
• Asbestosis, and
• Mesothelioma [US Environmental Protection Agency 2012a].

Smoking cigarettes with exposure to asbestos has a multiplicative effect on the risk of developing lung cancer (higher than the lung cancer risk from smoking alone or from asbestos exposure alone) [Agency for Toxic Substances and Disease Registry 2001].

For more information on asbestos, please see Additional Environmental Health Resources.

Radon

The most common source of indoor radon is uranium in the soil or rock on which homes are built. As uranium naturally breaks down, it releases radon gas (which is a colorless, odorless, radioactive gas). Radon gas enters homes through

• Dirt floors,
• Cracks in concrete walls and floors,
• Floor drains, and
• Sumps.

Exposure to radon becomes a concern when radon becomes trapped in buildings and concentrations increase indoors. Lung cancer is the predominant health effect associated with exposure to elevated levels of radon. Radon causes thousands of preventable lung cancer deaths each year. EPA estimates that radon causes about 14,000 deaths per year in the United States; however, this number could range from 7,000 to 30,000 deaths per year. For persons that smoke and have high home radon levels, the risk of developing lung cancer is especially high [US Environmental Protection Agency 2012a].

For more information on radon, please see Additional Environmental Health Resources.

Biological Agents

Biological agents include

• Animal dander, saliva, urine,
• Bacteria,
• Cockroaches,
• House dust mites,
• Mildew,
• Molds,
• Pollen, and
• Viruses.

Sources of indoor biologic pollutants include plants, people, and animals. Building materials and/or conditions that support the growth, concentration or dissemination of indoor biologic pollutants should also be considered. It is important not to overlook these potential sources of biologic pollutants. Contaminated central air handling systems can become breeding grounds for

• Mold,
• Mildew, and
• Other sources of biological contaminants

that can be distributed throughout the home.

Some biological contaminants trigger allergic reactions, including

• Allergic rhinitis,
• Hypersensitivity pneumonitis, and
• Some types of asthma.

Infectious illnesses, such as influenza, measles, and chicken pox are transmitted through the air. Molds and mildews release disease-causing toxins. Symptoms of health problems caused by biological pollutants include [US Environmental Protection Agency 2012a]

• Coughing,
• Digestive problems,
• Dizziness,
• Fever,
• Lethargy,
• Shortness of breath,
• Sneezing, and
• Watery eyes.

Key Points

It is important not to overlook potential exposure sources of indoor air pollution.

Progress Check

5. Which of following statements is NOT TRUE?

A. Smoking cigarettes in additional to being exposed to asbestos increases the risk of cancer by an order of magnitude above smoking alone or asbestos exposure alone.

B. Building materials, home improvement products, and textiles used in the home can pose health risks.

C. Environmental tobacco smoke (ETS) is a public health hazard.

D. Radon rarely causes lung cancer.

Answer

The best choice and false statement is D. Radon progeny attach to airborne particulates such as cigarette smoke or dust and can be inhaled. During subsequent decay, the progeny emit high-energy alpha particles that may injure adjacent bronchial cells, thereby causing lung cancer. EPA estimates that radon contributes to between 7,000 and 30,000 lung cancer deaths each year.

Choice A is true. Smoking cigarettes in addition to being exposed to asbestos increases the risk of cancer by an order of magnitude above smoking alone or asbestos exposure alone. EPA estimates that radon contributes to between 7,000 and 30,000 lung cancer deaths each year.

Choice B is true. Building materials, home improvement products, and textiles used in the home can pose health risks. EPA estimates that radon contributes to between 7,000 and 30,000 lung cancer deaths each year.

Choice C is true. Environmental tobacco smoke (ETS) is an entirely preventable public health hazard. EPA estimates that radon contributes to between 7,000 and 30,000 lung cancer deaths each year.

What are Other Potential Sources and Pathways of Hazardous Exposure in the Home and Environment?

This section discusses additional sources and pathways of exposure to hazardous substances in the home and environment that the health care provider should consider when taking an exposure history. The clinician should also consider the following possible sources when eliciting information on exposures in the home and environment:

• Household products,
• Lead products and waste,
• Pesticides,
• Recreational hazards,
• Soil contamination, and
• Drinking Water supply.

For educational resources on these and related topics, please see Additional Environmental Health Resources.

Household Products

The following household products are potential sources of exposure that should be considered when taking an exposure history:

• Aerosol sprays,
• Air fresheners,
• Automotive products,
• Candles (leaded wick),
• Cleansers,
• Disinfectants,
• Dry-cleaned clothing,
• Fuels,
• Hobby supplies,
• Moth repellents,
• Paint strippers and other solvents,
• Paints, and
• Wood preservatives.

EPA's Total Exposure Assessment Methodology (TEAM) studies found levels of about a dozen common organic pollutants to be 2 to 5 times higher inside homes than outside, regardless of whether the homes were located in rural or highly industrial areas. Commonly used compounds that can have serious adverse health effects are listed in the table below [US Environmental Protection Agency 2012a].

Pesticides

Pesticides are potentially hazardous, especially to children. Pesticide exposure can occur through

• Dermal contact,
• Inhalation, or
• Ingestion.

According to a recent survey, 75% of U.S. households used at least one pesticide product indoors during the past year. Products used most often were insecticides and disinfectants. Another study suggests that 80% of most people's exposure to pesticides occurs indoors and that measurable levels of up to a dozen pesticides have been found in the air inside homes [US Environmental Protection Agency 2012a].

Exposure to high levels of cyclodiene pesticides, commonly associated with misapplication, has produced various symptoms, including

• Dizziness,
• Headaches,
• Muscle twitching,
• Nausea,
• Tingling sensations, and
• Weakness.

In addition, EPA is concerned that cyclodienes might cause long-term damage to the liver and the central nervous system, as well as an increased risk of cancer [US Consumer Product Safety Commission (CPSC) 2012; US Environmental Protection Agency 2012a].

Despite the ban on certain pesticides in the United States, exposure can still occur through improper

• Use,
• Storage, and
• Disposal.

Some banned pesticides are used in foreign countries and may return to this country on imported foods. There have been reports of unlicensed pesticide applicators in the United States spraying inside homes with pesticides intended for use in outdoor settings resulting in illness and even death [Wasley et al. 2002]. Proper use (including use of licensed pesticide applicators, following all product safety instructions, etc.) and storage of household pesticides in their original containers along with proper cleaning of food, especially raw fruits and vegetables, can help protect consumers.

Lead

Lead poisoning continues to be a significant health problem in the United States. Although lead was banned from paint for home use in 1978, millions of homes, particularly those built before 1950 still contain high amounts of lead in paint that is peeling and accessible for ingestion by children.

Lead has long been recognized as a harmful environmental pollutant. Humans are exposed to lead through many ways including through

• Air,
• Drinking water,
• Food,
• Contaminated soil,
• Deteriorating paint, and
• Dust.

Airborne lead enters the body when an individual breathes or swallows lead particles or dust once it has settled. Lead was used in

• Gasoline,
• Paint,
• Water pipes, and
• Many other products

before it was known how harmful it could be.

Old lead-based paint is the most significant source of lead exposure in the United States today. Harmful exposures to lead can be created when lead-based paint is improperly removed from surfaces by

• Dry scraping,
• Open-flame burning, or
• Sanding.

Lead affects practically all systems within the body. At high exposure dose levels it can cause

• Convulsions,
• Coma, and
• Even death.

Lower exposure dose levels of lead can adversely affect the

• Brain,
• Central nervous system,
• Blood cells, and
• Kidneys.

The effects of lead exposure on fetuses and young children can be severe. They include

• Delays in physical and mental development,
• Increased behavioral problems,
• Lower IQ levels, and
• Shortened attention spans.

Fetuses, infants, and children are more vulnerable to lead exposure than adults since lead is more easily absorbed into growing bodies, and the tissues of small children are more sensitive to the damaging effects of lead. Children may have higher exposures since they are more likely to eat lead paint chips in addition to having lead dust on hands or toys/objects that they may place in their mouths. [Agency for Toxic Substances and Disease Registry 2005; US Environmental Protection Agency 2012a].

Additional information on this topic can be found in the Additional Environmental Health Resources.

Recreational Hazards

Recreational areas and products can pose a hazard to health.

The United States has made tremendous advances in the past 25 years to clean up the aquatic environment by controlling pollution from industries and sewage treatment plants. Today, nonpoint source (NPS) pollution remains the nation's largest source of water quality problems. It's the main reason that approximately 40% of our surveyed rivers, lakes, and estuaries are not clean enough to meet basic uses such as fishing or swimming [US Environmental Protection Agency 2012b].

Wooden playground structures that have not been treated with protective sealants may expose children to potentially hazardous wood preservatives. Chromated copper arsenate (CCA) is a chemical wood preservative containing chromium, copper, and arsenic. It is used in pressure treated wood to protect wood from rotting due to insects and microbial agents. CCA treated wood has a greenish tint and has been used in thousands of

• Decks,
• Picnic tables,
• Play sets, and
• Railings.

The EPA has worked with manufacturers since 2003 to eliminate CCA from children's play structures. Unfortunately, many older playgrounds still exist [US Envirronmental Protection Agency 2011].

Some play sands and clays have been reported to contain asbestos-like fibers. Other materials used in arts and crafts involve potentially hazardous:

• Heavy metals such as lead and cadmium,
• Silica,
• Solvents, and
• Talc.

Toxic materials may be encountered in

• Making stained glass and jewelry,
• Model building,
• Oil and airbrush painting,
• Soldering, and
• Woodworking.

Persons do not need to be directly involved in these activities to become exposed; merely being in the vicinity of a work area may lead to exposure.

Federal legislation (the Labeling of Hazardous Art Materials Act) requires that all chronically hazardous materials be labeled as inappropriate for children's use [US Consumer Product Safety Commission (CPSC) 1995].

Drinking Water Supply

Both contaminated public drinking water supplies and contaminated private wells may be sources of toxic exposure, especially for industrial solvents, heavy metals, pesticides, and fertilizers. For example, an EPA groundwater survey [US Environmental Protection Agency 1985] detected trichloroethylene in approximately 10% of the wells tested. It is estimated to be in 34% of the nation's drinking water supplies. Up to 25% of the water supplies have detectable levels of tetrachloroethylene. Some solvents can volatilize from showers and during laundering of clothes, thereby creating a risk of toxicity via inhalation. Nitrates, a common contaminant of rural shallow wells, pose a risk of methemoglobinemia, especially to infants [Agency for Toxic Substances and Disease Registry 1997, 2013].

Contamination of drinking water supplies may come from the source water and/or the distribution system after water treatment has already occurred. There are many potential sources of water contamination, including

• Local land use practices (fertilizers, pesticides, concentrated feeding operations),
• Manufacturing processes,
• Naturally occurring chemicals and minerals (for example, arsenic, radon, uranium), and
• Sewer overflows or wastewater releases.

The presence of contaminants in water may lead to adverse health effects if exposure occurs, including

• Gastrointestinal illness,
• Neurological disorders, and
• Reproductive problems.

Infants, young children, pregnant women, the elderly, and people whose immune systems are compromised (i.e., those with AIDS, undergoing chemotherapy, on transplant medications, etc.), may be especially susceptible to illness from some contaminants [US Centers for Disease Control and Prevention 2014].

Soil Contamination

Ingestion of contaminated soil poses a risk of toxicity, especially to children under the age of six, because of natural mouthing or pica behaviors. Lead is a common soil contaminant. Dioxin also adsorbs to soils. Certain pesticides such as chlordane can remain in the soil for years.

Sources of soil contamination include

• Agriculture,
• Chemical and microbial contaminants,
• Municipal wastewater (and associated biosolids), and
• Industry.

Chemical contaminants range from heavy metals like mercury to polychlorinated biphenyls (PCBs) to relatively new emerging contaminants. Sediments and soils may contain multiple chemical contaminants combined with microbial pathogens. Emerging contaminants of concern such as endocrine-disrupting chemicals (EDCs) that might be found in soil, may come from municipal wastewater, concentrated animal feeding operations (CAFOs) and other sources [US Environmental Protection Agency 2013].

Key Points

The clinician should consider all possible sources and exposure pathways to hazardous substances when eliciting information on exposure(s) in the home and environment.

Progress Check

6. Which of the following statements is NOT TRUE?

A. Lead is a common soil contaminant.

B. Fishing and swimming in contaminated lakes and streams may exposure participants to toxins contained in polluted waters.

C. Both contaminated public drinking water supplies and contaminated private wells may be a source of toxic exposure.

D. Lead poisoning is not a significant health problem in the United States.

Answer

The best choice and false statement is D. Lead poisoning continues to be a significant health problem in the United States. Although lead was banned from paint for home use in 1978, millions of homes, particularly those built before 1950, may still contain high amounts of lead in paint that is peeling and accessible for ingestion by children.

Choice A is true. There are many ways in which humans are exposed to lead through Air, Drinking water, Food, Contaminated soil, Deteriorating paint, and Dust. Lead is a common soil contaminant and lead poisoning continues to be a serious health problem in the United States.

Choice B is true. Contaminated recreational areas and products have the potential to adversely affect health. For example, fishing and swimming in contaminated lakes and streams may pose an exposure risk to toxins contained in polluted waters. Lead is a common soil contaminant and lead poisoning continues to be a significant health problem in the United States.

Choice C is true. Both contaminated public drinking water supplies and contaminated private wells may be sources of toxic exposure, especially for Industrial solvents, Heavy metals, Pesticides, and Fertilizers. Lead is a common soil contaminant and lead poisoning continues to be a serious health problem in the United States.

What Are the Components of an Exposure History?

What should an Exposure History be Composed Of?

An exposure history has three components:

1. Exposure Survey,
2. Work History, and
3. Environmental History.

The main aspects of an exposure history (summarized in Table 4) will be elicited through the exposure history form. For the sample form and links to available formats, see Appendix I.

Although a positive response to any question on the form indicates the need for further inquiry, a negative response to all questions does not necessarily rule out a toxic exposure etiology or significant previous exposure. Each clinical encounter may not require an extensive environmental and occupational exposure evaluation, but having exposure history information in the patient's medical record can alert the health care provider to potential exposure risks that may lead to adverse health effects. As in all data-gathering activities, sound clinical judgment should be exercised when analyzing and interpreting patient data within a clinical context.

Part 1. Exposure Survey

• Exposures
  • Current and past exposure to metals, dust, fibers, fumes, chemicals, biologic hazards, radiation, noise, and/or vibration,
  • Typical workday (job tasks, location, materials, and agents used),
  • Changes in routines or processes, and
  • Other employees or household members similarly affected.
• Health and Safety Practices at Work Site
  • Ventilation,
  • Medical and industrial hygiene surveillance,
  • Employment exams,
  • Personal protective equipment (e.g., respirators, gloves, and coveralls),
  • Lockout devices, alarms, training, and drills,
  • Personal habits (Smoke and/or eat in work area?),
  • Wash hands with solvents?,
  • Shower before leaving work?,
  • Change shoes and clothing before leaving work?, and
  • Launder work clothing at work?

Part 2. Work History

• Description of all previous jobs including short-term, seasonal, and part-time employment and military service, and
• Description of present jobs.

Part 3. Environmental History

• Present and previous home locations,
• Present and previous daycare/school settings (as applicable),
• Jobs of household members,
• Home insulating and heating and cooling system,
• Home cleaning agents,
• Pesticide exposure,
• Water supply (especially drinking water supply),
• Recent renovation/remodeling,
• Air pollution, indoor and outdoor,
• Hobbies and recreational activities (e.g., painting, photography, sculpting, welding, woodworking, piloting, restoring automobiles, shooting firearms, creating stained glass, creating ceramics, soldering, and gardening),
• Hazardous wastes/spill exposure,
• Home ventilation/moisture control/flooding, and
• Food source(s).

Key Points

• Each clinical encounter may not require an extensive environmental and occupational exposure evaluation, but having exposure history information in the patient's medical record can alert the health care provider to potential exposure risks that may lead to adverse health effects.
• It is important for primary health care providers to obtain a complete exposure history for the medical record of each patient.
• Obtaining the components of the exposure history can be accomplished in several ways including patient assisted completion of exposure history forms.

Progress Check

7. Which of the following statements in NOT TRUE?

A. All patients should complete the exposure history forms, although the form may not need extensive evaluation in every clinical situation.

B. A negative response to all questions should rule out a toxic exposure etiology or significant previous exposure.

C. An exposure history form has three components: exposure history, work history, and environmental history.

D. Hobbies are generally a very important part of the environmental history.

Answer

The best choice and false statement is B. Although a positive response to any question on the form indicates the need for further inquiry, a negative response to all questions does not necessarily rule out a toxic exposure etiology or significant previous exposure.

Choice A is true. All patients should complete exposure history forms, although the form may not need extensive evaluation in every clinical situation. Negative response to all questions does not rule out a toxic exposure etiology or significant previous exposure.

Choice C is true. An exposure history form has three components: Exposure survey, Work history, and Environmental history. Negative response to all questions does not rule out a toxic exposure etiology or significant previous exposure.

Choice D is true. Hobbies are generally a very important part of the environmental history. Negative response to all questions does not rule out a toxic exposure etiology or significant previous exposure.

What is Included in the Exposure Survey (Part 1) of an Exposure History Form?

Past and current exposures are recorded on Part 1 of an Exposure History Form (Appendix I), which is designed for easy completion by the patient and a quick scan for pertinent details by the clinician.

The questions are crafted to investigate

• Changes in routines and work site characteristics,
• Details about known toxicant exposure,
• Known exposure to metals, dust, fibers, fumes,
• Chemicals, physical agents, and biologic hazards,
• Other persons affected,
• Protective equipment use,
• Temporal patterns and activities, and
• Personal habits.

If the patient answers yes to one or more questions on Part 1, the clinician should follow up by asking the patient progressively more detailed questions about the possible exposure. Special attention should be directed to the

• Route,
• Dose,
• Duration, and
• Frequency of any identified exposure.

Let's now work on the case presented at the beginning of this case study.

Scenario 1

• 52-year-old male accountant with angina
• Chief complaints: headache and nausea

The chart of the patient described in Scenario 1 of the case study reveals that he has worked as an accountant in the same office for the past 12 years. On Part 1 of the completed Exposure History Form, he indicates that no other workers are experiencing similar or unusual symptoms, and he denies recent changes in his job routine.

The patient was asked these three questions: "Are family members experiencing the same or unusual symptoms?", "Do your symptoms get either worse or better at work?", and "Do your symptoms get either worse or better on weekends?". His explanations of these answers reveal a possible temporal relationship between his symptoms and his home.

The clue and the clinician/patient dialogue follow.

Sample Dialogue

Clinician: I see that you noted that your wife is having headaches.

Patient: Yes; frequently. She has had more than usual in the last 3 or 4 weeks. She usually has one every month or so; this past month she had three.

Clinician: You also stated that your headaches are worse on weekends.

Patient: Yes, they seem to be. If I wake up on a Saturday or Sunday with a headache, it usually gets worse as the day progresses. In fact, that's usually when I feel nauseated too.

Clinician: Do your symptoms seem to be aggravated by certain activities around the home? A hobby or task?

Patient: No, I usually wake up with the headache. I don't think there's a connection with anything I do.

Clinician: Do your symptoms change at all at work?

Patient: Now that you mention it, if I wake up with a headache, by the time I get to work – it takes about 25 minutes – the headache is usually gone.

Clinician: Your angina attack occurred on a Sunday morning. Describe your weekend leading up to the attack.

Patient: It was a fairly quiet weekend. We had dinner at home Friday evening and just relaxed. On Saturday I spent the day packing old books and storing them in the attic and chopping and stacking firewood. I took one nitroglycerin tablet before doing the heavy work, at about 2:00 PM. Saturday night we had friends over for dinner. We had a fire in the fireplace and visited until about 11:00 PM. I had one glass of wine with dinner. I was beginning to feel a little stiff and sore from the work I did that afternoon. Sunday morning I woke up with a headache again. A few minutes after awakening, while I was still in bed, I had the attack. It was mild, not the crushing pain I've had in the past. I had the headache all day.

Dialogue Analysis and Conclusion

The preceding dialogue reveals that the patient's symptoms may be associated with the home environment, and his cardiac symptoms, headache, and nausea may be related.

His symptoms seem to be exacerbated at home and lessen at work. Further questioning is needed to pursue this lead.

Further Sample Dialogue

Clinician: What does your wife do for a living?

Patient: She's an attorney.

Clinician: Do either of you have a hobby?

Patient: My hobby is photography. My wife is an avid gardener.

Clinician: I assume this is digital photography? Have you ever been involved with non-digital photography using film and chemical processing of prints?

Patient: No, digital photography only.

Clinician: Does your wife use any pesticides or chemicals in the garden?

Patient: No, she does strictly organic gardening and uses only natural means of pest control.

Clinician: Do you work on your car?

Patient: No.

Clinician: Have you gotten any new furniture or remodeled your home in the past few years?

Patient: No.

Clinician: What is your source of heating and cooking in the home?

Patient: We have a natural gas, forced-air heating system. We cook with gas and use the fireplace a lot in winter for supplemental heat.

Clinician: How long have you lived in this home and how old is your furnace?

Patient: We've lived there for 23 years. The furnace was replaced about 12 years ago.

Clinician: I see that you recently insulated your home. What exactly did you do?

Patient: Yes. Last month I added extra insulation to the attic, insulated the crawl space, replaced all the windows with double-paned windows, and weatherized all doorways.

Clinician: Have you noticed that the headaches coincide with days you have used the fireplace?

Patient: There could be a connection. I definitely use the fireplace more on weekends. This past Saturday I had a fire blazing all day.

Dialogue Analysis and Conclusion

A temporal relationship between the headaches and being in the home has been revealed. Some sources of toxicants have been eliminated (formaldehyde and other volatile organic chemicals from new furniture and rugs and toxic chemicals used in hobbies – gardening).

There may be a correlation between symptoms and use of the fireplace. The fireplace could increase negative pressure in the house, causing back drafting of furnace gases. The furnace is old; it may be malfunctioning or producing excessive carbon monoxide. The patient's symptoms, including his angina attack, would be consistent with carbon monoxide poisoning.

Although the patient's symptoms could be associated with his preexisting disease, evidence is strong enough at this point to investigate the possibility of a contributing environmental exposure.

It would be appropriate to ask the patient to contact the local gas company to check the furnace and stove for malfunctions and leaks. The fireplace should be checked for proper drafting and for deposits of creosote in the chimney.

A carboxyhemoglobin (COHb) level on the patient may confirm carbon monoxide poisoning. The patient should be advised to ventilate the house until the furnace is checked or to stay out of the house until the gas company deems it safe.

COHb levels are important in the diagnosis of carbon monoxide exposure. In nonsmoking patients, a COHb level greater than 5% confirms exposure (Tomaszewski 1999). A COHb level performed on this patient is 6%, which is high for a nonsmoker. The gas company discovers a cracked heating element in the 12-year-old furnace, which resulted in the circulation of carbon monoxide throughout the house. The use of the fireplace most likely increased the back drafting of fumes. The furnace is replaced, the exposure ceases, and the patient's symptoms abate.

The exposure history form may also alert the clinician to past exposures.

Most often, neither the job title nor the patient's initial description of job duties reveal clues of exposure. It is usually helpful to have a patient describe a routine work day, as well as unusual or overtime tasks. Patients tend to use jargon when describing their jobs. It is the clinician's challenge to persistently question the patient to elucidate possible exposures; it is not necessary to have foreknowledge of a particular trade. Start with general questions and work toward obtaining more specific exposure related details.

Part 1 of the form reveals another clue – this patient was exposed to asbestos about 30 years ago. The questioning that the clinician conducts, despite having neither knowledge of the patient's trade nor understanding of the jargon, follows.

Further Sample Dialogue about Asbestos Exposure

Clinician: You state here that you were exposed to asbestos, fiberglass, and welding fumes way back in 1976.

Patient: Yes, during my days as a shipwright.

Clinician: Did you actually handle the asbestos?

Patient: No, the pipe laggers were the tradesmen that handled the asbestos. Oh, you might be setting a bracket or plate next to a pipe and accidentally hit the pipe and dislodge some asbestos, but otherwise, shipwrights didn't handle it. You only had asbestos where there were steam lines from the boiler carrying high-pressure steam to other units like a winch or an auxiliary motor.

Clinician: What does a shipwright do? What was a routine day for you?

Patient: There was no routine day. The shipwrights were the cream of the journeymen crop; we did everything from outfitting, to establishing the cribbing on the launching gang, to shoring. I worked on the outfitting docks. We did ship reconversion. I did a lot of work on the forepeak and hawse pipes when I wasn't working below deck.

Clinician: What exactly were your tasks below deck?

Patient: Most transporters were converted to passenger ships after the war; there was a lot of shifting of equipment and pipes. Basically, the ships were gutted. They would be completely revamped. The shipwrights would do all the woodworking, finish work, plates, and so on. Then, when everything was in place, it would be insulated, and the pipes would be lagged.

Clinician: So you worked throughout the ship? And when you finished your tasks, the laggers would come in?

Patient: No. There might be 10 different tradesmen working in an afterpeak at one time. You'd be working next to welders, flangers, pipe fitters, riveters, laggers; you name it. These conversions were done round-the-clock, seven days a week; it could take a year and a half to complete a conversion. All the tasks were being done simultaneously.

Clinician: How long would the lagging take?

Patient: The lagging could take 6 to 10 months, sometimes longer. They were constantly cutting these sections of asbestos to fit the pipes. Then they would attach the sections with a paste and wrap it with asbestos wrapping.

Clinician: Could you see the asbestos in the air?

Patient: Oh yes. Sometimes it was so thick you couldn't see 5 feet in front of you. It was white and hung in the welding fumes like smog.

Clinician: Did you use any protective equipment? Masks? Respirators?

Patient: No. Nobody ever said it was dangerous. We were bothered more by the fiberglass and welding fumes than anything. We thought fiberglass was more dangerous because it was itchy and caused a rash. The air was blue from the welding fumes; if you worked in that for a year, you knew it was affecting you. It inspired me to go back to school and get my accounting degree. But we were blue-collar workers; we were more concerned with welders' flash, a boom breaking, or someone getting crushed between plates than we were with asbestos.

Clinician: You worked as a shipwright for 6 years?

Patient: Yes, about that. Five of those years as an outfitter on conversions.

Dialogue Analysis and Conclusion

The dialogue in which the clinician engaged the patient neither determines whether the patient's asbestos exposure was significant, nor does it confirm that he suffered adverse effects from the exposure. It is merely a starting point for investigation.

The questioning establishes that approximately 30 years ago this patient received a possibly severe exposure to asbestos fibers for duration of 5 or 6 years. Because quantitative data on this patient's exposure are likely impossible to obtain, a qualitative description ("Sometimes it was so thick you couldn't see 5 feet in front of you") can facilitate assessment of the exposure when consulting with an occupational medical specialist.

In this scenario, the disclosure should prompt the clinician to, along with baseline physical exam and laboratory testing/imaging results, monitor the patient closely for early detection of treatable health effects from asbestos exposure. A chest radiograph would be advised, and pulmonary function tests should be considered. When investigating possible asbestos related pulmonary effects, a NIOSH certified B-reader is recommended for standardized rating of chest x-ray findings. However, it should be noted that persons with asbestos related disease may have a normal chest x-ray. Influenza and pneumococcal vaccines should be offered in accordance with Centers for Disease Control and Prevention guidelines as well as other applicable recommended preventive services.

Consulting an occupational medical specialist could help determine the best way to evaluate and treat this patient.

In this scenario, the clinician successfully diagnosed an illness likely due to an environmental toxic exposure (carbon monoxide) and noted a significant past exposure (asbestos) that needs follow-up.

Had the clinician failed to pursue an exposure history, the patient's current illness might have been misdiagnosed, treatment might have been inappropriate, and/or measures might not have been implemented to prevent further carbon monoxide exposure. This could have led to continuing harmful health effects for the patient and other residents of the household from carbon monoxide poisoning.

Key Points

• It is not necessary to understand the jargon of a particular trade; persistent questioning by the clinician can clarify the tasks involved and this may reveal possible exposures.
• If a patient responds positively to one or more questions on Part 1 of an Exposure History Form, the health care provider should follow up by asking the patient progressively more detailed exposure related questions.
• The clinician should pay special attention to the route, dose, duration, and frequency of any identified exposure.
• Along with baseline physical exam and laboratory testing/imaging results, the clinician should perform any necessary monitoring for early detection of treatable health effects associated with identified exposure(s).
• Consultation with board certified specialists in occupational medicine can assist the primary health care provider with the assessment and management of exposed or potentially exposed patients.

Progress Check

8. If the patient answers "yes" to one or more questions on Part 1 of an Exposure History Form, the clinician should do what?

A. Follow up by asking the patient progressively more detailed questions about the possible exposure.

B. Pay special attention to the route, dose, duration, and frequency of any identified exposure.

C. Along with baseline physical exam and laboratory testing/imaging results, perform any recommended monitoring for early detection of treatable health effects.

D. All of the above.

Answer

The best choice is D. If the patient answers YES to one or more questions on Part 1 of an Exposure History Form, the clinician should follow up by asking the patient progressively more detailed questions about the possible exposure, pay special attention to the route, dose, duration, and frequency of any identified exposure, and along with baseline physical exam and laboratory testing/imaging results, perform any necessary monitoring for early detection of treatable health effects.

Although it is true that if the patient answers YES to one or more questions on Part 1 of an Exposure History Form, the clinician should follow up by asking the patient progressively more detailed questions about the possible exposure, it is also true that the clinician should pay special attention to the route, dose, duration, and frequency of any identified exposure, and along with baseline physical exam and laboratory testing/imaging results, perform any necessary monitoring for early detection of treatable health effects.

What Is Included in the Work History (Part 2) of an Exposure History Form?

Nearly 3 million nonfatal workplace injuries and illnesses were reported by private industry employers in 2012. This resulted in an incidence rate of 3.4 cases per 100 equivalent full-time workers according to estimates from the Survey of Occupational Injuries and Illnesses (SOII) conducted by the U.S. Bureau of Labor Statistics. The rate reported for 2012 continues the pattern of statistically significant declines that, with the exception of 2011, occurred annually for the last decade [US Department of Labor 2012].

Primary care providers see an estimated 80% of occupational and environmental-related illnesses. The work history represents the primary tool for recognizing work-related medical injuries and diseases [Thompson et al. 2000].

Part 2 of the Exposure History Form is a comprehensive inventory of hazardous exposures in the patient's present and past occupations.

In evaluating Part 2 of the form, the clinician should note every job the patient has had, regardless of duration. Information on part-time and temporary jobs could provide clues to toxic exposure. Details of jobs may reveal exposures that are not expected based on the job titles. Asking if any processes or routines have been changed recently can be helpful. Military service may have involved toxic exposure.

Scenario 2

• 52-year-old male who owns a commercial cleaning service
• Chief complaints: headache and nausea

Scenario 2 involves another instance of a 52-year-old male who is brought in by his wife to see his primary care physician for an evaluation.

He has been in excellent health until approximately 1 week ago, when he began staying up later and later at night according to the wife. She was not too concerned until he began awakening her to talk about the "revolutionary" new ideas he had about creating an international, commercial cleaning service. She notes he was "full of energy" and talked rapidly about many ideas that he had. She became quite concerned when at 3:00 A.M. (European time) her husband called the manager of the rayon mill, who was in Europe, to discuss his ideas. He then began telephoning European banks in an attempt to find partners for his business venture. When his wife confronted him about the inappropriateness of his phone calls, he became enraged and accused her of purposefully attempting to sabotage his venture.

The patient complains of recurring headaches and nausea that started approximately 1 to 2 weeks ago and of recent angina attacks. This patient is the owner of a commercial cleaning service and is extremely proud to tell the clinician he performs some of the cleaning himself.

Questioning the patient extensively about the cleaning products fails to yield any suspicious exposure possibilities. Reviewing Part 2 of the Exposure History Form, the clinician notes

• Detergents,
• Ammonia, and
• Cleansers.

Pursuance of Part 2, Work History, however, reveals a clue. The clinician's investigation follows.

Sample Dialogue

Clinician: You own a commercial cleaning service?

Patient: Yes. I've been in business for 10 years, and I'm going to be worldwide. Would you like to purchase stock in my company?

Clinician: We can discuss that a little later. Do you do the cleaning yourself?

Patient: I don't do as much as I used to. I have a crew of about 6 full-time employees. I do more managing than cleaning, but have been known to roll up my sleeves and pitch in when needed.

Clinician: You clean residences and commercial businesses?

Patient: Yes, I currently have 20 residential accounts and 15 commercial accounts, but have I told you that I will be international?

Clinician: Yes, you did, but right now I'd like to know about the commercial accounts that are local.

Patient: The local ones are downtown administrative offices for the school district, several realty offices downtown, and the business offices of the viscose rayon mill. I have 6 accounts in the Shaw Building downtown (small medical offices) and 5 retail stores in the Hilltop Mall, but I don't know why you will not listen to how I will revolutionize the commercial cleaning industry. I'm in touch with people that control the world currency markets. I know this because God spoke to me, telling me how to corner the cleaning market.

Clinician: That is interesting and I'd like to hear more after we finish covering a few more questions about your health.

Patient: Okay, I guess I can answer a few more questions...but you will want to hear about this lucrative opportunity!

Clinician: So your headaches have been occurring for about 1 week now? Have there been any changes in your routine – work or otherwise – in the last week?

Patient: I've worked more hours than usual over the last week. I've been doing a special project for the rayon mill. They built new offices. We moved all the old offices into the new building. That has entailed cleaning and moving

• Furniture,
• Files,
• Books, and
• Exhibits.

It's been tedious, but I have plenty of energy. Fortunately, most of the staff members have been either out on vacation or at an international conference in Europe, so the building has been empty.

Clinician: Are any of your workers having similar symptoms?

Patient: No, nobody else has complained about feeling sick.

Clinician: What exactly do they produce at that plant?

Patient: They make viscose – transparent paper. I used to work there during summers when I was in college. It was hot, hard work. The whole place smelled like sulfur – rotten eggs. We used wood pulp cellulose, treated it with acids and other chemicals, and made cellulose filaments. I worked on the:

• Blending,
• Ripening, and
• Deaeration process.

You know I called the plant manager to help his business grow to international status.

Clinician: Can you smell the chemicals in the office building you're working in?

Patient: Some days there's a faint odor. Nothing like when I worked on the xanthating process. The business office building is on the northeast end of the complex. It's pretty remote from the processing plant.

Clinician: So how many extra hours have you worked the past week?

Patient: Only about 4 to 6 hours more per day this past week. Also, this past weekend I put in an extra 10 hours. I had to finish setting up the exhibits. I didn't trust the crew to handle the fragile exhibits, so I did the job myself. My crew is good but not as good as me.

Patient's wife: Tell the doctor about the bottle you broke!

Patient: On Friday, about 2 weeks ago, I worked late setting up a huge model of the xanthating process. It was tedious work and I was stressed by the time constraints to get the job done. I had broken a bottle from the exhibit when I disassembled the thing. I'm really not certain that I broke the bottle; it most likely was stored improperly.

Clinician: What was in this bottle you broke?

Patient: I think it was carbon disulfide. I think I might have put the broken glass and the cleanup rags on the floor of my truck. This stuff had a sweet odor.

Clinician: How did you clean it up?

Patient: I changed into some protective clothing and a face mask because my eyes and nose burned. There wasn't a lot to clean up because it seemed to evaporate quickly.

Clinician: Did you get any of the chemical on you?

Patient: I don't think any got on me when the bottle fell, but I'm not certain.

Clinician: How much of the chemical was in the bottle? Did you report the accident to anyone at the plant?

Patient: The bottle was about liter size. It wasn't full. There was only a small amount of liquid in the bottle. No, I didn't report the accident. Frankly, I cleaned it up the way I was taught when I worked at the mill before. They know that I'm good. I helped them to become the organization they are today. I'll just talk with the manager when he returns from Europe later this week.

Dialogue Analysis and Conclusion

The preceding conversation reveals a possible connection with the spill and this patient's symptoms. It warrants further investigation. The results of the patient's physical examination are normal, and the mental status exam shows symptoms and behavior that are typical of a manic episode. The patient is

• Grandiose,
• Irritable,
• Has a marked decrease in his need for sleep,
• Has pressured speech, and
• Possibly is having auditory hallucinations.

The patient identifies the chemical spilled as carbon disulfide, which is consistent with the patient's symptoms.

After obtaining permission from the patient, the clinician calls to consult with the poison control center regarding this patient's carbon disulfide exposure.

Sample Dialogue About the Call

Clinician: My patient is a contract employee at a local textile company. He thinks he broke a bottle that was labeled carbon disulfide in the process of his work. He didn't report the accident and just cleaned it up himself. I am concerned that he may be experiencing health effects from the possible exposure. He is complaining of

• Nausea,
• Headache, and
• Difficulty sleeping

and appears to be exhibiting signs of

• Agitation,
• Grandiose delusions,
• Pressured speech, and
• Possible auditory hallucinations.

Poison Control Center: It would not surprise me. Carbon disulfide is a dangerous substance. Strict industrial controls should be in effect to prevent exposure. This chemical can cause

• Nausea,
• Headache,
• Insomnia,
• Agitation,
• Mania, and
• Hallucinations,

all the symptoms your patient seems to be currently experiencing. The acute symptoms are mild to moderate irritation of skin, eyes, and mucous membranes from liquid or concentrated vapors. Skin absorption causes

• Headache,
• Fatigue,
• Unsteady gait,
• Vertigo,
• Hyperesthesia,
• Central nervous system depression,
• Garlicky breath,
• Nausea,
• Vomiting,
• Diarrhea,
• Abdominal pain,
• Coma,
• Convulsion, or
• Death.

Clinician: Can you send me information on carbon disulfide?

Poison Control Center: Certainly. I'll send you the information on carbon disulfide right away. I suggest that the accident be reported to the safety manager at the textile plant.

Dialogue Analysis and Conclusion

Consultation with the Occupational and Environmental Physician from the Poison Control Center confirms that this patient's symptoms could indeed be caused by exposure to carbon disulfide.

The clinician orders a

• CBC;
• ECG;
• Urinalysis;
• Liver, kidney, and thyroid function tests;
• Blood serology; and
• An electrolyte panel.

The clinician received a digital Material Safety Data Sheet (MSDS) on carbon disulfide (see Appendix II) from the textile plant safety manager.

The clinician reviews the Health Hazard Data section of the MSDS, and notes all pertinent information in the patient's medical record, along with the prior information sent electronically from the Poison Control Center.

Air sampling in the office in which the incident occurred reveals airborne concentrations of 0.8 parts of carbon disulfide per million parts of air (0.8 ppm). The Occupational Safety and Health Administration (OSHA) enforceable standard (permissible exposure limit or PEL) for carbon disulfide in workplace air is 20 parts per million (ppm) averaged over 8 hours of exposure. The concentrations were most likely much higher at the time of the incident 2 weeks ago. However, exposure to carbon disulfide has continued for a limited number of hours each week and the patient drives around with the contaminated rags and bottle in his truck.

Results of the laboratory tests on this patient are all within normal limits. Other employees at risk of exposure from this spill are also examined; none incurred acute exposure or suffered ill effects. Once the patient's exposure ceases he improves and experiences no further symptoms.

Key Points

• Primary care providers see an estimated 80% of occupational and environmentally related illnesses.
• In evaluating patient's work history, the clinician should note every job the patient had, regardless of duration.

Progress Check

9. In evaluating work history, the clinician should

A. Note every job the patient had, regardless of duration.

B. Pay attention to the information on part-time, temporary jobs and details of jobs including specific job tasks.

C. Ask if any processes or routines have been changed recently.

D. All of the above.

Answer

The best choice is D. In evaluating Part 2, Work History of the Exposure History Form, the clinician should note every job the patient had, regardless of duration. Information on part-time and temporary jobs could provide clues to toxic exposure. Details of jobs (including specific job tasks) may reveal exposures that are not expected based on the job titles. Asking if any processes or routines have been changed recently can also be helpful.

Although it is true that in evaluating Part 2, Work History of the Exposure History Form, the clinician should note every job the patient had (regardless of duration), the clinician should also pay attention to the information on part-time, temporary jobs, and details of jobs (including specific job tasks as they may reveal exposures that are not expected based on the job titles), and ask if any processes or routines have been changed recently.

What Is Included in the Environmental History (Part 3) of an Exposure History Form?

Part 3 of the Exposure History Form contains questions regarding the home and surrounding environment(s) of the patient. Dialogue with the patient should include queries about

• The location of the house,
• The house and drinking water supply, and
• Changes in air quality.

The dialogue should also include other potential exposure settings such as

• Daycare,
• Recreational and/or
• School environments, as applicable.

Proximity to industrial complexes and hazardous waste sites could result in residents being exposed to toxicants in the air, water, or soil. Contamination in communities is a growing public health concern; affected persons usually seek care from their primary care providers first. If a group of people with similar symptoms and exposures is identified, and an environmental problem is suspected, the clinician should call the state health department or the Agency for Toxic Substances and Disease Registry toll-free at 1-888-42-ATSDR (1-888-422-8737).

Hobbies are also potential sources of toxicant exposure. For instance,

• Gardening,
• Model building,
• Photography,
• Pottery-making,
• Silk screening,
• Stained-glass making, and
• Woodworking

have all been associated with exposure to hazardous substances. Ask the patient what his or her hobbies are. All members in a household may be exposed to the hazardous substances from one person's hobby, and small children may be especially susceptible. For more information on taking a complete exposure history for adults and for children, please see "What Are Additional Environmental Health Resources?" section.

Scenario 3

• 52-year-old male, retired advertising copywriter with angina
• Chief complaints: headache and nausea

Scenario 3 involves another patient described in the case study. In this scenario, the patient has been retired for two years; he took early retirement from a stressful job in advertising shortly after being diagnosed with angina.

The patient's answers to the questions on the Exposure Survey (Part 1 of the form) were no: he denies exposure to

• Chemicals,
• Dust,
• Fibers,
• Metals,
• Physical and biologic agents, and
• Radiation.

He is not aware of a connection between his symptoms and activity or time; and to his knowledge, other persons are not experiencing similar symptoms.

A clue appears on Part 3 of this patient's exposure history – the patient lives two miles from an abandoned industrial site, and prevailing winds blow toward his house.

In an effort to investigate this lead, the clinician initiates the following dialogue.

Sample Dialogue

Clinician: You state that you live several miles downwind from an abandoned industrial site. Do you know what chemicals might have been used at the site or what type of industry it was?

Patient: There was a fire at the site several weeks ago. The newspaper said that they used methylene chloride to make some kind of plastic. The firefighters found drums of methylene chloride buried on the property.

Clinician: Do you ever smell chemicals in the air?

Patient: Yes, in the mornings when the wind blows from that direction, I smell a sweet odor. My neighbors have mentioned it too. In fact, they told me that the smell is really strong when they do laundry or dishes, and when they shower.

Clinician: Have you smelled it in your water?

Patient: No.

Clinician: What is the source of your home and drinking water?

Patient: I have city water, but my neighbors have a private well.

Clinician: Do you know if any agency is testing your neighborhood for contamination?

Patient: Not as far as I know.

Dialogue Analysis and Conclusion

The preceding dialogue has uncovered the possibility that the patient was exposed to a toxicant. Furthermore, this patient may represent an index case; others may also be exposed. To follow up this lead, the clinician contacts the state health department. The health department confirms that the site contains buried drums of methylene chloride and that it is under investigation.

An industrial hygienist employed by the health department informs the clinician that the methylene chloride can indeed exacerbate signs and symptoms of angina. The odor threshold for the chemicals is 100-300 parts per million (ppm). An 8-hour exposure to 250 methylene chloride can cause a COHb level of about 8%.

The laboratory reports that the patient's COHb is 6%, indicating probable exposure to methylene chloride in this nonsmoker. COHb, which forms when methylene chloride metabolizes to carbon monoxide, can be detected in blood at levels of 4% to 9% when ambient air concentrations of methylene chloride are about 220 ppm. Many factors can influence body burden, including

• Exposure level and duration,
• Route of exposure,
• Physical activity, and
• Amount of body fat.

A conference call is made, and

• The emergency response coordinator,
• A toxicologist,
• An industrial hygienist, and
• A physician discuss the patient's signs and symptoms.

The clinician is given publicly available contact information on board certified specialists with expertise and experience in treating patients exposed to hazardous substances including methylene chloride.

Although the levels are above background levels, the health department's tests of ambient air reveal no immediate crisis in the vicinity, although the levels are above background levels; test results of water samples from private wells in the area are pending. ATSDR informs the EPA regional office of the situation. EPA provides immediate assistance to the affected area, cleanup is initiated, and threats to the surrounding population are mitigated.

Key Points

• Contamination in communities is a growing public health concern; affected persons usually seek care from their primary health care providers first.
• All members in a household may be exposed to the hazardous substances from one person's hobby; small children may be especially susceptible.
• Ask the patient about residence water supply, proximity to industrial sites, etc. as valuable exposure source clues.

Progress Check

10. Which of the following statements is correct?

A. Contamination is communities is a growing public health concern; affected persons usually seek care from their primary care providers first.

B. If a group of people with similar symptoms and exposures is identified, and an environmental exposure problem is suspected, the clinician should call the EPA.

C. When a person's hobby is identified as a possible exposure risk, questions should focus on the patient's exposure as household members are generally not at risk.

D. None of the above.

Answer

Choice A is correct. Proximity to industrial complexes and hazardous waste sites could result in residents being exposed to toxicants in the air, water, or soil. Contamination in communities is a growing public health concern; affected persons usually seek care from their primary care providers first.

Choice B is NOT CORRECT. If a group of people with similar symptoms and exposures is identified, and an environmental exposure problem is suspected, the clinician should call the state health department or the Agency for Toxic Substances and Disease Registry toll-free at 1-888-42-ATSDR (1-888-422-8737).

Choice C is NOT CORRECT. When a person's hobby is identified as a possible exposure risk, further questioning should investigate potential exposure to both the patient and other household members.

The choice D is NOT CORRECT. Proximity to industrial complexes and hazardous waste sites could result in residents being exposed to toxicants in the air, water, or soil. Contamination in communities is a growing public health concern; affected persons usually seek care from their primary care providers first. If a group of people with similar symptoms and exposures is identified, and an environmental exposure problem is suspected, the clinician should call the state health department Agency for Toxic Substances and Disease Registry toll-free at 1-888-42-ATSDR (1-888-422-8737). When a person's hobby is identified as a possible exposure risk, further questioning should investigate potential exposure to both the patient and other household members.

What Instructions Should Be Given to Patients?

Health care providers should educate patients about the many steps they can take to prevent exposure to hazardous substances in the home, other non-work and workplace settings [Association of Reproductive Health Professionals 2010]. Providers also should advise patients who work in occupations such as

• Agriculture,
• Construction,
• Gardening,
• Landscaping, or
• Pest control

about limiting or mitigating chemical exposure at the workplace. It is important for health care providers to know about exposures to potentially hazardous materials their patients have had throughout their life. To do this, patients need to describe

• Workplace exposures,
• Exposures at home, and
• Other exposures they may have had.

To obtain a complete, detailed exposure history, physicians need to be able to communicate in a way that facilitates this process. Letting the patient know the purpose and the importance of providing detailed information before and during the history taking process may increase the quality and quantity of information received. Obtaining this information is vital toward preventing exposure or exposure related adverse health effects.

Physicians should also provide patient self-care advice, clinical follow-up instructions, and fully address patient questions using appropriate risk communication messaging techniques. By utilizing effective risk communication techniques, the clinician can promote patient behaviors that may reduce risk of exposure and exposure related adverse health effects.

Preventive messages targeted to at risk populations are also important in preventing adverse health effects from exposure.

Imparting the Importance of the Exposure History

Patients need to understand that unless an exposure history is pursued by the clinician, the etiologic diagnosis might be missed, treatment may be inappropriate, and exposure can continue.

Use of effective risk communication strategies while taking an exposure history can facilitate the gathering of complete, detailed information.

When Counseling Patients, Providers Should

When counseling patients, providers should

• Recommend that patients try to become familiar with all chemicals used or encountered in their work and non-work settings and learn about the potentially toxic properties of these chemicals.
• Direct patients to appropriate sources of information about chemicals.
• Instruct patients on steps to take to mitigate exposure or refer them to their employer or to an environmental and occupational health expert who can suggest exposure-reducing strategies (e.g., substitute a safer chemical, wash exposed skin, launder clothing from work separately to prevent contamination of other clothing, etc.)
• Ask if patients have access to and are using appropriate protective gear.
• Advise patients to avoid contact with clothing, shoes or other "take home" work items that other household members may bring home if there is a potential for toxicant exposure.
• Advise patients to take extra care to avoid exposure if they are pregnant or planning pregnancy because standard personal protective equipment may not be sufficient to guard from exposure to reproductive toxicants. Advise them to change clothes before leaving the workplace and to have potentially contaminated clothing laundered at work, if possible.

Patient Self Care and Clinical Follow Up Instructions

Self-care advice creates awareness and suggests actionable behaviors that may reduce the risk of exposure to hazardous substances in the work and non-work setting as well as exposure related adverse health effects. Patients should be advised to consult their physician if they or their children develop signs or symptoms that may indicate exposure related adverse health effects.

Where Can Patients Get Information About Their Exposures?

There are many printed and online sources of information about exposure to hazardous substances including many federal government agencies like ATSDR, NIOSH, OSHA, and EPA. Universities and U.S. Poison Control Centers may also be able to supply information about potential health hazards.

Key Points

• Patients need to understand why an exposure history is important.
• Patients should be given instructions on how to prevent exposure to hazardous substances in both work and non-work environments.
• Primary health care providers and patients should be aware of the many publicly available clinical, environmental and occupational health informational and educational resources available to them.
• ATSDR has developed Patient Education and Care Instruction Sheets that may facilitate health care provider communications and follow up with the patient.
• Physicians should provide patient self-care advice and clinical follow up instructions using appropriate risk communication messaging techniques.

Progress Check

11. When counseling patients, providers should

A. Instruct patients on steps to take to mitigate exposure.

B. Direct patients to appropriate sources of information about chemicals.

C. Advise patients to take extra care to avoid exposure if they are pregnant or planning pregnancy.

D. Provide patient self-care advice and clinical follow up instructions using effective risk communications messaging techniques.

E. All of the above.

Answer

The best choice is E. When counseling patients, providers should instruct patients on steps to take to mitigate exposure, direct patients to appropriate sources of information about chemicals, advise patients to take extra care to avoid exposure if they are pregnant or planning pregnancy, and provide patient self-care advice and clinical follow up instructions using effective risk communication messaging techniques.

Additional Environmental Health Resources

This section provides a resource listing for more information on

• Hazardous exposures from environmental and occupational sources,
• Potential adverse health effects, and
• The prevention, evaluation, treatment and management of exposed or potentially exposed patients.

It serves as an overview rather than an exhaustive list of publicly available resources that may be of use to the primary health care provider in providing care to patients exposed or potentially exposed to hazardous substances from environmental and occupational sources.

Publicly available clinical consultation and referral resources are available to assist primary health care providers in the detection, treatment, and prevention of disease(s) resulting from toxic exposure(s). Many federal agencies including

• The Agency for Toxic Substances and Disease Registry (ATSDR),
• The Centers for Disease Control and Prevention (CDC),
• The U.S. Environmental Protection Agency (EPA),
• The National Institute of Occupational Safety and Health (NIOSH), and
• The Occupational Safety and Health Administration (OSHA)

are appropriate sources for information about exposure to hazardous substances and potentially related adverse health effects. Universities and U.S. Poison Control Centers may also be able to supply information about potential health hazards. Many of these same resources can be valuable sources of information for lay audiences.

A variety of printed and online sources, including books, databases, journals, websites, and information can also be obtained from sources such as U.S. Poison Control Centers, board certified specialists with expertise and experience in treating patients with exposures to toxic substances, government agencies, employers, health departments, manufacturers, and unions.

Agency for Toxic Substances and Disease Registry (ATSDR)

ATSDR

ATSDR Toxicological Profiles

ATSDR Case Studies in Environmental Medicine (CSEM)

ATSDR ToxFAQs^TM

Centers for Disease Control and Prevention (CDC)

CDC

The National Institute for Occupational Safety and Health (NIOSH)

NIOSH

Occupational Safety and Health Administration (OSHA)

OSHA

U.S. Environmental Protection Agency (EPA)

EPA

Safety Data Sheets (SDS) (formally known as Material Safety Data Sheets [MSDS]

The objective of the Safety Data Sheets (SDS) (formally known as Material Safety Data Sheets (MSDS)) is to concisely educate workers about the hazards of materials they use so they can protect themselves and respond to emergency situations. The federally mandated OSHA Hazardous Communication Standard states that workers must have access to relevant SDSs and be educated on their contents and application in a format they can understand.

Some state and local "right-to-know laws" may be more comprehensive than the federal regulation.

The SDS (formally known as MSDS) is a component of the right-to-know law. Manufacturers and importers are required to provide an SDS for each hazardous chemical in a shipment. Users of the chemicals must keep copies of SDSs and make them available to workers, clinicians, and others.

SDSs contain information on the chemical properties of the substance, handling precautions, known health effects, and conditions that might worsen with exposure. The information on human health effects, however, can be vague and may have limited clinical value. The SDS may not provide information on the combined effects of multiple chemical exposures. Clinical decisions should not be based solely on information obtained from SDSs (sample MSDS; see Appendix II). Search the Occupational Safety and Health Administration at https://www.osha.gov/Publications/OSHA3514.html for a more detailed description of the various required parts of the SDS (formally called MSDS).

To identify an SDS for a specific chemical, search "(name of chemical) Safety Data Sheet" using your Internet browser.

U.S. Poison Control Centers

U.S. Poison Control Centers

Clinical Resources

American Association of Poison Control Centers

American College of Medical Toxicology (ACMT)

American College of Occupational and Environmental Medicine (ACOEM)

American College of Preventive Medicine (ACPM)

Association of Occupational and Environmental Clinics (AOEC)

Pediatric Environmental Health Specialty Units (PEHSUs)

Key Points

• There are many publicly available environmental health information and education resources designed for different audiences.
• A variety of printed and online sources are available to the clinician, including books, databases, websites, journals, and Safety Data Sheets (SDS; formally known as Material Safety Data Sheets; [MSDSs]).
• Publicly available information on clinical consultation and referral resources enhance the role that primary health care providers have in detecting, treating, and preventing disease(s) resulting from environmental and occupational exposure(s).

Progress Check

12. Which of the following statements about SDS (formerly MSDS) is INCORRECT?

A. The SDS is a component of the right-to-know law.

B. Information contained in SDSs includes the chemical properties of the substance, handling precautions, known health effects, and conditions that might worsen with exposure.

C. Clinicians may depend on the information on human health effects from SDSs to make clinical decisions.

D. Employers must keep copies of SDSs for hazardous chemicals used in the workplace and make them available to workers, clinicians and others.

Answer

The best choice and INCORRECT statement is C. The information on human health effects can be vague and may have limited clinical value. The SDS may not provide information on the combined effects of multiple chemical exposures. Clinical decisions should not be made solely from information obtained from SDSs.

Choice A is a correct statement. The SDS is a component of the right-to-know law, governed by the Occupational Safety and Health Administration (OSHA).

Choice B is a correct statement. Information contained in SDSs include the chemical properties of the substance, handling precautions, known health effects, and conditions that might worsen with exposure.

Choice D is a correct statement. Employers must keep copies of SDSs for hazardous substances used in the workplace and make them available to workers, clinicians, and others.

Appendix I and II

Appendix I - Exposure History Form

Appendix II - Material Safety Data Sheet

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