Petitioned Public Health Assessment
Soil Pathway Evaluation,
Isla de Vieques Bombing Range,
Vieques, Puerto Rico

VI. ATSDR Child Health Initiative

ATSDR recognizes that in communities faced with contamination of their water, soil, air, or food, infants and children can be more sensitive to environmental exposure than adults. This sensitivity is a result of the several factors, including (1) because they play outdoors, children are more likely to be exposed to certain media (e.g., soil); (2) children are shorter than adults, which means they can breathe dust, soil, and vapors close to the ground; and (3) children are smaller than adults, therefore childhood exposure results in higher doses of chemical exposure per body weight. To account for this greater susceptibility, ATSDR assumes a higher ingestion rate for children than adults. Because children can sustain permanent damage if these factors lead to toxic exposure during critical growth stages, ATSDR as part of its Child Health Initiative is committed to evaluating their special interests at sites such as Vieques.

Based on a thorough review of the available data, ATSDR concludes that children are not being exposed to harmful levels of chemicals in the soil on Vieques. As described in the Public Health Evaluation section (IV.C), most of the chemicals detected on Vieques are below conservative comparison values and; therefore, are not at levels of health concern. Childhood exposures were further evaluated for the seven metals (arsenic, cadmium, chromium, iron, lead, manganese, and vanadium) detected above comparison values, plus mercury. According to the toxicological and epidemiological literature, children can be more susceptible to arsenic, cadmium, iron, lead, and mercury exposures than adults. But whether children are more susceptible to chromium, manganese, and vanadium than are adults has not been established.

• Children can experience health effects from lower arsenic doses (due to less inorganic arsenic being converted into organic arsenic) than those reported in the literature for adults. Nevertheless, the health effects levels are an order of magnitude higher than the exposure dose expected to result from children who incidentally ingest soil on Vieques. Furthermore, a 50% reduction in health effects levels to compensate for the greater susceptibility in children would still result in higher effects levels than the expected exposure for children contacting arsenic in the soil on Vieques.
• Although children can experience health effects from a lower cadmium dose (due to the possibility that children can absorb more cadmium) than that reported for adults in the literature, the effects levels are still two orders of magnitude higher than the exposure dose expected to result from children incidentally ingesting soil on Vieques. Furthermore, a 50% reduction in effects levels to account for the greater susceptibility in children, would still result in health effects levels much higher than the exposure expected for children contacting cadmium in the soil on Vieques.
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  Children are more susceptible to accidentally poisoning themselves with iron-containing supplements than are adults. ATSDR specifically addressed childhood exposures in comparison to health effect levels of iron in the Public Health Evaluation section (IV.C) of this PHA, concluding that the dose expected to result from children incidentally ingesting soil on Vieques is well below documented health effects levels.
• Children are more susceptible to health effects from exposure to lead than are adults. The health effects levels reported in the literature, however, are two orders of magnitude higher than the exposure dose expected for children incidentally ingesting soil on Vieques. In addition, the blood lead level expected to result from exposure to lead in the soil is below CDC's level of health concern for children.
• During critical periods of development, children are more susceptible than adults to metallic mercury and methylmercury exposure. The health effects levels reported in the literature, however, are several orders of magnitude higher than the exposure dose expected to result from children incidentally ingesting soil on Vieques. Furthermore, a 50% reduction in effects levels to account for the greater susceptibility in children would still result in health effects levels several orders of magnitude higher than the exposure expected for children contacting mercury in the soil.