Helping the Penobscot Indian Nation: Review of Anadromous Fish for Consumption

A flowing river through a valley of forest and rocks.

“Each time we do a health consultation or health assessment we determine the very specific environmental exposures to a community with input from the community members. This project demonstrates the impact of a strong collaboration between Penobscot Indian Nation and ATSDR in addressing specific exposures and health concerns.”

— Tarah Somers, MSN, MPH, BN, ATSDR Region 1 director

The Penobscot Indian Nation used ATSDR’s health consultation on anadromous (migratory) fish in the nearby river to learn about possible health risks such as cancer from eating fish contaminated with per- and polyfluoroalkyl substances (PFAS), dioxin, and methylmercury.

Health consultations are one of the many ways ATSDR analyzes environmental data to determine possible harm to a person’s health. Consultations can be either a verbal or written response ⎯ from ATSDR or one of their health department partners ⎯ to a specific question about health risks related to a specific site, chemical release, or the presence of hazardous material. A consultation may lead to site restrictions, repairs, clean-up, environmental sampling, or other environmental public health actions related to surveillance, evaluation, or education. In 2021, ATSDR released a health consultation focused on anadromous fish consumption from the Penobscot River.

Generations of Penobscot Indian Nation (PIN) members have eaten fish and other aquatic species from the Penobscot River as a significant source of food. However, the food source and health of the PIN were at risk, due to contaminated discharge from a nearby paper and pulp mill into the Penobscot River. In 2004, the PIN tribal chief asked ATSDR to evaluate potential health effects of contaminants released into the Penobscot River. It was imperative to understand the level of environmental exposure from eating fish and other food from the river ⎯ which many relied on ⎯ and any related harmful health effects.

ATSDR reviewed available fish sampling data, calculated recommended fish consumption limits, and published a health consultation on its findings in 2006. In this consultation, ATSDR found concerning levels of contaminants such as dioxins, chlorinated dibenzofurans (furans), polychlorinated biphenyls (PCBs), and methylmercury. The potential health effects of exposure included various cancers, reproductive issues, pregnancy complications, and immune system weakening that threatened all PIN members, regardless of age.

After the initial report, ATSDR partnered with the Environmental Protection Agency (EPA) to build on this research in 2014 as a part of a Regional Applied Research Effort (RARE) project. For this project, ATSDR reviewed contaminants in fish tissue and other edible aquatic species and plants. The findings from this research and additional tissue data from more than 75 composite samples from 2017–2018 provided ATSDR with the information to release the second health consultation in 2021.

This report focuses on the health implications of eating contaminated anadromous (migratory) fish collected from the Penobscot river and demonstrates how federal agencies can work with Tribal Indian Nations to address environmental concerns. The PIN identified fish commonly eaten and used the information to identify potential environmental exposures. Tribal leadership appreciated the collaborative effort and took action to share the report as soon as it was released.

ATSDR identified anadromous fish species in the river that had high levels of dioxin, methylmercury, and per- and polyfluoroalkyl substances (PFAS). These contaminants represented a health hazard for the PIN members who ate any quantity of the sampled fish species. Several potential health effects were identified and described in this fact sheet.

As a result, ATSDR met with PIN leadership and recommended that tribal members stop eating anadromous fish identified as high risk in the health consultation. In the future, the PIN hopes ATSDR’s efforts can justify stricter rules for removing contaminants before they are discharged into the river, to protect the tribe’s health and their food source for generations to come.