Science Inventory

Regionally Applied Research Efforts (RARE) Report titled "The Penobscot River and Environmental Contaminants: Assessment of Tribal Exposure Through Sustenance Lifeways


DeMarini, D., V. Marshall, R. Hillger, S. Warren, A. Swank, T. Hughes, A. Elskus, C. Byrne, J. Ferrario, C. Orazio, R. Dudley, J. Diliberto, S. Stodola, S. Mierzykowski, K. Pugh, AND C. Culbertson. Regionally Applied Research Efforts (RARE) Report titled "The Penobscot River and Environmental Contaminants: Assessment of Tribal Exposure Through Sustenance Lifeways. U.S. EPA Office of Research and Development, Washington, DC, 2015.


EPA in collaboration with the Penobscot Indian Nation, U.S. Geological Survey (USGS), Agency for Toxic Substances and Disease Registry (ATSDR), and the U.S. Fish and Wildlife Service (USF&WS) collectively embarked on a four year research study to evaluate the environmental health of the riverine system by targeting specific cultural practices and using traditional science to conduct a preliminary contaminant screening of the flora and fauna of the Penobscot River ecosystem. This study was designed as a preliminary screening to determine if contaminant concentrations in fish, eel, snapping turtle, wood ducks, and plants in Regions of the Penobscot River relevant to where PIN tribal members hunt, fish and gather plants were high enough to be a health concern. This study was not designed to be a statistically validated assessment of contaminant differences among study sites or among species. The EPA preliminary risk assessment indicates that consumption of fish (especially eel) and snapping turtle at the Wabanaki Exposure Inland Non-Anadromous tribal consumption rates is associated with a risk of potential concern.


The traditional methodology for health risk assessment used by the U. S. Environmental Protection Agency (EPA) is based on the use of exposure assumptions (e.g. exposure duration, food ingestion rate, body weight, etc.) that represent the entire American population, either as a central tendency exposure (e.g. average, median) or as a reasonable maximum exposure (e.g. 95% upper confidence limit). Unfortunately, EPA lacked exposure information for assessing health risks for New England regional tribes sustaining a tribal subsistence way of life. As a riverine tribe, the Penobscot culture and traditions are inextricably tied to the Penobscot River watershed. It is through hunting, fishing, trapping, gathering and making baskets, pottery, moccasins, birch-bark canoes and other traditional practices that the Penobscot culture and people are sustained. The Penobscot River receives a variety of pollutant discharges leaving the Penobscot Indian Nation (PIN) questioning the ecological health and water quality of the river and how this may affect the practices that sustain their way of life. The objectives of this Regional Applied Research Effort (RARE) study were to: (1) Develop culturally sensitive methodologies for assessing the potential level of exposure to contaminants that Penobscot Indian Nation tribal members may have from maintaining tribal sustenance practices; (2) Conduct field surveys and laboratory analysis on targeted flora and fauna for chemical exposure to dioxins/furans, polychlorinated biphenyls (PCBs), total mercury and methyl-mercury; (3) Assist the Agency for Toxic Substances and Disease Registry (ATSDR) by providing the necessary data to conduct a Public Health Assessment for the Penobscot Indian Nation; (4) Establish protocols for assessing the level of exposure to PCBs, dioxins/furans and mercury to PIN tribal members as a consequence of gathering tribal plants for medicinal and nutritional purposes; as well as consuming fish, wood duck, and snapping turtle as a primary source of nutrition; and (5) Survey surface water, drinking water, and sediment from the Penobscot River and Indian Island to assess the exposure of PIN tribal members to environmental genotoxicants that continue cultural sustenance practices. This research initiative collected and analyzed sediment and biota to determine the level of contaminant exposure to Penobscot tribal members. Natural resource utilization patterns and exposure pathways were identified based on discussions with the Tribal elders. Identification of Tribal exposure factors (exposure pathways and contaminant concentrations) was essential for accurately assessing potential long-term Penobscot Indian Nation tribal members’ exposure. Based on this study, ATSDR’s Public Health Assessment (PHA) concluded that the Penobscot Indian Nation (PIN) tribal members who eat fish and snapping turtle at the ingestion levels suggested in the Wabanaki Traditional Cultural Lifeways Exposure Scenario Report (Wabanaki Exposure Scenario) may be exposed to harmful levels of mercury, dioxins/furans, dioxin-like PCBs, and other PCBs. ATSDR is most concerned about mercury in fish and snapping turtle taken from the Penobscot River. Mercury is most harmful to children and developing fetuses. It is especially important for pregnant and breastfeeding women, women who may become pregnant, and children to limit their consumption of fish and snapping turtle in order to decrease their risk of neurological damage due to mercury exposure. The ATSDR recommends that Penobscot Indian Nation tribal members follow the existing Penobscot Indian Nation Department of Natural Resources’ fish advisory and the State of Maine Safe Eating Guidelines for all fish caught in the Penobscot River and limit their consumption of snapping turtle. ATSDR recommends that PIN members eat only 1-2 fish meals per month from the Penobscot River, and limit their consumption of snapping turtle to 2-3 meals per month. If Penobscot River fish and turtle are both eaten, ATSDR recommends no more than some combination of 1-2 (10 oz.) servings of fish, or 2-3 (8 oz.) servings of turtle per month. ATSDR indicates that PIN tribal members who eat wood duck, fiddlehead fern, or medicinal roots at the Wabanaki Exposure Scenario-suggested ingestion rates from the areas where the samples were collected for this study should not be exposed to harmful levels of mercury, PCBs, dioxins/furans or dioxin-like PCBs. As shown in the Exposure Assessment section, EPA’s preliminary risk assessment is consistent with these ATSDR recommendations. ATSDR also indicates that incidental ingestion of, and dermal exposure to, Penobscot River sediment should not pose a human health hazard. The Salmonella mutagenicity assay was used to assess the mutagenic potencies of organic extracts of the Penobscot River water and sediment, as well as of drinking water samples. Mutagenicity is a statistical indicator of some cancer-causing (carcinogenic) chemicals. Most samples were either not mutagenic or, compared to published data for comparable extracts, had low to moderate mutagenic potencies. Thus, there is little evidence that extracts of these environmental media have mutagenic activity that might be due to the classes of compounds that this assay readily detects, such as polycyclic aromatic hydrocarbons, nitroarenes, and aromatic amines.

Record Details:

Product Published Date:08/15/2015
Record Last Revised:02/04/2016
OMB Category:Other
Record ID: 309033