PFAS Exposure and Thyroid Related Health Outcomes in Communities along the Cape Fear River, NC
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The Cape Fear River basin is the largest in North Carolina (NC), providing drinking water for >1 million people. Per- and polyfluoroalkyl substances (PFAS) have been detected throughout the Cape Fear Basin, including both historically used PFAS (e.g., PFOA and PFOS) and newly identified fluoroethers (e.g., GenX). In 2017, GenX and other fluoroethers were present in Wilmington, NC, drinking water as a result of discharge from an upstream manufacturing plant. This discharge may have been occurring since 1980. We found six newly identified PFAS in blood from Wilmington residents collected in 2017-2018, In addition to these newly identified chemicals, the median levels of PFOS and PFOA were 2 and 4 times higher, respectively, than the national values for these chemicals, suggesting that residents in Wilmington, NC, have had relatively high exposure to a diverse range of PFAS. This elevated exposure is not limited to Wilmington, NC. Blood samples collected in 2018 from 30 residents living around the chemical plant in Fayetteville, NC, approximately 90 miles upstream of the Wilmington, also had elevated levels of PFOS compared to national values. Local and state community groups are concerned about the impact of PFAS in drinking water.
PFAS represent a broad class of chemicals. To-date, data on biological persistence and human health effects are limited to historically used PFAS. While individual chemicals have been studied, there has been limited work focusing on this complex exposure and the appropriate strategies to aggregate and evaluate the health effects of these chemicals. PFAS are associated with adverse thyroid function across many life stages including children, pregnant women, and adults. Thyroid function is critical for regulation of metabolism for all individuals and can impact weight, cholesterol, and heart rate. These outcomes have all been associated with PFAS. Because the thyroid is critical for many key health outcomes, we consider it a sentinel outcome to evaluate the impact of PFAS on the health of residents of the Cape Fear River Basin.
To address community concerns about PFAS exposure and health effects, we propose the following specific aims for our community-engaged project:
Specific Aim 1. Partner with local community groups to address community concerns and share results with affected communities in a timely and appropriate manner.
We have partnered with local environmental groups and local and state public health agencies to facilitate communication about the study throughout the study, assist with recruitment of a representative sample of the region, and host community meetings for sharing of findings. We will create a Community Science Advisory Board for the study to review study protocols, provide input on how to best report back results to the community as a whole as well as individual participants, and to help inform the public health messaging for health care providers.
Specific Aim 2. Characterize PFAS exposure among people living along the Cape Fear River.
We will characterize variation in the magnitude and types of PFAS exposure in populations along the Cape Fear River. Building on the GenX Exposure study and working with established community partners, we will follow two populations along the Cape Fear River: Fayetteville and Wilmington. In 2017, we established one cohort in Wilmington of 344 people; in 2019, we created a second cohort in Fayetteville with 153 residents. For this project we will expand this population in each region to create a cohort of 1000 PFAS exposed individuals ages 6 and older. We will collect blood samples in Years 1 and 3 to evaluate PFAS exposures in communities along the Cape Fear River. This expanded cohort of ~1000 individuals and multiple measures of exposure over time will provide a rich dataset to answer the community question: what am I exposed to?
Specific Aim 3. Assess the impact of multiple PFAS on thyroid function over the lifecourse.
Alteration in thyroid hormones can have impact on human health at many points in development and aging. In this PFAS-exposed cohort, ranging in age from 6 to 86, we will measure thyroid hormones and potential secondary effects of thyroid disruption (e.g., weight, cholesterol), and to be able to prospectively evaluate the association of PFAS in different age groups.
We have started enrollment of our cohort, building on the initial GenX Exposure Study cohort of participants from Wilmington and Fayetteville, NC. We have enrolled participants from Wilmington area and have collected blood, urine, and saliva samples to answer questions related to PFAS exposure and thyroid and COVID outcomes. We have drafted a paper on hypothyroid outcomes and PFAS and plan to submit this manuscript in the coming year.