Browsing by Subject "PFAS"
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Item Open Access An Examination of PFAS for North Carolina Policymakers and Researchers(2021-04-30) Kluck, Johanna; Nocera, Karly; Zhang, QixuanThis Master’s Project aims to explore factors impacting the occurrence, distribution, toxicology and remediation of PFAS – a type of emerging contaminant – in North Carolina’s water. Research methods utilized include a literature review, interviews, and quantitative data analysis of Department of Environmental Quality’s water quality samples. Due to a lack of publicly available information and regulatory oversight, many PFAS-related concerns – such as identifying individual households at risk – are unable to be effectively addressed in the scope of this project. The team sought to synthesize existing knowledge and identify gaps in order to inform both the academic community’s future research and upcoming policy efforts. To better connect and communicate ongoing research with non-academic communities, as well as identify areas of PFAS knowledge that need further investigation, our final product involves multiple deliverables: (1) a scientific paper with an extensive literature review, and (2) an ESRI StoryMap conveying our findings and synthesis in a publicly accessible format and language.Item Open Access Analyzing the Feasibility of a Centralized Treatment System for the Implementation of Destructive PFAS Treatment Technology(2023-04-26) Carpenter, Jack; Guimond, Austin; O'Callaghan, Ariel; von Turkovich, NataliePer- and polyfluoroalkyl substances (PFAS), are emerging contaminants that pose a significant threat to water systems across the U.S. PFAS compounds are difficult to break down and long-term exposure to them can have adverse health effects. 374Water is a technology company that has developed a destructive solution for organic wastes including PFAS through a process called supercritical oxidation. This study examined the financial feasibility of implementing their technology in a centralized wastewater treatment system. It assessed whether the centralized model is viable for 374Water and for individual utilities in North Carolina and Maine. Study results showed a positive business case for Maine. In North Carolina, where there is limited PFAS policy, project implementation was not feasible. 374Water AirSCWO™ implementation should be focused on states with strict PFAS disposal regulations that drive up biosolid disposal costs.Item Open Access Antibody Responses to Vaccines and PFAS Exposure in Early Childhood(2021-04-22) Bao, NancyPer- and polyfluoroalkyl substances (PFAS), are human-made chemicals commonly incorporated into personal care products, cookware, food packaging, and other industrial uses. Previous studies have found that early life exposure to PFAS is associated with health effects in both animal and human studies. There are growing concerns over the potential health consequences such as immunological health associated with prenatal and early childhood PFAS exposure. Studies have found that exposure to environmental stressors during early periods of fetal growth and development may have implications for the development of later life adverse health effects. Few studies have assessed the association between PFAS exposure and waning immunity to vaccines during early childhood. Of these studies, PFAS exposure has been inversely associated with antibody responses to vaccines against infectious diseases such as diphtheria and tetanus. Antibody responses to vaccines are commonly used as biomarkers to assess immune function and development. The objective of this study was to evaluate the impacts of PFAS exposures on critical windows of immune function and maturation in early childhood. Early childhood immune function was evaluated using antibody responses to the Diphtheria-Tetanus-acellular Pertussis (DTaP) vaccine. Multiple linear regression analyses (adjusted for child’s age, biological sex of child, and maternal age) were conducted to evaluate the associations between maternal and child serum PFAS levels in a North Carolina birth cohort (n=47) and antibody responses to the DTaP vaccine in children (ages 3-6). Maternal serum PFAS were used to assess prenatal exposure. Child serum was analyzed for diphtheria and tetanus antibody titers as well as postnatal PFAS exposure. Prenatal PFAS exposure measured from maternal serum was not significantly associated with tetanus antibody titers; however, a positive and significant association (p<0.05) was observed between prenatal PFNA exposure and diphtheria antibody titers. Postnatal PFAS exposure was not significantly associated with diphtheria antibody titers. Postnatal PFOA exposure was positively associated with tetanus antibody responses (p<0.05). The results do not suggest that prenatal and early childhood exposure to PFAS is associated with declines in immune responses to vaccines. Other factors associated with environmental PFAS exposure and vaccine antibody responses should be explored to expand on these findings.Item Open Access Characterizing Environmental Per- and Polyfluoroalkyl Substance (PFAS) Exposure and Effects in North Carolina Communities(2022) Hall, Samantha MariePer- and polyfluoroalkyl substances (PFAS) are synthetic chemicals used in a wide array of products and applications (e.g., nonstick cookware, waterproof and water-repellent textiles, firefighting foam). Following their decades of use, PFAS have garnered concern as “forever chemicals” due to their extreme persistence in the environment and in humans. PFAS have further elicited concern because they have been linked to adverse health effects in humans, and their huge number (over 12,000 different chemicals) and complex chemistry make them very challenging to analyze and study for exposure and toxicology. Two particular PFAS chemicals, perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS), are drinking water contaminants that can be found in the blood of the vast majority of people. PFOA and PFOS are also linked to toxic effects like kidney and testicular cancer, increased blood cholesterol, and reproductive outcomes. These two chemicals are being phased out of use and federal drinking water standards are likely upcoming. However, the replacements for these two chemicals are much less well-characterized, and many of these newer, replacement PFAS chemicals can be found in the environment of North Carolina due (at least in part) to industrial pollution.
The overarching goal of this dissertation was to characterize the potential exposure and health effects of PFAS in North Carolina communities. The surface water and drinking water in some areas of North Carolina have been found to be contaminated with PFAS; however, there are additional routes of PFAS exposure beyond drinking water, such as ingestion of house dust or placental transfer during pregnancy. This dissertation explores various routes of PFAS exposure and better characterizes the specific PFAS analytes that can be found in North Carolina and the concentrations in which they are present. Additionally, this dissertation evaluates this exposure and potential associations with some adverse health outcomes in a few North Carolina communities.
In Chapter 2, the relationships between PFAS exposure during pregnancy and birth outcomes are explored. This chapter includes data on PFAS concentrations in placenta samples from 120 participants in Durham, North Carolina and evaluates the subsequent associations between placental PFAS exposure and birth outcomes (e.g., infant birth weight, gestational age). A total of 11 PFAS were measured in placental tissues collected in 2010-2011, and the compounds PFOS, PFOA, PFNA, and PFDA were detected in all placenta samples. A few placental PFAS were associated with birth outcomes. The most striking result was that placental PFOS was associated with changes in birth weight, but the direction of change depended on the sex of the infant. For male infants, placental PFOS was associated with lower birthweight, and in female infants, placental PFOS was associated with higher birthweight.
In Chapter 3, the exposure to PFAS through drinking water is evaluated in a community with known PFAS water contamination. This chapter includes data on PFAS concentrations in blood serum and drinking water samples from 49 participants in Pittsboro, North Carolina. The community receives its drinking water from the Haw River, a part of the Cape Fear River watershed. Blood and water samples were collected at two different timepoints to explore temporal variability in contamination. This community was found to have blood levels of PFAS about two to four times higher than the U.S. average. This chapter also includes results on the associations between PFAS blood level and clinical chemistry measurements, such as serum lipids, as indicators of health. Negative associations were found between serum PFOS and PFHxA with decreased electrolytes and decreased liver enzymes. Positive associations were found between serum PFOA and PFHxS with increased total cholesterol and increased non-HDL cholesterol.
In Chapter 4, the effects and toxicokinetics of PFAS in a pregnant rabbit model are evaluated. This chapter includes data from an animal study of 21 pregnant rabbits provided with drinking water that is representative of the PFAS exposure observed in Pittsboro, North Carolina. Rabbits were exposed to this environmentally-relevant mixture of ten different PFAS during and before pregnancy. After exposure, the wastes and tissues were evaluated to measure the PFAS concentration that accumulated. This provided information on where PFAS are distributed in the body after exposure. The liver of the pregnant rabbit was also evaluated to determine if there was an increase in lipids in the liver, or any changes in liver lipid metabolism. For this study, few differences were noted between treated animals and control animals, indicating that the environmentally-relevant dose had little effect on pregnant rabbits. However, due to the lack of PFAS accumulation in blood, tissue, or in wastes, it is likely that the dose of PFAS given through drinking water was too low.
In Chapter 5, the levels of PFAS in indoor house dust were evaluated. This chapter includes data on PFAS concentrations in indoor dust from 184 homes in Durham, North Carolina, as well as 49 fire stations across the U.S. and Canada. House dust and fire station dust PFAS concentrations were then evaluated for associations with characteristics of the building (e.g., square footage, amount of carpeting, age of building construction). Levels of precursor PFAS, such as fluorotelomer alcohols, were typically higher in dust than the perfluoroalkyl acids. This study, along with previous literature, shows that the legacy PFAS in dust has been decreasing, but the precursor PFAS has been increasing in U.S. house dust. Few associations were found between building characteristics and dust PFAS. However, one notable result was that higher 8:2 FTOH was found in dust from buildings with more carpeting, indicating that carpets may be an important source of exposure to fluorotelomer alcohols (possibly from stain-proofing treatment).
Collectively, this dissertation provides important information on the potential exposure and health effects of PFAS in North Carolina communities.
Item Open Access Exploring Associations Between Prenatal PFAS Exposure and Childhood Asthma(2021-04-28) Bogar, LanePer- and polyfluoroalkyl substances (PFAS) are a large class of man-made chemicals used extensively in consumer and industrial products, making them ubiquitous in the built and natural environment. These chemicals pose a cause for concern, as there is increasing experimental and epidemiological evidence suggesting that exposure is associated with adverse health outcomes, especially prenatal PFAS exposure during critical periods of development. This study explored the associations between prenatal PFAS exposure, measured via maternal serum levels collected during pregnancy, and childhood asthma incidence in a cohort of 155 women, and 165 of their children from North Carolina. PFAS were detected in all serum samples and levels were similar to those in the general population. Statistical analyses incorporated potential predictors and covariates, including sex, age and race. After adjusting for these factors, statistically significant associations with asthma were found. Future efforts are needed to examine prenatal PFAS exposures and respiratory outcomes in later life.Item Open Access Great Lakes Drinking Water: A Gaps Analysis of Policy Regulation and Funding Mechanisms Supporting Safe, Affordable and Equitable Access to Drinking Water in Michigan and Wisconsin(2023-04-27) Fleck, ErinThe Great Lakes, the world’s largest freshwater resource, provide abundant freshwater to the Midwest United States, despite record-setting drought throughout the Western United States. And yet situations like the lead poisoning crisis in Flint, Michigan, and the PFAS crisis affecting the entire country continue to threaten public health across the region. An analysis of federal, state, and local drinking water management policies focused on Michigan and Wisconsin will identify gaps and challenges that exist within the current management system that prevent all Midwesterners from enjoying safe, affordable and equitable access to drinking water. Through two case studies on either side of Lake Michigan, this analysis identifies specific opportunities for improvement in both funding and regulatory mechanisms that could be implemented to better guarantee safe drinking water in the region.