Analysis of PFAAs in American alligators part 2: Potential dietary exposure of South Carolina hunters from recreationally harvested alligator meat

Abstract

Exposure to perfluorinated alkyl acids (PFAAs) has been linked to many harmful health effects including reproductive disorders, developmental delays, and altered liver and kidney function. Most human exposure to environmental contaminants, including PFAAs, occurs through consumption of contaminated food or drinking water. This study uses PFAA data from meat samples collected from recreationally harvested American alligators (Alligator mississippiensis) in South Carolina to assess potential dietary exposure of hunters and their families to PFAAs. Consumption patterns were investigated using intercept surveys of 23 hunters at a wild game meat processor. An exposure scenario using the average consumption frequency, portion size, and median perfluorooctane sulfonic acid (PFOS) concentration in alligator meat from all hunt units found the daily dietary exposure to be 2.11ng/kg body weight per day for an adult human. Dietary PFOS exposure scenarios based on location of harvest suggested the highest daily exposure occurs with alligator meat from the Middle Coastal hunt unit in South Carolina. Although no samples were found to exceed the recommended threshold for no consumption of PFOS found in Minnesota state guidelines, exposure to a mixture of PFAAs found in alligator meat and site-specific exposures based on harvest location should be considered in determining an appropriate guideline for vulnerable populations potentially exposed to PFAAs through consumption of wild alligator meat.

Examining toxic trace element exposure in American alligators

“…The life history characteristics of the alligator make it an attractive species for use as a sentinel, specifically their long-life spans, high site fidelity, varied diet, and their ability to live in proximity to humans (Wilkinson et al, 2016). Throughout the southeastern U.S. alligators are consumed as large game via recreational hunting and are a direct source of toxic element exposure to humans locally (FFWCC, 2015; Tipton et al, 2017a, 2017b; Smith et al, 2017). The locations sampled in this study are unique in that there are ongoing alligator monitoring programs in place which makes samples accessible for temporal studies, and the sites in Florida allow recreational hunting of alligators (FFWCC, 2015; Tipton et al, 2017a, 2017b; Smith et al, 2017).…”

“…Throughout the southeastern U.S. alligators are consumed as large game via recreational hunting and are a direct source of toxic element exposure to humans locally (FFWCC, 2015; Tipton et al, 2017a, 2017b; Smith et al, 2017). The locations sampled in this study are unique in that there are ongoing alligator monitoring programs in place which makes samples accessible for temporal studies, and the sites in Florida allow recreational hunting of alligators (FFWCC, 2015; Tipton et al, 2017a, 2017b; Smith et al, 2017). To determine how the alligator can best be utilized as a sentinel species for local trace element exposure and to understand the exposure the alligators in this study experience relative to what is known for exposure and outcomes, the measurements in this study are evaluated by comparison to existing wildlife and human data.…”

“…The similar diets of alligators and humans in this region make alligators a worthy candidate to observe toxic element concentrations that humans may be exposed to via fish consumption (Rice et al, 2007). Additionally, it is common in the southeastern United States for the routine consumption of alligator meat via both commercial sales and recreational hunting (Rice et al, 2007; Delany et al, 1999; FFWCC, 2015; Tipton et al, 2017a, 2017b; Smith et al, 2017). Reptiles are cold-blooded and have a slower metabolism than mammals, which often raises concerns regarding their legitimacy as a sentinel for humans.…”

Hunting and Game Consumption Patterns of Hunters in South Carolina

“…Consumption of wild-caught game with elevated levels of contaminants represents a potential exposure pathway to hunters, their families, and other households with which they share game (Coburn et al 2005), although these risks are likely to vary based on species, location of animals harvested, and overall consumption patterns (Oldenkamp et al 2017;Tipton et al 2017). Hunters who participated in our survey indicated they typically hunt and consume multiple species and 137 meals per year of the 11 game animals we surveyed.…”

“…In fact, Oldenkamp et al (2017) documented significantly higher levels of several trace elements (e.g., selenium and mercury) in muscle tissue of wildlife collected from these areas in South Carolina in comparison to relatively uncontaminated sites. Likewise, Tipton et al (2017) measured concentrations of perfluorinated alkyl acids in alligator meat harvested by recreational hunters and found that exposure risk to hunters varied geographically across South Carolina. Furthermore, South Carolina currently has 68 water bodies under fish-consumption advisories, primarily for mercury and polychlorinated biphenyls (South Carolina Department of Health and Environmental Control 2016).…”