Exposure to perfluoroalkyl substances and associations with serum thyroid hormones in a remote population of Alaska Natives.

Perfluoroalkyl substances (PFASs) are known to accumulate in traditional food animals of the Arctic, and arctic indigenous peoples may be exposed via consumption of subsistence-harvested animals. PFASs are suspected of disrupting thyroid hormone homeostasis in humans. The aim of this study is to assess the relationship between serum PFASs and thyroid function in a remote population of Alaska Natives. Serum samples were collected from 85 individuals from St. Lawrence Island, Alaska. The concentrations of 13 PFASs, as well as free and total thyroxine (T4), free and total triiodothyronine (T3), and thyrotropin (TSH) were quantified in serum samples. The relationships between circulating concentrations of PFASs and thyroid hormones were assessed using multiple linear regression fit with generalized estimating equations. Several PFASs, including perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA), were positively associated with TSH concentrations when modeled individually. PFOS and PFNA were significantly associated with free T3 and PFNA was significantly associated with total T3 in models with PFAS*sex interactive terms; these associations suggested negative associations in men and positive associations in women. PFASs were not significantly associated with concentrations of free or total T4. Serum PFASs are associated with circulating thyroid hormone concentrations in a remote population of Alaska Natives. The effects of PFAS exposure on thyroid hormone homeostasis may differ between sexes.

Persistent Organochlorine Pesticide Exposure Related to a Formerly Used Defense Site on St. Lawrence Island, Alaska: Data from Sentinel Fish and Human Sera.

St. Lawrence Island, Alaska, is the largest island in the Bering Sea, located 60 km from Siberia. The island is home to approximately 1600 St. Lawrence Island Yupik residents who live a subsistence way of life. Two formerly used defense sites (FUDS) exist on the island, one of which, Northeast Cape, has been the subject of a $123 million cleanup effort. Environmental monitoring demonstrates localized soil and watershed contamination with polychlorinated biphenyls (PCB), organochlorine (OC) pesticides, mercury, and arsenic. This study examined whether the Northeast Cape FUDS is a source of exposure to OC pesticides. In total, 71 serum samples were collected during site remediation from volunteers who represented three geographic regions of the island. In addition, ninespine stickleback (Pungitius pungitius) and Alaska blackfish (Dallia pectoralis) were collected from Northeast Cape after remediation to assess continuing presence of OC pesticides. Chlordane compounds, DDT compounds, mirex, and hexachlorobenzene (HCB) were the most prevalent and present at the highest concentrations in both fish tissues and human serum samples. After controlling for age and gender, activities near the Northeast Cape FUDS were associated with an increase in serum HCB as compared to residents of the farthest village from the site. Positive but nonsignificant relationships for sum-chlordane and sum-DDT were also found. Organochlorine concentrations in fish samples did not show clear geographic trends, but appear elevated compared to other sites in Alaska. Taken together, data suggest that contamination of the local environment at the Northeast Cape FUDS may increase exposure to select persistent OC pesticides.

Differential gene expression and developmental pathologies associated with persistent organic pollutants in sentinel fish in Troutman Lake, Sivuqaq, Alaska.

Persistent organic pollutants (POPs) are lipophilic compounds that bioaccumulate in animals and biomagnify within food webs. Many POPs are endocrine disrupting compounds that impact vertebrate development. POPs accumulate in the Arctic via global distillation and thereby impact high trophic level vertebrates as well as people who live a subsistence lifestyle. The Arctic also contains thousands of point sources of pollution, such as formerly used defense (FUD) sites. Sivuqaq (St. Lawrence Island), Alaska was used by the U.S. military during the Cold War and FUD sites on the island remain point sources of POP contamination. We examined the effects of POP exposure on ninespine stickleback (Pungitius pungitius) collected from Troutman Lake in the village of Gambell as a model for human exposure and disease. During the Cold War, Troutman Lake was used as a dump site by the U.S. military. We found that PCB concentrations in stickleback exceeded the U.S. Environmental Protection Agency's guideline for unlimited consumption despite these fish being low trophic level organisms. We examined effects at three levels of biological organization: gene expression, endocrinology, and histomorphology. We found that ninespine stickleback from Troutman Lake exhibited suppressed gonadal development compared to threespine stickleback (Gasterosteus aculeatus) studied elsewhere. Troutman Lake stickleback also displayed two distinct hepatic phenotypes, one with lipid accumulation and one with glycogen-type vacuolation. We compared the transcriptomic profiles of these liver phenotypes using RNA sequencing and found significant upregulation of genes involved in ribosomal and metabolic pathways in the lipid accumulation group. Additionally, stickleback displaying liver lipid accumulation had significantly fewer thyroid follicles than the vacuolated phenotype. Our study and previous work highlight health concerns for people and wildlife due to pollution hotspots in the Arctic, and the need for health-protective remediation.

Avoiding digester upset.

The acetate uptake bioassay (AUB) is a predictive measure for determining the stability of anaerobic digesters, but its use is rare due to the limited availability of gas chromatography equipment at wastewater treatment facilities. A water displacement system was compared and evaluated as an alternative to gas chromatography analysis for conducting the AUB. Results indicated that methane generation rates measured by the two methods were statistically the same. Precision of the method varied by less than 5%. Accuracy was quantified by measuring near stoichiometric volumes of carbon dioxide gas production from abiotic tests using sodium carbonate and hydrochloric acid. The method detection limit (MDL) was 0.6 mL. The effective use of a water displacement system as a surrogate for gas chromatography analysis could make the adoption of the AUB for predicting digester stability a practical option for treatment facilities.

Prospective Case-control Study of Contact Tracing Speed for Emergency Department-based Contact Tracers.

INTRODUCTION: In Snohomish County, WA, the time from obtaining a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test and initiating contact tracing is 4-6 days. We tested whether emergency department (ED)-based contact tracing reduces time to initiation and completion of contact tracing investigations. METHODS: All eligible coronavirus disease 2019 (COVID-19)-positive patients were offered enrollment in this prospective case-control study. Contact tracers were present in the ED from 7 AM to 2 AM for 60 consecutive days. Tracers conducted interviews using the Washington State Department of Health's extended COVID-19 reporting form, which is also used by the Snohomish Health District (SHD). RESULTS: Eighty-one eligible SARS-CoV-2 positive patients were identified and 71 (88%) consented for the study. The mean time between positive COVID-19 test result and initiation of contact tracing investigation was 111 minutes with a median of 32 minutes (range: 1-1,203 minutes). The mean time from positive test result and completion of ED-based contact tracing investigation was 244 minutes with a median of 132 minutes (range: 23-1,233 minutes). In 100% of the enrolled cases, contact tracing was completed within 24 hours of a positive COVID-19 test result. For comparison, during this same period, SHD was able to complete contact tracing in 64% of positive cases within 24 hours of notification of a positive test result (P < 0.001). In the ED, each case identified a mean of 2.8 contacts as compared to 1.4 contacts identified by SHD-interviewed cases. There was no statistically significant difference between the percentage of contacts reached through ED contact tracing (82%) when compared to the usual practice (78%) (P = 0.16). CONCLUSION: When contact tracing investigations occur at the point of diagnoses, the time to initiation and completion are reduced, there is higher enrollment, and more contacts are identified.

PFAS in drinking water and serum of the people of a southeast Alaska community: A pilot study.

Per- and polyfluoroalkyl substances (PFAS) have become a target of rigorous scientific research due to their ubiquitous nature and adverse health effects. However, there are still gaps in knowledge about their environmental fate and health implications. More attention is needed for remote locations with source exposures. This study focuses on assessing PFAS exposure in Gustavus, a small Alaska community, located near a significant PFAS source from airport operations and fire training sites. Residential water (n = 25) and serum (n = 40) samples were collected from Gustavus residents and analyzed for 39 PFAS compounds. In addition, two water samples were collected from the previously identified PFAS source near the community. Fourteen distinct PFAS were detected in Gustavus water samples, including 6 perfluorinated carboxylic acids (PFCAs), 7 perfluorosulfonic acids (PFSAs), and 1 fluorotelomer sulfonate (FTS). ΣPFAS concentrations in residential drinking water ranged from not detected to 120 ng/L. High ΣPFAS levels were detected in two source samples collected from the Gustavus Department of Transportation (14,600 ng/L) and the Gustavus Airport (228 ng/L), confirming these two locations as a nearby major source of PFAS contamination. Seventeen PFAS were detected in serum and ΣPFAS concentrations ranged from 0.0170 to 13.1 ng/mL (median 0.0823 ng/mL). Perfluorooctanesulfonic acid (PFOS) and perfluorohexanesulfonic acid (PFHxS) were the most abundant PFAS in both water and serum samples and comprised up to 70% of ΣPFAS concentrations in these samples. Spearman's correlation analysis revealed PFAS concentrations in water and sera were significantly and positively correlated (r = 0.495; p = 0.0192). Our results confirm a presence of a significant PFAS source near Gustavus, Alaska and suggest that contaminated drinking water from private wells contributes to the overall PFAS body burden in Gustavus residents.

Elevated mercury and PCB concentrations in Dolly Varden (Salvelinus malma) collected near a formerly used defense site on Sivuqaq, Alaska.

Environmental pollution causes adverse health effects in many organisms and contributes to health disparities for Arctic communities that depend on subsistence foods, including the Yupik residents of Sivuqaq (St. Lawrence Island), Alaska. Sivuqaq's proximity to Russia made it a strategic location for U.S. military defense sites during the Cold War. Two radar surveillance stations were installed on Sivuqaq, including at the Northeast Cape. High levels of persistent organic pollutants and toxic metals continue to leach from the Northeast Cape formerly used defense (FUD) site despite remediation efforts. We quantified total mercury (Hg) and polychlorinated biphenyl (PCB) concentrations, and carbon and nitrogen stable isotope signatures, in skin and muscle samples from Dolly Varden (Salvelinus malma), an important subsistence species. We found that Hg and PCB concentrations significantly differed across locations, with the highest concentrations found in fish collected near the FUD site. We found that 89% of fish collected from near the FUD site had Hg concentrations that exceeded the U.S. Environmental Protection Agency's (EPA) unlimited Hg-contaminated fish consumption screening level for subsistence fishers (0.049 µg/g). All fish sampled near the FUD site exceeded the EPA's PCB guidelines for cancer risk for unrestricted human consumption (0.0015 µg/g ww). Both Hg and PCB concentrations had a significant negative correlation with δ13C when sites receiving input from the FUD site were included in the analysis, but these relationships were insignificant when input sites were excluded. δ15N had a significant negative correlation with Hg concentration, but not with PCB concentration. These results suggest that the Northeast Cape FUD site remains a point source of Hg and PCB pollution and contributes to higher concentrations in resident fish, including subsistence species. Moreover, elevated Hg and PCB levels in fish near the FUD site may pose a health risk for Sivuqaq residents.

Associations between serum polybrominated diphenyl ethers and thyroid hormones in a cross sectional study of a remote Alaska Native population.

Polybrominated diphenyl ethers (PBDEs) are ubiquitous environmental pollutants. Arctic indigenous peoples are exposed to PBDEs through a traditional diet high in marine mammals. PBDEs disrupt thyroid homeostasis. The aim of this study was to assess the relationship between serum PBDEs and thyroid function in a remote population of St. Lawrence Island Yupik. Serum samples were collected from 85 individuals from St. Lawrence Island, Alaska and measured for concentrations of PBDEs, free and total thyroxine (T4), free and total triiodothyronine (T3), and thyroid stimulating hormone (TSH). The relationships between PBDEs and thyroid hormones were assessed using multiple linear regression fit with generalized estimating equations. Serum concentrations of several Penta-BDE congeners (BDE-28/33, 47, and 100) were positively associated with concentrations of TSH and free T3, while serum concentration of BDE-153 was negatively associated with total T3 concentrations. Both BDE-47 and 153 remained significantly associated with thyroid hormones when BDE-47, BDE-153, and BDE-209 were covariates in the same model. There were no significant relationships between serum concentrations of PBDEs and either free or total T4. Individual PBDEs are associated with thyroid hormones in serum from a remote population of Alaska Natives, and directions of effect differ by congener.

Exposure to polybrominated diphenyl ethers and perfluoroalkyl substances in a remote population of Alaska Natives.

BACKGROUND: Many Alaska Native communities rely on a traditional marine diet that contains persistent organic pollutants (POPs). The indoor environment is also a source of POPs. Polybrominated diphenyl ethers (PBDEs) and perfluoroalkyl substances (PFASs) are present both in the traditional diet and the home indoor environment. OBJECTIVES: We assessed exposure to PBDEs and PFASs among residents of two remote Alaska Native villages on St. Lawrence Island. Ninespine stickleback (Pungitious pungitious) and Alaska blackfish (Dallia pectoralis) were used to detect accumulation of these compounds in the local environment. METHODS: Concentrations of PBDEs and PFASs were measured in dust collected from 49 households on St. Lawrence Island, as well as in blood serum from 85 island residents. Resident ninespine stickleback and Alaska blackfish were used as sentinels to detect accumulation of PBDEs and PFASs in the food web. RESULTS: Serum concentrations of perfluorononanoic acid (PFNA) and perfluoroundecanoic acid (PFUnDA) were elevated, despite low concentrations of PFASs in dust samples. Concentrations of PBDEs in dust and serum were similar to those from the contiguous United States. Statistical associations between dust and serum concentrations are apparent for a small number of PBDEs, suggesting a possible route of exposure. Predominant compounds were similar between human sera and stickleback; however, blackfish accumulated PFASs not found in either stickleback or human sera. CONCLUSION: Household dust contributes to PBDE exposure, but not PFAS exposure. Elevated concentrations of long chain PFASs in serum are likely due to exposure from traditional foods. The presence of both PFASs and PBDEs in sentinel fish species suggests atmospheric deposition and bioaccumulation, as well as local environmental contamination.

Community-based participatory research projects and policy engagement to protect environmental health on St Lawrence Island, Alaska.

OBJECTIVES: This article synthesizes discussion of collaborative research results, interventions and policy engagement for St Lawrence Island (SLI), Alaska, during the years 2000-2012. METHODS: As part of on-going community-based participatory research (CBPR) studies on SLI, 5 discrete exposure-assessment projects were conducted: (a) a biomonitoring study of human blood serum; (b-d) 3 investigations of levels of contaminants in environmental media at an abandoned military site at Northeast Cape--using sediment cores and plants, semi-permeable membrane devices and blackfish, respectively; and (e) a study of traditional foods. RESULTS: Blood serum in residents of SLI showed elevated levels of polychlorinated biphenyls (PCBs) with higher levels among those exposed to the military site at Northeast Cape, an important traditional subsistence-use area. Environmental studies at the military site demonstrated that the site is a continuing source of PCBs to a major watershed, and that clean-up operations at the military site generated PCB-contaminated dust on plants in the region. Important traditional foods eaten by the people of SLI showed elevated concentrations of PCBs, which are primarily derived from the long-range transport of persistent pollutants that are transported by atmospheric and marine currents from more southerly latitudes to the north. INTERVENTIONS: An important task for all CBPR projects is to conduct intervention strategies as needed in response to research results. Because of the findings of the CBPR projects on SLI, the CBPR team and the people of the Island are actively engaging in interventions to ensure cleanup of the formerly used military sites; reform chemicals policy on a national level; and eliminate persistent pollutants internationally. The goal is to make the Island and other northern/Arctic communities safe for themselves and future generations. CONCLUSIONS: As part of the CBPR projects conducted from 2000 to 2012, a series of exposure assessments demonstrate that the leaders of SLI have reason to be concerned about the health of people due to the presence of carcinogenic chemicals as measured in biomonitoring and environmental samples and important traditional foods.