Characterization of per- and polyfluoroalkyl substances (PFAS) concentrations in a community-based sample of infants from Samoa.

Per- and polyfluoroalkyl substances (PFAS) are persistent contaminants with documented harmful health effects. Despite increasing research, little attention has been given to studying PFAS contamination in low- and middle-income countries, including Samoa. Using data and biosamples collected through the Foafoaga o le Ola ("Beginning of Life") Study, which recruited a sample of mothers and infants from Samoa, we conducted an exploratory study to describe concentrations of 40 PFAS analytes in infant cord blood collected at birth (n = 66) and infant dried blood spots (DBS) collected at 4 months post-birth (n = 50). Of the 40 PFAS analytes tested, 19 were detected in cord blood, with 10 detected in >50% of samples (PFBA, PFPeA, PFOA, PFNA, PFDA, PFUnA, PFTrDA, PFHxS, PFOS, and 9Cl-PF3ONS); and 12 analytes were detected in DBS, with 3 detected in >50% of samples (PFBA, PFHxS, and PFOS). PFAS concentrations were generally lower than those reported in existing literature, with the exception of PFHxS, which was detected at higher concentrations. In cord blood, we noted suggestive (p < 0.05) or significant (p < 0.006) associations between higher PFHxS and male sex; higher PFPeA and residence in Northwest 'Upolu (NWU) compared to the Apia Urban Area (AUA); lower PFUnA and 9Cl-PF3ONS and greater socioeconomic resources; lower PFOA and higher parity; higher PFDA and higher maternal age; and lower PFUnA, PFTrDA, and 9Cl-PF3ONS and higher maternal BMI. In DBS, we found suggestive (p < 0.05) or significant (p < 0.025) associations between lower PFBA and residence in NWU versus AUA; lower PFBA and PFHxS and higher maternal age; and higher PFBA and higher maternal BMI. Finally, we observed associations between nutrition source at 4 months and DBS PFBA and PFHxS, with formula- or mixed-fed infants having higher concentrations compared to exclusively breastfed infants. This study represents the first characterization of PFAS contamination in Samoa. Additional work in larger samples is needed to identify potentially modifiable determinants of PFAS concentrations, information that is critical for informing environmental and health policy measures.

Evaluating contamination of seafood purchased from U.S. retail stores by persistent environmental pollutants, pesticides and veterinary drugs.

Studies have reported health risks associated with seafood contamination, but few data exist on levels in commercially available seafood in the US. To better understand, the magnitude of foodborne exposure and identify vulnerable populations in the US, we measured concentrations of veterinary drugs, persistent organic pollutants (POPs) (polycyclic aromatic hydrocarbons [PAHs], polybrominated diphenyl ethers [PBDEs] and polychlorinated biphenyls [PCBs]), and legacy and current-use pesticides in 46 seafood samples purchased from retail outlets. Measured levels were used to estimate risk based on available maximum residue limits (MRLs) and toxic equivalence (TEQ) factors for analytes. Only seventeen of the 445 analytes were detected, at low substance frequencies. However, half of the samples tested positive for one or more analyte, with total concentrations ranging from below the limit of detection (LOD) to as high as 156 µg/kg wet weight. Based on the risk assessment for individual pesticides and veterinary drugs, the hazard quotients (HQ) were all <1, indicating no risk. However, for the sum of PCB126 and PCB167, two dioxin-like PCBs detected in our samples, the TEQ was nearly two orders of magnitude higher than the WHO limits in one catfish sample. Moreover, vulnerable groups with higher rates of consumption of specific fish types may face higher risks.

Characterization of Per- and Polyfluoroalkyl Substance (PFAS) concentrations in a community-based sample of infants from Samoa.

Per- and polyfluoroalkyl substances (PFAS) are persistent contaminants with documented harmful health effects. Despite increasing research, little attention has been given to studying PFAS contamination in low- and middle-income countries, including Samoa, where there is more recent modernization and potential window to examine earlier stages of PFAS exposure and consequences. Using data and biosamples collected through the Foafoaga o le Ola ("Beginning of Life") Study, which recruited a sample of mothers and infants from Samoa, we conducted an exploratory study to describe concentrations of 40 PFAS analytes in infant cord blood collected at birth (n=66) and dried blood spots (DBS) collected at 4 months post-birth (n=50). Of the 40 PFAS analytes tested, 19 were detected in cord blood, with 11 detected in >10% of samples (PFBA, PFPeA, PFHpA, PFOA, PFNA, PFDA, PFUnA, PFTrDA, PFHxS, PFOS, and 9Cl-PF3ONS); 12 analytes were detected in DBS, with 3 detected in >10% of samples (PFBA, PFHxS, and PFOS). PFAS concentrations were generally lower than those reported in existing literature, with the exception of PFHxS, which was detected at higher concentrations. In cord blood, we noted associations between higher PFHxS and male sex, higher PFPeA and residence in Northwest 'Upolu (NWU) compared to the Apia Urban Area (AUA), and lower PFUnA and 9Cl-PF3ONS with greater socioeconomic resources. In DBS, we found associations between higher PFBA and greater socioeconomic resources, and between lower PFBA and PFHxS and residence in NWU versus AUA. However, the latter association did not hold when controlling for socioeconomic resources. Finally, we observed associations between nutrition source at 4 months and DBS PFBA and PFHxS, with formula- or mixed-fed infants having higher concentrations compared to exclusively breastfed infants. This study presents the first evidence of PFAS contamination in Samoa. Additional work in larger samples is needed to identify potentially modifiable determinants of PFAS concentrations, information that is critical for informing environmental and health policy measures.

Assessing per- and polyfluoroalkyl substances in globally sourced food packaging.

The purpose of this study was to investigate the presence and levels of per- and polyfluoroalkyl substances (PFAS) in food packaging originating from different geographic locations. Food packaging samples were extracted and analyzed by targeted analysis with liquid chromatography-mass spectrometry (LC-MS/MS) before and after a total oxidizable precursor (TOP) assay. Additionally, full-scan high resolution MS (HRMS) was used to screen for PFAS not included in the targeted list. Of the 88 food packaging samples, 84% had detectable levels of at least one PFAS prior to oxidation with a TOP assay, with 6:2 fluorotelomer phosphate diester (6:2 diPAP) found most frequently and at the highest levels (224 ng/g). Other frequently detected substances (in 15-17% of samples) were PFHxS, PFHpA and PFDA. Shorter chain perfluorinated carboxylic acids PFHpA (C7), PFPeA (C5) and PFHxS (C6) were present at levels up to 51.3, 24.1 and 18.2 ng/g, respectively. Average ∑PFAS levels were 28.3 ng/g and 381.9 ng/g before and after oxidation with the TOP assay. The 25 samples with highest frequency of detection and amounts of measured PFAS were selected for migration experiments with food simulants to better understand potential dietary exposure. PFHxS, PFHpA, PFHxA and 6:2 diPAP were measured in the food simulants of five samples at concentrations ranging from 0.04 to 12.2 ng/g and at increasing concentrations over the 10-day migration period. To estimate potential exposure to PFAS that had migrated from food packaging samples, weekly intake was calculated and ranged from 0.0006 ng/kg body weight/week for PFHxA exposure in tomato packaging to 1.1200 ng/kg body weight/week for PFHxS exposure in cake paper. These values were below the established EFSA maximum tolerable weekly intake (TWI) of 4.4 ng/kg body weight/week for the sum of PFOA, PFNA, PFHxS and PFOS.

A State-of-the-Science Review of Interactions of Per- and Polyfluoroalkyl Substances (PFAS) with Renal Transporters in Health and Disease: Implications for Population Variability in PFAS Toxicokinetics.

BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) are ubiquitous in the environment and have been shown to cause various adverse health impacts. In animals, sex- and species-specific differences in PFAS elimination half-lives have been linked to the activity of kidney transporters. However, PFAS molecular interactions with kidney transporters are still not fully understood. Moreover, the impact of kidney disease on PFAS elimination remains unclear. OBJECTIVES: This state-of-the-science review integrated current knowledge to assess how changes in kidney function and transporter expression from health to disease could affect PFAS toxicokinetics and identified priority research gaps that should be addressed to advance knowledge. METHODS: We searched for studies that measured PFAS uptake by kidney transporters, quantified transporter-level changes associated with kidney disease status, and developed PFAS pharmacokinetic models. We then used two databases to identify untested kidney transporters that have the potential for PFAS transport based on their endogenous substrates. Finally, we used an existing pharmacokinetic model for perfluorooctanoic acid (PFOA) in male rats to explore the influence of transporter expression levels, glomerular filtration rate (GFR), and serum albumin on serum half-lives. RESULTS: The literature search identified nine human and eight rat kidney transporters that were previously investigated for their ability to transport PFAS, as well as seven human and three rat transporters that were confirmed to transport specific PFAS. We proposed a candidate list of seven untested kidney transporters with the potential for PFAS transport. Model results indicated PFOA toxicokinetics were more influenced by changes in GFR than in transporter expression. DISCUSSION: Studies on additional transporters, particularly efflux transporters, and on more PFAS, especially current-use PFAS, are needed to better cover the role of transporters across the PFAS class. Remaining research gaps in transporter expression changes in specific kidney disease states could limit the effectiveness of risk assessment and prevent identification of vulnerable populations. https://doi.org/10.1289/EHP11885.

Per- and polyfluoroalkyl substances (PFAS) measured in seafood from a cross-section of retail stores in the United States.

Seafood is a dominant source of human exposure to per- and polyfluoroalkyl substances (PFAS). Existing studies on foodborne PFAS exposure have focused on only a subset of these compounds. Here, we conducted a pilot study to screen 33 PFAS in 46 seafood samples from a cross-section of national and local stores in the US. Low levels of 8 PFAS were measured in 74% of the samples, predominated by PFHxS (59%). Total PFAS ranged between 0.12 and 20 ng/g; highest levels were measured in Estonia-sourced smelt. The highest median levels were of PFOA (0.84 ng/g) with elevated concentrations found in Chinese clams (2.4 ng/g), which exceeds the EU established maximum limits (MLs). Measured levels of PFHxS, PFOA, and PFNA also exceeded MLs in 24%, 7%, and 5% of the samples, respectively. For average consumption levels, exposures were below the EU established tolerable weekly intakes (TWIs). However, for more frequent consumption of flounder, catfish, and cod, exposures exceeded regulations, which warrants identifying vulnerable high seafood consuming populations. Accidental PFBS cross contamination from sample storage bags resulted in 100% detection in samples, highlighting the problem with post-purchase food handling practices such as storage and cooking that could also have a substantial impact on human exposure, potentially in larger amounts than the (sea)food itself.

Black fungus outbreak in India - A direct consequence of COVID-19 surge: A myth or reality.

The deadly second wave of COVID-19 has seen an unprecedented surge in mucormycosis associated mortality in India, overwhelming the heath authorities with challenges beyond measure. Also known as black fungus, this life-threatening fungal infection usually manifests in the nose, spreads to the eyes, and in some cases also to the brain. Immune suppression, pre-existing conditions, prolonged and indiscriminate use of steroids, and unhygienic environments are some of the widely recognized risk factors for contracting black fungus in individuals recovered from COVID-19. However, diagnosis of the infection remains insufficient due to the lack a holistic understanding of the possible risks, symptoms, and exposure pathways and therefore no definite protocol exists for managing this fatal infection. Here, we synthesize the current state of knowledge on black fungus outbreak in India and identify key gaps in its understanding with respect to potential risk factors leading to the widespread infection. We looked at 3354 black fungus cases in India, enlisting ailment history (particularly diabetes) and steroid usage in COVID-19 patients as the key factors responsible for exacerbating risks associated with the disease. However, we also press on the possibilities that other less studied non-traditional risk factors may also have a role in causing the infection. Black fungus is therefore a reality of COVID-19, with or without diabetes or steroid use needs to be investigated. We believe such a review is imperative for making informed decisions specially around timely diagnosis and channelizing efforts in controlling the spread of COVID-19 associated mucormycosis.

A pathway level analysis of PFAS exposure and risk of gestational diabetes mellitus.

Per- and polyfluoroalkyl substances (PFAS) have been found to be associated with gestational diabetes mellitus (GDM) development, a maternal health disorder in pregnancy with negative effects that can extend beyond pregnancy. Studies that report on this association are difficult to summarize due to weak associations and wide confidence intervals. One way to advance this field is to sharpen the biologic theory on a causal pathway behind this association, and to measure it directly by way of molecular biomarkers. The aim of this review is to summarize the literature that supports a novel pathway between PFAS exposure and GDM development. Epidemiological studies demonstrate a clear association of biomarkers of thyroid hormones and glucose metabolism with GDM development. We report biologic plausibility and epidemiologic evidence that PFAS dysregulation of maternal thyroid hormones and thyrotropin (TSH) may disrupt glucose homeostasis, increasing the risk of GDM. Overall, epidemiological studies demonstrate that PFAS were positively associated with TSH and negatively with triiodothyronine (T3) and thyroxine (T4). PFAS were generally positively associated with glucose and insulin levels in pregnancy. We propose dysregulation of thyroid function and glucose metabolism may be a critical and missing component in the accurate estimation of PFAS on the risk of GDM.

Estimating polybrominated diphenyl ether (PBDE) exposure through seafood consumption in Switzerland using international food trade data.

Seafood is a major source of human exposure to polybrominated diphenyl ethers (PBDEs). The intake of these globally distributed and bioaccumulative contaminants depends on both consumption patterns (which seafoods are consumed) and on their origins. Here, we investigate exposure to PBDEs through seafood consumption as a function of species, origins and consumption levels. We estimate the contribution of seafood consumption to PBDE exposures in the Swiss population using two approaches. The first approach estimates exposures by estimating the composition of the Swiss seafood diet using trade data and national statistics on total seafood consumption. This naïve approach could be used for any country for which no individually reported consumption data are available for a population. The second approach uses dietary survey data provided by the Swiss Federal Statistical Office as part of the menuCH study for exposure estimates. To support region- and species-specific estimates of exposures for both approaches, we built a database of PBDE concentrations in seafood by analysis of published PBDE levels in fish from food markets or freshwater resources from various countries. We find estimated PBDE exposures ranging from 0.15 to 0.65 ng/kg bw/day for the trade data-based diet. These were close to the median exposures of 0.68 ng/kg bw/day for the Swiss population based on the menuCH survey, indicating that the composition and consumption rate derived from trade data are appropriate for calculating exposures in the average adult population. However, it could not account for PBDE exposures of more vulnerable (high seafood consuming) populations captured only by the survey data. All estimates were lower than the PBDE Chronic Oral Reference Doses (RfD's) suggested by the EPA, but could increase substantially to a value of 7 ng/kg bw/day if fish are sourced from the most contaminated origins, as in the case of Vietnamese shrimp/prawn, Norwegian salmon, and Swiss whitefish. Exposures as high as 8.50 ng/kg bw/day are estimated for the survey-based diet, which better captures the variability in consumption by individuals, including extreme high and low values. In general, the most frequently consumed species reported by Swiss consumers are consistent with those predicted using trade data.