Occurrence and potential ecological risks of PFAS in Pampulha Lake, Brazil, a UNESCO world heritage site.

Per- and polyfluoroalkyl substances (PFAS) comprise >4000 synthetic substances used in industrial applications and consumer products. PFAS used daily in households and manufacturing plants end up in domestic sewage, and industrial effluents can be discharged to surface water. Urban watersheds located in low and middle-income countries (LMIC), which lack sanitation infrastructure, are potential recipients of waste containing PFAS. Yet, only a few studies report PFAS occurrence in urban reservoirs and lakes, especially those located in the Global South due to resource limitations. This is the first study aimed to assess PFAS occurrence and ecological risks in Pampulha Lake, Brazil, a site which represents the reality of many other urban watersheds in LMIC as it is surrounded by densely populated areas and manufacturing plants. Surface water samples were collected monthly for 1 year from four sampling points at Pampulha Lake. Sample analysis was based on US Environmental Protection Agency Method 1633, which employs solid phase extraction followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Species sensitivity distribution (SSD) curves were built to identify potentially susceptible species based on detected water concentrations. Bioaccumulation was estimated for fish tissue. Short-chain (perfluorobutanesulfonic acid, PFBS and perfluorohexanoic acid, PFHxA) and long-chain PFAS (perfluorodecanoic acid, PFDA; perfluorooctanoic acid, PFOA; perfluorododecanoic acid, PFDoA; and perfluorooctanesulfonic acid, PFOS) were detected at the µg L-1 range. Total PFAS concentrations in the wet season were generally higher than in the dry season, likely due to limited capacity of the treatment plant processing water from tributaries which receive raw sewage. More than 5 % of aquatic species are potentially susceptible to chronic effects of PFOS at detected concentrations (0.2-2.2 µg L-1). Predicted bioaccumulation of PFOS in fish was above advisory diet intake levels for humans. Results emphasize the need for studies related to PFAS occurrence in watersheds located in LMIC.

Global quantification of emerging and legacy per- and polyfluoroalkyl substances in indoor dust: Levels, profiles and human exposure.

This study investigated the occurrence and distribution of per- and polyfluoroalkyl substances (PFASs) in house dust samples from six regions across four continents. PFASs were detected in all indoor dust samples, with total median concentrations ranging from 17.3 to 197 ng/g. Among the thirty-one PFAS analytes, eight compounds, including emerging PFASs, exhibited high detection frequencies in house dust from all six locations. The levels of PFASs varied by region, with higher concentrations found in Adelaide (Australia), Tianjin (China), and Carbondale (United States, U.S.). Moreover, PFAS composition profiles also differed among regions. Dust from Australia and the U.S. contained high levels of 6:2 fluorotelomer phosphate ester (6:2 diPAP), while perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) were predominant in other regions. Furthermore, our results indicate that socioeconomic factors impact PFAS levels. The assessment of human exposure through dust ingestion and dermal contact indicates that toddlers may experience higher exposure levels than adults. However, the hazard quotients of PFASs for both toddlers and adults were below one, indicating significant health risks are unlikely. Our study highlights the widespread occurrence of PFASs in global indoor dust and the need for continued monitoring and regulation of these chemicals.

Preliminary assessment of exposure to persistent organic pollutants among pregnant women in Puerto Rico.

BACKGROUND: Puerto Rico has over 200 hazardous waste sites, as well as higher rates of several adverse health outcomes compared to the mainland US. In response to concerns of potential links between environmental contaminant exposure and preterm birth, the Puerto Rico Testsite for Exploring Contamination Threats (PROTECT) birth cohort was formed. Biomarkers of exposure for several contaminants have been found to be elevated in this cohort compared to women of child-bearing age in the National Health and Nutrition Examination Survey (NHANES). However, exposure to persistent organic pollutants (POPs) has not been evaluated. METHODS: In this preliminary analysis, we measured four classes of POPs, including perfluoroalkyl substances (PFASs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and several persistent pesticides in serum samples collected at 16-20 weeks gestation from the first 48 women enrolled in PROTECT. We performed descriptive analyses for each analyte, assessed correlations between analytes using Spearman correlations, and compared serum levels in PROTECT women to levels in NHANES women aged 18-40. RESULTS: Several PFASs were detected in 96-100% of samples, with moderate to strong correlations between most PFASs (range r = 0.44-0.88). BDE47, BDE153, PCB 138-158, PCB153 and p,p'-dichlorodiphenyldichloroethene (p,p'-DDE) were detected in the majority of samples, with strong correlations between PCBs and p,p'-DDE (range r = 0.59-0.74). The median concentration for each analyte was lower than, sometimes by a factor of 4 (e.g. BDE47, p,p'-DDE), the median concentration reported in NHANES women aged 18-40. CONCLUSION: Although participants in the ongoing PROTECT birth cohort have higher exposure to many environmental contaminants, this preliminary study suggests that they have lower exposure to several POPS, specifically PCBs, OCPs, PFASs, and PBDEs.

Sulfluramid use in Brazilian agriculture: A source of per- and polyfluoroalkyl substances (PFASs) to the environment.

N-Ethyl perfluorooctane sulfonamide (EtFOSA) is a perfluorooctane sulfonate (PFOS) precursor and the active ingredient in sulfluramid, a pesticide which is used extensively in Brazil for management of leaf cutting ants. Here we investigate the occurrence of EtFOSA, PFOS, and other per- and polyfluoroalkyl substances (PFASs) in soil, eucalyptus leaves, water (ground, riverine, and coastal (estuarine/marine)) and coastal sediment from an agricultural region of Bahia State, Brazil. This area contains a larger number of eucalyptus plantations where sulfluramid is suspected to be applied. Soil, leaves, and coastal water (marine/estuarine) contained ∑PFAS concentrations of up to 5400 pg g-1, 979 pg g-1, and 1020 pg L-1, respectively, with PFAS profiles generally dominated by PFOS and perfluorooctane sulfonamide (FOSA). Coastal sediment contained ∑PFAS concentrations of up to 198 pg g-1, with PFOS, FOSA, and perfluorooctanoic acid (PFOA) being the most frequently observed PFASs. These substances are all potential EtFOSA transformation products, pointing to sulfluramid as a possible source. In riverine water, ∑PFAS concentrations of up to 8930 pg L-1 were observed. PFOS and PFOA were detected in all river water samples. Groundwater also exhibited PFAS contamination (5730 pg L-1 ∑PFASs), likely from sulfluramid use. The observation of other PFASs (e.g. perfluorobutanoic acid) in freshwater suggests that other PFAS sources (in addition to sulfluramid) may be important in this region. Overall, these data support the hypothesis that sulfluramid use contributes to the occurrence of PFASs in the Brazilian environment.