Occurrence and tissue distribution of perfluoroalkyl substances (PFASs) in sharks and rays from the eastern Mediterranean Sea

Longitudinal poly- and perfluoroalkyl substances (PFAS) levels in Dutch infants.

Due to widespread industrial applications and increased discharges, concentrations of polyfluoroalkyl substances (PFAS) in potential drinking water sources have risen significantly, putting more people at risk of PFAS exposure. This study aimed to systematically clarify the occurrence characteristics (concentrations, detection frequencies, and temporal trends) of PFAS in global potential drinking water sources over the past decade, assess their oral exposure risks, and identify key PFAS species with high detection frequencies, high contamination levels, or high toxicity risks, thereby providing scientific support for the development of targeted control technologies and management strategies. This study systematically searched and reviewed the relevant literature published between 2014 and 2024 on PFAS levels in global potential drinking water sources, extracting data on PFAS concentrations, detection information, and sampling characteristics. Using the U.S. Environmental Protection Agency (EPA) Reference Dose (RfD) for oral exposure as the Acceptable Daily Intake (ADI), we evaluated the exposure risks of eight specific PFAS via the Risk Quotient for Specific Contaminants (RQRSC) model and analyzed the annual detection trends of the top thirty PFAS with the highest detection frequencies. Regarding total PFAS contamination, China, Brazil, Germany, South Africa, and the Danube River Basin exhibited particularly high levels, with China being the most severely contaminated. Risk assessment indicated that 45.6% of global potential drinking water sources were at high risk (RQRSC > 1), while 48.4% were at low risk (RQRSC < 0.2). Among the evaluated PFAS, PFOA, PFOS, PFDA, and GenX were associated with higher toxicity exposure risks. For the identified key concern PFAS, it is necessary to simplify detection techniques, promote targeted large-scale safe treatment technologies, and explore intelligent monitoring tools to reduce regulatory lag, thereby effectively monitoring, preventing, and controlling PFAS contamination.

Fate, distribution, and transport dynamics of Per- and Polyfluoroalkyl Substances (PFASs) in the environment

Metabolome-wide association study of four groups of persistent organic pollutants and abnormal blood lipids

Per- and polyfluoroalkyl substances (PFASs) are persistent and bioaccumulative substances that have many adverse effects on human bodies. This study investigated the PFASs distribution characteristics in urine samples of workers from an acrylic fiber plant and a chemical plant. It was found that perfluorobutanoic acid (PFBA) was the predominant PFASs both in urine samples from the chemical plant (detection frequency: 86.52%; median value: 39.01 ng/mL) and the acrylic fiber plant (detection frequency: 88.16%; median value: 44.36 ng/mL). Meanwhile, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) were detected with very low frequencies and low concentrations. Furthermore, the results showed that PFASs levels in urine samples of workers from different units of the plants were quite different. PFASs concentrations of urine samples in males were higher than those in females, especially for PFBA, PFHxA, and PFDoA. The age had limited effects on the PFASs distribution in urine samples in this study, as short-chain PFASs were the dominant compounds. The correlations between PFASs concentrations in urine and gender/ages of workers were finally analyzed by Pearson correlation. The overall results may indicate that short-chain PFASs (such as: PFBA and PFBS) were becoming dominant for human exposure, especially occupational workers.

Killer whales (Orcinus orca) have been deemed one of the most contaminated cetacean species in the world. However, concentrations and potential health implications of selected 'contaminants of emerging concern' (CECs) and new persistent organic pollutants (POPs) in endangered Southern Resident and threatened Bigg's (Transient) killer whales in the Northeastern Pacific (NEP) have not yet been documented. Here, we quantify CECs [alkylphenols (APs), triclosan, methyl triclosan, and per- and polyfluoroalkyl substances (PFAS)] and new POPs [hexabromocyclododecane (HBCCD), PFOS, PFOA, and PFHxS] in skeletal muscle and liver samples of these sentinel species and investigate in utero transfer of these contaminants. Samples were collected from necropsied individuals from 2006 to 2018 and analyzed by LC-MS/MS or HRBC/HRMS. AP and PFAS contaminants were the most prevalent compounds; 4-nonylphenol (4NP) was the predominant AP (median 40.84 ng/g ww), and interestingly, 7:3-fluorotelomer carboxylic acid (7:3 FTCA) was the primary PFAS (median 66.35 ng/g ww). Maternal transfer ratios indicated 4NP as the most transferred contaminant from the dam to the fetus, with maternal transfer rates as high as 95.1%. Although too few killer whales have been screened for CECs and new POPs to infer the magnitude of contamination impact, these results raise concerns regarding pathological implications and potential impacts on fetal development and production of a viable neonate. This study outlines CEC and new POP concentrations in killer whales of the NEP and provides scientifically derived evidence to support and inform regulation to mitigate pollutant sources and contamination of Southern Resident killer whale critical habitat and other marine ecosystems.

BackgroundPrenatal exposure to perfluoroalkyl substances (PFAS) has been associated with lower birth weight in epidemiologic studies. This association could be attributable to glomerular filtration rate (GFR), which is related to PFAS concentration and birth weight.ObjectivesWe used a physiologically based pharmacokinetic (PBPK) model of pregnancy to assess how much of the PFAS–birth weight association observed in epidemiologic studies might be attributable to GFR.MethodsWe modified a PBPK model to reflect the association of GFR with birth weight (estimated from three studies of GFR and birth weight) and used it to simulate PFAS concentrations in maternal and cord plasma. The model was run 250,000 times, with variation in parameters, to simulate a population. Simulated data were analyzed to evaluate the association between PFAS levels and birth weight due to GFR. We compared simulated estimates with those from a meta-analysis of epidemiologic data.ResultsThe reduction in birth weight for each 1-ng/mL increase in simulated cord plasma for perfluorooctane sulfonate (PFOS) was 2.72 g (95% CI: –3.40, –2.04), and for perfluorooctanoic acid (PFOA) was 7.13 g (95% CI: –8.46, –5.80); results based on maternal plasma at term were similar. Results were sensitive to variations in PFAS level distributions and the strength of the GFR–birth weight association. In comparison, our meta-analysis of epidemiologic studies suggested that each 1-ng/mL increase in prenatal PFOS and PFOA levels was associated with 5.00 g (95% CI: –21.66, –7.78) and 14.72 g (95% CI: –8.92, –1.09) reductions in birth weight, respectively.ConclusionResults of our simulations suggest that a substantial proportion of the association between prenatal PFAS and birth weight may be attributable to confounding by GFR and that confounding by GFR may be more important in studies with sample collection later in pregnancy.CitationVerner MA, Loccisano AE, Morken NH, Yoon M, Wu H, McDougall R, Maisonet M, Marcus M, Kishi R, Miyashita C, Chen MH, Hsieh WS, Andersen ME, Clewell HJ III, Longnecker MP. 2015. Associations of perfluoroalkyl substances (PFAS) with lower birth weight: an evaluation of potential confounding by glomerular filtration rate using a physiologically based pharmacokinetic model (PBPK). Environ Health Perspect 123:1317–1324; http://dx.doi.org/10.1289/ehp.1408837

Background and Aim: Polyfluoroalkyl substances and perfluoroalkyl substances (PFAS) include numerous anthropogenic chemicals used in firefighting foams, non-stick cookware, food packaging, and waterproof clothing. Research has shown some PFAS exposures appear to be decreasing in the general population of Canada. In contrast, prior to a human biomonitoring research completed in Old Crow, Yukon and the Mackenzie Valley, Northwest Territories, much less was known on exposure patterns for Dene and Gwich’in populations. This research aims to describe exposure patterns among these populations by identifying determinants and potential sources of PFAS exposure for participants. Method: Nine PFAS (including: perfluorooctanoic acid (PFOA), perfluorooctane sulphonic acid (PFOS), perfluorohexane sulphonic acid (PFHxS), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUdA), perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), and perfluorobutane sulphonic acid (PFBS)) were quantified using liquid chromatography mass spectrometry in blood samples collected in Old Crow (n=54) and the Dehcho Region, Northwest Territories (n=125). Results: This research showed that, for most PFAS, levels in Old Crow and the Dehcho Region, Northwest Territories were similar or lower to those observed in the Canadian Health Measures Survey. The key exception to this was perfluorononanoic acid (PFNA) which, relative to the CHMS (0.51 μg/L), was approximately 1.8 times higher in Old Crow (0.94 μg/L) and 2.8 times higher in Dehcho (1.42 μg/L) than observed in the general Canadian population. This presentation will report results describing the associations, using multivariable logistic regression, between PFAS levels and consumption of traditional food, lifestyle factors, and demographics. Conclusions: The results highlight the importance of expanding PFAS analytical suites beyond PFOS and PFOA for both human biomonitoring as well as environmental sampling in northern environments. Keywords: Biomonitoring; Contaminants; Indigenous; Traditional Foods; PFAS; PFNA

To explore the level of perfluoroalkyl substances (PFASs) and their precursors in 18 market milk samples of China. The 18 milk samples were selected in 8 provinces of China, including Ningxia, Neimeng, Beijing, Tianjin, Hebei, Shanxi, Chongqing, and Guangdong. 8 PFASs and 11 PFAS precursors were measured by ultra-high performance liquid chromatography-tandem quadruple mass spectrometry (UPLC-MS/MS). The dietary exposure assessment was made. Three PFASs were detected in milk samples which were PFOA, PFUdA, and PFOS. The numbers of detected samples were 5, 12, and 14, respectively. Their concentration ranges were < Limit of determination (LOD)-431.94 pg/ml, < LOD -15.95 pg/ml and < LOD -126.98 pg/ml, respectively. Three PFAS precursors were also found above the detection limits, namely, 4:2 FTS, 6:2 FTS, and 6:2 diPAP. Only one sample was detected 4:2 FTS at the concentration of 3.75 pg/ml. The detected samples of 6:2 FTS and 6:2 diPAP were 12 and 3. Their concentration ranges were < LOD -2.49 pg/ml and < LOD -24.56 pg/ml, respectively. The ranges estimated daily intake of PFOA and PFOS of the detected samples were 2.49 × 10⁻³-405.89 × 10⁻³ ng · kg⁻¹ · d⁻¹ and 36.10 × 10⁻³-119.32 × 10⁻³ ng · kg⁻¹ · d⁻¹. Our results suggested that there were different contamination levels of PFASs and their precursors in the 18 market milk produced from different regions in china. The estimated daily intake of PFASs from the milk in our study were far below the tolerable daily intake set by European Union (PFOS: 150 ng · kg⁻¹ · d⁻¹, PFOA: 1 500 ng · kg⁻¹ · d⁻¹).

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous environmental contaminants commonly detected in human serum. Previous studies have observed associations between maternal serum PFAS and adverse pregnancy and birth outcomes such as lower birth weight or pre-eclampsia; however, few studies have explored these associations with birth outcomes and placental tissue PFAS concentration. The placenta is a vital contributor to a healthy pregnancy and may be involved in the mechanism of PFAS reproductive toxicity. Our goal was to measure placental PFAS concentrations and examine associations with birth outcomes (e.g., birth weight, gestational duration). Placenta samples (n = 120) were collected during delivery from women enrolled in the Healthy Pregnancy, Healthy Baby cohort (HPHB) in Durham, North Carolina. All placenta samples contained detectable PFAS, with perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) being the most abundant and most frequently detected (all >96% detection frequency). While placental PFAS concentrations did not differ by infant sex, higher PFAS levels were observed in placenta from nulliparous women, suggesting that parity influences the accumulation of PFAS in the placenta. We used linear regression models to examine associations between placental PFAS and birth outcomes. After adjustment for parity, tobacco use, maternal age, and maternal race, we found that placental PFOS was associated with lower birth weight for gestational age in male infants and higher birth weight for gestational age in female infants. Similar findings were seen for PFNA for birth weight for gestational age. These differences in birth outcomes based on infant sex highlight a need to explore mechanistic differences in PFAS toxicity during gestation for male and female infants.

Occurrence and transport of per- and polyfluoroalkyl substances (PFAS) in the leachate of a municipal solid waste landfill in Tehran, Iran (a Middle-Eastern megacity).

The pollution level and source of perfluoroalkyl substances (PFASs) in mainstream and tributary of Daling River in northeast China were investigated in present study. Concentrations of PFASs in surface water and sediment ranged from 4.6 to 3,410 ng/L and from 0.08 to 2.6 ng/g dry weight, respectively. The lowest levels of PFASs were found in vicinity of a drinking water source located in upstream of Daling River. Xihe tributary, which is adjacent to two local fluorine industrial parks, contained the highest level of PFASs. Short-chain PFASs, including perfluorobutanoic acid and perfluorobutane sulfonate, were of higher levels due to their emerging as alternative products for perfluorooctane sulfonate. High level of perfluorooctanoic acid was also found in Daling River. Based on these results, it can be concluded that the relatively severe pollutions of Xihe tributary were caused by long-term development of the two local fluorine industry parks.

Perfluoroalkyl substances and severity of nonalcoholic fatty liver in Children: An untargeted metabolomics approach

Per- and polyfluoroalkyl substances (PFAS), man-made chemicals with highly fluorinated carbon chains, are used in many commercial applications. Trace levels of several long-chain PFAS, including perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), have been detected in the blood of almost every American, while short-chain PFAS are seldom detected. These findings may reflect lower exposure to short-chain PFAS or that, in humans, short-chain PFAS eliminate efficiently in urine. Because of changes in manufacturing of long-chain PFAS, short-chain PFAS and fluorinated alternatives, including perfluoroalkyl ether carboxylic acids (e.g., GenX, ADONA), are increasingly used. Moreover, detection of PFAS and fluorinated alternatives in drinking water has raised concerns about potential implications to human health from exposure through contaminated water. We developed an analytical method adequate for large biomonitoring programs like the National Health and Nutrition Examination Survey (NHANES), and report concentrations of 15 C3-C11 PFAS, GenX, and ADONA in urine and serum collected in 2016 from a convenience sample of 50 American residents with no known exposure to these chemicals. In serum, we did not detect GenX or ADONA; detection frequency and concentration patterns of other PFAS agreed with those from NHANES. In urine, we did not detect fluorinated alternatives, and rather infrequently short-chain PFAS (e.g., perfluorobutanoate in 56% of samples, median&amp;#61;0.2 µg/L; 95th percentile&amp;#61;0.6 µg/L). Despite widespread presence in serum, long-chain PFAS in urine were non-detectable (&amp;lt;0.1 µg/L). These results suggest limited exposure to both short-chain PFAS and select fluorinated alternatives in this convenience population, and stress the relevance of selecting the correct biomonitoring matrix to characterize exposure. Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the CDC.

Emerging and legacy per- and polyfluoroalkyl substances in water, sediment, and air of the Bohai Sea and its surrounding rivers