Aug 2026· Environmental Epidemiology· Vol 10, pp. e522· 0 citations· 50 references
Medicine
TL;DR
Cumulative PFOS was associated with reduced processing speed and modified the impact of recent exposure, and the need to evaluate exposure mitigation strategies, including decontamination practices is highlighted.
Abstract
Background: This pilot study aimed to examine associations between recent occupational exposure to per- and polyfluoroalkyl substances (PFAS) and domain-specific cognitive performance and explore whether cumulative perfluorooctane sulfonic acid (PFOS) modified these associations. Methods: Sixty-five actively serving firefighters in Central Texas (June 2023–March 2025) participated. Recent exposure was assessed using total concentrations (pg/µl) of perfluorobutanoic acid, perfluorobutane sulfonic acid, and PFOS measured in single post-incident wash-water samples from three sites (June–August 2024), with site-specific results extrapolated to all firefighters at each site. Cumulative exposure was measured using PFOS concentrations (pg/µl) in whole blood collected from February to March 2025. Cognitive outcomes included standardized z-scores for processing speed and global cognition derived from the NIH Toolbox Cognition Battery. Linear regression models evaluated PFAS–cognition associations, adjusting for covariates and testing interaction effects. Results: After adjustment, each doubling of cumulative PFOS corresponded to an estimated 11.1-point decline in processing speed (β = −1.07, 95% confidence interval = −1.59, −0.55, P < 0.001). Among firefighters with lower cumulative PFOS, higher recent PFAS exposure was associated with a 7.5-point reduction in processing speed. This effect was amplified with increasing cumulative PFOS (interaction β = 0.74, P = 0.01). No significant associations were observed for global cognition. Conclusion: PFAS exposure may differentially relate to cognitive domains in firefighters. Cumulative PFOS was associated with reduced processing speed and modified the impact of recent exposure. These preliminary findings warrant confirmation in larger studies and highlight the need to evaluate exposure mitigation strategies, including decontamination practices.
Limiting to directly measured exposures, incorporating the full NHANES design in the primary regression, and triangulating across complementary mixture frameworks provide a more rigorous platform than prior single-pollutant or design-naive approaches.
Rifa Tasnia, E. Obeng-Gyasi· Journal of Xenobiotics· 0 citations
OBJECTIVE
Epidemiological and toxicological studies have associated perfluoroalkyl and polyfluoroalkyl substances (PFAS) with adverse effects on multiple organ systems. However, the potential link between PFAS exposure and obstructive sleep apnea (OSA) remains limited.
METHODS
2,960 participants were selected from two cycles of National Health and Nutrition Examination Survey. OSA was evaluated by the multivariable apnea prediction index, and serum concentrations of nine PFAS were detected. Weighted logistic regression, RCS, and WQS regression were used to assess individual, nonlinear, and mixture associations.
RESULTS
PFDeA and PFUA showed significant inverse dose-response relationships, with quartile-based analyses showing protective effects for PFDeA, PFHxS, Me-PFOSA-AcOH, PFUA, and n-PFOS. RCS analyses revealed L-shaped nonlinear relationships for PFDeA and PFUA. Sex-stratified analyses identified a female-specific inverse association for Sm-PFOS (P for interaction = 0.025). WQS regression indicated significant protective mixture effects (OR = 0.69, P = 0.007), predominantly driven by PFUA, followed by n-PFOA and PFHxS.
CONCLUSION
The relationships between PFAS exposure and OSA risk are characterized by compound-specific, concentration-dependent, and sex-dimorphic patterns.
Per- and polyfluoroalkyl substances (PFAS) represent an emerging concern due to their persistence, bioaccumulation, and emerging associations with different cancers and other diseases. Biomonitoring studies worldwide report elevated PFAS serum concentrations in firefighters compared with other occupations and the general population. The aim of this study was to quantify PFAS serum concentration in current and former firefighters and a general population comparison group in the UK. PFAS serum concentrations were analysed in a total sample of 1224 participants, including 942 firefighters from eight Fire and Rescue Services (FRSs) and 282 individuals from the general population. PFAS concentrations varied across tested FRSs, with geometric mean serum levels for some analytes higher than those observed in the general population. These included PFHxS (4.1 times higher), PFOS sum (1.5 times higher) and PFHPS (about 1.6 times higher), compounds that have been historically associated with the use of aqueous film forming firefighting foams. Furthermore, four PFAS (8:2 FTS, FOSA, PFBS, and PFPeS) were detected exclusively in firefighter serum and not in the general population, of which three are commonly detected in firefighter turnout gear. Descriptively, PFAS geometric mean concentrations tended to be higher among older firefighters and those with longer service duration. The general population cohort, drawn from a region which has subsequently been found to have some of the UK’s highest PFAS environmental contamination, showed relatively high baseline serum PFAS levels, suggesting the contribution of high background environmental exposure in this cohort. Reported data highlights the need for PFAS monitoring among firefighters, including evaluation of occupational exposure pathways, with attention to likely sources such as firefighting foam types and formulations; the type of chemicals applied to turnout gear; PPE use, frequency and type of decontamination. Further research should also include wider monitoring of the general population, including evaluation of likely sources and pathways of exposure.
A. Stec, Thomas Snelgrove, Kathryn Riley et al.· Scientific Reports· 0 citations
The findings suggest that exposure to low levels of some alternative and precursor PFAS may be widespread in Canada and reinforce the role of pregnancy and breastfeeding as excretion pathways for legacy PFAS and support previous investigations demonstrating that exposure to some PFAS may be lower amongst financially disadvantaged populations.
Michael M. Borghese, Rebecca Lelievre, Sara Packull-McCormick et al.· Environmental Health· 0 citations
Per- and polyfluoroalkyl substances (PFAS) are pervasive organic compounds that have garnered significant attention due to their potential impacts on human health, particularly in relation to asthma, though current evidence remains limited. This study aimed to examine the association between PFAS exposure and adult asthma using a sample of 7106 participants aged 20 years and older from the NHANES survey, spanning 2003 to 2018. Survey-weighted multivariable logistic regression models, subgroup analysis, weighted quantile sum and Bayesian kernel machine regression models were employed to probe the relationship between PFAS and asthma. In the multivariable logistic regression analysis, higher log10-transformed perfluorooctane sulfonic acid (PFOS) and PFNA concentrations were significantly associated with lower odds of asthma (PFOS: OR = 0.76, 95% CI: 0.61–0.96; PFNA: OR = 0.77, 95% CI: 0.60–0.99). The inverse link between PFAS co-exposure and asthma incidence persisted across multi-pollutant models, weighted quantile sum regression, and Bayesian kernel machine regression models, with PFOS emerging as the primary negative influencer. In conclusion, this study highlights PFAS exposure is inversely associated with asthma risk in adults.
Tiankai Shan, Kai Wu, Jing-Xian Jiang· Medicine· 0 citations
Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants widely detected in human biological samples. As regulatory restrictions on long-chain PFAS such as PFOA and PFOS have increased, short-chain alternatives, including perfluorohexanoic acid (PFHxA) have been widely adopted due to their lower bioaccumulation potential. However, their potential neurodevelopmental effects remain poorly understood. In this study, we investigated the long-term behavioral and neurobiological consequences of chronic PFHxA exposure beginning during the neurodevelopmental period and continuing throughout the lifespan. Behavioral assessments revealed that PFHxA exposure selectively impaired spatial memory. In both the novel object recognition and object location tests, PFHxA-exposed mice failed to show a significant preference for novel or relocated objects, indicating deficits in recognition and spatial memory. In contrast, no significant differences were observed in long-term memory, motor function, or social behaviors. Collectively, these findings suggest that chronic PFHxA exposure may induce subtle cognitive alterations and highlight the potential neurodevelopmental hazard of this short-chain PFAS.
Dong Hun Lee, BaDa Cho, Jieun Seo et al.· Toxicology· 0 citations