# A Cross-Sectional Analysis of Blood Spot per- and Polyfluoroalkyl Substances (PFAS) from Adolescents in Chitwan Valley, Nepal

## TL;DR

This study measured PFAS levels in blood samples from Nepalese adolescents and found that eating local fish is linked to higher PFAS exposure.

## Contribution

This is the first study to document PFAS exposure in Nepalese adolescents and identifies dietary fish consumption as a key exposure pathway.

## Key findings

- PFOS was detected in 46% of samples, PFNA in 25%, and PFOA in 12.5%.
- Participants who ate local fish more than once per month had significantly higher PFOS levels.
- Findings suggest dietary exposure is a significant pathway for PFAS in this population.

## Abstract

Background/Objectives: Per- and polyfluoroalkyl substances (PFAS) are globally widespread contaminants linked to adverse health outcomes, including immune dysregulation. We aimed to characterize PFAS exposure among adolescents in Nepal. We conducted a cross-sectional study in Chitwan District, Nepal, during September–October 2023, enrolling 73 adolescents from the Chitwan Birth Cohort. Methods: Dried blood spots from 48 participants were analyzed for 45 PFAS by liquid chromatography–tandem mass spectrometry. Sociodemographic and contextual behavioral covariates information (e.g., water source and local fish consumption) were collected via questionnaire. We used linear regression to analyze the association between contextual behavioral covariates and PFAS concentrations. Results: PFOS was detected in 46% of samples, followed by PFNA (25%) and PFOA (12.5%); other PFAS were rarely detected. Participants who consumed locally caught fish more than once per month had significantly higher PFOS levels (β = 0.35, p = 0.006). Conclusions: Frequent fish intake was the only factor significantly associated with PFAS levels, suggesting a dietary exposure pathway. This study provides the first documentation of PFAS exposure among Nepalese adolescents, revealing low-level exposures. Findings underscore the need for ongoing surveillance of environmental contaminants in vulnerable populations.