Per and poly-fluoroalkyl substances and respiratory health in an Inuit community

Abstract

Background: Concentrations of plasma per and poly-fluoroalkyl substances (PFAS) are elevated in the Inuit population of Nunavik and may be causing adverse health effects. Respiratory health outcomes have been associated with PFAS, but have not been explored in Inuit communities. The aim of the study was to examine the association between PFAS and respiratory health outcomes, and the moderating role of nutritional biomarkers.

Methods: We included up to 1298 participants of the Qanuilirpitaa? 2017 survey aged 16-80 years. Generalized regression models were used to estimate the associations between six individual PFAS congeners and four self-reported symptoms, four spirometry measures, and physician-diagnosed asthma. Outcomes associated with PFAS from single chemical models were further explored using Bayesian Kernel Machine Regression (BKMR). The modifying effect of n-3 PUFA in red blood cell quartiles and vitamin D deficiency were examined on the associations between PFAS and respiratory outcomes.

Results: PFNA and PFOS were associated with asthma (odds ratio (OR) 1.61, 95% confidence interval (CI) 1.12, 2.32; OR 1.45 95% CI 1.04, 2.03). PFOA, PFNA, PFDA and PFHxS were associated with a decrease in the ratio between the forced expiratory volume in the first second and forced vital capacity (FEV1/FVC). No associations were observed with self-reported respiratory symptoms. No associations were observed between a PFAS mixture and asthma. Some associations were modified by nutritional factors, namely, stronger associations between PFOA and PFHxS and asthma with lower n-3 PUFA levels and stronger associations between PFDA, PFUnDA and PFOS and FEV1/FVC with vitamin D deficiency.

Conclusion: These findings add to the growing literature on the impacts of PFAS on respiratory health, and the importance of their global regulation. Associations were modified by nutritional factors pointing to the nutritional value of traditional Inuit foods.

Fig. 1

Association between PFAS congeners and predicted probability of having asthma stratified by n-3 PUFA in red cells. Interaction p-value = 0.05 for PFOA and n-3 PUFA and interaction p-value = 0.002 for PFHxS and n-3 PUFA. sex, age, personal income, marital status, smoking status, second-hand smoking, marijuana use, waist circumference, overcrowding, food security, n-3 PUFA quartiles, vitamin D, fruit/vegetable intake, and mercury

Fig. 2

Overall effect of PFAS mixture on asthma based on BKMR. Model is adjusted for sex, age, personal income, marital status, smoking status, second-hand smoking, marijuana use, waist circumference, overcrowding, food security, n-3 PUFA quartiles, vitamin D, fruit/vegetable intake, and mercury

Fig. 3

Bivariate exposure-response functions of each PFAS congener and asthma by BKMR analyses. Figures show the associations for each PFAS congener in the column while holding a second PFAS congener in the row constant at different quartiles, and the rest of PFAS congeners at the median. Models are adjusted for sex, age, personal income, marital status, smoking status, second-hand smoking, marijuana use, waist circumference, overcrowding, food security, n-3 PUFA quartiles, vitamin D, fruit/vegetable intake, and mercury concentrations