Exposure to volatile organic compounds and polycyclic aromatic hydrocarbons is associated with the risk of non-alcoholic fatty liver disease in Korean adolescents: Korea National Environmental Health Survey (KoNEHS) 2015-2017

Non-alcoholic fatty liver disease (NAFLD) is one of the most frequent liver diseases among adolescents. Several animal studies have suggested that volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) increase NAFLD risk. However, few epidemiological studies have confirmed the association between VOCs, PAHs and NAFLD in the general adolescent population. Therefore, we analyzed 798 adolescents from the Korean National Environmental Health Survey (KoNEHS), 2015-2017, to examine the associations of urinary metabolites of VOCs and PAHs with serum alanine aminotransferase (ALT) activity and NAFLD prevalence. We performed linear regression, logistic regression, and Bayesian kernel machine regression (BKMR) to evaluate the association of urinary VOCs and PAHs metabolites with ALT levels and NAFLD prevalence. After adjusting for all covariates, urinary benzylmercapturic acid and 2-hydroxyfluorene levels were found to increase ALT activity and NAFLD prevalence. Additionally, the BKMR analyses showed a significantly positive overall effect on ALT ac-tivity and NAFLD prevalence with urinary concentrations of VOCs and PAHs metabolites, with 2-hydroxyfluor-ene as the biggest contributor. Our study suggests that exposure to low-level VOCs and PAHs may have a detrimental effect on NAFLD risk in adolescents. Given the increasing prevalence of NAFLD in adolescents, future cohort studies are confirmed to comprehend the effect of these chemicals on NAFLD risk.