Abstract
BACKGROUND: Temporal trends of chemicals in the population are key to identifying changing sources of chemicals and determining the effectiveness of various legislative measures. OBJECTIVE: The present study focused on time comparisons to explore a possible decrease in PAH metabolite levels in the Czech population. Legislative measures occurred between sampling periods, including restricting smoking and the Air Protection Act. METHODS: Ten metabolites of PAHs were measured in urine samples collected in 2011-2012 from mothers and children from DEMOCOPHES-CZ study (N = 235) and in 2019-2020 from children, teenagers, and young adults from CELSPAC studies (N = 809). Multivariate linear regression, Kruskal-Wallis ANOVA, and Mann-Whitney test (MW) were used to investigate differences in OH-PAHs between periods, age categories, and exposure determinants. RESULTS: Median concentrations significantly decreased between 2011-2020 by 30-35% for 1-OH-NAP, 2-and 3-OH-FLUO, 85% for 1-OH-PHE, and 44% for 2/3-OH-PHE, while 2-OH-NAP increased by 29% in non-smoking adults. In children, median concentrations of all metabolites decreased by 10-51%, with 2-OH-NAP rising by 49%. Smokers showed the largest differences, with significant decreases of 46-59% in the median concentrations of 2-OH-NAP, 2/3-OH-PHE, 9-OH-PHE, and 1-OH-PYR, and 76-91% in OH-FLUOs, 1-OH-NAP, and 1-OH-PHE. Fish and offal consumption, season, locality, and type of cooking were significant factors associated with levels of OH-PAHs, explaining 4-9% of the variability. Smoking was the main contributor in 2011, explaining up to 45% variability; no difference was found between smokers and non-smokers in 2019. New reference values of OH-PAHs in urine were calculated for the Czech population. IMPACT: This study analyses the temporal trends of OH-PAHs in the population in the context of introduced legislative measures. In addition, it examines OH-PAH exposure in children, adolescents, and young adults in relation to lifestyle factors and establishes new reference values for polycyclic aromatic hydrocarbons that are important for public health decision-making. Biomonitoring over time is an essential tool for establishing new measures to protect public health. Created in BioRender. Komprdova, K. (2025) https://BioRender.com/u10q831 .