The CELSPAC - FIREexpo biomonitoring study investigates the long-term effects of chemical exposure on firefighters' wellness and fitness. It aims to provide science-based measures to minimize the health risks of the firefighting occupation. Here, we present the study design, cohort profile, and first results with respect to internal per- and polyfluoroalkyl substances (PFAS) and polycyclic aromatic hydrocarbons (PAH) levels in study participants. Participants (n = 166) were divided into three subcohorts: i) newly recruited firefighters, ii) professional firefighters with several years' experience, and iii) the control group. Participants underwent physical performance tests, provided information on their lifestyle and diet, and urine and blood samples 1-4 times within an 11-week period. 12 serum PFAS and 10 urinary hydroxylated PAH (OH-PAH) levels were determined using HPLC-MS/MS and compared between subcohorts and samplings. The association of internal exposure with reported lifestyles and occupational factors was investigated using Spearman's correlation, principal component analysis, and multivariate regression analysis. ΣPFAS levels in firefighters were significantly higher than in the control group and were mostly associated with the length of firefighting career, age, blood donation, and population size. 10.9 % and 7.6 % of measurements exceeded the HBM-I or HBM-II value for PFOS and PFOA, respectively. Urinary ΣPAH levels increased significantly after training with burning wooden pallets, but none of them exceeded the no observed genotoxic effect level. Firefighters' occupational exposure, its sources, and pathways, need to be systematically monitored and investigated on a long-term and individual basis. The CELSPAC - FIREexpo study helps to clarify the degree of occupational exposure to the given compounds and the subsequent risks to firefighters.

Exposure to bisphenols is related to negative effects on male reproduction. The bisphenols exposure is associated with several modes of action including negative impact on the blood–testis barrier (BTB) in testes or direct effect on spermatozoa. Bisphenols have been detected in human seminal plasma, but the possible mechanism of seminal transfer of bisphenols is not clear. Some authors consider the transfer through the blood–testis barrier to be crucial. Therefore, in this work, we compared normozoospermic men and men after vasectomy who have interrupted vas deferens and their ejaculate does not contain testicular products. We measured the concentration of bisphenol A (BPA), bisphenol S (BPS) and bisphenol F (BPF) in the urine and seminal plasma of these men using liquid chromatography tandem mass spectrometry (LC/MSMS). We found that the ratio of urinary and seminal plasma content of bisphenols did not differ in normozoospermic men or men after vasectomy. From the obtained data, it can be concluded that the pathways of transport of bisphenols into seminal plasma are not primarily through the testicular tissue, but this pathway is applied similarly to other routes of transmission by a corresponding ejaculate volume ratio. To a much greater extent than through testicular tissue, bisphenols enter the seminal plasma mainly as part of the secretions of the accessory glands.