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Data concerning the irritative effects of current exposure to fumes of bitumen on the airways in humans are limited. To assess the effects of fumes of bitumen on the airways a cross-shift study was conducted with monitoring of inflammatory process in upper and lower airways of workers exposed to fumes of bitumen and a reference group. All workers were examined immediately before and after shift. At both time points, spirometry was performed and nasal lavage fluid (NALF), induced sputum and spot urine were collected. Cellular composition and inflammatory mediator profile of the NALF and sputum samples were analyzed. Personal air sampling in each mastic asphalt worker's breathing zone was carried out to measure exposure to fumes of bitumen. The present cross-shift study with 202 mastic asphalt workers exposed to fumes of bitumen and 55 roadside construction workers as the reference group showed that fumes of bitumen released under high processing temperatures by mastic asphalt handling can exert acute and (sub-)chronic irritative effects on the upper and lower airway assessed with nasal lavage and induced sputum analysis. Airborne personal exposure to fumes of bitumen was associated with significant cross-shift declines in lung function parameters. Pre-shift lung function parameters (forced expiratory volume in 1 s [FEV(1)] and forced vital capacity [FVC]) were significantly higher in the exposure group that pointed to a 'healthy worker effect.' Possible carry-over effects could be observed in elevated pre-shift levels of several inflammation parameters in exposed workers indicating a (sub)chronic inflammation in these groups. Elevated interleukin-8 and protein levels in bitumen-exposed workers in sputum samples were found, but not in the nasal lavage fluid. The results emphasize irritative effects on the upper and lower airways under high exposure to fumes of bitumen. A more detailed analysis will be provided when all workers will be enrolled in that study. [ABSTRACT FROM AUTHOR]

Mastic asphalt workers may be exposed to polycyclic aromatic hydrocarbons (PAH) present in bitumen. We conducted a cross-shift study to determine genotoxic effects after exposure to bitumen. For this purpose, external and internal exposure of 202 mastic asphalt workers exposed to bitumen and 55 construction workers without exposure to bitumen was assessed. Exposure by inhalation to fumes of bitumen during the shift was measured by personal ambient monitoring. To assess overall exposure to bitumen (by inhalation and dermal absorption), 1-hydroxypyrene (1-OHP) and the sum of 1-, 2 + 9-,3-,4-hydroxyphenanthrene (OHPhe) were determined in pre- and postshift urine. 8-Oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) adducts, anti-benzo[a]pyrene-7,8-diol-9,10-epoxide (anti-BPDE) DNA adducts, DNA strand breaks and alkali-labile sites, and micronucleus frequencies were determined as biomarkers of genotoxic effects in white blood cells (WBC). Concentrations of fumes of bitumen were correlated with a moderate association with 1-OHP and OHPhe after work shift (r(s) = 0.25, P < 0.001 and r(s) = 0.36, P < 0.001). Significantly increased 8-oxodGuo adduct levels were observed after shift in both exposure groups (P < 0.0001). Paradoxically, decreased DNA strand break frequencies were observed after shift in both groups (P < 0.05). Postshift values in DNA strand break frequency were associated with 1-OHP (Spearman rank correlation coefficient 0.19, P = 0.01). Significantly more 8-oxodGuo adducts and DNA strand breaks were found in workers exposed to bitumen before and after shift compared with the reference group. However, no dose-dependent association was observed between exposure and genotoxic effects. Nevertheless, the findings indicate that workers exposed to bitumen exerted a higher level of DNA damage (8-oxodGuo and DNA strand breaks) in WBC compared with reference subjects. [ABSTRACT FROM AUTHOR]

Data concerning the influence of sequence variants of metabolizing enzymes on the effect modulation of current exposure to fumes of bitumen in humans are limited. To assess effect modulation of genetic variants of metabolizing enzymes, 18 single nucleotide polymorphisms (SNPs) in metabolic enzymes were analyzed regarding their impact on the urinary levels of metabolites of polycyclic aromatic hydrocarbons. Based on personal ambient monitoring data for bitumen emissions a group of 180 workers exposed to fumes of bitumen under high processing temperatures during a shift were divided into two exposure groups: 24 with high exposure (> 10 mg/m(3)) and 156 with low ( G, which showed increased levels of 1-OHP (p = 0.013) and OHPhe (p = 0.001). The GG variant of EPHX1 15543A > G showed a significant effect (p = 0.006) only on OHPhe. Selected variants of metabolic enzymes can modulate the metabolite levels under exposure to bitumen. The SNP-related modulation of these biomarkers did not exceed a factor of two and is more pronounced for OHPhe than for 1-OHP. [ABSTRACT FROM AUTHOR]