Elevated urinary mutagenicity among those exposed to bituminous coal combustion emissions or diesel engine exhaust

Abstract

Urinary mutagenicity reflects systemic exposure to complex mixtures of genotoxic/ carcinogenic agents and is linked to tumor development. Coal combustion emissions (CCE) and diesel engine exhaust (DEE) are associated with cancers of the lung and other sites, but their influence on urinary mutagenicity is unclear. We investigated associations between exposure to CCE or DEE and urinary mutagenicity. In two separate cross-sectional studies of nonsmokers, organic extracts of urine were evaluated for mutagenicity levels using strain YG1041 in the Salmonella (Ames) mutagenicity assay. First, we compared levels among 10 female bituminous (smoky) coal users from Laibin, Xuanwei, China, and 10 female anthracite (smokeless) coal users. We estimated exposure-response relationships using indoor air concentrations of two

Alterations to biomarkers related to long-term exposure to diesel exhaust at concentrations below occupational exposure limits in the European Union and the USA

“…In previous analyses,2 3 5 8–10 occupational exposure to DEE was found to be associated with alterations to biomarkers that may reflect the key characteristics of carcinogens 11. In particular, we found alterations to lymphocyte subsets that reflect inflammatory states, cytokines/chemokines that reflect immune function, arthrobacter luteus (Alu) retroelement copy number that reflects genomic instability, urinary mutagenicity that reflects recent exposure to genotoxic agents, circulating microRNAs (miRNAs) involved in post-transcriptional regulation12 and gene expression in nasal epithelial cells 2 3 5 8–10 13. Although we observed significant trends for many biomarkers, we did not determine if levels of most of these biomarkers were altered at DEE concentrations below occupational exposure limits (OELs) that have been adopted or recommended in the USA or Europe.…”

“…Although intended to protect the respiratory health of DEE-exposed workers, concerns remain over the new EU OEL, as it potentially leaves a considerable risk of DEE-related cancers. Indeed, we previously found evidence of a biological effect of DEE on urinary mutagenicity, a biomarker that reflects recent exposure to genotoxic pollutants, even below the EU OEL of 50 µg/m 3 for EC 13. The American Conference of Governmental Industrial Hygienists (ACGIH) recommends an even lower workplace exposure limit of 20 μg/m 3 to protect the health of exposed workers 16…”

Unveiling Urinary Mutagenicity by the Ames Test for Occupational Risk Assessment: A Systematic Review

“…Nitro-PAHs can covalently bind to DNA and originate DNA-adducts, which in turn are responsible for the frameshift mutations that were already detectable by the TA98 strain. Therefore, the YG1041 strain has an increased sensitivity to compounds of the nitro-, hydroxylamino- and amino-aromatic groups that surpasses its parental strain (TA98) [ 18 , 23 , 24 , 25 , 26 ].…”

“…Figure 2 represents the overall distribution of UM levels that were reported with creatinine urinary concentration normalization. However, this normalization was not performed in some studies [ 24 , 31 , 32 , 33 , 34 , 35 ].…”

“…Workers exposed to diesel engine exhaust in a testing facility (6.1–107.7 µg/m 3 ) presented higher mean UM using YG1041 strains than the controls (13.0 versus 5.6 revertants/mL equivalent of urine; Table 2 ). There was a positive exposure–response relationship between elemental carbon below the European occupational exposure limit (50 µg/m 3 ), which suggests that a safer threshold of exposure may be needed [ 24 ]. UM was also performed in samples collected from traffic policemen before the start of a working week and after it ended (after 6 days) [ 55 ].…”