Assessment of occupational exposure to diesel particulate matter through evaluation of 1-nitropyrene and 1-aminopyrene in surface coal miners, India.

DPM (diesel particulate matter) is ubiquitously present in the mining environment and is known for mutagenicity and carcinogenicity to humans. However, its health effects in surface coal mines are not well studied, particularly in India. In this study, DPM exposure and corresponding exposure biomarkers were investigated in four different surface coal mines in Central India. To document and evaluate the DPM exposure in surface coal miners, we characterized 1-NP (1-nitropyrene) in the mining environment as surrogate for DPM using Sioutas Cascade Impactor. Exposure biomarkers were analyzed by collecting post work shift (8-h work shift) urine samples and determining the concentrations of 1-aminopyrene (1-AP) as a metabolite of 1-NP and 8-hydroxydeoxyguanosine (8OHdG) as DNA damage marker. We observed high concentration of 1-NP (7.13-52.46 ng/m) in all the mines compared with the earlier reported values. The average creatinine corrected 1-AP and 8OHdG levels ranged 0.07-0.43 [Formula: see text]g/g and 32.47-64.16 [Formula: see text]g/g, respectively, in different mines. We found 1-AP in majority of the mine workers' urine (55.53%) and its level was higher than that reported for general environmental exposure in earlier studies. Thus, the study finding indicates occupational exposure to DPM in all the four mines. However, the association between 1-NP level and exposure biomarkers (1-AP and 8OHdG) was inconsistent, which may be due to individual physiological variations. The data on exposure levels in this study will help to understand the epidemiological risk assessment of DPM in surface coal miners. Further biomonitoring and cohort study are needed to exactly quantify the occupational health impacts caused by DPM among coal miners.