Health risk assessment and distribution of VOCs during excavation processes for the remediation of contaminated sites

摘要

The volatile organic compounds (VOCs) generated during remediation of contaminated soils in northern China during atypical site management were investigated. After collecting soil and gas samples, VOC concentrations in soil and gas particles were determined. Health risk during remediation of contaminated sites was evaluated using the National Academy of Sciences four guidelines for risk assessment; subsequently, the risk zone of each pollutant for the respiratory exposure pathways was drawn. Our results showed that restoration of VOC-contaminated sites may have serious risks for operating staff with respiratory exposure being the main route of VOC contamination. Regarding respiratory exposure pathways, the greatest noncarcinogenic toxicity was caused by 1,1,2-trichloroethane (noncarcinogenic risk 2.27 E + 03); the maximum carcinogenic toxicity was caused by 1,2-dichloroethane (carcinogenic risk 1.05 E - 01). 1,2-Dichloroethane posed the greatest noncarcinogenic and carcinogenic risks when exposure was via particulate matter inhalation, showing risk of 3.52 E - 04 and 2.23 E - 08, respectively. Regarding skin contact exposure pathways, carbon tetrachloride was the most significant noncarcinogenic risk (2.68 E - 07) and 1,1-dichloroethylene was associated with the maximum carcinogenic risk (4.31 E - 11). Based on the regional risk map of pollutants, higher health risk was determined at a certain distance from the excavation site of the contaminated location in the downwind.