Pollution Characteristics and Carcinogenic Risk Assessment of PAHs in Car Dust Collected from Commercial Car Wash in Changchun, Northeast China

Abstract

In the collection of dust, vacuum cleaners are used to clean everything inside the car, including floor/carpet, seat, console, etc. To investigate the characteristics, possible sources and carcinogenic risks of polycyclic aromatic hydrocarbons (PAHs) contamination in car dust, fourteen car dust samples were collected from commercial car washes in Changchun, Northeast China. The 16 priority PAHs were all detected in 100%, and PAHs were predominantly tetracyclic. The mean ∑16PAHs content was 9297.79 ± 5855.89 ng g−1, ranging from 2940.03 to 23,174.51 ng g−1. Black carbon, total carbon and PAHs were weakly correlated. The results of positive matrix factorization indicated that coal combustion contributed 30.03% of PAHs and biomass combustion contributed 24.70%. Vehicle exhaust from traffic emissions, mainly incomplete combustion of gasoline and diesel, contributed 45.27% of PAHs. The mean incremental lifetime cancer risk (ILCR) values for children and adults were 4.94 × 10−3 and 4.37 × 10−3, respectively, both above the threshold value of 10−4. This indicates that PAHs from car dust put both adults and children at high carcinogenic risk, and that children are exposed to a higher carcinogenic risk than adults. This study provides a basis for proposing targeted measures to control PAHs’ contamination from car dust.