Characteristics and health risk assessment of volatile organic compounds emitted from interior materials in vehicles: a case study from Nanjing, China

It has become a great habit for driving to work in people’s daily life in China. In order to understand the concentration of volatile organic compounds (VOCs) in vehicles and the health risks related to inhalation exposure to VOCs, this study investigated the pollution characteristics and health risks posed by VOCs emitted from interior materials in vehicles. A total of 47 of 62 VOCs were studied, using 23 randomly selected vehicles of different brands in Nanjing city, China. The potential cancer and non-cancer health risks associated with VOC inhalation were assessed based on conventional approaches proposed by the United States Environmental Protection Agency (USEPA). The mean concentration of total VOCs was 1126.85 μg/m³, with a range of 321.29 to 2321.94 μg/m³. Of these, halohydrocarbons and aromatic hydrocarbons were the dominant components of the detected VOCs. The concentrations of several individual VOC exceeded more than 100 μg/m³. The individual mean cancer risks for the 17 health-related VOCs ranged from 4.64 × 10⁻¹⁰ to 1.09 × 10⁻⁴, with a cumulative risk of 1.61 × 10⁻⁴. The mean cancer risks associated with naphthalene, chloroform, 1,4-dichlorobenzene, and 1,2-dibromoethylene were 1.09 × 10⁻⁴, 1.61 × 10⁻⁵, 1.11 × 10⁻⁵, and 1.07 × 10⁻⁵, respectively. These risks are higher than the acceptable risk levels defined by the USEPA and the World Health Organization (WHO). Of these, naphthalene was regarded as having a “definite risk”; chloroform, 1,4-dichlorobenzene, and 1,2-dibromoethylene were regarded as having a “probable risk”; and 1,2-dichloroethane and carbon tetrachloride were regarded as having “possible risk.” The individual mean non-cancer risks associated with 28 health-related VOCs and total VOCs were within acceptable ranges; naphthalene was the dominant pollutant.