Health risk assessment of indoor air quality in passenger cars

In order to understand the current situation of air pollution in passenger cars in China, BTEX (benzene, toluene, ethylbenzene and xylene), styrene, formaldehyde, acetaldehyde and acrolein in the cabins of 35 new cars from 16 various brands were quantified using thermal desorption-capillary gas chromatography/mass spectrometry and high-performance liquid chromatography. The health risks of the toxic materials at the measured concentrations were further evaluated. The results showed that, except for acetaldehyde, the other pollutants were all below the limit values recommended by GB/T 27630-2011 Guideline for Air Quality Assessment of Passenger Car; the concentration ranges were 3.00-73.00, 69.00-798.00, 18.00-469.75, 46.00-1 296.42, 12.00-46.00, 19.00-72.00, 43.29-323.00 and 5.20-7.60 μg/m³, respectively. The maximum concentrations of benzene, toluene and formaldehyde identified were only 66.63%, 72.00% and 72.55% the limit values. Only a small deviation of the measured xylene concentrations was discovered from sample to sample. The crew-averaged concentration of xylene was only 11.86% of the limit value. The maximum concentration of ethylbenzene was ⅓ its limit value, while the concentrations of styrene and acrolein were far below the regulatory caps. Both the measured concentrations of benzene and formaldehyde might have carcinogenic impacts on people exposed in such an environment. For vocational male drivers, the cancer-related risk induced by benzene and formaldehyde exposure in new cars was 18.86 and 60.67 times the baseline suggested by the US EPA. Compared to male drivers, only a reduction of 12.53% in cancer-related risk was found for female drivers. For a typical male driver, staying in a new car may result in 183% and 810% elevated cancer-related risk due to benzene and formaldehyde exposure, respectively. The risk for female drivers was slightly lower than that for male drivers. The non-cancer risk of xylene at the measured concentrations indoors was 78% higher than the US EPA baseline. Therefore, it is necessary to use more environmental-friendly interior materials to reduce the level of toxic substances and improve vehicle indoor air quality, providing a safer environment for drivers and passengers.