Benzene, toluene and xylenes in newly renovated homes and associated health risk in Guangzhou, China

Publication date: February 2014
Source:Building and Environment, Volume 72
Author(s): Zhengjian Du , Jinhan Mo , Yinping Zhang , Qiujian Xu
Decoration and refurbishment in homes is associated with rapid urbanization in China. Its popularity has led to indoor elevated levels of benzene, toluene, and xylenes (BTX), posing adverse health effects to occupants. In this study, concentration levels of BTX and associated health risk were investigated in homes with new renovations in urban and suburban areas in Guangzhou, China. All air samples were collected with passive samplers for 24 h exposure in winter 2012. The average concentrations of benzene, toluene, m/p-xylene and o-xylene were 18.5 μg/m³, 173.2 μg/m³, 58.1 μg/m³ and 40.8 μg/m³ respectively, similar to or higher than those reported in previous studies for new homes or recently renovated homes, but generally greater than those measured in old homes. Higher BTX concentrations were observed in urban homes than in suburban homes. The mean incremental lifetime cancer risk induced by inhalation exposure to benzene in newly renovated homes in Guangzhou was 6.8 × 10⁻⁶, higher than the acceptable risk level of 1.0 × 10⁻⁶ and those estimated for old homes. Taking into consideration the variation in exposure concentration, potency factor and exposure factors, the incremental risk decreased to 4.7 × 10⁻⁶. Monte Carlo simulation provides a clearer picture of cancer risk with a range of 1.0 × 10⁻⁶–1.2 × 10⁻⁵ for the selected population. Results of sensitivity analysis show that the accuracy of risk assessment could be enhanced by specifying the dose–response characterization and increasing the sample size. This study provides representative statistics regarding the BTX exposures and benzene cancer risk in newly renovated homes.