External Exposure to Short- and Medium-Chain Chlorinated Paraffins for the General Population in Beijing, China

Chlorinated paraffins (CPs) are a class of compounds that are currently produced and used in large amounts in commercial products worldwide. In this study, food, indoor air, indoor dust, and drinking water samples were collected to evaluate the external exposure levels of CPs and possible pathway for the general population in Beijing, China. Short chain CPs (SCCPs) and medium chain CPs (MCCPs) in 199 samples were analyzed using a gas chromatography tandem time-of-flight high-resolution mass spectrometry (GC-TOF-HR-MS) method. High levels of CPs were observed in the indoor environment from residential houses, offices, and student dormitories. The geometric mean concentrations (GM) of ∑SCCPs and ∑MCCPs in indoor dust were 92 μg g^-1 and 82 μg g^-1, respectively, while in indoor air, the concentrations were 80 ng m^-3 and 3.4 ng m^-3, respectively. The GM of ∑SCCPs and ∑MCCPs in the diet were 83 ng g^-1 dry weight (dw) and 56 ng g^-1 dw, respectively. The most important external exposure routes to CPs to the general populations in Beijing were food intake and indoor dust ingestion. Indoor dust and indoor air posed higher risks for toddlers and infants than for adults.