Seasonal variations and inhalation risk assessment of short-chain chlorinated paraffins in PM of Jinan, China.

Short-chain chlorinated paraffins (SCCPs) were added to the Stockholm Convention on Persistent Organic Pollutants (POPs) at the eighth meeting of the conference of the parties in 2017. As a consequence, increasing environmental attention and international regulation on SCCPs is expected in the future. Inhalation uptake of particulate matter (PM) was an important exposure pathway for POPs into the human body. In the present study, a total of eighty PM samples were collected in the four seasons of the year at an urban site (Shandong University, Jinan) in Shandong province to investigate the seasonal changes of SCCPs and their inhalation exposure risks to human health. The concentrations of SCCPs ranged from 9.80 to 105 ng m, with the mean value of 38.7 ng m. The highest concentrations of SCCPs were detected in winter, while the lowest concentrations were in summer. SCCPs concentrations were positively correlated with the mass concentrations of PM (r = 0.629, p < 0.01), and negatively correlated with the ambient temperature (r = -0.447, p < 0.01). The SCCPs congeners with 10 carbon atoms (C congeners) and 7 chlorine numbers (Cl congeners) were the predominant congeners, which contributed 35% and 37% of the total SCCPs contamination, respectively. The average inhalation exposure was estimated to be 1.75 × 10 mg kg day for adults, which is much lower than the "no observed adverse effect level" (NOAEL) of 100 mg kg day given by European risk assessment for SCCPs.