Short-chain chlorinated paraffin (SCCP) pollution from a CP production plant in China: Dispersion, congener patterns and health risk assessment

Abstract

China is the largest chlorinated paraffin (CP) producer in the world. Given that CP production is a major source of short-chain CP (SCCP) pollution in China, the effects of CP production on the environment inside and outside of CP production plants are worth revealing. The concentrations and specific congener group patterns of SCCPs in various environmental matrices, such as air, soil and dust, inside and outside of a chosen CP production plant surrounded by farmlands and villages were analyzed to explore SCCP pollution and transportation behaviors. SCCP concentrations in air (129–1442 ng/m3) and soil (28–554 μg/g) samples inside the CP production plant were dramatically higher than those in air (91–333 ng/m3) and soil (102–441 ng/g) samples outside the CP production plant. Based on the congener abundance patterns among these samples, lighter groups (C10-11 and Cl5-6) were dominant in atmospheric environment, with greater long-range transport potential, whereas heavier groups (C12-13 and Cl7-10) were inclined toward deposition. It was clear that substantial amounts of SCCPs were released from the CP production plant, which contaminated the environment inside and outside of the plant. The daily occupational SCCP exposure of employees in the production hall (21.8 μg/day-kg) exceeded the tolerable daily intake (TDI, 10 μg/day-kg) given by Canadian Environmental Protection Act, suggesting that production employees were confronted with high health risk from SCCP exposure; while daily SCCP exposure of employees in office areas (0.57 μg/day-kg) and residents near the CP plant (1.22–25.5 × 10−2 μg/day-kg) were significantly lower, representing low health risk.