Gas/particle partitioning of short and medium chain chlorinated paraffins from a CP production plant using passive air sampler and occupational exposure assessment

Abstract

Short and medium chain chlorinated paraffins (SCCPs and MCCPs) attract increasing attentions due to their persistence, long–range transport capacity. Their gas/particle partitioning from the production emission source, the effects to the ambient environment and exposure for employees are worth revealing. Polyurethane foam based passive air samplers (PUF–PAS) was deployed to determine the environmental levels of SCCPs (63.4–719.7 ng/m3) and MCCPs (151.6–1009.2 ng/m3) in the gas–phase and particle–phase both in the outdoor air in a CP production plant and the indoor air in the workshops. Extremely high SCCPs were found in the chlorination workshop and outdoor samples nearby, attributing to the release during the production. In the workshops, dramatically higher SCCP concentrations were determined than outdoors. SCCPs and MCCPs predominated in the gas–phase with a proportion >80 %. C10–CPs and C14–CPs were dominated with a proportion higher than 20 % and 50 %, respectively. Significant correlations between log Kp’ and log PL0 and log KOA were observed in the outdoor air in a CP production plant and the indoor air in the workshops, respectively. A multivariate mechanism based on adsorption by organic matters and influenced by absorption processes might determine the gas/particle partitioning of CPs in the production source area. Two scenarios of occupational exposure i.e. working in the workshops and working outdoors were considered. Higher occupational exposure via inhalation to MCCPs was found for employees than SCCPs in the workshops, which was estimated to be 137.1 ng/kg/day at a worst case. No obvious adverse effects were observed for occupational employees in this CP production plant.