Affiliations: Key Laboratory of Environmental Chemistry and
Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy
of Sciences, Beijing 100085, China
Abstract: Although polychlorinated biphenyls (PCBs) are globally recognized
pollutant, an understanding of their resources as by-products in chemical
industry is poorly investigated. This paper presents data from a study that was
conducted in order to determine the extent of PCBs in
1,4-dichlorobenzene (p-DCB) mothballs. Total PCBs and dioxin-like PCBs were
detected in five mothball samples. Total PCB concentrations ranged from 328
ng/g to 1798 ng/g, while the levels of WHO-TEQ were between 0.16 pg/g and 13
pg/g. Mean concentrations of total PCBs and WHO-TEQ in the samples were 724
ng/g and 3.2 pg/g, respectively. The highest level of PCB congeners was that of
trichlorinated biphenyls (537 ng/g), which maybe due to the relatively low
chlorination in the process of p-DCB production. A mechanism of the formation
of PCBs from polychlorinated benzene in the presence of chlorine is also
suggested. The results suggested that re-estimation on the risk of p-DCB
products, especially the products for daily use such as mothballs, is
expected.
