| Polybrominated diphenyl ethers(PBDEs), extensively used as additive flame retardants, are a kind of persistent organic pollutants(POPs) that have a petential threat of human health. Researches in rencent years found that human exposure to PBDEs via indoor environment plays a major role, which is different with polychlorinated biphenyls(PCBs) that is mainly through food intake. However, the previous reserch focused on PBDEs in outdoor air, the study of indoor's PBDEs needs to be strengthened.Compared with active sampling method,passive sampling method is especially suitable for indoor air pollutant sampling in developing countries because of cost-effective, simultaneous monitoring at multi-site, no need for electricity and noise free operation. But the relevant reports on PBDEs in China is scarce in present. Minnan cities(Xiamen, Quanzhou, Zhangzhou, Longyan), which is populous and developed rapidly in economic and urbanization, are selected as the researching regions for PBDEs in indoor and outdoor air. Passive sampling method was used to collect the air samples in different seasons and inverstigate the concentrations, seasonal variations, congener profiles, possible sources and human inhalation exposure to PBDEs in indoor and outdoor air of Minnan cities. The major findings are listed below:(1) The annual average outdoor air concentrations of PBDEs of Minnan cities was 111.2pg/m3, ranged from 11.5 to 2124.4 pg/m3. The annual average outdoor air concentrations of PBDEs of Quanzhou(278.8pg/m3) was higher than Xiamen(207.5pg/m3) ? Zhangzhou(54.4pg/m3) and Longyan(48.0pg/m3).Congener profiles show that BDE-209 was the dominant component(spring:97±2%; summer:96±4%; autumn: 98±2%; winter : 98±2%).Industrial zones are the key sources of PBDEs, which was more important than the emissions of PBDEs form products in daily usage. PBDEs concentrations in central urban areas were higher than that of suburban areas because of the intensive usage of PBDEs containing products.(2) The geometric mean indoor air concentrations of PBDEs in homes of Minnan cities(spring:75.4 pg/m3; summer:69.4 pg/m3; autumn: 74.4 pg/m3; winter: 129.3 pg/m3) was slighely higher than that of offices(spring: 53.9 pg/m3; summer:100.9 pg/m3; autumn: 77.2 pg/m3; winter: 70.0 pg/m3). The indoor air concentration of PBDEs in homes of Minnan cities in winter was higher than other three seasons,but in offices, the highest season was summer. The difference of concentration between homes and offices was mainly resulted from ventilation habits.(3) Congener profiles show that BDE-209 was the major component, indicating that Deca-BDE was the major commercial PBDEs used in Minnan cities. Penta-BDE and Octa-BDE was also used and their proportions in offices were higher than that of homes. According to I/O ratios, indoor environment is a major pollution source of low brominate PBDEs, and the concentration of BDE-209 was mainly affacted by outdoor air.(4) Research of PBDEs in computer rooms show that there was a big difference with the flame retardant between equipments in computer rooms and household appliances. Researches on the indoor air of stores selling household electrical appliances show that electric and electronic equipments was the main sources of PBDEs. The average indoor air concentrations of PBDEs in factories was one or two orders of magnitude higher than others,which suggested that the main source of PBDEs was industrial production.(5) The human daily exposure dose of BDE-209 in spring, summer, autumn,and winterwas 1.20 × 10-2, 1.20 × 10-2, 1.42 × 10-2,and2.28 × 10-2 ng/kg-bw/day respectively for adult in Minnan cities. The Hazard quotient of BDE-209 range from 7.53×10-5~1.42×10-4 at all seasons, show that the inhalation exposure of PBDEs levels was in the acceptable range for the human being in Minnan cities. |
PDF Full Text Request