Investigation of organochlorine and organobromine contaminants in the atmosphere

Atmospheric concentrations of persistent organochlorine pesticides (toxaphene, chlordane, endosulphan, and DDT) and polybrominated diphenyl ether flame retardants (PBDEs) were investigated to determine their occurrences, sources, and transport in the atmosphere. Air samples were taken at remote and at potential source sites using high volume air samplers, and the concentrations for these compounds were determined in the gas and particle phases separately using gas chromatographic mass spectrometry. The concentrations of organochlorine pesticides at the sites were matched with historical usage of these compounds. Maps were developed by incorporating these concentrations with air trajectories for each sample to indicate the source areas of these compounds.; PBDEs are relatively new environmental contaminants compared to the organochlorine pesticides. PBDEs were detected in the atmosphere at all the sampling sites. The high concentrations of PBDEs observed at the sites near urban areas and manufacturing plants suggest that these areas could be sources of PBDEs. The PBDEs were categorized into three groups (penta-BDE, octa-BDE, and deca-BDE). Particle-to-gas partitioning for penta-BDE was an important process, but deca-BDE was mostly found in the particle-phase samples.; Unknown halogenated flame retardants were discovered during the course of PBDE analysis of the atmosphere. These compounds were identified by gas chromatographic mass spectrometry and confirmed with authentic materials. The concentrations of these compounds were quantified in air, fish, and sediment samples for the first time.