Concentration, phase distribution, and size distribution of atmospheric polychlorinated biphenyls measured in southern Taiwan

Polychlorinated biphenyl (PCB) samples in the ambient air of rural, urban, and industrial sites were collected by two PS-1 samplers and two Micro-Orifice Uniform Deposit Impactors (MOIDIs) from July 1993 to December 1994 in southern Taiwan. The total PCB concentrations averaged 2.50, 4.51, and 5.91 ng m(-3) for the rural, urban, and industrial sites, respectively. Mean gas phase distribution of total PCBs was 43.6%, 60.9%, and 63.1% for the rural, urban, and industrial sites, respectively. The patterns of PCB homologues were similar to the distribution of those found in the mixture of Aroclor 1242 and 1260. Particle-bound total PCBs averaged 10.3, 13.9, and 9.24 mu g g(-1) for rural, urban, and industrial sites, respectively. For both urban and industrial sites, the particle size distribution (dC/dlogDp vs. Dp) of both total PCBs and total particle mass was found to have bimodal size distribution. The industrial aerosols were dominant in the fine particle mode (Dp<2.5 mu m), while, at the urban site, they existed mainly in the coarse particle mode (Dp>2.5 mu m).