Investigation of gaseous phase and fractional particle phase pcb concentrations in urban atmosphere

PCBs are extensively used in industry until 1970s in open, semi-closed and closed systems. 1.3 million tons of PCB production is estimated worldwide. Due to this production, they showed huge distribution. when their semi volatile characteristics are also considered, PCBs detected to be persistent in the environment. After this finding, production of PCBs was halted and restrictions were applied on the use of PCB containing equipment. In this study, atmospheric concentrations of PCBs was investigated in Istanbul which is a crowded city. The study was conducted at both gaseous and particle phases. In order to obtain more detailed results particles were size segregated by a cascade impactor. Average total atmospheric concentration was determined to be 397 pg.m-3. PCBs was determined to be more intense around 1 µm particle size. Soil samples were also taken along with the air samples to determine air/soil fluxes. Average soil concentration was determined as 6 ng. g-1 DM. According to calculations made by available models, most of the congeners volatilize from soil and contribute to air concentrations. An emission inventory was prepared in order to determine the hot-spots covering the whole country. At first, PCB releasing industry types are detected and then calculation was accomplished by utilizing plant capacities. Annual average PCB emission was estimated as 920 kg. The most polluted area was detected to be Dilovasi. Junge-pankow model, which is used to estimate particle bond concentrations, was modeled by fuzzy-logic to give more realistic results. Clausius-clapeyron equation which is used in long-range transportation calculations are proposed to be used after correcting the concentration values by mixing height. According to modeling studies, Marmara Sea is likely to contribute to ambient levels by volatilization. Long-range transportations mostly occurred over Black Sea and potential sources are estimated to be Russia and Eastern Balkan countries. As a result, although PCBs are prone to global circulation, local sources are important contributors to Istanbul atmosphere.