Polychlorinated biphenyls in the ambient air of petroleum refinery, urban and rural areas

Atmospheric Dry Deposition of Polychlorinated Dibenzo-p-Dioxins/Dibenzofurans (PCDD/Fs) and Polychlorinated Biphenyls (PCBs) in Southern Taiwan

“…4(b)). An increasing trend with increasing chlorinated PCBs was observed in this study, it is due to the fact that low chlorinated PCBs are predominant in gas phase which are deposited mainly by diffusion and thus resulted in lower deposition velocities (Lee et al, 1996a). The calculated average deposition velocity for PCBs in this study is slightly lower than the previously reported values ranged from 1.26-5.9 cm/s (Tasdemir et al, 2004a;Tasdemir and Holsen, 2005;Cindoruk and Tasdemir, 2007;Bozlaker et al, 2008).…”

“…The calculated average deposition velocity for PCBs in this study is slightly lower than the previously reported values ranged from 1.26-5.9 cm/s (Tasdemir et al, 2004a;Tasdemir and Holsen, 2005;Cindoruk and Tasdemir, 2007;Bozlaker et al, 2008). The variations in deposition velocities are probably due to particle size distribution, the meteorological conditions, and different measurement techniques (Lee et al, 1996a;Franz et al, 1998).…”

“…A similar pattern was seen in ambient concentrations of PCBs, showing that the highest and lowest levels were found in an urban area (site B) and a rural area (site R). Higher concentrations of PCBs in urban areas than those of others have been reported in many studies, it is due to the fact that PCB-containing products were widely used in the urban areas (Lee et al, 1996a;Tasdemir et al, 2004;Yeo et al, 2004). It was also found that atmospheric concentrations of PCBs decreased with increasing chlorine substitution numbers, PCB#118 (46.6%, 5Cl) was the dominant species measured at all sampling sites, followed by PCB#105 (19.4%, 5Cl) and PCB#77 (18.0%, 4Cl).…”

Atmospheric Deposition of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans in Two Cities of Southern China

“…In this study, the mean dry deposition velocity of total PCDD/Fs (V d,T = 0.42 cm s -1 ) was proposed by Shih et al (2006). Dry deposition of gas-phase PCDD/Fs is mainly by diffusion, and due to the lack of measured data for PCDD/Fs, a selected value (0.010 cm s -1 ) for the gas-phase PAH dry deposition velocity, V d,g , as proposed by Sheu et al (1996) and used by Lee et al (1996), is used in the current work to calculate the PCDD/F dry deposition flux contributed by its gas phase. Dry deposition of particle-phase PCDD/Fs is mainly achieved by gravitational settling, and the dry deposition velocity of particle-phase PCDD/Fs, V d,p , can be calculated by Eq.…”

Distribution of Polybrominated Dibenzo-p-dioxins and Dibenzofurans and Polybrominated Diphenyl Ethers in a Coal-fired Power Plant and Two Municipal Solid Waste Incinerators

“…It is known to us that PCDD/Fs have been found in various sources, such as crematories, sinter plants and so on (Wang et al, 2003a;Wang et al, 2003b;Lee et al, 2004;Lee et al, 2005;Chen et al, 2011;Huang et al, 2011;Lin et al, 2011). PCBs and PCDD/Fs are known to entering soils via dry and wet disposition (Lee et al, 1996), and accumulate in animals (Lee et al, 2009); these are the characteristics PBDEs also possess.…”