Dry deposition of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in ambient air.
The PCDD/Fs in the ambient air associated with concentration and dry deposition flux of four seasons were characterized in rural area. The mean PCDD/F concentrations were 0.342, 0.221, 0.675, 0.741 pg m(-3) and the mean I-TEQ values were 0.027, 0.016, 0.024, 0.063 pg m(-3) in spring, summer, fall and winter, respectively. Ambient air in winter was higher by a factor of 3.4 and 3.9 for PCDD/F concentration and I-TEQ, respectively, than in summer. The study area is located in a Tropical region. Hence, domestic heating is not found in this area and is not responsible for the elevated winter concentration in comparison to other studies. A smooth plate with a sharp leading edge that is pointed into the wind by a wind vane was used for measuring dry deposition flux of PCDD/Fs. Atmospheric dry deposition fluxes of total PCDD/Fs were 140, 116, 137, and 207 pg m(-2)day(-1) in spring, summer, fall, and winter, respectively, and averaged approximately 150 pg m(-2)day(-1). The total dry deposition flux was found to decrease as the temperature increased. Calculated dry deposition velocities of total PCDD/Fs were 0.45, 0.52, 0.32 and 0.39 cm s(-1) in spring, summer, fall, and winter, respectively, and averaged 0.42 cm s(-1).
Shih
Minliang
M
Department of Environmental Engineering and Science, Chia Nan University of Pharmacy and Science, No. 60, Section 1, Erh-Jen Rd., Tainan 717, Taiwan, ROC. mshih@mail.chna.edu.tw
Lee
Wei-Shan
WS
Chang-Chien
Guo-Ping
GP
Wang
Lin-Chi
LC
Hung
Chia-Yang
CY
Lin
Kuo-Ching
KC
D000388:Air / Q000032:analysis* / Q000592:standards; D000393:Air Pollutants / Q000032:analysis*; D001572:Benzofurans / Q000032:analysis*; D011232:Chemical Precipitation; D000072338:Dibenzofurans, Polychlorinated; D004784:Environmental Monitoring; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis; D012621:Seasons; D013624:Taiwan
D000393:Air Pollutants; D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D000072317:Polychlorinated Dibenzodioxins