PCDD/Fs in air and soil around an e-waste dismantling area with open burning of insulated wires in south China.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in ambient air and farmland soil sampled in 2006 around an e-waste dismantling area with open burning of insulated wires in Longtang in south China were investigated. The total toxic equivalent concentrations of PCDD/Fs were 3.2-31.7 pg/m(3) in air and 5.8 12.4 ng/kg in farmland soil at an e-waste site and 0.063-0.091 pg/m(3) in air at a background site. PCDD/Fs in the air at the e-waste site were characterized with dominant 1,2,3,4,6,7,8-HpCDF and OCDF and higher concentrations of furans than dioxins, suggesting open burning of insulated wires was likely to be the main source of PCDD/Fs. Compared with the results in this study, the level of PCDD/F tended to lessen with the average TEQ concentration decreasing by 41 % and the pattern changed to be dominated by OCDD in the air of Longtang in 2010 when insulated wires were openly burned in only a small scale. Our results indicate that the lower chlorinated congeners with higher vapor pressures have enhanced atmospheric transport tendencies.