Atmospheric bulk deposition of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the vicinity of MSWI in Shanghai, China.

Abstract

Atmospheric bulk deposition samples were gathered month by month throughout a year at two sites in vicinity of a MSWI in Shanghai, to carry out an investigation on the atmospheric bulk deposition fluxes and seasonal variations of polychlorinated dibenzo-p-dioxinsand dibenzofurans (PCDD/Fs). The atmospheric bulk deposition fluxes of PCDD/Fs ranged from 23.5 to 560pgm-2·d-1 (1.01-23.9pg WHO-TEQ·m-2·d-1), with an average value of 136pgm-2·d-1 (5.08pg WHO-TEQ·m-2·d-1) in the Vicinity of the MSWI in Shanghai. The measured concentrations were well compared with those from urban or industrial sites in other regions in China and abroad. The seasonal trend of atmospheric bulk deposition fluxes of PCDD/Fs throughout a year exhibited as high levels in summer, moderate levels in winter, and low levels in spring and autumn. The principal component analysis (PCA) indicated not only the MSWI, but also vehicle emission was the indispensable source of PCDD/Fs in the vicinity of the MSWI, especially for the urban areas. The positive matrix factorization (PMF) apportioned 5 source categories: MSWI, diesel vehicles, atmosphere background, industrial combustion and un-leaded gas vehicles, accounting for 43.3%, 38.1%, 6.89%, 6.19% and 5.50% in average, respectively of PCDD/Fs in atmospheric bulk deposition in the vicinity of the MSWI in Shanghai, China.