FINGERPRINTS of CHLORINATED, BROMINATED AND MIXED HALOGENATED DIOXINS AT TWO E-WASTE RECYCLING SITES IN GUIYU/CHINA

This study describes the fingerprints of chlorinated, brominated and brominated-chlorinated dibenzofurans and dibenzodioxins at two e-waste open burning/smouldering sites in Guiyu, China. The total concentrations of PXDD/PXDF in the soils were in ppm range. The total furan (PXDF) to dioxin (PXDD) ratios were around 100 revealing that PBDEsA as direct furan precursors were responsible for the formation of most of the dioxin-like compounds at the sites. The high levels of mixed chlorinated-brominated dibenzofurans and dibenzodioxins present as main contaminants at the open burning site reveal a significant bromine-chlorine exchange in PBDEA/PBDF most probably from PVC and chlorine containing additives (e-g. chlorinated paraffins, tetrachlorobisphenol A, etc.). The comparable concentrations of halogenated PXDF and precursor PBDEs at both sites indicate that a significant share of PBDEs was converted into PBDF/PXDF. When considering that several thousand tons of PBDEA are present in the 20 to 50 million tons of e-waste reaching the waste recycling sector every year, and that developing countries process a significant amount of e-waste utilizing rudimentary thermal processes, the load of halogenated PXDD/PXDF formed and released can be expected on the scale of tons and therefore possibly higher than all current inventoried PCDD/PCDF sources combined