Halogenated flame retardants (HFRs) and water-soluble ions (WSIs) in fine particulate matter (PM) in three regions of South China.

Halogenated flame retardants (HFRs) and water-soluble ions (WSIs) were investigated in fine particulate matter (PM) collected from an urban site, a rural e-waste recycling (e-waste) site, and a background site in South China. Generally, the WSI concentrations were highest at the e-waste site and comparable at the other sites and secondary species (SO, NH, and NO) were dominant components at the three sites. The compositions and seasonal variations of WSIs at the e-waste site were distinct from those in the urban and background areas suggesting significant influence of e-waste recycling on PM components. Polybrominated diphenyl ethers (PBDEs) dominated the HFRs in PM from the e-waste site, and their concentrations (median = 883 pg/m) were significantly higher than those at the urban (375 pg/m) and background site (52.4 pg/m). However, novel decabromodiphenyl ethane (DBDPE) was the primary HFRs in the urban air, with noticeably elevated concentrations (median = 356 pg/m) compared to those in the other two areas (medians = 62.3 and 5.09 pg/m). The composition profiles of HFRs in the background air followed those in the e-waste areas, with substantial contributions of legacy chemicals. This was explained by the prevailing NE wind, which favored atmospheric transport of HFRs from the e-waste recycling area to the background area. Correlation analysis showed that most HFRs in the urban air are associated with Cl, implying an industrial emission sources. In the e-waste area, HFRs are associated with organic and elemental carbons (OC and EC) and K, confirming a common source of e-waste recycling. Significant correlations between HFRs and EC and Cl in the background air suggest that their occurrence in this region was attributed to both the e-waste and urban areas.