Nontarget Revealing of Polybrominated Organic Pollutants in Soil from Electronic Waste Dismantling Areas

The large-scale production and recycling of electric equipment have led to widespread contamination by persistent, bioaccumulative, and endocrine-disrupting brominated organic compounds. However, efficient methods for identifying these compounds in soil matrices remain limited. Here, a nontarget screening method was developed to detect characteristic bromine isotopic ions from mass spectrometry data acquired in data-independent analysis mode and applied to soil samples collected from e-waste dismantling sites in Taizhou (Zhejiang Province) and Guiyu (Guangdong Province), China. A total of 24 traditional and emerging polybrominated organic pollutants were identified, including Tetrabromobisphenol A (TBBPA) and its transformation products (TPs), brominated carbazoles (BCZs), bromoindoles (BIs), bromophenols (BPs), and hexabromocyclododecane (HBCDs). Six TBBPA TPs, BCZs, and BIs were identified for the first time in e-waste contaminated soils. Among these, TBBPA and its low-bromination homologues showed the highest detection rates and concentrations, reaching up to 4770 ng/g. Notably, six TBBPAs TPs were exclusively detected in Guiyu, while BCZs and BPs were found at all 12 sampling sites. HBCDs levels were lower than those of other e-waste sites. These findings highlight significant contamination by polybrominated compounds released through improper e-waste disassembly practices, providing critical data for monitoring and risk assessment.