Bioaccessibility and risk evaluation of heavy metals in dust from different workshops of an electronic waste treatment enterprise

To understand the contamination of heavy metals in the recycling process of e-waste and the health risks， dust samples from different workshops of a qualified e-waste treatment enterprise in Shanghai were collected， the content of Pb， Sb and Cd was determined by inductively coupled plasma mass spectrometry （ICP-MS）， and human gastrointestinal evaluation of bioaccessibility was simulated by physiological extraction experiments （PBET method）， and the health risks of heavy metals were evaluated. It was found that Pb content was highest in the dismantling workshop （654 mg/kg）， and Sd and Cd content were higher in the plastic crushing workshop （118 mg/kg and 4.09 mg/kg）， respectively. Morphological results showed that Cd was mainly in the carbonate-bound state， Pb in the Fe-Mn oxidation state， and Sb in the residue state. The terpolymer phase diagram and morphological bioaccessibility indicated that Pb and Cd were active and potentially risky， and Sb was stable. The bioaccessibility of gastrointestinal fluid showed that Pb and Cd were higher in the gastric phase than in the intestinal phase. At the same time， Sd was more available in the intestinal phase than in the gastric phase. Correlation analysis revealed that the bioaccessibility of heavy metals in gastrointestinal fluid was associated with their metal morphology. The results of risk assessment showed that dust mainly entered the human body through oral ingestion. Pb was the main metal causing non-carcinogenicity of dust in the dismantling workshop， Sb was the main metal causing non-carcinogenicity of dust in the crushing workshop and plastic crushing dust， and the carcinogenicity of Cd was within the acceptable range for all three kinds of dust. Further research should pay attention to the health risks of other heavy metals in dust.