Effects of PCBs and PBDEs on thyroid hormone, lymphocyte proliferation, hematology and kidney injury markers in residents of an e-waste dismantling area in Zhejiang, China

Polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are two typical categories of contaminants released from e-waste dismantling environments. In China, the body burdens of PCBs and PBDEs are associated with abnormal thyroid hormones in populations from e-waste dismantling sites, but the results are limited and contradictory. In this study, we measured the serum levels of PCBs and PBDEs and the thyroid hormone free triiodothyronine (FT3), free thyroxine (FT4) and thyroid-stimulating hormone (TSH) in 40 residents in an e-waste dismantling area and in 15 residents in a control area. Additionally, we also measured some lymphocyte proliferation indexes, hematologic parameters and kidney injury markers, including white blood cells, neutrophils, monocytes, lymphocytes, hemoglobin, platelets, serum creatinine and beta 2-microglobulin (β₂-MG). The results indicated that the mean level of ΣPCBs in the exposure group was significantly higher than that in the control group (964.39 and 67.98 ng g⁻¹, p < 0.0001), but the mean level of ΣPBDEs in the exposure group was not significantly higher than that in the controls (139.32 vs. 75.74 ng g⁻¹, p > 0.05). We determined that serum levels of FT3, FT4, monocytes and lymphocytes were significantly lower, whereas the levels of neutrophils, hemoglobin, platelets and serum creatinine were significantly higher in the exposed group (p < 0.05). The mean level of ΣPCBs was negatively correlated with levels of FT3, FT4, monocytes and lymphocytes (p < 0.05) and positively correlated with levels of neutrophils, hemoglobin, serum creatinine and β₂-MG (p < 0.05). Additionally, the mean level of ΣPBDEs was positively correlated with levels of white blood cells, hemoglobin and platelets (p < 0.05). Our data suggest that exposure to an e-waste dismantling environment may increase the body burdens of PCBs and the specific PBDEs congeners in native residents and that the contaminants released from e-waste may contribute to abnormal changes in body levels of thyroid hormone, hematology and kidney injury markers. - Highlights: • E-waste dismantling condition increased residents' body burdens of PCBs. • The serum FT3, FT4, monocytes and lymphocytes levels were lower in e-waste. • The neutrophils, Hb, platelets and serum creatinine levels were higher in e-waste. • PCBs were negatively associated with FT3, FT4, monocytes and lymphocytes levels. • PCBs were positively associated with neutrophils, Hb, serum creatinine and β₂-MG