Risk of neurodegeneration among residents of electronic waste recycling areas

Abstract

The abnormal disposal process of electronic waste (e-waste) always emits a variety of toxic substances that enter the human body through various environmental media and can have many adverse health effects. Metals are thought to be inextricably linked to neurodegeneration. In the present study, we tried to explore the neurodegenerative status of subjects exposed to e-waste and the association between metal intake and neurodegeneration. We recruited the residents near the e-waste recycling area (the exposed group) and the residents without any e-waste contact history (the reference group) for a comparative study with detection and analysis of metals, biomarkers associated with neurodegeneration or oxidative stress (OS). The results showed that the metals between the reference and exposed group were significantly different. The concentrations of Brain-derived neurotrophic factor (BDNF) and β-amyloid protein 42 (Aβ42) in the exposed groups were significantly lower, while the levels of Euchromatic Histone lysine Methyltransferase 1 (EHMT1), Bromodomain Adjacent to Zinc finger domain 2B (BAZ2B) and Malondialdehyde (MDA) were significantly higher than in the reference groups. Although the ratio of Aβ42/Aβ40 had no statistical significance in the two groups, the medians of the ratio in the exposed group was lower than in the reference group. The linear regression and mediating effect analysis showed that MDA (OS) might mediate the effects of metals on EHMT1(pAg-MDA <0.001, pMDA-EHMT1 <0.05, pAg-EHMT1 <0.001). It could be inferred from the results of the present investigation that e-waste exposure had a high risk of neurodegeneration, especially Sliver (Ag) and Nickel (Ni).

Keywords

• EHMT1
• Aβ42
• Oxidative stress
• Neurodegeneration
• Cognitive impairment
• Electronic waste