Metal Levels, Genetic Instability, and Renal Markers in Electronic Waste Workers in Thailand.

BACKGROUND: Informal electronic waste (e-waste) recycling is an increasingly important industry worldwide. However, few studies have studied the health risks in this group of workers. OBJECTIVE: To assess the associations between occupational exposures to metals and genetic instability and renal markers among e-waste recycling workers. METHODS: We recruited informal e-waste recycling workers from a community in northeastern Thailand. Participants completed a questionnaire, several health measurements, and provided urine and blood samples, which we then analyzed for a number of metals including lead (Pb), cadmium (Cd), and manganese (Mn). Samples were analyzed for a marker of RNA and DNA damage (ie, oxidative stress), 8-hydroxy-2'-deoxyguanosine (8-OHdG). Glomerular filtration rate (GFR) and fractional excretion of calcium (FECa%) were measured as markers of renal function. Correlations and regression models were used to assess associations between these various factors. RESULTS: We found significantly higher levels of Cd and Pb in blood of men compared with those in women. Men who worked >48 hours/week had significantly higher levels of 8-OHdG compared with men who worked ≤48 hours/week. Smoking was significantly associated with higher blood Pb and Cd concentrations among men. CONCLUSION: Our results suggest gender differences in both blood concentrations of metals associated with e-waste recycling and smoking and highlight potentially elevated oxidative stress associated with longer work hours. Health promotion efforts are needed among informal e-waste recyclers to reduce possible risks of renal damage and cancer.

Self-Reported Health and Metal Body Burden in an Electronic Waste Recycling Community in Northeastern Thailand.

OBJECTIVE: This study aims to summarize electronic waste (e-waste) worker health; examine associations between health and sociodemographic characteristics; and metal body burden. METHODS: In 2016, 131 e-waste recycling workers were enrolled in the study, completed a questionnaire, and gave blood and urine samples for heavy metal concentration assessment (lead, cadmium, copper, zinc, nickel). The relationship between symptoms, general health, and metals is assessed via generalized estimating equation models (adjusted for age, education, sex, and village). RESULTS: Cadmium in blood and copper in serum were most consistently associated with higher odds of poor health and prevalence of symptoms. We found inconsistent results between general health, symptom severity, and urinary nickel. Higher blood lead levels (BLL) were associated with fewer self-reported symptoms. CONCLUSIONS: Exposure to certain metals in e-waste recycling communities may adversely impact health status.

A Review of Biomarkers Used for Assessing Human Exposure to Metals from E-Waste.

Electronic waste recycling presents workers and communities with a potential for exposures to dangerous chemicals, including metals. This review examines studies that report on blood, hair, and urine biomarkers of communities and workers exposed to metals from e-waste. Our results from the evaluation of 19 publications found that there are consistently elevated levels of lead found in occupationally and non-occupationally exposed populations, in both the formal and the informal e-waste recycling sectors. Various other metals were found to be elevated in different exposure groups assessed using various types of biomarkers, but with less consistency than found in lead. Antimony and cadmium generally showed higher concentrations in exposed groups compared to reference group(s). Mercury and arsenic did not show a trend among exposure groups due to the dietary and environmental considerations. Observed variations in trends amongst exposure groups within studies using multiple biomarkers highlights the need to carefully select appropriate biomarkers. Our study concludes that there is a need for more rigorous research that moves past cross-sectional study designs, involves more thoughtful and methodical selection of biomarkers, and a systematic reporting standard for exposure studies to ensure that results can be compared across studies.

Distribution and predictors of 20 toxic and essential metals in the umbilical cord blood of Chinese newborns.

Early-life exposure to heavy metals and/or trace metal imbalances can have negative developmental effects. Here we sought to characterize exposure profiles for 20 heavy metals and trace elements in umbilical cord blood plasma and identify demographic predictors of exposure. Twenty metals were measured in cord plasma from 357 Chinese infants using ICP-MS. Relationships between demographic variables and metals were analyzed using generalized linear models and logistic regression. Ten metals (antimony [Sb], cobalt [Co], cesium [Cs], copper [Cu], lead [Pb], molybdenum [Mo], rubidium [Rb], selenium [Se], strontium [Sr], titanium [Ti], zinc [Zn]) were detected in all samples. Season of birth was the strongest predictor of metals in cord blood across analyses. Infants born in the spring had 0.1-0.2 µg L-1 higher logAs and logCo in their cord blood (ß [95%CI] = 0.22 [0.01,0.42], p = 0.04; 0.11 [0.01,0.22], p = 0.04), while infants born in the summer had higher Sb, logB, logHg, and logZn (ß [95%CI] = 0.74 [0.24,1.24], p = 0.004; 0.11 [0.00,0.21], p = 0.04; 0.29 [0.08,0.49], p = 0.007; 0.18 [0.06,0.31], p = 0.005), compared to those born in fall/winter. Prenatal heavy metal exposure and/or trace metal deficiencies are global concerns because of increasing awareness of downstream developmental effects.