BACKGROUNDElectronic waste (e-waste) is known to contain thousands of toxic chemicals and metals, many of which have identified endocrine disruption potentials even at low blood concentrations resulting from occupational and environmental exposures. E-waste crude reprocessing in Nigeria is massive and a growing number of Nigerians are occupationally exposed. The present study aimed to determine changes in gonadal hormone levels associated with occupational crude e-waste reprocessing in Nigerian male e-waste workers.

The volume of electronic waste (e-waste) received in Nigeria is reportedly on the increase and the effects on environmental health are yet to be fully ascertained. This study aimed to investigate haematological indices, lead and serum iron levels in workers occupationally exposed to electronic wastes in South-South, Nigeria. In this pilot study, 104 participants were enrolled from Benin City, South-South Nigeria; consisting of 63 E-waste Workers (EW) sex-and aged-matched with 41 Unexposed Participants (Control). Blood levels (5 mL) of the metals (lead and iron) were determined using Inductively Coupled Plasma-Mass Spectrometry while the haematological parameters [white blood cells (WBC), Lymphocytes ( LY); monocytes (MO), granulocytes(GR), red blood cells (RBC), haemoglobin (Hgb), haematocrit (HCT), mean cell volume (MCV), mean cell haemoglobin (MCH), mean cell haemoglobin concentration (MCHC) and platelets (PLT)] were determined using standard methods. Results obtained from this study show a significantly low serum iron (11.5 ± 2.14 µg/dL) in the EW compared with Control (168.9 ± 2.39 µg/dL); while blood lead level in EW (1.07±0.02 µg/dL) was significantly elevated compared with Control (0.72 ± 0.12). Total WBC and RBC, HCT, MO and MCV were all significantly elevated in EW compared with Control while LY and PLT in the EW were significantly decreased compared with Control. This study concludes that chronic occupational e-waste exposure may increase blood lead level, lower serum iron status and may have adversely altered some important haematological parameters in the studied population.

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Mixed chemical toxicity including genotoxicity is currently a major concern in rapidly industrializing developing countries. Simple biomarkers remain a constraint. Gamma-glutamyl-transpeptidase (GGT), a precursor of glutathione, protects against chemical toxicity including genotoxic effects and may serve as a marker for pre-neoplastic lesion. The objective of the study was to determine a possible relationship between GGT, uric acid and the angiogenic agent copper (Cu) in mixed chemical exposure. Sixty-six individuals occupationally exposed to mixed chemicals, mean age 34.4 ± 1.27 years, classified into 3 groups based on duration of exposure as follows: 1-10, 11-20 and > 20 years respectively, were enrolled into the study. Twentyseven, age-and sex-matched apparently healthy, occupationally unexposed individuals served as controls. The results showed that serum GGT was higher but not significantly different in exposed participants compared with controls; while its levels varied significantly with duration of exposure across the exposure groups. Like GGT, uric acid was significantly higher in the exposed than in controls and both significantly positively correlated with duration of exposure. Copper was higher in the exposed than the unexposed controls and correlated positively with GGT but not significantly. This observed up-regulation of GGT and its positive correlation with uric acid levels may be a protective response against oxidative stress arising from or related to the depletion of thiol group; thus enhancing maintenance of GSH levels; and may serve as an inexpensive early biomarker of mutagenicity in mixed chemical exposure.

BackgroundCopper (Cu) and iron (Fe) are essential trace elements that when in excess are capable of causing cytotoxic effects leading to lipid peroxidation and promoting oxidative stress. Resveratrol (RES) is a natural polyphenol with antioxidant and anti-inflammatory properties. This study was carried out to evaluate the protective role of RES in Fe and Cu sulphate-induced oxidative stress in Drosophila melanogaster. MethodsAdult wild type flies were fed Cu2+ and Fe2+ (1 mM each) and/or RES (30 and 60 mg/kg diet) for 7 days. Survival, negative geotaxis and emergence rate were evaluated by daily recording of fruit fly mortality and final analysis. Fruit flies were anaesthetized using CO2 gas, homogenized and centrifuged at 4,000 rpm for 10 minutes at 4 °C. Aliquots of the supernatants were used for the estimation of biochemical markers using spectrophotometry. ResultsFruit flies co-treated with FeSO4 + CuSO4 (1 mM each) + RES (30 and 60 mg/Kg) significantly elevated H2O2, NO, lipid peroxidation, acetylcholinesterase as well as GSH, GST, catalase and total thiols (p<0.05) compared with the Cu2+ + Fe2+ (1mM each) treated group. Flies co-treated with FeSO4 + CuSO4 (1mM each) + RES (30 and 60mg/Kg) also had significantly improved (p< 0.05) eclosion and climbing rates compared with the Cu2+ + Fe2+ (1mM each) treated group. ConclusionThis study demonstrated that RES reduced Cu2+ and Fe2+-induced radical generation in D. melanogaster and improved the antioxidant buffering capability of the flies. Therefore, RES could be used in management of disorders involving oxidative stress.