Toxic metal levels in Nigerian electronic waste workers indicate occupational metal toxicity associated with crude electronic waste management practices

The poor management of electronic wastes (e-waste) in Nigeria exposes workers to toxic chemicals in waste electrical and electronic equipment. In this study, we evaluated the toxic metal levels in Nigerians occupationally exposed to e-waste. Whole blood levels of Lead (Pb), Mercury (Hg), Arsenic (As), Cadmium (Cd), and Chromium (Cr) were determined in Nigerian e-waste workers (n=63) and in age-matched non-exposed participants (n=41), using standard electrothermal atomic absorption spectrometry and inductively coupled plasma-mass spectrometry methods. The results showed statistically significant (p<0.01) elevated body burden of toxic metals in e-waste workers (Pb, 0.95 ± 0.00 µmol/L; Cr, 405.99 ± 6.34 µmol/L; Cd, 108.54 ± 1.60 nmol/L; As, 10.09 ± 0.01 µmol/L; and Hg, 25.02 ± 0.14 nmol/L) compared with non-exposed group ((Pb, 0.03 ± 0.00 µmol/L; Cr, 178.44 ± 5.99 µmol/L; Cd, 56.99 ± 1.42 nmol/L; As, 1.02 ± 0.0008 µmol/L; and Hg, 1.62 ± 0.0672 nmol/L). These data indicate that the elevated body burden of toxic metals in the e-waste exposed  population is an indication of occupational metal toxicity associated with crude e-waste management practices in Nigeria. In addition, the potential health implications of exposure to these toxic metals, such as chronic kidney disease, cancer; preceded by genome instability and depressed immune response were highlighted.Keywords: Metal toxicity, e-waste, Nigeria, Occupational exposure

Toxic metal levels in Nigerian electronic waste workers indicate occupational metal toxicity associated with crude electronic waste management practices

The poor management of electronic wastes (e-waste) in Nigeria exposes workers to toxic chemicals in waste electrical and electronic equipment. In this study, we evaluated the toxic metal levels in Nigerians occupationally exposed to e-waste. Whole blood levels of Lead (Pb), Mercury (Hg), Arsenic (As), Cadmium (Cd), and Chromium (Cr) were determined in Nigerian e-waste workers (n=63) and in age-matched non-exposed participants (n=41), using standard electrothermal atomic absorption spectrometry and inductively coupled plasma-mass spectrometry methods. The results showed statistically significant (p<0.01) elevated body burden of toxic metals in e-waste workers (Pb, 0.95 \ub1 0.00 \ub5mol/L; Cr, 405.99 \ub1 6.34 \ub5mol/L; Cd, 108.54 \ub1 1.60 nmol/L; As, 10.09 \ub1 0.01 \ub5mol/L; and Hg, 25.02 \ub1 0.14 nmol/L) compared with non-exposed group ((Pb, 0.03 \ub1 0.00 \ub5mol/L; Cr, 178.44 \ub1 5.99 \ub5mol/L; Cd, 56.99 \ub1 1.42 nmol/L; As, 1.02 \ub1 0.0008 \ub5mol/L; and Hg, 1.62 \ub1 0.0672 nmol/L). These data indicate that the elevated body burden of toxic metals in the e-waste exposed population is an indication of occupational metal toxicity associated with crude e-waste management practices in Nigeria. In addition, the potential health implications of exposure to these toxic metals, such as chronic kidney disease, cancer; preceded by genome instability and depressed immune response were highlighted

Study of Antioxidant Status in Morticians Exposed to Formaldehyde in Benin City, Nigeria

Background: Subacute and subchronic formaldehyde inhalation has been reported to deplete the activities of antioxidant enzymes, stimulate oxidative stress and thus promote genotoxicity, amongst others.AIM: To investigate the toxicity and pathobiology of inhaled chemicals in workers occupationally exposed to histological and embalmment chemicals(mainly formaldehyde) in Benin City, using markers of cellular oxidative damage: super oxide dismutase (SOD), catalase (CAT), Glutathione peroxidise (GPx) andmalondialdehyde ( MDA)as biochemical indices.Materials/Methods: The exposed group (n=36) comprised of male embalmers (morticians) who have had occupational exposure for a minimum of five years, while apparently healthy age-matched male subjects (n=34) without considerable exposure to formaldehyde served as control subjects. From blood samples obtained, SOD, CAT, GPx and MDA were determined using standard methods.Results: From the results obtained, SOD and GPxactivities of exposed group (12.17±1.65 Unit/ml; 9.55± 0.56 Unit/ml) were higher and significantly different from non-exposed subjects (6.37±0.73 Unit/ml; 6.81 ±0.60 Unit/ml) respectively. No significant difference in CAT activities between exposed group (1295.90±122.02 Unit/ml) and non-exposed subjects (947.92±340.71 Unit/ml) was observed. MDA concentration showed a similar pattern (exposed group: 0.02±0.00 Unit/ml; non-exposed group: 0.02±0.00Unit/ml).Conclusion: This study concludes that there was no significant formaldehyde-induced depressive effect on antioxidant status in chronic occupationally exposed morticians in Benin City. The comparatively higher antioxidant activities observed in exposed subjects could have possibly resulted from cellular adaptation to chronic formaldehyde exposure.Keywords: Occupational exposure, formaldehyde, toxicity, antioxidants

Lignocellulose integration to 1G-ethanol process using filamentous fungi : Fermentation prospects of edible strain of Neurospora intermedia

Background: Integration of first- and second-generation ethanol processes is one among the alternate approaches that efficiently address the current socio-economic issues of the bioethanol sector. Edible filamentous fungus capable of utilizing pentoses from lignocelluloses and also possessing biomass application as potential animal feed component was used as the fermentation strain for the integration model. This study presents various fermentation aspects of using edible filamentous fungi in the integrated first and second generation ethanol process model. Results: Fermentation of edible strain of N. intermedia on the integrated first and second-generation ethanol substrate (the mixture of dilute acid pretreated and enzymatically hydrolyzed wheat straw and thin stillage from the first-generation ethanol process), showed an ethanol yield maximum of 0.23 +/- 0.05 g/g dry substrate. The growth of fungal pellets in presence of fermentation inhibitors (such as acetic acid, HMF and furfural) resulted in about 11 to 45% increase in ethanol production as compared to filamentous forms, at similar growth conditions in the liquid straw hydrolysate. Fungal cultivations in the airlift reactor showed strong correlation with media viscosity, reaching a maximum of 209.8 +/- 3.7 cP and resulting in 18.2 +/- 1.3 g/L biomass during the growth phase of fungal pellets. Conclusion: N. intermedia fermentation showed high sensitivity to the dilute acid lignocellulose pretreatment process, with improved fermentation performance at milder acidic concentrations. The rheological examinations showed media viscosity to be the most critical factor influencing the oxygen transfer rate during the N. intermedia fermentation process. Mycelial pellet morphology showed better fermentation efficiency and high tolerance towards fermentation inhibitors

Subsistence farmers’ differential vulnerability to drought in Mpumalanga province, South Africa: Under the political ecology spotlight

This paper examines social differences and drought vulnerability among subsistence livestock farmers in Mpakeni, Mpumalanga province, South Africa. This paper asks, how do social differences between households and power relations shape vulnerability to drought? This is against the backdrop that parallel exposure to climatic risks does not translate to similar vulnerability among households residing in the same community. In-depth interviews were used to obtain primary data from purposively selected participants in Mpakeni. Some key findings reveal that being a non-local elite, a migrant settler and some female-headed households, especially those burdened by the additional tasks of caregiving, amplifies the challenges of securing forage when depleted in communal grazing fields. This is partly due to reduced time allocated to shepherding their livestock to the bank of a local river. Also, non-local elite and those who lacked social ties to the headman found it difficult to get compensated when their livestock were eaten by wild animal upon illegal entry to a game reserve rich in vegetation. This paper argues that vulnerability studies that focus independently on issues like gender, ethnicity and class may miss the dynamics that shape individuals’ vulnerability to drought, which could have severe consequences for implementing effective interventions

Sex Dimorphism in Serum Lecithin: Cholesterol Acyltransferase and Lipoprotein Lipase Activities in Adult Sickle Cell Anaemia Patients with Proteinuria

Proteinuria in subjects with sickle cell anaemia (SCA) is an indication of an ongoing renal insufficiency and it’s prevalence varies between sexes. We evaluated sex differences in the activities of Lecithin: cholesterol acyltransferase (LCAT), Lipoprotein lipase (LPL) and the levels of lipoproteins in SCA patients with proteinuria. Fifty SCA patients (30 males aged: 26.4 ± 7.3 years and 20 females, aged 25.4 ± 2.6 years) and 50 age and sex matched control SCA patients were recruited for the study. Random urine specimens were collected and tested for the presence of albumin by urine dipstick technique. A 24 h urinary protein was quantitated using sulphosalicylic acid technique. Fasting serum total cholesterol, triglyceride, urea and creatinine were determined using enzymes catalyzed colorimetric methods. HDL cholesterol was determined in the supernatant after precipitation with manganese chloride–phosphotungstic acid solution. LCAT was measured using the Anasolv LCAT assay with proteoliposome as substrate. LPL was determined by incubating the serum in glyceryl trioleate substrate, the glycerol liberated was measured in an aliquot of the incubating mixture. In male SCA controls there was 18.2 and 6.9% increase in the activities of LPL and LCAT respectively when compared with females but in SCA patients with proteinuria there was 8.4 and 5.2% decreases in the male SCA patients compared with females. The concentration of 24 h urine protein in the SCA male subjects with proteinuria was significantly higher (0.25 g/day; P < 0.001) compared with the SCA female patients with proteinuria (0.09 g/day). There are sex differences in the activities of LCAT and LPL in SCA patients with proteinuria. Metabolism of these lipolytic enzymes may be modulated differently in SCA patients with proteinuria