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Electronic 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.
This cross-sectional study which was carried out in Benin City, South-South Nigeria recruited male e-waste workers (n=63); and apparently healthy non e-waste workers (n=41), as exposed and unexposed participants respectively. Male fertility hormones which includes luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone (TESTO) and prolactin (PROL); as well as progesterone (PROG), estrogen (EST) and inhibin (INH) were determined using enzyme linked immunosorbent assay (ELISA) methods; whole blood levels of chromium, cadmium, arsenic and mercury were determined using Inductively Coupled Plasma Mass Spectrometry.
Levels of TESTO, PROG, LH and FSH; as well as PROL and EST were significantly lower in e-waste workers compared with unexposed participants (p<0.05). In contrast, serum INH was significantly higher in e-waste exposed population compared with the unexposed. In addition, chromium correlated significantly and negatively with testosterone, progesterone and estrogen, while inhibin correlated positively with chromium. Similar correlation patterns were observed for cadmium, arsenic and mercury.
Nigerian e-waste workers experienced reduced levels of key gonadal hormones and this may be associated with occupational exposure to endocrine disrupting metals in e-waste.
United Nations Environment Programme (UNEP). Basel convention on the control of transboundary movements of hazardous waste and their disposal. Châtelaine, Switzerland: United Nations Environment Programme; 2014.
Sthiannopkao S, Wong MH. Handling e-waste in developed and developing countries: initiatives, practices, and consequences. Sci Total Environ 2013;463-464:1147-53. doi: 10.1016/j. scitotenv.2012.06.088.
Cobbing M. Toxic tech: not in our backyard. Uncovering the hidden flows of e-waste. Amsterdam : Greenpeace International;2008.
Davis G, Herat S. Opportunities and constraints for developing a sustainable e-waste management system at local government level in Australia. Waste Manag Res 2010;28:705–13. doi: 10.1177/0734242X09343008..
Terada C. Recycling electronic wastes in Nigeria: putting environmental and human rights at risk. Northwestern J. Intl Human Rights 2012;10:154–72.
Adaramodu AA, Osuntogun AO, Ehi-Eromosele CO. Heavy metal concentration of surface dust present in e-waste components: the Westminister electronic market, Lagos case study. Res Environ 2012;2:9-13. DOI: 10.5923/j.re.20120202.02
Bergman A, Heindel JJ, Jobling S, et al. State of the science of endocrine disrupting chemicals. Geneva, Switzerland: United Nations Environment Programme and the World Health Organization; 2012.
Morcillo P, Esteban MA, Cuesta A. Heavy metals produce toxicity, oxidative stress and apoptosis in the marine teleost fish SAF-1 cell line. Chemosphere 2016;144:225-33. https://doi.org/10.1016/j.chemosphere.2015.08.020.
Balabanic DABE, Rupnik MC, Klemencic AKD. Negative impact of endocrine-disrupting compounds on human reproductive health. Reprod Fertil Develop 2011; 23: 413-6.
Sugawara T. Screening systems for endocrine disruptors. Reproductive and Developmental Toxicology. 1st edition. London: Academic Press of Esevier;2011.
Petit W, Ademec C. The endocrine system. The Encyclopedia of Endocrine Diseases and Disorders. 1st Edition. New York: Facts on File, Inc.;2005.
Guyton AC, Hall JE. Textbook of Medical Physiology. 12th edition. Elsevier Saunders Inc. Philadephia; 2010.
Hamadouche NA, Nesrine S, Abdelkeder A. Lead toxicity and the hypothalamic-pituitary-testicular axis. Not Sci Biol 2013;5:1-6.
Sadeghniat K, Aminian O, Chavoshi F, et al. Relationship between blood lead level and male reproductive hormones in male lead exposed workers of a battery factory: a cross-sectional study. Iran J Reprod Med 2013;11:673-6.
Swaran JS, Flora VP, Geetu S. Reproduction and developmental toxicology. 1st ed. London: Academic Press of Elsevier;2011.
Pant N, Kumar G, Upadyay AD, et al. Correlation between lead and cadmium concentration and semen quality. Andrologia 2014. https: doi.org/10.1111/and12342.
Allouche L, Hamadouche M, Touabti A. Chronic effects of low lead levels on sperm quality, gonadotropins and testosterone in albino rats. Exp Toxicol Pathol 2009;61:503–10. DOI: 10.1016/j.etp.2008.12.003.
Llanos MN, Ronco AM. Fetal growth restriction is related to placental levels of cadmium, lead and arsenic but not with antioxidant activities. Reprod Toxicol 2009;27:88–92.
Tian LL, Zhao YC, Wang XC, et al. Effects of gestational cadmium exposure on pregnancy outcome and development in the offspring at age 4.5 years. Biol Trace Elem Res 2009;24:25–29.
Jana K, Jana S, Samanta PK. Effects of chronic exposure to sodium arsenite on hypothalamo–pituitary–testicular activities in adult rats: possible an estrogenic mode of action. Reprod Biol Endocrinol 2006;4:1–13.
Pizent A, Tariba B, Zivkovic T. Reproductive toxicity of metals in men. Arh Hig Rada Toksikol 2012; 63: 35-46. doi: 10.2478/10004-1254-63-2012-2151.
Marouani N, Tebourbi O, Mahjoub S, et al. Effects of hexavalent chromium on reproductive functions of male adult rats. Reprod Biol 2012;12:119–33.
Kumar S, Sathwara NG, Gautam AK, et al. Semen quality of industrial workers occupationally exposed to chromium. J Occup Health 2005;47:424-430.
Ogungbuyi O, Nnorom IC, Osibanjo O, et al. E-waste country assessment Nigeria. Secretariate of Basel Convention; Geneva, Switzerland: 2012.
Fong BM, Lee TS, Tam S. Determination of mercury in whole blood and urine by inductively coupled plasma mass spectrometry. J Anal Toxicol 2007;31:281-7.
Igharo GO, Anetor JI, Osibanjo OO, et al. Toxic metals in Nigerian electronic waste workers indicates occupational metal toxicity associated with crude electronic waste management practices. Biokemistri 2014;26:107-133.
Jensen TK, Bonde JP, Joffe M. The influence of occupational exposure on male reproductive function. Occup Med 2006;56:544-53.
Li X, Gao Y, Wang J, et al. Exposure to environmental endocrine disruptors and human health. J Public Health Emerg 2017;1:8. doi: 10.21037/jphe.2016.12.09.
Bashir MR, Suresh S. Developmental and reproductive disorders: role of endocrine disruptors in testicular toxicity. Reproductive and developmental toxicology. Elsevier. London. 2011: pp.904.
Ayala A, Muñoz MF, Argüelles S. Lipid peroxidation: production, metabolism, and signaling mechanisms of malondialdehyde and 4-hydroxy-2-nonenal. Oxidative Med Cell Longevity 2014; Article ID 360438, 31 pages http://dx.doi.org/10.1155/2014/360438.
Aprioku JS. Pharmacology of free radicals and the impact of reactive oxygen species on the testis. J Reprod Infertil 2013;14:158-72.
Pizzimenti S, Ciamporcero, Daga M, et al. Interaction of aldehydes derived from lipid peroxidation and membrane proteins. Front Physiol 2013;4:242. doi: 10.3389/fphys.2013.00242.