Abstract A06: Electronic waste in Nigeria: potential for genotoxicity and metalloid induced carcinogenesis
Authors: Owumi Solomon E. , Gbadegesin Michael A. , Osuagwu Ferdnand C. , Onuchukwu Eberechukwu , Ayoola Bolaji , Odunola Oyeronke A. , Uwaifo Anthony O. 
Published: May 2019

Background: Used and discarded electronic items from developed countries often end up in developing countries. If still functional, they are traded as second-hand goods. But, with a diminished lifespan, they rapidly transit into unusable electronic waste (e-waste). The majority of these countries have no regulations for the disposal or recycling of e-waste. Consequently, the environmental hazard of e-waste is exacerbated by crude recycling methods: primarily as a source of livelihood, poor city dwellers scavenge and trade plastic and metal components from e-waste dump. The remainders are burnt in the open spewing toxic fumes into the atmosphere. Leachates from e-waste dumps percolate into the groundwater, may bio-accumulate on entering the food chain with potentials for toxic exposure. Globally, e-wastes pose a major public health-threat primarily to the populations of developing countries, their genomic integrity, and long-term health.

Methods: Using Atomic Absorption Spectrometry (AAS) we determined the presence of Cadmium (Cd), Nickel (Ni), Chromium (Cr), Lead (Pb), Iron (Fe), Zinc (Zn) and Copper (Cu) in e-waste contaminated soil, e-waste ashes and water leachate from a dumpsite in Lagos, Nigeria, compared to soil sample 1000 meter away. We also assessed the effect of e-waste leachates on E. coli PQ-37 genomic integrity by the SOS inducing potency (SOSIP). E. coli PQ-37 was exposed to the samples and 4-Nitro-quinoline-oxide (4NQO) (positive control). Colorimetric changes were measured by spectrophotometry at 630nm (genotoxicity) and 450nm (viability).

Results and Discussion: The detected heavy metals (ranges; Cd: 4 -18; Ni:12-26; Cr:4- 26; Pb:3-46; Fe:3489 – 8080; Zn:8-280; and Cu:1250–6700 μg/L) in test samples evaluated (p&lt;0.05) compared to soil sample 1000m away (Cd, Ni, Cr and Pb &lt;1μg/L), and (Fe: 254μg/L, Zn:8μg/L and Cu:10μg/L). In all samples, Fe (8080 μg/L) was highest. In excess quantity, heavy metals have been implicated in disease state: Cd, Ni and Cr (carcinogenic cell transformation), Cu (liver diseases), Fe (Parkinson) and Zn (anti-nutrient with Cu, and reduced immune function). Viability of E. coli PQ37 cultures was above 90%, E. coli deoxyribonucleic acid (DNA) damage increased proportionally to a two fold increase in e-waste concentration (ranges; 0.16 - 10μg/mL) it was exposed to. Taken together our results indicate the presence of significant source of mutagenic agents from inadequately processed e-waste in the Nigerian environment. This threatens the genomic stability of both people and the biosphere, which has adverse implications for public and ecological health. Ongoing measurements are focusing on the presence of other toxic and carcinogenic products from e-waste such as dioxins, polybrominated flame-retardants and phthalate esters. In addition, it is necessary to foster public enlightenment, regulation and the safe disposal of e-waste in susceptible communities.

Citation Format: Solomon E. Owumi, Michael A. Gbadegesin, Ferdnand C. Osuagwu, Eberechukwu Onuchukwu, Bolaji Ayoola, Oyeronke A. Odunola, Anthony O. Uwaifo. Electronic waste in Nigeria: potential for genotoxicity and metalloid induced carcinogenesis. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr A06.