Environmental Heavy Metal Contamination from Electronic Waste (E-Waste) Recycling Activities Worldwide: A Systematic Review from 2005 to 2017

Abstract

The recycling of electronic waste (e-waste) contaminates ecosystems with metals, though a compilation of data from across sites worldwide is lacking, without which evidence-based comparisons and conclusions cannot be realized. As such, here, a systematic review of the literature was conducted to identify peer-reviewed studies concerning e-waste sites (published between 2005 and 2017) that reported on the concentration of heavy metals (Cd, Hg, As, Pb and Cr) in soil, water and sediment. From 3063 papers identified, 59 studies from 11 countries meeting predefined criteria were included. Reported metal concentrations were summarized, and a narrative synthesis was performed. This review summarized 8286 measurements of the aforementioned metals in soils (5836), water (1347) and sediment (1103). More than 70% of the studies were conducted in Asia. In nearly all cases, the average metal concentrations in a particular medium from a given site were above guideline values; suggesting soils, water and sediment at, or near, e-waste recycling sites are contaminated. Across all media, concentrations of Pb were generally highest, followed by Cr, As, Cd and Hg. The synthesized information demonstrates that e-waste sites worldwide are contaminated with metals, that geographic data gaps exist, that the quality of most studies can be improved and that action is needed to help reduce such levels to protect human health and the environment.

Effects of Electronic and Electrical Waste–Contaminated Soils on Growth and Reproduction of Earthworm (Alma nilotica)

“…The high levels of metals in soils from e‐waste recycling sites are not surprising given that the processing of e‐waste is associated with contamination of soil with a range of metals, as documented from a systematic review of the literature worldwide (Houessionon et al, 2021). Some of these metals, such as Cu, Co, Ni, and Zn, are essential elements needed for optimal health, growth, development, disease resistance, and reproduction but may become toxic when intake is excessive, especially above permissible limits (Mahmood et al, 2012).…”

“…Most (80%) of the e‐waste generated worldwide is handled by the informal work sector (sector that is not taxed or monitored by the government in respect to environmental safety policies), and much of this work occurs in low‐ and middle‐income countries where legal and policy frameworks are not enforced or do not exist (Cazabon et al, 2017; Forti et al, 2020). Informal recycling of e‐waste tends to release enormous amounts of pollutants such as metals and organo‐halogenated compounds into the soil environment near recycling activities (Houessionon et al, 2021; Luo et al, 2009). Metals in particular comprise approximately 60% of the weight of e‐waste (Vats & Singh, 2014), and tend to persist in the environment, thus posing potential risks to resident soil organisms (Masindi & Muedi, 2018).…”

Estimation of Children’s Soil and Dust Ingestion Rates and Health Risk at E-Waste Dismantling Area

“…The potentially harmful environmental and human health effects of primitive electronic-waste (e-waste) recycling processes, including manual disassembly, roasting, acid leaching, and open burning, have caused concern around the world, particularly in rapidly industrializing and urbanizing developing countries such as China, India, and Vietnam [ 1 , 2 ]. Notably, heavy metal pollution is ubiquitous in the environment and bodies of people living near e-waste disposal sites [ 3 , 4 ]. Heavy metal elements accumulate in the human body and interfere with the human endocrine system [ 5 ], damage the body’s cardiovascular and nervous systems [ 6 , 7 ], and can even lead to cancer [ 8 ].…”

Soil Contamination and Bioaccumulation of Heavy Metals by a Tropical Earthworm Species (Alma nilotica) at Informal E‐Waste Recycling Sites in Douala, Cameroon

“…Electronic waste (e‐waste) recycling activities constitute a major source of metal discharge into the natural environment, though relatively little is known about the impacts that such contamination is having on local environments, especially soil (Houessionon et al, 2021). Soil is a dynamic natural resource for the survival of living organisms, though it also serves as a key reservoir of persistent pollutants like heavy metals (Islam et al, 2015; Proshad et al, 2018).…”