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.
Objective: The e-waste recycling is increasing worldwide, yet there remain outstanding environmental and occupational health concerns. Most research conducted on e-waste recycling has focused on only few countries (e.g., China, Ghana), thus there is a need to increase understanding of e-waste workers' (recyclers') knowledge and practices in other locations, that is purpose of this study. Methods: In a cross-sectional study conducted in Cotonou, Benin, 45 e-waste recyclers were interviewed from September to November 2018. Survey data was collected concerning their demographics, professional practices, and knowledge of occupational and environmental risks associated with e-waste recycling. Results: Most participants reported the following methods of material recovery of electronic items in declining orders: dismantling (97.8%) > sorting (91.1%) > incinerating (88.9%). Only 44.2% of the recyclers reported wearing ≥ 1 piece of personal protective equipment (PPE). More than 90% of e-waste workers noted that they disposed the e-waste in natural sites. About half, 46.7% believed that e-waste can pollute water and 71.1% considered that it can pollute air and soil. Recyclers reported several diseases including respiratory (67.4%), heart (62.8%), eye (65.1%), kidney (41.9%) and cancers (30.2%) could be linked to their work, respectively. Interestingly, we also found associations between the number of electronic items dismantled per month and self-report symptoms from the e-waste recyclers such as finding blood in urine and stool, wounds, dizziness, and itchy skin. Our results also indicated associations between the number of How to cite this paper: Houessionon,
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