A device-specific prioritization strategy based on the potential for harm to human health in informal WEEE recycling

In developing countries the recovery of valuable materials from Waste Electrical and Electronic Equipment (WEEE) is carried out via uncontrolled practices, posing potentially severe risks both to human health and the environment. The assessment of the risk, which depends on both the kind and hazardous properties of the substances contained in WEEE, is currently limited as the exposure scenario for the single informal practice cannot be fully characterized for this purpose. In this context, this work proposes and evaluates a strategy to identify the relative potential harm of different kinds of WEEE by their content in metals, selected as the target substances of concern. This was based on the individual metal content, primarily located in the Printed Circuit Boards (PCBs) of the different devices. The metal composition of the individual PCBs was identified and the dominant unregulated metal recovery practices reviewed to identify the most suitable parameter to express the toxicity of these metals. Based on a mass-normalised cumulative toxicity, via the inhalation route, individual components were assessed from compositional variation found in the literature. The results is a semi-quantitative ranking of individual components, revealing significant differences in potential harm posed by different electronic appliances and an opportunity to provide prioritisation strategies in future management.