Uncaptured mercury lost to the environment from waste electrical and electronic equipment (WEEE) in scrap metal and municipal wastes

Mercury is a persistent toxic substance and once in the environment it can be transformed by bacteria into methylmercury which bioaccumulates in food chains. Prevention of mercury releases are key to protecting human health. Alternatives to mercury in products are now available and further phase-outs are underway as the Minamata Convention progresses toward its aims. In the European Union, mercury is a priority substance for safe removal from WEEE collected and treated. Despite mercury phase outs, WEEE items will continue to necessitate mercury depollution for many years to come. Capture of mercury-added product waste and their replacement products at source protects health, the environment and progresses the circular economy in terms of job creation and critical raw materials recovery. This paper presents an analysis of mercury-containing WEEE observed in scrap metal sites and kerbside waste collection in Ireland, these items did not undergo depollution and so the mercury contained within is lost to the environment. Mercury-added products found in metal scrap included desktop PCs, laptops, screens, LCD, LED and plasma screens and monitors, and assorted fluorescent and special lamps. It is estimated that a minimum of 17.89 kgs of mercury was released to the environment in 2018 due to inappropriate WEEE management from demolition, renovation, and home maintenance activities. Whilst the impact of the Restriction of Hazardous Substances Directive in reducing mercury content in products is undoubtably positive, mercury emissions due to historic WEEE, professional WEEE, and batteries are not fully understood. The key loss of mercury was due to inappropriate gas discharge lamp handling at scrap metal sites and in municipal wastes. Protecting local environments from exposure and ensuring the safe recovery of mercury should be prioritised. The findings of this research highlight an urgent need to develop indicators of mercury-added product stocks and flows to optimise hazardous waste management in support of the circular economy. Improved material flow analysis with respect to mercury-added products are necessary for more accurate esti-mates in national inventories, thereby aiding global efforts to eliminate anthropogenic mercury releases espe-cially from secondary release sources.

Automated summary

Mercury is a persistent toxic substance that can transform into methylmercury in the environment and bioaccumulate in food chains. Preventing mercury releases is crucial for protecting human health. Alternatives to mercury products are available, and the Minamata Convention is working towards further phase-outs. This study highlights the need to develop indicators for mercury-added product stocks and flows to optimize hazardous waste management and support the circular economy.