By Freya Baker
Electric vehicles (EVs) are considered by many to be a key component in the future of sustainability. However, with the rejection of heavily polluting combustion engines that the automotive industry has historically relied on, manufacturing companies are turning to lithium-ion batteries (LIB) to power their vehicles. This is only one application of lithium-ion batteries; they are also found in other electronics such as laptops, power-tools, various-sized appliances, and in electrical energy storage systems, where they function as a rechargeable power source [1]. Cobalt is one of the primary metals that lithium batteries are composed of, making up between 10 and 30 percent of the batteries’ cathode (negative electrode). The process of removing cobalt alloys and ores from mines is called cobalt mining, and has serious consequences for both the environment and human health, both of which will be central to the discussion in this article [2].
Cobalt is a hard, silvery-greyish-blue, ductile metal element, with various oxidation states (it’s charge can be different in different conditions). It is an essential trace element for humans, serving as the metal element in vitamin B12. Vitamin B12 is necessary to produce red blood cells that carry oxygen and support life, however when cobalt is not bound in this vitamin, and rather is free in the blood, it can have severely toxic effects. Finally, cobalt has high thermal stability and high energy density, making it suitable for use in batteries, as the chance of catching on fire is low and large amounts of energy can be stored [5].
The majority (70%) of this mining occurs in the Democratic Republic of the Congo (DRC)[6]. There are several techniques to mine cobalt, with the majority involving extracting cobalt ores (mineral deposit in the earth’s crust) and copper nickel alloys from the earth. These must undergo the smelting process (heating and melting) in an electric furnace in order to extract the cobalt metal [2]. For use alongside lithium in the battery cell, cobalt must undergo more refinery processes.
Besides being an environmental pollution problem, cobalt mining often infringes on child labor laws and human rights in terms of a safe workplace [6]. On top of this, a large chunk of cobalt mines in the DRC are ‘artisanal mines’, are unregistered, and therefore do not abide by guidelines for safe mining practices and metal extraction. This leads to miners being more exposed to cobalt and less assurance that cobalt is not leaching into the ground or waterways.
A study conducted in the DRC found 0.001 μg/L of cobalt in drinking water, 20 μg/g in soil, and 11 μg/g in indoor and outdoor dust. Dust is a pertinent exposure pathway, particularly for children, giving their tendencies to touch many surfaces (and the floor) and put their hands in their mouths [4]. Another study, found substantially increased levels of cobalt in the urine of individuals living near to mining zones, pointing to contaminated vegetables, cereals, and fish as sources of exposure, suggesting both soil and waterways are tainted by cobalt [7]. A third study, by Van Brusselen et al., found that miners in the ‘copper belt’ (parts of Zambia and the DRC) were at a significantly higher risk of their children being born with serious birth defects. They theorize that cobalt present in the air, water supplies and soil, is very likely to be the cause [8]. Unbound cobalt can have a variety of effects on the human body: from being highly neurotoxic, to causing endocrine, cardiovascular and respiratory issues in humans. Miners are known to be affected by lung-problems which scientists and doctors believe to be a form of pneumoconiosis, a serious hard-metal induced lung disease [4]. These studies make it abundantly clear that the mining of cobalt is not a contained process and is entering the ecosystem around it and causing human health problems.
Looking beyond the direct implication that the mining of cobalt has, it is also relevant to consider how lithium-ion batteries, and the other types of batteries involving cobalt (nickel-cadmium and nickel-metal hydride batteries), are disposed of [9]. Electronic waste is often incinerated, allowing cobalt and the other metals involved in batteries to enter the air, then to penetrate the earth and leech into the ground, giving access to waterways. An addition, concern in the ‘copper belt’ region, is untapped sources of uranium, emitting alarming levels of radioactivity in mining areas, which could only compound on the already negative effects of cobalt [8].
As nations pledge to lower their carbon emissions and the demand for EVs continues, the demand for cobalt does as well, and although more awareness (especially for the humanitarian side of this problem) is being raised, little is being done to mitigate the environmentally detrimental effects of cobalt mining. There are, however, some potential mitigation strategies that could reduce the aforementioned negative effects. The first of these is to provide artisanal miners with the resources and funds to mine safely and comply with regulations that prevent cobalt from migrating to where it does not belong. Secondly, in order to mitigate the need to mine within populated areas where human health implications are large, polymetallic nodules can be collected from the sea floor. These contain cobalt, nickel, copper, and manganese. On the topic of manganese, it is also possible for the cobalt in the cathode of batteries to be replaced with manganese, which can be mined more sustainably and at a lower energy cost [10]. Finally, battery recycling, if executed correctly could create a circular supply chain of cobalt, meaning mining efforts could be significantly reduced [11].
Ultimately it is up to the EV and tech giants to champion efforts to increase the sustainability and reduce the environmental pollution of cobalt mining. The limited amount of information online regarding mining and refinery practices in the DRC requires these same companies to prioritize transparency and accountability for the impact of their operations.
Bibliography
1. US EPA O. Used Lithium-Ion Batteries [Internet]. US EPA. 2019. Available from: https://www.epa.gov/recycle/used-lithium-ion-batteries
2. Taylor JC, Young RS. cobalt processing | Uses, Supply, & Facts [Internet]. Encyclopaedia Britannica. 2020. Available from: https://www.britannica.com/technology/cobalt-processing
3. Lindsay D, Kerr W. Cobalt close-up. Nature Chemistry. 2011 May 23;3(6):494–4.
4. Leyssens L, Vinck B, Van Der Straeten C, Wuyts F, Maes L. Cobalt toxicity in humans—A review of the potential sources and systemic health effects. Toxicology [Internet]. 2017 Jul;387:43–56. Available from: https://www.sciencedirect.com/science/article/pii/S0300483X17301555
5. https://www.howstuffworks.com/about-dave-roos.htm. Cobalt: Essential for Batteries and Bright Blues [Internet]. HowStuffWorks. 2019. Available from: https://science.howstuffworks.com/environmental/earth/geology/cobalt.htm
6. Kelly A. Pollution causing birth defects in children of DRC cobalt miners – study. The Guardian [Internet]. 2020 May 6; Available from: https://www.theguardian.com/global-development/2020/may/06/pollution-causing-birth-defects-in-children-of-drc-cobalt-miners-study
7. Banza CLN, Nawrot TS, Haufroid V, Decrée S, De Putter T, Smolders E, et al. High human exposure to cobalt and other metals in Katanga, a mining area of the Democratic Republic of Congo. Environmental Research. 2009 Aug;109(6):745–52.
8. Brusselen DV, Kayembe-Kitenge T, Mbuyi-Musanzayi S, Kasole TL, Ngombe LK, Obadia PM, et al. Metal mining and birth defects: a case-control study in Lubumbashi, Democratic Republic of the Congo. The Lancet Planetary Health [Internet]. 2020 Apr 1;4(4):e158–67. Available from: https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(20)30059-0/fulltext
9. Azo CleanTech. Recycling Batteries and The Toxic Hazards of Battery Disposal [Internet]. AZoCleantech.com. 2008. Available from: https://www.azocleantech.com/article.aspx?ArticleID=132
10. Perras R. Manganese is Replacing Cobalt: How This Mineral Is Saving the Future of the Electric Vehicle Industry [Internet]. Entrepreneur. 2021. Available from: https://www.entrepreneur.com/article/386143
11. Holland M. Reducing the health risks of the copper, rare earth and cobalt industries: Transition to a circular low-carbon economy. www.oecd-ilibraryorg [Internet]. 2020 Jan 31 [cited 2022 Jan 14]; Available from: https://www.oecd-ilibrary.org/environment/reducing-the-health-risks-of-the-copper-rare-earth-and-cobalt-industries_88ce1db4-en
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