Does cobalt and copper mining lead to birth defects in DR Congo?

Does cobalt and copper mining lead to birth defects in the mining province Katanga (DR Congo)? That’s the research question that was addressed in a paper published today in The Lancet Planetary Health by a group of researchers from Belgian and Congolese universities. The research team included SIM² KU Leuven member Prof. Erik Smolders (Department of Earth and Environmental Sciences), who heads the flagship research topic on the “Risk assessment of metals and metalloids in the environment”. The study adds to the growing concern about the toxicity of prenatal exposure to mining-related pollution and highlights the importance of sustainable/responsible primary mining methodologies as well as the massive rollout of lithium-ion battery recycling practices.


Primary mining of cobalt and copper

One of the inconvenient truths about the transition to a climate-neutral economy is that the primary mining of several key metals may come at a significant environmental and health cost. This is particularly the case for cobalt, which is a key ingredient for lithium-ion NMC batteries.

The latter represent not only the technology of choice for a multitude of electronics but are also key for both electric vehicles and stationary renewable energy storage (RES). As such, cobalt is an enabler for the transition to a climate neutral economy, as also targeted by the European Commission (cf. The European Green Deal; EC,COM(2019)176).

However, the EU imports about 65% of its cobalt (approximately 10,000 tonnes/year) from geopolitically unstable countries such as the Democratic Republic of the Congo (DRC), Zambia or Central African Republic, where labour violations and environmental problems are widespread, in particular in the case of artisanal mining.

Only 35% is produced from secondary sources, such as the recycling of spent lithium-ion NMC batteries. Cobalt recycling typically has a much lower environmental footprint than primary mining and should thus be stimulated (cf. EU CROCODILE project and the review paper “Recycling lithium-ion batteries from electric vehicles” by Harper et al. in Nature).

Impact of environmental contamination on birth defects in DRC

Widespread environmental contamination caused by mining of cobalt and copper has led to concerns about the possible association between birth defects and exposure to several toxic metals in southern Katanga, Democratic Republic of the Congo (DRC).

The Belgian-Congolese research team, therefore, aimed to assess the possible contribution of parental and antenatal exposure to trace metals to the occurrence of visible birth defects among neonates. The results were published in the leading medical journal: The Lancet Planetary Health.

The study included 138 neonates with visible birth defects (about 0·1% of the 133,662 births in Lubumbashi during the study period) and 108 control neonates. The researchers found that mothers having paid jobs outside the home and fathers having mining-related jobs were associated with a higher risk of birth defects.

The authors claim this is the first study of the effects of mining-related pollution on newborns in sub-Saharan Africa. Paternal occupational mining exposure was the factor most strongly associated with birth defects.

Responsible mining

The study adds to the growing concern about the toxicity of prenatal exposure to mining-related pollution and highlights the importance of sustainable/responsible primary mining methodologies as well as the massive rollout of lithium-ion battery recycling practices. The authors conclude their paper as follows:

"Following the precautionary principle, our results call for sustainable mining practices to minimise exposure of fathers of childbearing age to toxic metals. Future studies should not only address the association between metal exposure of pregnant women throughout pregnancy longitudinally, but also focus on the father."

Full reference paper

Daan Van Brusselen, Tony Kayembe-Kitenge, Sébastien Mbuyi-Musanzay, Toni Lubala Kasole, Leon Kabamba Ngombe, Paul Musa Obadia, Daniel Kyanika wa Mukoma, Koen Van Herck, Dirk Avonts, Koen Devriendt, Erik Smolders, Célestin Banza Lubaba Nkulu, Benoit Nemery, Metal mining and birth defects: a case-control study in Lubumbashi, Democratic Republic of the Congo, The Lancet Planetary Health, 4(4), 2020, e158-e167. https://doi.org/10.1016/S2542-5196(20)30059-0


Want to know more about SIM² KU Leuven’s risk assessment work in this area?

Since March 2020, the KU Leuven Institute for Sustainable Metals and Minerals (SIM² KU Leuven) comprises a flagship research topic on the “Risk assessment of metals and metalloids in the environment”.

The environmental risk of metals and metalloids is controlled by the speciation of these compounds. This means that total concentrations are only poor indicators of risk. SIM² KU Leuven performs the risk assessment of metals and metalloids in the environment and in the food chain. The assessments can be desk-top based or use environmental monitoring and testing of speciation and toxicity. The risk assessments can be generic, e.g. for REACH or CLP, can be regional based, i.e. defining clean-up limits and can be site specific, i.e. at mine sites, landfills, waste treatment or in workplaces.

For more information, please contact Prof. Erik Smolders. Follow SIM² on LinkedIn: https://www.linkedin.com/company/18118889

Scroll to Top