Article Access: Trace metal contamination of groundwater in southeastern Democratic Republic

by Karabo Cohen


In what is arguably the first of its kind, researchers Bamba Muhaya and Benjamin Badahri from the University of Lubumbashi present a compelling case for a public health risk given rise to by an increase of anthropogenic activity, (as a result of human activity) in the Katuba and Kenya municipalities of Lubumbashi City, situated in the southeasternmost region of the Democratic Republic of Congo; more specifically, the trace metal contamination of groundwater because of ore processing plants, mines, dumps, tailings and landfills, as well as this region having great ore deposits of metals that are often found in groundwater as a result of rock-water interaction. Lubumbashi, according to Bloomberg UK, is where the operation of the country's largest mining company is observed, and as of the research compounding the report being conducted, the vast majority of people in the area do not have access to tap water, hence the primary source of drinking water being the private groundwater wells. In the recent literature, this idea of human activity having a potentially irreversible impact on ecological systems, biodiversity and environmental processes has been defined as the Anthropocene, however, international organizations set up for cooperation in the field of geology (i.e. the International Union of Geological Sciences and the International Commission on Stratigraphy) have not yet recognized this term as an official specification of geological time.

Regarding its methodology, the study involves sampling campaigns where between the dry season in 2016 and the rainy season in 2017, two groundwater samples are collected once a month from hand-dug wells ranging 2-15 metres and drilled wells ranging from 20 to 60. In Katuba, this is at two sites in each of its nine administrative areas, and in the Kenya municipality, the same number of sites in each of its three administrative areas. This is all followed by a note on the analytical methods - sample pretreatment and trace metal analysis. Samples collected from the study areas are acidified with concentrated hydrochloric acid so that no degradation is to take place before they can be analysed. As per the literature in chemistry, temperature, light exposure and pH conditions are among some of the things which contribute to sample degradation. In addition to this, the authors produce a description of the study area, Lubumbashi, as a way of outlining the setting and nature of their work, and a map is therein embedded.

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It shows the location of the Upper-Katanga province and Lubumbashi city in the southeastern Democratic Republic of Congo, as well as the sampling sites in Katuba and Kenya municipalities (communes). The description of the trace metal analysis which was carried out as part of the study’s methods following the other components of the ‘materials and methods’ section is where the report finds itself at one of its most technical points, involving mass spectrometry and quartz injectors, alongside the results and discussion. The key takeaways from here are that nineteen trace elements (e.g. cadmium, bismuth, uranium, nickel, copper etc.) were recorded at different concentrations in all of the groundwater samples; during Katuba municipality’s rainy season, the highest mean concentrations of many potentially toxic elements (e.g. arsenic, lead and barium) were noted in samples from several hand-dug wells; high mean concentrations of potentially toxic elements were similarly recorded in groundwater samples from other sites in other seasons; and most importantly, these mean trace element concentrations found in the Kenya and Katuba groundwater exceed what are the acceptable limits put forward by the World Health Organisation (WHO), the United States Environmental Protection Agency (US EPA) and or the European Union (EU) in recent years.

Although various researchers have worked around the adversity of human consumption of trace metals in Lubumbashi, this is supposedly the first published report presenting quantitative research on the quality of the water in Lubumbashi. Conclusions that can be drawn from the data serve as a worrying account of the unsanitary conditions the people of the two Lubumbashi areas are subjected to and perhaps the level of intervention needed by the most capable authorities e.g. mining regulation, the installation of taps and funding in the form of foreign and or domestic aid which may facilitate the latter: given the possibility that the alleviation of this issue is enhanced by the work of non-governmental organisations. Unsurprisingly, Muhaya and Badahri do go on to propose solutions for mitigation and prevention, these include: the carrying out of more research which compares seasonal variation of metal contamination in the groundwater; enhanced regulation of the Congolese Water Supply Company on the part of the provincial and national governments; an end to consumption of the highly contaminated water which is directed by the municipal authority, and lastly; the implementation of Congolese Mining Regulations so as to reduce pollution.

For many hundred years, human beings making up different communities have discarded waste products and facilitated access to liquid resources in several ways, often reflecting the technology best available to those communities and (especially in today’s world) the degree in which they are deprived. And while the chime of industrialization in developing and or emerging countries may serve as a glimmering herald of futures where the material well-being for millions of people has risen, the negative externalities of intense industrial and agricultural activity may have untold effects on the health of people residing in the local areas.



Bamba, B. M., & Benjamin, B. B. (2022). Trace metal contamination of groundwater and human health risk in Katuba and Kenya municipalities of Lubumbashi city, Southeastern Democratic Republic of Congo. African Journal of Environmental Science and Technology, 16(3), 91-110.



Karabo Cohen is a finishing A-Level student at the Rutlish School in History, Politics, Economics. He currently plans to attend university for history and politics.