This research was carried out with the aim to assess the pollution that threatens agricultural soils in urban areas in the Haut-Katanga region (DR Congo) by searching for heavy metals in the arable soil bordering the Kimpulande drain, in the nearby of the Shituru commune, the City of Likasi. This drain has been utilized since the 1930s by the Gécamines, the largest state-owned mining company in the country, to dispose of wastewaters from the copper and cobalt industry. The population living in Shituru utilizes the arable soil bordering the Kimpulande drain to grow edible plants. Based on the results from physicochemical analysis of soil samples from the first 40 centimeters and the determination of the spatial distributions of pH, electrical conductivity, and concentrations of selected heavy metals (Cu, Co, Cd, and Fe), it was concluded that the study area is composed of an alkaline soil (pH = 7.54) of which the average electrical conductivity is about 700 µS/cm. Unlike average concentrations of cobalt and iron, those of copper and cadmium have similar behavior, given that their average values decrease with soil depth. Besides, the soil utilized for urban agriculture of edible plants is polluted on the surface by cadmium (> 3 mg/kg) and copper (> 40 mg/kg). It is contaminated in depth by cadmium (> 1 mg/kg) and cobalt (from 20 up to more 100 mg/kg). This is not the case for copper and iron, given that their concentrations remained smaller compared to the limits set by the quality standards (QS) applicable to soils for agricultural use. Given the toxicity related to the presence in the arable soil of heavy metals to high concentrations, it was deduced that the Shituru in-force agricultural practices might result in the population's exposure to serious health problems. Consequently, the urban agriculture of edible plants on arable soils threatened by mineral pollution must be prohibited to protect the population's health.

The world is currently experiencing a water crisis in terms of both quantity and quality due to water ever-growing demand in large-scale consumer sectors such as agriculture, industry and tourism. This crisis results from the increasing pressure on water resources brought about the world population growth, continued urbanization and rapid industrialization as sources of an increased release of contaminated water into watercourses. Faced with this worrying situation, strategies have been developed throughout the world for improving both the availability and access to water. Different technologies, both established and emerging ones, are utilized in view to treat wastewaters, including those of the mining origin. The present work reviews the different uses of water in the mining industry and identifies its different sources of polluted water. It analyses some wastewater treatment techniques and their applicability in the reclamation of wastewater generated by the DR Congo mining industry. The adopted approach, in dealing with the relevant issue of water crisis experienced worldwide in terms of both quantity and quality, is expected to help improving practices in the management of wastewater of mining origin, increasing access to water and its sustainable use.

Urban agriculture has become a common practice in major urban agglomerations, particularly in the mining region of Katanga, in the Democratic Republic of Congo (DRC). However, this agriculture is based on the production of vegetables grown on the soil contaminated by industrial water and domestic wastewater, wherein one finds heavy metals and pathogenic microbes capable of endangering the consumer’s health. This work has been carried out in view of contributing to the consumer’s health protection and endeavours at establishing, based on physicochemical and mineral analyses  of  water  samples,  the  soil  used  in  the  urban  agriculture  and  edible  plants,  a  link  between  the  use  of contaminated waters in the urban agriculture, the build-up of heavy metals in the soil and the possible contamination by heavy metals of vegetables grown (amaranths and broccolis) in the Kasungami district and consumed by the population living in the City of Lubumbashi (DRC). The results given by the analyses of water, soils and vegetable samples revealed that, apart from cobalt, other heavy metals were present in water used in the urban agriculture to concentrations below quality standards. As for the soil, it contained heavy metals to concentration reputed phytotoxic. However, only the broccolis were contaminated with lead, contrarily to amaranths in which heavy metals were present to concentrations below quality standards. These findings enabled concluding that urban agriculture of vegetables encountered in the large agglomerations of the DRC could endanger the consumers’ health and measures need to be taken in view of preventing heavy metal from entering the food chain.

This research looked at the state of the environment in the areas where amaranth urban agriculture is practised in the municipality of Katuba, City of Lubumbashi, the Democratic Republic of Congo. Samples of water used for watering, the soil where urban agriculture is practised, and amaranths have been subjected to characterization analyses to look for chemical and microbiological pollutants. These analyses revealed that water and amaranths are polluted from the mineral and microbial standpoint, unlike soil samples. Indeed, water samples contained Paramecia, Entamoeba histolytica's eggs and colonies of faecal contamination germs, mesophilic flora, and other pathogen germs such as Aeromonas hydrophila and Pseudomonas aeruginosa. As for amaranth samples, their concentrations of cobalt were greater than the value set by the quality standards. The Paramecia, Entamoeba histolytica’s eggs, Escherichia coli, and Klesiella planticola contaminate them. For the above, consuming these amaranths poses health risks to the population. Public authorities must take the necessary measures to organize the practice of urban agriculture of edible plants to bring it up to standard and protect the consumers’ health.

Since 2002, Thamilemba quarter, located in the City of Lubumbashi (DRC), is a home to mining activities for the hydrometallurgical extraction of copper and cobalt. Consequently, great amounts of mineral wastes were improperly stored resulting in toxic metals liberation and contamination of the surrounding soil and the near to surface waters. This research determined major physicochemical parameters and measured the trace metal elements (TMEs) concentrations in samples of soil, water and plants. Based on data given by the samples analysis, it established the spatial distributions of metals in both the upper and deep soil (20 cm) through the data mathematical processing with the Matlab 7.1 software. The samples analysis results were compared to quality standards to ascertain the population's fear about the environment pollution is justified or not. An average pH value of 7.69 was measured in the soil and a value of 9.1 in whitish substances found at some spots. The soil samples presented TMEs concentrations above standards (0.5 mg/kg) or phytotoxic levels in the upper soil layers (Co, Cu, Fe and Zn) and in the deep layers (Co, Cu, Fe, Zn and Pb). Water samples contained TMEs to concentrations (Cu, Co, Mn, Zn and Pb) greater than drinking water quality standards set by the World Health Organization (WHO). The plant samples contained TMEs to high levels: Saccharum officinarum (Co, Cd, Ni, Mg and Pb) and in Musa acuminate (Co, Cd, Ni, Mn, Zn and Pb). These findings show that toxic metals endanger the wildlife and human health and confirm the population fears about the environment deterioration.