Heavy metal concentration in irrigation water, soil and dietary risk assessment of Amaranthus viridis grown in peri-urban areas in Kinshasa, Democratic Republic of the Congo

The urban agriculture in developing countries plays a huge important socioeconomic role in confronting the challenge of eradicating hunger, improving food security and the social daily life of the population. However, the quality evaluation of water used for urban agriculture irrigation as well as the accumulation of pollutants such as heavy metals in fresh produces are still largely unstudied. The purpose of this study was to investigate the concentration of metals (Cr, Co, Ni, Cu, Zn, As, Cd, Pb and Hg) in irrigation water from rivers, soil and Amaranthus viridis (A. viridis), in order to evaluate the potential human dietary risks. The research was conducted in eight sites characterized by intensive agriculture performed in watersheds in Kinshasa, capital of Democratic Republic of the Congo. The results showed high metal concentrations in A. viridis leaf varying considerably among sampling sites (P