Chromium uptake in tolerant crops and its toxicological risk to human consumers in Mozambique

Chromium (Cr), classified by the International Agency for Research on Cancer (IARC) as a carcinogen, poses significant risks to human health. This study evaluated the uptake of Cr in Arachis hypogaea, Vigna unguiculata, and Zea mays cultivated in Cr-contaminated soils and assessed the associated toxicological risks to human consumers. A greenhouse experiment was conducted using soils contaminated with Cr at 10 and 30 mg kg^-1. Chromium concentrations in soils and plant tissues were quantified using ICP-OES, and bioconcentration and translocation factors (TFs) were determined to assess Cr uptake and movement within the plants. The lifetime incremental cancer risk (ILCR) was determined to evaluate potential long-term health risks. Results showed that all three species accumulated significant amounts of Cr in roots and aerial tissues, with bioconcentration factors (BFs) greater than one in most treatments. However, TFs remained below or equal to one for most cases, indicating limited upward movement of Cr. Importantly, ILCR values were within permissible limits, suggesting no significant carcinogenic risk for consuming these crops. These findings indicate that A. hypogaea, V. unguiculata, and Z. mays are resistant to Cr contamination and can be safely cultivated and consumed in soils containing up to 30 mg kg^-1 of Cr. This study provides valuable insights for ecotoxicological risks and for the safe management of Cr-contaminated agricultural soils in Mozambican industrial areas.