Risk Assessment of Heavy Metals from Algerian Urban Wastewater in Agricultural Soils and Fava Beans

Abstract

Description of the subject. This work involves assessing the degree of Cadmium, Chromium and Iron bioaccumulation in agricultural soils in the M'sila area and in fava beans grown and irrigated with purified wastewater. Objectives. The objective was to assess the risk level incurred by the population consuming this vegetable, and evaluate cancer factors. Method. In our study, we opted for fava beans, which were planted in a plastic greenhouse, and irrigated at the same times and in the same quantities with purified wastewater from the wastewater treatment station. The study was conducted over a period of 12 weeks. The experiment was carried out in three stages (time) during plant growth so as monitor heavy metals behaviour of (Cr, Cd and Fe) from the soil towards the various plant organs. Heavy metals levels are evaluated through ICP-OES. Results. The results revealed levels of heavy metals in the soil, values extend from 0 to 400 mg/kg. On the other hand, values vary between 0 and 9.75 mg/kg were obtained from the various organs of the bean. This suggests that sandy soils allow greater transfer of trace elements to plants than heavier (more clayey) soils. As far as the carcinogenic risk quotient (CRQ) is concerned, the results obtained in broad fava beans (Fe: 5.15- 6.22× 10-6) are higher than the admissible limit set by the United States Environmental Protection Agency (USEPA, 2022), which is 10-6, representing a risque for public health. Conclusions. Special consideration should be given to the accumulation of heavy metals in various food products, as they present dangers for the population and must be reduced to acceptable levels.