Critical risk analysis of metals toxicity in wastewater irrigated soil and crops: a study of a semi-arid developing region

Abstract

Toxic elemental exposure through consumption of contaminated crops is becoming a serious concern for human health. Present study is based on the environment and health risk assessment of wastewater irrigated soil and crops in a semi-arid region Faisalabad, Pakistan. The concentrations of potentially toxic elements (Cu, Cr, Mn, Fe, Pb, Zn, Ni) were analysed by atomic absorption spectrometer in five different crops (Corn, rice, wheat, sugarcane and millet), while, their topsoil’s and multi targeted risks analysis were assessed. Results showed, the mean values of Pb and Zn were higher in crop than Food and Agriculture Organization guidelines for food additives and contaminants. A strong positive correlation was found among wastewater and crop’s toxic metals (r 2 values in Cu, Zn, Pb, Ni and Cr were 0.913, 0.804, 0.752, 0.694, 0.587 respectively). Whereas, a strong correlation was also found among soil and wastewater lead (r 2 = 0.639). The calculations of Nemerow Integrated Pollution Index (NIPI) showed the soil samples maximum pollution limit (NIPI > 3) and Potential Ecological Risk Index (PERI) was found to be higher than maximum limit (PERI > 600) for all samples. While, for non-carcinogenic risk, Hazard Index (HI) values in adult were near threshold (HI > 1) for all crop samples. In children, the HI values for Corn, Rice and Wheat were above threshold limit and for Sugarcane and Millet, these were near to threshold. Cancer risk values for Cr found higher than safe limit (1 × 10 –6 ) in adult and children for crop samples. Crop irrigation by wastewater irrigation is a prominent alternative option for water scarce countries, however prior testing and treatment of such wastewater streams must be employed to minimize the adverse impacts on human health and environment.

Sorption of chemical contaminants on degradable and non-degradable microplastics: Recent progress and research trends

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The Impact of Treated Wastewater Irrigation on the Metabolism of Barley Grown in Arid and Semi-Arid Regions

“…Thus, the use of treated wastewater (TWW) for agricultural irrigation has gained global attention since water consumption has significantly increased due to the growing demand for food [ 4 ]. Currently, around 20 million hectares are irrigated with TWW in 50 countries, contributing to 40% of the food produced [ 5 ].…”

“…Several studies have revealed that the use of TWW can improve physicochemical properties and enhance the productivity of many economically important crops [ 5 , 16 , 17 ]. For example, the use of TWW enhanced the chlorophyll content, photosynthetic efficiency, and forage yield in alfalfa ( Medicago sativa ) [ 18 ].…”

Ecotoxicological impacts of industrial effluents on irrigation water quality, animal health and the role of calcium alginate in effluents treatment

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