The absence of environmental law to protection of irrigation water with from accumulation of heavy metals in soil and crops in the region of Al-Ristmuia in Iraq

Abstract

Heavy metals exposure through consumption of contaminated crops is becoming a serious concern for human health in the absence of environmental law. Present study is based on the environmental and health risks associated with the use of treated wastewater produced from Al-Rustamia old plant for irrigation various crops cultivated in the soils around the station.  The physicochemical parameters pH and electrical conductivity, were determined for the samples. Irrigated water, soil and vegetable samples for Zn, Pb, Ni and Cd concentrations and transfer factor from soils to plants (TF) were analyzed, while, their crop’s and multi targeted risk, daily intake of metals (DIM) and health risk index (HRI) were calculated. Results showed, the mean values of Zn, Pb, Ni and Cd were lower in soil and crop than Food and Agriculture Organization guidelines for food additives and contaminants. The irrigated soil was contaminated with Zn 56.5, Pb 15.1, Ni 9.30 and Cd 0.850 mgkg^-1. The trend of heavy-metal concentrations in all samples was Zn > Pb > Ni > Cd. daily intake of metals in crops species for Zn (0.011 – 0.019 mgkg^-1), Pb (2.0×10^-5 – 5.9×10^-5 mgkg^-1), Ni (2.4×10^-4 – 5.2×10^-4 mgkg^-1) and Cd (1.3×10^-5 – 3.3×10^-5 mgkg^-1) are unexceeded the permissible limits. The Health Risk Index (HRI) varied from 0.037 – 0.063 for Zn, 5. ×10^-3 – 1.4 ×10^-2 for Pb, 1.2 ×10^-2 – 2.6 ×10^-2 for Ni and 1.3 ×10^-2 – 3.3 ×10^-2 for Cd. The HRI was >1 for the elements indicating a unpotential health risk. 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.