Abstract
The aim of this study was to determine the influence of sewage water irrigation on chromium (Cr) accumulation in soil and forage species and to assess the health risk of grazing livestock via forage consumption. The experimental design of the research and all experiments were done in Sargodha University Botanical Department. Measurement of Cr in water samples and soil and plant samples prepared for analysis by wet digestion was done using atomic absorption spectrophotometer (AA-6300 Shimadzu Japan). The average Cr concentrations in soil samples, forage crops and in water were determined. In the root samples of forage species, the highest concentration was 0.625 mg/kg (dw) in winter forage T. alexandrinum and the lowest mean concentration was 0.053 mg/kg (dw) in summer forage S. bicolor. In the leaf samples of forage species, the highest mean concentration of Cr in leaves was 0.583 mg/kg (dw) occurred in T. alexandrinum in winter forage and the lowest mean concentration was 0.035 mg/kg (dw) occurred in E. colona grown in summer forage. The present Cr values in the leaf samples of forages species were lower than this permissible limit. In the present study, the values of health risk index were lower than 1 in case of all Cr values. So, it can be said that forage species irrigated with sewage water in the study area is safe for consumption of livestock. However, though the general values were lower than the permissible maximum limit, it was observed that the metal accumulation in the forage species irrigated with sewage water was higher. Therefore, especially in agricultural applications, attention should be paid to contamination of soil and food chain components when watering with wastewater.