Cadmium (Cd) and Copper (Cu) Exposure and Bioaccumulation Arrays in Farm Ruminants: Impact of Forage Ecotypes, Ecological Sites and Body Organs

Abstract

Copper (Cu) and cadmium (Cd) metal distribution in soil–plant ecosystems and their public health risk impact on ruminants (cows, buffalo, and sheep) are explored in the present investigation. Five different forage crops were selected, and the foraging responses of three types of ruminants (cows, buffalo, and sheep) at three ecological sites were evaluated. The soil of these three ecological sites was metal polluted (due to wastewater irrigation) and was studied to evaluate the metal contamination and pollution load index. For the assessment of Cd and Cu, soil, vegetation, blood, hair, and feces samples were collected and analysed using an atomic absorption spectrophotometer. High consumption of fodder crops (Sorghum bicolor Kuntze, Sesbania bispinosa (Jacq.) W. Wight, Cynodon dactylon (L.) Pers., Suaeda fruticosa (L.) Forssk., and Tribulus terrestris L.) by cows and buffalo at site-III resulted in an increase in daily Cu and Cd intake. The pollution load index was higher at site-II and site-III, indicating a severe health risk scenario for local inhabitants. Cd and Cu were at their maximum levels in fodder crops. A significant increase in the concentrations of Cd and Cu was found in the blood, hair, and feces of cows and buffalo at site-III. Ecological indicators such as the bioaccumulation factor, the pollution load index, and the enrichment factor were found to be higher in buffalo than cows. The Cd level in forages was highest at the site-III Cd level and in the order of S. bispinosa > S. fruticosa > T. terresteris > C. dactylon > S. bicolor. Although these levels were lower than the permissible maximum limit, they were generally higher in the forage crops. Exposure of local inhabitants to the consumption of milk and meat from these cattle showed the serious health risks consequences. This situation can be properly managed by general monitoring of soil and vegetation pollution, avoiding metal contamination in the soil and food chain components, and using treated waste water and other alternate water sources for forage irrigation.