Microbial, Metal Composition and Health Risk of Selected Vegetables Irrigated with Different Water Sources in South Africa

Global water scarcity informed by the population explosion is championing the need to adopt wastewater in the practice of smallholder farmers producing vegetables. While the availability and the nutrient composition of the wastewater can be appealing, the resulting consequence may be fatal. The study employed standard laboratory procedures to evaluate the physicochemical, microbial and trace element parameters of irrigated plant samples. Irrigating with pond water resulted in an E. coli value of 2000 cfu/100mL which is higher than the upper permissible level for wastewater (1000 cfu/100mL). The water quality index of 4479.49 showed that the wastewater is not fit for irrigation purposes. Arsenic (As), Lead (Pb) and Cobalt (Co), Nickel (Ni) and Zinc (Zn) were found to be within permissible levels with human health risk assessment less than 1 at P > 0.05 and the metal pollution index less than 100. The observation presented the need for treatment solutions to handle microbiological components for wastewater in the study area to reduce the risk of consumption of farm produce contaminated with microbial and metal pollutants of concerns with health risk concerns.