Contamination of Agro-Ecosystem and Human Health Hazards from Wastewater used for IrrigationDDepartment of Soil and Environmental Sciences, Faculty of Agriculture, Gomal University, Dera Ismail Khan (NWFP), Pakistan.

摘要

The use of untreated/inadequately treated wastewater for irrigation in agriculture has been practiced for many years in arid zones of industrialized as well as developing countries. Farmers mostly use wastewater for growing the vegetables and fodders in urban areas because of unavailability of enough suitable water, wastewater's high nutrient value, reliability and proximity to urban market. Wastewater is loaded with salts, heavy metals and disease causing micro organism. Continuous use of untreated city effluents for growing vegetable may result in soil degradation, accumulation of heavy metal in soil in phyto-toxic concentrations and contamination of soil-water-plant system with pathogens. The intake of contaminated vegetables may lead to public health risks of transmission of enteric diseases. Also excessive intake of heavy metal ions may result in human health hazards due to their toxic effect. This review paper, therefore, discusses heavy metal and pathogen load in wastewater and their contribution towards pollution of agro-ecosystem and their consequent impact on human health.