Wastewater Re-use in Agriculture in Vietnam
The main project objective was optimizing and sustaining the overall benefits of wastewater irrigation in peri-urban areas in Vietnam, accompanied by a reduction of health and environmental risks. After a comprehensive survey of wastewater irrigation practices, it was revealed that 93% of the cities sampled use wastewater for agriculture or aquaculture or both. The wastewater irrigated areas in most cities account for around 1-2% of the total agricultural land around the cities. Extrapolation of these findings to the national level gives a range of 6,000 to 9,500 hectares as a national figure for wastewater irrigated agriculture. From prevalence estimates in 29 provinces it was calculated that 33.9 million people in Vietnam are infected with Ascaris (prevalence 44.4%), Trichuris (prevalence 23.1%) and 21.8 million with hookworms (prevalence 28.6%). Vegetable cultivation where night soil is used as fertilizer is a risk factor for hookworm infection especially among adult women.