New research has found that India and four other countries – China, Pakistan, Mexico and Iran account for the most cropland in the world irrigated by dirty wastewater, putting millions of lives at serious health risks
The study relies on advanced modelling methods to provide a comprehensive estimate of the global extent to which farmers use urban wastewater on irrigated cropland.
Researchers analysed data with geographic information systems (GIS). 65 per cent of all irrigated areas are within 40 km downstream of urban centres and are affected by wastewater flows to a large degree.
In these circumstances, and where safer water is in short supply, wastewater offers a consistent and reliable means of irrigating fields, including high-value crops, such as vegetables, which often require more water than staple foods. In most cases, however, farmer’s use of this water is motivated by basic needs. When they simply do not have alternatives.