In this April 1, 2017 photo, foam from detergents flows into a field of black beans as it is irrigated with wastewater near Tepatepec, Hidalgo state, Mexico. Farmers who irrigate with wastewater face health risks, including roundworm and other parasite infections, according to the World Heath Organization. But most of the Mezquital farmers downplay the risks, claiming that generations of families have not suffered. In fact they often wash their hands in the brown water before settling down to eat lunch in the fields. (AP Photo/Rebecca Blackwell)