…Jonathan Cosillos…[is] one of more than 300 people the Mexican government has identified with illnesses tied directly to heavy metal contamination from a mining accident that spilled 11 million gallons of toxic chemicals into the Sonora River in August 2014…It’s been more than a year and new medical cases continue to emerge. Researchers and environmental experts in Mexico are now warning that the government’s slow response, combined with outdated water quality standards, have placed the population under unnecessary risk…“There’s a high risk if people begin their treatment late. The longer some contaminants are in the organism, the more difficult it is to get rid of them,”…said [environmental health specialist]…