Mexicans fear for their health, after mine spill More than 20 000 Mexicans still don't have direct access to clean drinking water in the northen border state of Sonora. Citizens are asking the government for independent analysis of the toxicity levels of the Sonora river, contaminated last week by 40 000 metric cubes of sulphuric acid spilled by the Buena Vista del Cobre mine, the largest in Mexico. A natural sound version of an AFPTV report.