The government doubts the gravity of problems cited in an environmental report charging that more than 37 million Americans were exposed to hazardous levels of bacteria or toxic chemicals in tap water last year. The Environmental Protection Agency immediately branded the report by an environmental group "misleading," saying no public health crisis exists in drinking water. "The vast majority of Americans consistently receive high-quality water," EPA spokesman David Ryan said. "The vast majority of Americans should have no fear of turning on their tap and drinking water." The National Wildlife Federation used thousands of government documents for its report, which concluded that lax enforcement of safe water laws posed a major health threat to the nation. The group said some 110,000 cases of illness from drinking polluted water were reported between 1971 and 1985.