Prolonged exposure to crude oil and chemical dispersants is a public health danger, environmental scientists warned [on May 27]. With no immediate end in sight, there were growing concerns over the effects on public health of a prolonged exposure to the oil as well as to the more than 3,640,000 litres (800,000 gallons) of chemical dispersants sprayed on the slick. Environmentalists and fishing groups in Louisiana say prolonged exposure to the oil, in the form of tiny airborne particles as well as dispersants, could be wreaking devastating damage on public health. They also accuse BP of threatening to sack workers who try to turn up for clean-up duty wearing protective respirators, and the Obama administration of refusing to release results of air and water quality tests that would show the impact of crude oil and dispersants on the environment. Wilma Subra, a chemist who has served as a consultant to the Environmental Protection Agency, said Every time the wind blows from the south-east to the shore, people are being made sick. It causes severe headaches, nausea, respiratory problems, burning eyes and sore throats." Long-term health effects include neurological disorders and cancer. Subra said there was even greater concern for those recruited to lay booms and skim crude off the water, since they were in closer proximity to the oil and the chemical dispersants. Clint Guidry, of the Louisiana Shrimp Association, has accused BP of threatening to sack workers who turn up wearing respirators.