Air quality monitoring equipment is installed on the pier at the beach on Dauphin Island, Alabama May 10, 2010, two days after tar balls washed up onshore. Oil workers, volunteers and the military have been battling to shut off a gushing oil leak in the Gulf of Mexico and stop the huge spreading slick from reaching major ports, tourist beaches, wildlife refuges and fishing grounds. REUTERS/Brian Snyder (UNITED STATES - Tags: DISASTER ENERGY ENVIRONMENT)