Oil from the massive Gulf of Mexico spill reached the white sands of Pensacola in north-eastern Florida, forcing local authorities Thursday to close down area beaches to swimming at the height of summer.
"There's oil both in the water and in the sand," said Warren Bielenberg, an official with the Gulf Islands National Seashore, one of the areas affected by the spill.
"There's a double red flag, so it's not permitted to swim," he said.
A health advisory was issued for Escambia County and runs from Perdido Key to Santa Rosa Island and the east side of Pensacola Beach, Bielenberg said.
Santa Rosa Island is one of the biggest tourist attractions of the region.
"The beaches are open, but it's not allowed for people to be in the water," said Bielemberg.
"There are some people still going to the beaches," he said. "They are using umbrellas and just enjoying the sun."
Florida Governor Charlie Crist visited the Pensacola beaches on Wednesday to witness the effects of the spill.
"That is disgusting," Crist said. "To see something like this in such a beautiful place is unbelievable."
The wide-spread slick could spell disaster for Florida, one of the world's top destination for tourists, with more than 80 million visitors a year.
Florida officials have mounted an aggressive beach and coastline cleanup effort to stop the oil from reaching state beaches.
Florida's 1,260 miles (2,000 kilometers) of western coastline is home to scores of tourist destinations, natural habitats and an important fishing industry.
At a time of high unemployment in other sectors, tourism in Florida generates more than a million jobs, bringing the state 65 billion dollars in revenue in 2008.
Explore further: Study shows Beijing haze linked directly to gaseous pollutants from traffic, industrial emissions