Updated

Gulf beaches from Louisiana to the Florida Panhandle have been closed or slapped with health warnings nearly 10 times more often this summer than last because of oil from BP's massive deepwater leak, according to a report Wednesday by a national environmental group.

While many beaches were spared, more than 2,200 closings, health advisories or notices were issued by state or local authorities through Tuesday because of oil from the nearly three-month-long spill. That compared with 237 closings and advisories in the same period last year, mainly due to bacteria or viruses in the water, according to the Natural Resources Defense Council's annual survey of beach water quality.

The NRDC report said the oil spill affected 49 of 253 beach segments it monitors in Louisiana, Alabama, Mississippi and Florida. Texas beaches haven't had any advisories or closings so far.

Tar balls, oil sheen, globs of crude and petroleum smells have marred some beaches in the stretch since the disaster began with an April 20 drill rig explosion that killed 11 workers. BP finally capped the well July 15, a temporary measure until the gusher can be plugged underground, but government scientists estimate between 94 million and 184 million gallons of oil poured into the Gulf.

There has been no clear downward trend in warnings or closings since the cap stopped crude from pouring into the sea, the group said. Oil remains in the water and the incidence of beach landings goes up and down.

There is little distinction between closings and advisories because it's up to each state to determine whether they want to close a beach or issue a health advisory for swimmers and beachgoers, according to the study.

The organization typically studies bacteria and viruses at popular beaches. The health effects of oil can be similar: rashes, nausea and stomach ailments, said the organization's program director David Beckman. Oil also poses long-term neurological and reproduction risks.

"The visual image of seeing oil on a beach or smelling that kind of industrial oil at a place that you go to escape from the city to enjoy nature is really an assault on the senses," Beckman said.

Louisiana beaches were the hardest hit: 11 of the 28 monitored beach segments have been closed this year, with 793 combined days of closings compared to 180 advisory days this time last year.

In Alabama, there were 307 combined days of beach advisories, compared to no advisory days at this time last year. Gulf Shores Public Beach in Alabama was the only beach along the Gulf Coast to receive the organization's 5-star rating for water quality, based on 2009 data, but has been closed for 53 days due to the oil spill, according to the study.

Florida, which relies most on beachgoers to drive tourism dollars, had only 16 of its 180 beaches in the western part of the Panhandle impacted, resulting in 442 days of advisories. That compares to no advisory days for the same time last year.

Still, tourism officials as far south as Miami say they're losing business because of a public perception that oil is a threat, even though no crude has landed beyond the western Panhandle.

At least 60 percent of vacation spending in Florida during 2008 was in beachfront cities. Worried that reports of oil would scare tourists away, state officials are promoting interactive Web maps and Twitter feeds to show travelers — particularly those from overseas — how large the state is and how distant their destinations may be from the spill.

First Lady Michelle Obama walked barefoot along a Panhandle beach this month to encourage wary tourists to visit and she, the president and their two children are planning a Panhandle vacation next month.