By Sheilah Downey (sheilahd@foodconsumer.org)

Many of America's beaches are contaminated with human and animal wastes, states a report issued today, and the effects of climate change are making matters worse.

Nationwide, beach closing days topped 20,000 in 2008 for the fourth consecutive year, according to the report from the Natural Resources Defense Council (NRDC).

The highest level of beachwater contamination was found in the Great Lakes area for the third straight year, where 13 percent of beaches violated public health standards, said the NRDC report.

The study found that seven percent of beachwater samples taken from beaches throughout the United States violated health standards, with contamination including human and animal wastes.

"Nobody wants their trip to the beach to send them to the bathroom, or worse, the emergency room," said Nancy Stoner, NRDC water program co-director. "It is vitally important to remember that if it has recently rained -- or you see or smell a pipe discharging onto the beach, keep your head above water or avoid swimming altogether."

Exposure to contamination, due to dirty stormwater runoff and sewage overflows, can lead to illnesses like the flu, dysentery, hepatitis, pinkeye and other health problems.

From 2005 to 2008, beaches in the Great Lakes area "consistently test the dirtiest," states the report. The Southeast and the Delmarva Peninsula proved relatively cleaner than other regions.

States with the highest percentage of samples that exceeded health standards included Louisiana, 29 percent, Ohio, 19 percent, and Indiana with 18 percent.

The NRDC reported the effects of climate change on beaches for the first time, studying the effects of increased temperatures and more frequent rain storms. Those two climactical events will increase the germs that cause stomach flu, diarrhea and neurological problems at beaches nationwide.

The report offers a five-star rating guide for 200 of American's most popular beaches. For the full report go to www.nrdc.org/beaches.