In the report, published in the April 15 issue of ACS' Environmental Science & Technology, Michael J. Sadowsky and colleagues cite several previous studies showing that E. coli and bacteria indicating fecal contamination can accumulate and grow in beach sand. "These results indicate that E. coli originating from several sources may survive and potentially replicate in sand and sediment, possibly increasing fecal counts found on beaches," the report states. The researchers point out that while most E. coli strains are harmless, some strains do cause gastrointestinal diseases in human. Symptoms include vomiting and diarrhea, as well as more serious conditions.
The 2-year study tracked seasonal variations in E. coli in water, sand, and sediment at the Duluth Boat Club Beach in Duluth-Superior Harbor on Lake Superior. It concluded that beach sand and sediment serve as sinks and sources for E. coli from humans and waterfowl that can contribute to beach closures.
Original article: "Beach Sand and Sediments are Temporal Sinks and Sources of Escherichia coli in Lake Superior" Note: This story has been adapted from a news release issued by American Chemical Society.