Beachgoers should take notice: sitting on the wet sand or swimming in the sea for too long may increase the risk of catching an unpleasant stomach bug, a new study found.
The University of Florida study found that the more time spent on the wet sand or in the water, the greater the chance of suffering from gastroenteritis.
While water pollution monitoring is a standard part of "quality control" in many tourism-dependent cities, the same cannot be said of the sand.
"Our objective was to understand whether beach sand could pose a health risk to beachgoers," said Tonya Bonilla, a reseacher at the Unievrsity of Florida's College of Veterinary Medicine's department of infectious diseases and pathology.
"What we found was that there was no increased health risk due to exposure to sand on the upper beach," she said.
But "the longer the period of time people spent in the water and in the wet sand, the higher the probability they would experience some gastrointestinal illness," Bonilla said.
Beach sand often has some degree of contamination from seabird waste, or other fecal waste. Microbes concentrate naturally around the waterline, in the water and also are tracked around on bathers' feet, researchers found.
They looked at three beaches north of Miami: Hobie Beach, Hollywood and Fort Lauderdale.
"There is an increase risk of acquiring gastroenteritis the longer a bather either sits in the wet sand or stays in the water," said Jay Fleisher professor College of Osteopathic Medicine-Nova Southeastern University.
"The probability that an individual will become sick increases over expected non-exposure rates from six out of 1,000 people for 10 minutes exposure to aprox. Twelve out of 100 people for a two hours stay in the wet sand," he said.
"For exposure to water, these rates increase from seven out of 1,000 people affected over expected non-exposure rates for a 10 minutes stay to aproximately seven out of 100 people exposed for a 70-minute stay," Fleisher added.