Who is at Risk Everyone who heavily uses nearshore areas for recreation is at risk. However, children, the elderly, and people with weakened immune systems are most susceptible to becoming ill. Pathogens can persist in sand longer than in water. Though water is off-limits during a beach closure, sand contact is still allowed. This can put children at risk if they put contaminated sand in their mouths.
Further studies document the risk of bacteria contamination to kayakers, surfers, and swimmers.
Despite the risk to children from exposure to contaminated sand, beach closings are based on water concentrations of bacteria. The U.S. EPA recommends that beaches be closed when concentrations reach 235 colonies per 100 ml of water. See also, fact sheet and A Lake Michigan Bill of Rights for Illinois Citizens . Lake Michigan Federation. Waterways for Our Future , Friends of the Chicago River, et al., Chicago.