Nearly 100 beaches across the country are closed or have swimming advisories

Authorities in at least 10 states have closed beaches or warned people not to swim in the water due to high levels of bacteria ahead of the Fourth of July holiday.

Some of the closures are related to bacteria from fecal waste, while others are due to high levels of cyanobacteria, also known as blue-green algae, found in freshwater.

Florida, Illinois, Michigan, New Jersey and New York have reported dangerous levels of fecal waste on certain beaches over the past week. Illinois has warnings issued for 16 beaches, and Michigan announced two beach closures and five swimming advisories.

In Vermont, six locations are on high alert due to excessive cyanobacteria, so the state is telling people not to swim there.

Many beaches in the US close every year due to harmful levels of bacteria. Environment America, an environmental research and policy center, found that more than half of the beaches in the USA tested experienced at least one day with unsafe levels of fecal contamination in 2022 based on Environmental Protection Agency standards.

Swim in waters with high levels of bacteria it can cause gastrointestinal illnesses and skin infections, especially in children, the elderly, and individuals with weakened immune systems.

Research suggests that cyanobacterial algal blooms are happening more frequently due to climate change, and exposure to them can cause lifelong health problems. Cyanobacteria produce microcystin, a toxin that can damage the kidneys, liver or reproductive system if consumed in large quantities. ‘

As of Friday, Iowa was seeing high levels of microcystin at two beaches and high levels of E. coli at five others.

In Massachusetts, 34 beaches closed, mainly due to high levels of E. coli or enterococci – types of bacteria that signal the presence of fecal waste. Enterococcus is measured in both marine and freshwater, while E. coli is measured only in freshwater.

Robert Goldstein, commissioner of the Massachusetts Department of Public Health, said increased bacteria levels are common in the state after heavy rains. Rainwater collects bacteria from the environment, such as animal or human excrement, and then transports them to bodies of water.

“After the heavy rains we’ve had here in the Northeast over the last few weeks, there is an increase in the number of beaches that need to be closed,” Goldstein said.

About 5% of Massachusetts beaches are closed for the season, Goldstein estimated. The current closures represent just a small fraction of the state’s 1,100 public and semi-public beaches, she added.

The Florida Department of Health has also determined that several beaches in Monroe and Hillsborough counties have poor water quality due to high levels of enterococci.

In San Diego, three beaches have been closed and two have warnings due to dangerous levels of bacteria. And in southeastern Virginia, several sites are under a similar warning.

Goldstein said bacteria levels can change frequently, so people should check the health department’s website for the latest updates on where it’s safe to swim and be aware of beach safety warnings.

People can also take steps to minimize the amount of bacteria they add to the environment. Goldstein suggested that beachgoers clean up after their pets and dispose of trash properly, which could prevent animal feces from entering the water.

“Whatever bacteria they are introducing into the environment, it is likely that those bacteria, after heavy rains, will end up in the bodies of water around us,” he said.