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Escaping Quarantine? Watch Out for Toxic Algae

Wednesday, June 10, 2020

With summer beginning and millions of Americans experiencing what feels like the thousandth week of quarantine, enjoying the outdoors is one of the few ways many of us can escape the claustrophobia and drudgery of the COVID-19 pandemic.

But the return of warmer weather brings another public health threat – toxic algae blooms. People who plan to spend time visiting ponds, lakes, rivers, streams or even the ocean this summer need to be on the lookout for these hazardous outbreaks.

Blue-green algae, which are actually tiny organisms called cyanobacteria, can produce dangerous toxins that cause nausea, vomiting and longer-term impacts like liver failure and cancer when people are exposed through recreational contact or consume the toxins through drinking water. Simple things we all enjoy doing in the summer – swimming, boating, sitting on a beach or even walking near an infected body of water – can make people sick.

Algae outbreaks are triggered by nitrogen and phosphorus from fertilizer and manure that run off farm fields and get into bodies of water. Heat makes the problem worse: As water heats up throughout the summer, algae blooms occur more frequently and get bigger. And outbreaks don’t just make people sick – they can also kill dogs and have severe impacts on wildlife.

New algae bloom appearances have already been increasing across the country over the past few weeks, even though it’s early in the season. In May, a dog died in Minneapolis after it was exposed to an outbreak in Cedar Lake. Algae blooms also appeared in May in two Minneapolis lakes, Lake of the Isles and Lake Nokomis.

If you see algae that is bluish-green, or looks like pea soup, in a lake or other body of water where you hadn’t seen a bloom before, inform the local health department and ask it to test the algae for toxins. You can also contact local media and try to get coverage of the issue.

Lakes that have had annual algae outbreaks in recent years have already started seeing them this year. Blooms started appearing in April in several lakes in Washington state; Lake Pontchartrain in Louisiana; and Lake Okeechobee in Florida.

Because no federal agency tracks outbreaks, EWG uses news reports as a proxy to track the problem. We created an interactive map that shows the locations of algae blooms reported in the media since 2010.

The number of news reports about algae outbreaks has increased every year since we began tracking them. In 2019, there were news reports about 530 U.S. outbreaks – a 17 percent increase from the 452 stories published in 2018. With higher-than-normal temperatures predicted this summer for much of the country, we expect a similar trend in 2020.  

Reports of Algae Blooms Are on the Rise

EWG will track news reports of blooms all summer. To find out whether there’s an algae outbreak in a body of water you plan to visit, contact your local health department and continue to check our analysis

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