EWG News and Analysis
The latest from EWG’s staff of experts >>
The Many Hazards of Toxic Algae Outbreaks
This summer, EWG is tracking outbreaks of potentially toxic algae across the U.S. We have been startled to find that these outbreaks are erupting everywhere: from the East Coast to the West Coast, from the Great Lakes to the Gulf of Mexico.
Though outbreaks of algae vary in type, severity and health hazards, all toxic algae outbreaks have serious consequences.
They Make People Sick
Every summer, people fall ill following exposure to algae outbreaks. Exposure can be caused by contact, ingestion or inhalation. Short-term health effects can range from skin irritation and numbness to fever and headaches. Long-term exposure can lead to cancer, liver failure and sperm damage. Some studies have even linked ingestion of cyanotoxins to brain inflammation.
What is traditionally called blue-green algae is actually a class of microscopic organisms called cyanobacteria. Cyanobacteria can be toxic and can also produce various types of cyanotoxins that have different hazards. Here’s a breakdown of the various health risks of each type of cyanotoxin.
They Threaten Children’s Health
For children pumped to play in and around the water, lake or beach vacations can be ruined by water infested with slimy blue-green algae. With their small, developing bodies, children are especially endangered by algae exposure.
The Centers for Disease Control and Prevention found that in 2009-2010, 61 people in Ohio, New York and Washington got sick from toxic algae outbreaks in lakes, and two-thirds of them were children or teenagers. Children may be at a greater risk of illness from the toxins generated by toxic algae outbreaks because they more frequently come in contact with or ingest contaminated water.
Here are some helpful tips for parents looking to shield their children from algae exposure. Be sure to keep an eye on young children around potentially contaminated water and warn them about the exposure risks and telltale signs of outbreaks.
They Poison Our Drinking Water
In 2014, half a million people in and around Toledo, Ohio, were told not to drink their tap water – or even shower in it – for three days after bacteria from a massive algae outbreak in Lake Erie got into the water supply.
Toledo was the first major U.S. city where toxic algae outbreaks made tap water unsafe for human consumption. But it probably won’t be the last, especially since the number of these outbreaks across the nation seems to be multiplying each year. Because algae outbreaks are so widespread and seem to be growing, they may be fouling tap water even in places where officials have not issued a do-not-drink warning.
They Contaminate the Air We Breathe
Recent studies indicate that the toxins produced by some outbreaks can become airborne, where they can be inhaled by people in, on or near contaminated water.
Whether by sunbathing on the shore or taking a cruise on a boat, inhalation of contaminated water can cause coughing, wheezing, shortness of breath and other respiratory ailments.
They Harm or Even Kill Pets
There are many documented cases of dogs and other pets becoming seriously ill or even dying from the toxins from algae outbreaks. Splashing in or drinking contaminated water can be dangerous for pets. If you believe your pet may have been exposed, be on the lookout for symptoms such as lethargy, seizures, diarrhea or vomiting. Exposure to high levels of cyanotoxins can lead to liver failure and death.
They Provide a Breeding Ground for Mosquitos
Algae outbreaks thrive in still, warm water – and so do mosquitos. Recent news stories from Florida report that residents are concerned their homes near blue-green algae outbreaks are breeding grounds for mosquitos, which can carry dangerous diseases like West Nile virus, encephalitis and malaria.
Much is still unknown about the relationship between algae outbreaks and mosquitos, but it is still important to act in an abundance of caution. Check out EWG’s Guide to Bug Repellents on tips on how to avoid mosquitos and other disease-carrying insects.
They Worsen Climate Change
Scientists have new evidence that algae outbreaks are significant sources of greenhouse gases. A study earlier this year found that as algae outbreaks decrease the level of oxygen in lakes and other bodies of water, carbon and methane emissions from decomposing plants rise exponentially. And as climate change gets worse, the resulting warmer waters are causing more algae outbreaks, creating a toxic feedback loop.
They Devastate Ecosystems
Dying algae consume oxygen in water, creating dead zones where nothing can survive, including microorganisms. The toxins in algae outbreaks can be ingested by small fish and shellfish. As those animals are consumed by larger aquatic creatures, they can cause large fish kills and die-offs of other animals.
The same emissions that contribute to climate change can also enter the water cycle as acid rain that damages forests and other ecosystems, and pollute the air we breathe.
They Wreak Havoc on Economies
Because people can be exposed to cyanotoxins just by being around contaminated water, algae outbreaks understandably scare away people from visiting affected lakes, rivers or beaches. Communities that struggle with regular, serious toxic algae outbreaks, like some cities in South Florida and around Lake Erie, can lose billions of dollars from lost tourism and recreation.