All genera of cyanobacteria have dermatotoxins (LPS) in their cell walls. These toxins may cause irritation upon contact with the skin27 as well as eye irritation, conjunctivitis, hives, nasal obstruction and asthma8.
Amino acid cyanotoxins include the neurotoxin β-N-methylamino-L-alanine (BMAA), which is thought to be widespread in many cyanobacteria. They are associated with neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and Alzheimer's disease.
Exposure to high levels of blue-green algae and their toxins can cause diarrhea, nausea or vomiting; skin, eye or throat irritation; and allergic reactions or breathing difficulties. Pet and livestock illness/deaths can happen if animals consume large amounts of water containing blooms, scums or benthic mats.
Not all blooms are harmful, but some cyanobacteria can produce cyanotoxins that can cause serious illness or death in pets, livestock and wildlife. These toxins can also make people sick, and in sensitive individuals also cause a red, raised rash or skin, ear and eye irritation.
Algal blooms are an overgrowth of cyanobacteria that can produce numerous types of toxins (specifically, cyanotoxins). The two most serious types of cyanotoxins (called microcystin and anatoxin), can cause liver or neurologic injury. Shock, liver failure, respiratory arrest and even death can occur.
Health risks associated with blue-green algae exposure
Have people died from blue-green algae?
In severe cases, the toxins can cause damage to the liver and nervous system and there have been human deaths associated with non-routine exposure to algal toxins through dialysis.
They have the distinction of being the oldest known fossils, more than 3.5 billion years old, in fact! It may surprise you then to know that the cyanobacteria are still around; they are one of the largest and most important groups of bacteria on earth.
How long does it take to get sick from cyanobacteria?
Symptoms of acute cyanobacterial poisoning may develop within minutes, hours, or days, but most commonly manifest within 24 hours of exposure. Skin rashes may take up to two days to appear.
But the blooms are spreading northwards with climate change. New research shows that the Monoporeia affinis in the northern Bothnian Sea also eat and grow well on cyanobacteria, even the toxic species.
There are no specific antidotes for cyanotoxins or specific treatments for illnesses caused by cyanobacteria and their toxins in humans. For ingestion of contaminated water or food: Stop the exposure by avoiding contaminated food or water.
Neurotoxic shellfish poisoning, paralytic shellfish poisoning, and Ciguatera fish poisoning are the most common. Algal blooms are mostly formed by two phytoplanktons like diatoms and dinoflagellates. Karenia brevis red tide is a harmful algal bloom that produces brevitoxin.
Treatment for People Who Have Been Exposed to Cyanobacterial Toxins
Talk to your healthcare provider for advice about how to relieve your symptoms. ...
Call the national, toll-free Poison Help line, 1-800-222-1222, which connects you to your local poison center and is your resource for help in a poisoning emergency.
Microcystins are the most common cyanobacterial toxins and there are more than 200 forms or congeners with microcystin-LR being the most studied. They can be inside algal cells but are also commonly found in dissolved form, having been released from living or more commonly dead cells.
Cyanobacteria produce toxins that can affect various parts of the body. Different species of cyanobacteria can produce toxins that can damage the liver (hepatotoxins), affect the central nervous system (neurotoxins) and produce toxic alkaloids that affect the renal system and gastrointestinal tract.
You can also be exposed by breathing air that contains cyanobacterial cells or toxins. Wind surfing, jet-skiing, boating, or watering lawns are activities where this might occur. Dietary supplements contaminated with cyanobacterial toxins are another potential route of exposure.
Adverse health effects of cyanotoxins include allergic–like reactions (e.g., rhinitis, asthma, eczema, and conjunctivitis), flu– like symptoms, gastroenteritis, respiratory irritation, skin rashes, and eye irritation.
Fortunately, cyanobacteria can be effectively treated with the antibiotic erythromycin. This treatment is safe for fish, plants, and invertebrates and does not harm the beneficial bacteria in your freshwater tank.
Most species are not toxic, but some blue-green algae can produce neurotoxins (nerve) toxins or hepatotoxins (liver) during blooms that may be harmful to humans. People maybe exposed to these toxins in three ways: swallowing water, direct skin contact, and breathing aerosolized bacterial toxins that are in the air.
The over saturation of oxygen in the particular area coated starves the cyanobacteria and it melts away usually by the next day from that area. I have also had luck with just adding it to a tank at a little bit higher concentrations than 1ml to 10 gallons.
Neurotoxins. Anatoxins, guanitoxin (formerly known as anatoxin-a(S)), and saxitoxins are neurotoxins made by cyanobacteria. All three of these toxins can cause progression of muscle twitches when ingested. High doses of saxitoxin may cause progressive muscle paralysis.
Cyanotoxins (if present) are usually contained within the cyanobacteria cell. When the cells die, the toxins are released into the water where they can be ingested. Cyanotoxins are not absorbed through the skin.
If you are concerned about the potential occurrence of cyanotoxins in drinking water please contact your public water system. CAN I BOIL MY WATER TO MAKE IT SAFE TO DRINK? No, boiling water will not remove cyanotoxins and may increase toxin levels.
If you prefer to avoid using a product in your tank, increase the flow in the area where cyano grows, do water changes, skim well, and double check the age of your bulbs. Over a period of weeks, it will eventually die off.
How did cyanobacteria almost wipe out life on Earth?
Since life was totally anaerobic 2.7 billion years ago when cyanobacteria evolved, it is believed that oxygen acted as a poison and wiped out much of anaerobic life, creating an extinction event.
