Ohio EPA has identified three known toxins in Grand Lake St. Marys, each a result of biological processes in blue-green algae, a cyanobacteria that forms as algal blooms in water conditions caused by a combination of elevated nutrient runoff and environmental conditions.

This fact sheet provides general health information on each of the three known toxins in Grand Lake St. Marys.

Microcystin Cylindrospermopsin Saxitoxin Anatoxin
WHO Guidelines (parts per billion) 1 ppb drinking water, 20 ppb swimming water Not Established Not Established na
Grand Lake St. Marys Levels (ppb) – as of 6/23/2010, full data here – 4.7 ppb Near Intake
– 0.5 Camp Beach
– 1.1 East Beach
– 0.7 West Beach
– 9.0 West Beach
– 0.1 DNR Boat Ramp
– .03 ppb West Beach
– Non-Detect DNR Boat Ramp
Potential Major Health Effects – Allergic Reactions
– Liver Damage
– Potential Carcinogen
– Liver Damage
– Liver Failure
– Internal Hemorrhaging
– Heart and Kidney Damage
– Internal Organ Damage/Failure
– Potential Carcinogen/Genotoxin
– Paralytic Shellfish Poisoning (PSP) on ingestion
– Respiratory Failure
– Paralysis
– Death
– Loss of coordination – Muscular fasciculations -Convulsions – Death by respiratory paralysis
Poisoning Symptoms (not comprehensive, seek medical attention immediately if you suspect illness) – Skin Rash/Hives/Blisters
– Watery Eyes/Runny Nose
– Weezing/Coughing
– Chest Pain/Trouble Breathing
– Upset Stomach/Nausea
– Vomiting/Diarrhea
– Nausea
– Vomiting
– Diarrhea
– Skin Rash
– Hives
– Blisters
– Upset Stomach
– Tingling
– Numbness
– Weakness
– Paralysis
– Floating Sensation
– Respiratory Distress
– Staggering
– Loss of Coordination
Other Facts Microcystin levels in GLSM have been lowered in recent months. Cylindrospermopsin is a known liver toxin, though the WHO has not yet set guidelines for safe levels. Saxitoxin is a known neurotoxin, though the WHO has not yet set guidelines for safe levels.  Pure saxitoxin has been designated by the U.S. military as a chemical weapon. Also called “Very Fast Death Factor”

 For more information, sources, and citiations, please see:

Cyanobacteria Toxins and Symptoms

OEPA GLSM Water Quality Testing Results

Microcystin Wiki

Cylindrospermopsin Wiki

Saxitoxin Wiki

The information contained here is informational in nature only and is not intended in any way to be used for medical diagnosis, treatment, or other health or medical purpose.  If you feel you might be experiencing an illness related to contact with contaminated water, the ingestion of contaminated fish, shellfish, birds, or other wildlife, or for any other reason, seek professional medical attention immediately.