What is a cyanotoxin and how can it be released into the water?
Cyanotoxins are produced within cyanobacterial cells and are either released into water at cell death or rupture (intracellular) or by continuous excretion (extracellular). The most common cyanotoxins found are microcystins, cylindrospermopsin, anatoxins, and saxitoxins.
The human health effects of being exposed to a cyanotoxin will vary depending on the type of toxin, how the exposure occurred, and the dosage. Short-term illness can include skin rashes, hay fever-like symptoms, gastrointestinal and respiratory symptoms. Drinking water contaminated with high concentrations of microcystin and cylindrospermopsin can cause liver and kidney damage, while anatoxin can affect the nervous system.
The Environmental Protection Agency (EPA) has developed 10-day Drinking Water Health Advisories for microcystin and cylindrospermopsin. These are short-term levels that are not expected to cause adverse effects for up to ten days of exposure. For example, if microcystin levels in drinking water do not exceed 0.3 micrograms per liter (µg/L), then it is not expected to be dangerous to children under 6 years of age unless ingestion exceeds 10 consecutive days. Currently there are no EPA health advisories for anatoxins or saxitoxin. Some states have developed guidance levels for anatoxin and saxitoxin.
When treatment methods are used on intact cyanobacterial cells, precautions need to be taken to avoid prematurely rupturing the cells and releasing the toxin. Please read “A Summary of Cyanotoxin Treatment Processes and Their Relative Effectiveness” to learn more about how certain treatments will affect cyanobacterial cells and cyanotoxins.
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How do I prepare my public drinking water system in case a bloom occurs in my source water?
