Third-party organizations are currently developing certification standards for in-home devices and are evaluating how reliably they can remove cyanotoxins from drinking water. The NSF International has certified some filters in their ability to reduce microcystin to below the national Health Advisory levels. More information about these treatment units and the contaminants they can remove can be found at: http://www.nsf.org/Certified/DWTU/.

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Drinking water with elevated cyanotoxins levels can be harmful to humans if used in dialysis treatment. The U.S. Environmental Protection Agency recommends dialysis centers and those using in-home dialysis use an alternative source of water if their current water source becomes contaminated with elevated levels of cyanotoxins. Please consult your local health department or physician.

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No, boiling water will not remove cyanotoxins and may increase toxin levels.

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Given the current scientific understanding, it is unlikely that showering, bathing, washing hands, doing laundry, etc. in tap water with cyanotoxin levels near or below the Health Advisory will be harmful to human health. However, infants and young children under the age of six should be supervised while bathing and during other tap water-related activities to prevent accidental ingestion of water. You may also accidentally consume water that is used to prepare or wash your food, make beverages or make ice. If a drinking water advisory is issued, the U.S. Environmental Protection Agency recommends using alternative water sources for these activities as well as using alternative water sources to make infant formula.

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Cyanotoxins can be harmful to animals if they drink tap water contaminated with elevated levels of cyanotoxins. Contact a veterinarian if animals show signs of illness.

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The U.S. Environmental Protection Agency (U.S. EPA) publishes Health Advisories for unregulated contaminants to help states and water systems assess local situations and during emergency situations and spills. They are not a federally enforceable federal regulatory limit. The Health Advisories provide the contaminant levels less than or equal to which adverse human health impacts are unlikely to occur over a certain time period. As new information becomes available, the U.S. EPA may develop updated advisories.

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The U.S. Environmental Protection Agency issued 10-Day Health Advisories for the cyanotoxins microcystins and cylindrospermopsin (see Table 1). Two distinct Health Advisories were developed for two population groups 1) infants and children younger than six years old and 2) adults and children six years and older. For more information please see https://www.epa.gov/nutrient-policy-data/drinking-water-health-advisory-documents. Health Advisories were developed for a 10-day exposure based on the most current science.

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Reducing nutrient pollution, such as excess nitrogen and phosphorus, is essential to decreasing cyanotoxins in drinking water sources. Excess nutrients may originate from agricultural, industrial and urban sources as well as from atmospheric deposition. Things you can do to reduce nutrients in drinking water sources include: using phosphate-free detergents, disposing of your pet waste properly, applying fertilizers only when necessary and at the recommended amount and volunteering in local watershed protection efforts. Additional prevention activities can be found at https://www.epa.gov/nutrientpollution/what-you-can-do.

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Using the the U.S. Environmental Protection Agency’s national Health Advisory levels for microcystins and cylindrospermopsin as a guide, ranges of cyanotoxin levels in drinking water can be shown with the following advisory levels: green, yellow and red (see Figure 1). Green corresponds to drinking water toxin levels where adverse health impacts are unlikely to occur for everyone. Yellow indicates drinking water toxin levels where the risk of adverse health impacts is higher for infants, young children under the age of six and other vulnerable populations (including: pregnant women, nursing mothers, those receiving dialysis treatment, the elderly and other sensitive populations). Red indicates drinking water toxin levels above which the risk of adverse health impacts is higher for everyone drinking the water. Drinking water systems can elect to issue Drinking Water Advisories using these categories as guides.

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You may receive a drinking water advisory from your public water supply if cyanotoxins above Health Advisories are found in your tap water. If a drinking water advisory is issued, follow the recommendations described in the advisory notification. If you are concerned about the potential occurrence of cyanotoxins in drinking water please contact your public water system.

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The Health Advisory levels for microcystins and cylindrospermopsin are non-regulatory concentrations of drinking water contaminants at which adverse health effects are not anticipated to occur over a 10-day exposure period. Because it is difficult to determine in advance the duration of elevated algal toxin levels, the U.S. Environmental Protection Agency (U.S. EPA) recommends that water systems begin to take actions once the elevated levels have been confirmed by additional samples. Additionally, because of time needed to process sequential analytical tests, it can take several days following the detection of a bloom and/or cyanotoxins before concentrations above the Health Advisories are confirmed in finished water. Therefore, the U.S. EPA recommends initiating the response activities as soon as practicable.

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Contact your water public water supply to find out what they are doing to reduce the risks of harmful algal blooms and/or cyanotoxins in your drinking water.

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If you or your family members have consumed water that may have contained cyanotoxins at levels above the national Health Advisories and you are experiencing cyanotoxin-related illnesses, contact your healthcare provider for medical attention. Data for illnesses associated with exposure are being collected nationally at the Centers for Disease Control and Prevention (CDC). To report a cyanotoxin-associated illness for humans and animals, please contact your state or local health department.

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For general information, please visit http://www.epa.gov/cyanohabs or contact your public water system, state, or local government. For information about harmful algal bloom-associated illnesses, please visit http://www.cdc.gov/habs

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Populations such as nursing mothers and pregnant women, those with pre-existing liver conditions, those receiving dialysis treatment, the elderly and other sensitive populations may be at risk of experiencing adverse health effects of cyanotoxins at lower levels. As a precautionary measure, such vulnerable populations should consider following the health advisories stated for infants and young children under the age of six.

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Two different Health Advisories were developed because of the variations in body weight and drinking water intake between the different age groups. Bottle-fed infants and young children under the age of six have higher water intake relative to body weight as compared to adults and children six years and older. Therefore, the Health Advisories are lower for younger children than for children six years and older and adults. Additionally, other groups of individuals may be more vulnerable to cyanotoxins including: pregnant women, nursing mothers, those with pre-existing liver conditions, those receiving dialysis treatment, the elderly and other sensitive populations. As a precautionary measure, the lower level Health Advisories could also apply to these individuals.

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The Health Advisories are lower for younger children than for older children because young children under the age of six consume more water relative to their body weight when compared to adults and older children. Therefore, younger children are at an increased risk of adverse health impacts of cyanotoxins at lower levels.

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