Freshwater Algae Blooms_ Contributing Factors and Health Concerns by pptfiles


									                                            Freshwater Algae Blooms: Contributing Factors and Health Concerns
                                                                         Massachusetts Department of Public Health, Bureau of Environmental Health

                       What are algae blooms?

                        Algae blooms form when cyanobacteria (also known as blue-green algae), which are
                       photosynthetic bacteria that grow in water, multiply quickly and form scums or mats on                                                                                                      MDPH Guidelines
                       the surface of the water.

                        Cyanobacteria are a natural part of the ecosystems of lakes and ponds, but can                                                                                MDPH reviewed World Health Organization guidance and current scientific
                       cause problems when they undergo explosive growth. Blooms in New England are                                                                                    literature in order to develop a protocol for evaluating potential health concerns
                       most common in summer.                                                                                                                                          related to the presence of cyanobacteria.

                        Depending on the severity of the bloom the water could range from appearing                                                                                   The ability of cyanobacteria to multiply quickly makes monitoring their numbers
                       slightly colored to resembling pea soup or paint. Blooms frequently appear blue or
                                                                                                                                                                                       important. Because health risks rise with cell counts, the goal of any monitoring
                       green but could be another color, such as brown or red.
                                                                                                                                                                                       plan is to be able to take action before levels are reached that pose health risks.
                        Algae blooms can cause odor and taste issues in the water, fish kills, and illness in
                       humans and animals. Decomposing blooms can rob the water of the dissolved oxygen                                                                                MDPH recommends an advisory or closure when:
                       vital to fish and other aquatic life.                                                                                                                           • A visible scum or mat layer is present
                        In addition, certain species of cyanobacteria can manufacture toxins which pose a
                                                                                                                                                                                       • The blue-green algal cell count exceeds 70,000 cells/milliliter
                       health risk to people and animals coming in contact with or ingesting the water.                                                                                • The microcystin level of lysed cells exceeds 14 parts per billion (ppb)

                                                                                                                             Health Concerns

                                                                                                • Health concerns related to algal toxins vary depending on the type of exposure
                                                                                                (contact or ingestion) and the concentrations of toxin present. Contact with high
                                                                                                levels of cyanobacteria has been found to contribute to eye, ear, and skin
                                                                                                irritation. Ingestion can lead to more serious health effects such as muscle
                                                                                                cramps or twitching.

                                                                                                • If elevated levels of the algal toxin microcystin are present in the water and
                                                                                                ingested, serious liver damage can result. Exposure to elevated levels of the
                                                                                                algal toxin anatoxin can cause serious neurological damage. Small children and
                                                                                                pets are more susceptible than adults to the effects of toxins. Livestock and pet
                                                                                                deaths from ingestion of algal toxins have been reported.

                                                                                                • If you see water that appears to have an algae bloom, do not come into
                          Contributing Factors                                                  contact with or ingest the water. Treating water by boiling does not get rid of any
                                                                                                toxins present. Prevent contact and ingestion by kids and pets.

• Certain environmental conditions, such as warm weather, sunlight, and an                      • Dogs can get very ill and even die from licking algae out of their fur. Rinse
abundance of nutrients in the water, are more favorable to the rapid growth of                  dogs off immediately if they come into contact with water with an algae scum or
blue-green algae.                                                                               bloom.

• Excess levels of nutrients in water bodies can come from anthropogenic, or
human-related, sources. Phosphorus and nitrogen, which are found in human
and animal waste and fertilizers, are two important nutrients used by blue-green                                                                                                      For More Information or To Report a Bloom
algae in their growth.
                                                                                                                                                                              Vanessa Yandell is the Algae Project Coordinator for the Massachusetts
• Examples of sources that can input large amounts of nutrients to water bodies                                                                                               Department of Public Health, Bureau of Environmental Health
are agricultural activities, leaking septic or sewer systems, stormwater runoff,
lawn fertilizers, and pet and wildlife waste.                                                                                                                                 Phone: 617.624.5757
• People can lessen the inputs of these nutrients to water bodies by properly                                                                                                 Website:
maintaining septic systems, planting or maintaining native vegetation around the
water’s edge, using low- or no-phosphate dishwasher detergent, applying
fertilizer correctly, and picking up pets’ waste. Do not feed birds or geese.                                                                                                 Additional Resources:
                                                                                                                                                                              U.S. Centers for Disease Control and Prevention:
• It is also important to realize that most storm drains empty directly into water                                                                                            U.S. Environmental Protection Agency:
bodies without treatment. Never put or pour anything into a storm drain. Wash                                                                                       
your car on your lawn or at a commercial car wash instead of on your driveway.
Avoid fertilizing onto pavement or directly into a storm drain.

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