Cyanobacteria Health Risks: Be Afraid and Be Careful
By Maggy Hurchalla
State agencies are not giving us adequate warnings about the health risks of cyanobacteria exposure. The Department of Health website minimizes the problem. It says cyanobacteria occur naturally all over the world. What is happening in Lake Okeechobee and other Florida waters is not natural.
DOH says “sensitive” people may be affected. That suggests health effects are rare. That is not true. Martin Memorial Hospital has reported 72 emergency room visits after contact with blooms.
DOH points out that coincidence is not proof, so studies on long-term effects can be ignored until proven. That’s like saying we should have waited for a 30-year-long placebo-controlled study with measured doses before concluding cigarette smoking was dangerous.
DOH insists there is not adequate evidence of long-term effects. Worldwide studies in the last few years show strong evidence of serious health effects from long-term, moderate exposure. That includes liver failure, low sperm count, diabetes, ALS, and dementia.
The state testing program is inadequate. Florida DEP tests for toxins outside cyanobacteria blooms, contrary to USGS guidelines. This has left residents around the lake believing that results show the blooms in the lake are not toxic. This is misleading and dangerous.
DEP does not adequately or consistently post warnings. Children around the lake are swimming in and around blooms, and eating fish from the lake. They are not safe and people should be told that.
DEP does not test for BMAA, DAG, or other neurotoxins produced by cyanobacteria. They are produced by Microcystis–which is prevalent in the lake–and have been documented by independent testing.
DEP has not tested sediments, fish, or crops grown with contaminated water. There is ample evidence that when cyanobacteria die, toxins are released into the water column and the sediments and are recycled into the food chain. Experiments have shown that food crops absorb toxins from irrigation water.
Don’t panic and flee. This is an international problem: 17 cows died in Oregon, 9 dogs in Utah, and 21 sea otters in Monterey Bay. More than 100 people died when cyanobacteria-tainted municipal water was used for kidney dialysis in Brazil. Unnatural blooms and high toxin levels have been found in the Baltic Sea, in Arabian desert reservoirs, in the Kansas City water supply, and in New Hampshire Lakes. This is a growing worldwide problem we can’t run away from.
We have to solve it now. We have a particularly hard time dealing with long-term, low-level exposures that we can’t see or feel immediate reactions to. Think about cigarettes, DDT, and lead. Most of us lived through exposure, but lots of people suffered or died before our government took action. We should have learned a lesson about waiting too long when we know there is a problem that will only get worse.
We can’t solve it by killing it. Trying to destroy it or bag it is ineffective. Trying to kill cyanobacteria in large water bodies would require killing most all living things there, too. If you do kill the cyanobacteria, the toxin spills into the water–it does not go away. The strategies for dealing with cyanobacteria need to be based on existing research rather than wishful thinking and convincing sales pitches.
We need to deal with the causes. Worldwide researchers agree that warming, increased fertilizer use, and more use of static reservoirs for water supply are causing the blooms.
As warming continues, they will get worse. We need to insist that government officials at every level recognize climate change and take serious action.This is a very bad time to let up on fuel efficiency standards for cars or pollution control at coal burning power plants.
The only immediate way to decrease harmful blooms is to control nutrients. That effort has to include increased regulation of fertilizer use and regulations requiring treatment at the source of the nutrient pollution. New and existing reservoirs will have cyanobacteria problems.
We need to research how to deal with that now. Natural alternatives to static storage must be prioritized whenever possible. The only way to “get the water right” in terms of quantity, quality, and timing is natural, moving storage.
We have the solutions. Comprehensive Everglades Restoration Plan (CERP) construction is necessary for the survival of the coastal estuaries, Everglades National Park, Miami’s water supply, and Florida Bay. But CERP won’t solve the cyanobacteria problem. Reducing discharges to the coastal estuaries will not prevent cyanobacterial blooms in Lake Okeechobee.
Accumulating toxins in stormwater treatment areas is a problem that has to be addressed.
Florida needs to preserve wetlands rather than “mitigating them” with cash payments.
The nutrient runoff from wetlands is significantly lower than from uplands or from developed areas.
Septic systems have been identified as adding 4% to 9% of the nitrogen entering coastal estuaries. Florida’s 2.6 million septic systems need a cost-effective solution. The three biggest problems from septic are:
- Old, high-density and high-intensity systems in areas of high water table, poor soils, and ditches to surface water. Those “hot spots” need to be converted to sewer systems
- Lack of regular pumpouts and broken tanks and drainfields. The legislature passed a law requiring regular pumpouts and maintenance… then they rescinded the law. If the state is not going to require regular maintenance, it should not allow new septic systems
- The state continues to allow new development on septic systems at densities and intensities that will require conversion to sewer. The state should consider regulations that have been found effective around the Chesapeake Bay in decreasing the impact of septic systems from new development. But switching to sewers will continue to cause problems until we stop recycling the nutrients in treated sewage.
The Polluter Pays Amendment was approved by Florida voters in 1998. The legislature has refused to implement it. Controlling pollution at the source should be a cost of doing business, and mandatory, monitored nutrient standards are necessary to do that.
Florida DEP issued a report some years ago pointing out that state water management districts’ stormwater treatment rules were inadequate–especially concerning nitrogen. We need radical changes to stormwater treatment rules for new development or the problem will continue to get worse.
Irrigation-quality (IQ) water from sewage plants needs stricter standards and more enforcement.
The current standard is 10mg/L nitrogen. That’s too high. Using recycled water for irrigation is good, but the idea that its nutrients would be used up by grass is flawed. High-nutrient IQ water has the same problem as summer fertilizer: most of it washes off to surface waters.
We need more monitoring and research. Politicians like to “do something” but doing something when you don’t know what you are doing is expensive and dangerous.
Finally, on the subject of what we can do now about Lake discharges:
- We can’t allow the dike to break
- We can’t pump the lake down so low we kill the Lake marshes–that will make algae blooms worse
- We can’t keep causing serious health risks around the lake and the coastal estuaries
The problem with the lake is it alternates between having too much water and too little water. In Florida the extremes of drought and flood are unpredictable, and we have more extremes than we have averages. We keep the lake too full in the dry season for water supply, and if it’s not needed, we dump it as the hurricane season approaches.
Most of the water supply from Lake Okeechobee is for sugarcane. We guarantee the industry all the irrigation water they might ever want and all the drainage and cleanup capacity they might ever want. We ignore the consequences to everyone else.
A lake regulation schedule that put health ahead of water supply could keep lake levels lower, avoid dike breaks, avoid high and low extremes, keep the marshes healthier, and reduce coastal discharges. That would require giving sugar less of a guarantee on water supply. Surely human health and the health of the lake are worth it.