Potentially harmful algal blooms in Leeds and Thousand Islands
The Leeds, Grenville, and Lanark District Health Unit is warning area residents there may be potentially harmful algal blooms within local bodies of water.
As the summer moves along and bodies of water warm up, there is a chance that residents may start to see harmful algal blooms develop.
This includes blue-green algae. Potentially harmful blooms are a natural, seasonal phenomenon that may appear in our lakes, rivers, and ponds. Many of these blooms are harmless, however, some have the power to produce toxins that are harmful to people and pets. The presence of harmful blooms and toxins can only be confirmed in a laboratory setting, so the health unit recommends taking a cautious approach when entering any bodies of water.
Toxins are released when algal cells break down, and these toxins can cause skin irritation, nausea and vomiting, and in high concentrations, liver problems.
The health unit is advising people using surface water for recreation and drinking to become familiar with potentially harmful algae so they can make informed decisions on when to avoid the water. Algal blooms degrade with time, however, it is not possible to say whether the toxins have completely dissipated. Once the toxin is released, where it goes depends on the local characteristics of water movement. The toxin will eventually dilute into the body of water, like any other soluble compound.
Surface water is never a safe source of drinking water without effective treatment. The health unit is reminding residents these toxins are not typically removed using treatment methods such as boiling, chlorination, or ultraviolet light treatment. Surface water requires specialized treatment. If your water comes from a surface body of water such as a lake or a river, you may want to contact a water treatment specialist or choose another source of water for drinking.
The health unit also recommends avoiding activities that increase your exposure to toxins in the water during an active bloom. When deciding whether to resume recreational use of the water, consider the following factors:
- Faster moving water will dilute and move the toxins more quickly, further decreasing the risk to health. Each property will have a different water flow pattern, so a local assessment is useful.
- Skin irritation is the first sign that the level of toxin is significant in the water, so if this occurs, it is important not to go in the water. A few more days will help to clear the water if it is moving well unless another bloom has occurred.
- Bacteria, viruses, and other microbes that can affect health are commonly found in surface water such as lakes and rivers, so it is important to avoid swallowing the water at all costs. Young children are more likely to swallow water, so they should be watched carefully when playing or swimming.
- Be cautious eating fish caught in water where a harmful algae bloom has occurred. Toxins are concentrated in the liver. So avoid consuming the liver, kidneys, and other organs of fish caught in an area affected.
- Algae exists in nature, however, nutrient levels can contribute to an increase in blooms of algae. You can help reduce nutrient levels by reducing the use of household fertilizers, agricultural runoff, and ensuring your septic system is in good working order.
Residents are encouraged to contact the Ministry of Environment, Conservation, and Parks Spills Action Centre to report any new potentially harmful blooms.