What is Cyanobacteria?

Cyanobacteria, also referred to as blue-green algae (BGA), are common photosynthetic bacteria inhabitants of Alberta’s surface waters. Under favorable conditions, such as warm water and increased nutrient content, these bacteria can form nuisance “algal blooms”. The blooms are of interest to public health because some genera have the capability of producing very potent toxins, such as neurotoxins, hepatotoxins, and lipopolysaccharide endotoxins.

What to look for?

Although often referred to as “blue-green” in color, cyanobacterial blooms range in color and can be blue, green, brown or red, depending upon the species composition and age of the bloom. Identification of cyanobacteria can be difficult because of its microscopic size, range in color and the presence of other organisms that may resemble a bloom. Other floating organisms that may be misidentified as cyanobacteria, include green algae, duckweed and pollen.

What are the public health concerns?

Public Health Concerns Health effects from exposures to cells and their toxin have been documented. Dermal contact with the cyanobacteria can cause skin rashes and irritation. Contact with the head can cause itchy, red eyes and ear infections. Inhalation of water may cause allergic-like reactions, runny noses or sore throats. Ingestion of toxins can cause a range in symptoms, including, but not limited to:

• Gastrointestinal illness, including diarrhea and vomiting;
• Liver and kidney damage;
• Neurological symptoms, such as numb lips, tingling fingers and toes or dizziness.

Although there have not been any documented human related deaths from recreational exposure to cyanobacteria or its toxin, there have been animal (dogs and livestock) deaths from ingestion of water from affected with cyanobacteria.

What are the guidelines?

The Guidelines for Canadian Recreational Water Quality (2012) outline two health guidelines for cyanobacteria in recreational waters: 1. Total microcystins: 20 µg/L (expressed as microcystin-LR) 2. Total cyanobacteria: 100 000 cells/mL Exceedances of these values or development of a bloom indicates the potential for exposure to cyanobacterial cells and/or their toxins in amounts that are harmful to human health.

How Can I Print My Results?

To save as a pdf click “Save/Print Results”. If you are using the Chrome web browser simply choose ' Save as PDF' as the printer destination. For other browsers you may need to download a PDF saver (Bullzip, CutePDF, doPDF are some third party options) and follow their installation instructions. Once a PDF saver is installed you would select it as the printer destination.

For further information contact:

Health Protection Branch
Alberta Health
P.O Box 1360, Station Main
Edmonton, Alberta, T5J 1S6
Telephone: 1 (780) 422-4518
Fax: 1 (780) 427-1470

Microsytins (μg/L)

There are several known classes of cyanobacterial toxins that can pose concerns for recreational water users. Microcystins are a common groups of cyanobacterial toxins that affect the liver (hepatotoxins). The different structures of the various microcystins result in very different toxicities and microcystin-LR is one highly toxic example that is regularly found in Alberta lakes. Alberta Health uses a laboratory test called protein phosphatase inhibition (or PPI) to measure the total toxicity due to all microcystin variants present in a beach water sample. PPI measures the inhibition of the enzyme that is the target of microcystins. This inhibition is expressed in relation to equivalents of microcystin-LR and represents a measure of the total toxicity of the water sample due to all microcystins present. Detection limits for the PPI test were 0.05 µg/L (2010-2014) and 0.1 µg/L (2015). The Health Canada Recreational Water Guideline for Total Microcystins is 20 µg/L (expressed as microcystin–LR). Exceedance of this value indicates the potential for exposure to cyanobacterial toxins in amounts which may, in some cases, be sufficient to be harmful to human health. Microcystin data generated by Alberta Health are provided to local Medical Officers of Health to inform risk assessment of recreational beach water during the open water season and issuance of public health advisories.

Cell Count (cells/mL)

Total cyanobacteria cell count is a general indication of the potential for bloom development and is often used by public health officials for early detection of blooms. All species of cyanobacteria present in the water sample are counted and summed, including both microcystin-producing and non microcystin-producing species. The Health Canada Recreational Water Guideline for total cyanobacteria is 100 000 cells/mL. This guideline is intended to be protective against exposure to high densities of cyanobacterial material as direct contact can cause skin irritation and allergic reactions. This guideline is also protective against other less commonly monitored toxins that may be produced by cyanobacterial blooms (e.g., anatoxin and cylindrospermopsin). Exceedance of the guideline value indicates the potential for exposure to cyanobacterial materials in amounts which may, in some cases, be sufficient to be harmful to human health. Total cyanobacterial cell count data generated by Alberta Health are provided to local Medical Officers of Health to inform risk assessment of recreational beach water during the open water season and issuance of public health advisories.

mcyE Gene (copy/mL)

The ability to produce microcystin toxins is coded by the mcy genes in the DNA of certain cyanobacterial species. mcyE is one such gene that can be used as a molecular marker to detect cyanobacteria in beach water samples that have the potential to produce Microcystins. This test is currently in the research and development phase and is not currently used for risk assessment and issuance of public health advisories in Alberta. This test shows promise as a rapid, cost effective future tool for evaluation of cyanobacterial blooms in Alberta water bodies.

Visibility

Alberta Health Services environmental health officers with training in visual inspection of recreational sites assess beach water for color changes and presence of surface scums and diffuse blooms. Although often referred to as “blue-green” in color, cyanobacterial blooms range in color and can be blue, green, brown or red, depending upon the species composition and age of the bloom. Identification of cyanobacteria can be difficult because of its microscopic size, range in color and the presence of other organisms that may resemble a bloom. Exceedances of Health Canada Recreational Water Quality Guidelines are commonly associated with visual confirmation of a cyanobacterial bloom. Visual inspection is an effective monitoring tool to provide early warning of bloom formation and assist with the interpretation of laboratory results (i.e., cell count and microcystin data). Visual inspection results from environmental health officers are provided to local Medical Officers of Health to inform risk assessment of recreational beach water during the open water season and issuance of public health advisories. Most public health advisories for cyanobacterial blooms in Alberta are based primarily on visual confirmation results.

For further information contact:

Health Protection Branch
Alberta Health
P.O Box 1360, Station Main
Edmonton, Alberta, T5J 1S6
Telephone: 1 (780) 422-4518
Fax: 1 (780) 427-1470