IJC’s Health Professionals Advisory Board Recommends Actions to Reduce Risks from Cyanobacterial Harmful Algal Blooms


In a report released today, the Health Professionals Advisory Board (HPAB) of the International Joint Commission (IJC) outlines several actions to augment and improve efforts to monitor and control human risks from exposure to cyanobacteria and its associated toxins, which are often present in harmful algal blooms in the Great Lakes during the warmer months.

Cyanobacteria may grow and bloom rapidly as floating mats of blue-green scum or algae when waters have abundant or excess nutrients such as nitrogen or phosphorus. Water temperature, wind and water currents can stimulate their growth, particularly during the warmer summer and fall periods. Some of these blooms produce cyanotoxins that impact the liver, nervous system and skin in humans and animals. The incidence and type of cyanobacterial algal blooms are expanding throughout the Great Lakes as a result of increased nutrient pollution and climate change throughout the region. Recent testing suggests that cyanobacteria species common to the southern United States can now be found the Great Lakes basin.

The board identified several challenges to maintaining safe waters for recreation and for providing safe drinking water where cyanobacterial harmful algal blooms exist. A standard method to test for multiple bacteria and toxins is not yet available, and considerable gaps in knowledge exist about optimal water treatment strategies for the multiple strains of cyanobacteria and their toxins found throughout the Great Lakes.

Given that the Great Lakes are the source of drinking water for approximately 35 million people and for multiple recreation activities, the board recommends several actions to protect human health:

  • Further research and improvements for the removal of cyanotoxins from Great Lakes drinking water;
  • Monitor drinking water source cyanotoxins to match water treatment to prevalent cyanotoxins;
  • Further research to improve laboratory testing for cyanotoxins and establish standardized methods for Great Lakes monitoring programs;
  • Develop routine cyanotoxin monitoring and modeling in the Great Lakes to predict the occurrence of toxic levels and for public notifications;                                                                                                                 
  • Additional toxicity studies to establish protective human exposure limits for the full range of cyanotoxins commonly encountered in the Great Lakes. 

The report, Human Health Effects of Cyanobacterial Toxins in the Great Lakes Region: A Science and Monitoring Assessment, is available on the HPAB’s web page at www.ijc.org

The International Joint Commission was established under the Boundary Waters Treaty of 1909 to help the United States and Canada prevent and resolve disputes over the use of the waters the two countries share. The IJC’s responsibilities include reporting on progress made under the Great Lakes Water Quality Agreement between the nations toward restoring and maintaining the chemical, physical and biological integrity of the Great Lakes and connecting waters. The Health Professionals Advisory Board advises the IJC and its transboundary boards about current and emergent clinical and public health issues for transboundary environmental health.

For more information:

Jennifer Boehme, HPAB Secretary                       boehmej@windsor.ijc.org          519-257-6710

David Buckeridge, HPAB Canada Co-chair             david.buckeridge@mcgill.ca       514-398-8355

Sally Cole-Misch, Public Affairs Officer                 colemischs@windsor.ijc.org        519-257-6733