Florida Lake Management Society Annual Conference, Naples, Florida, June 4 – 7, 2007
THE STATUS OF INTERNATIONAL REGULATIONS AND GUIDELINES FOR HUMAN EXPOSURE TO CYANOBACTERIA
John Burns MACTEC Engineering & Consulting Newberry, FL
Cyanobacteria and their toxins are an emerging issue for Florida lake managers and other surface water managers responsible for water quality, water supply, and human health. Since the first report of a toxic cyanobacterial bloom published in Nature (1878), wildlife mortality events
isolated reports of human illness
following exposure in the occurrence
cyanobacteria are found throughout cyanobacterial blooms, following
accelerated eutrophication of water bodies, and for elucidation of cyanotoxin groups, have reporting during the later half of the 21st
the availability of analytical tools and techniques
contributed to the
increased frequency water managers and
of the health
professionals are now increasingly responding supplies and recreational waters, but are often clear understanding of potential ecological and protect human health.
to cyanobacterial bloom events in limited by the availability of algal human health risks, and guidelines
public water toxin data, a necessary to
The World Health Organization (WHO) has developed a provisional guideline for microcystin-LR in drinking water. Many other countries have developed their own guidelines and regulations based on the WHO guideline and have added additional toxins to their lists. Human health effects following recreational exposure to cyanobacteria is an additional concern. Recreational contact guidelines offered by the WHO are linked to the probability of health effects at three levels: 1) low (2-4 µg L-1 MCYST), 2) moderate (20 µg L-1 MCYST), and 3) high (scum formation). Australia and others have recommended a recreational contact standard of 20 µg L-1 for 'high risk' activities such as swimming to 100 µg per liter for 'low risk' activities such as fishing or boating.
Federal guidelines for drinking water and recreational exposure to cyanotoxins in the US are not available, but cyanobacterial toxins are listed on the USEPA Contaminated Candidate List. Several states have individually adopted cyanobacterial toxin guidelines to help protect human health in the absence of federal guidelines.
Session 4 – Page 20