The U.S. EPA recently issued health advisories values for two cyanotoxins ? microcystin and cylindrospermopsin ? ahead of its public meeting and webinar, scheduled for today. The health advisory values are:
- 0.3?g/L for microcystin and 0.7?g/L for cylindrospermopsin for children less than six years old
- 1.6 ?g/L for microcystin and 3.0 ?g/L for cylindrospermopsin for children six and up and adults
These relatively low numbers, based on 10 days of exposure, will be challenging for water systems and state primary agencies to meet, as water temperatures increase during the summer and algal blooms are more likely to occur.
EPA?s advance materials for the public meeting and webinar detail a ?step-wise? approach for systems to reduce risk from cyanotoxins in drinking water:
- Conduct system specific evaluation;
- Preparation and observation;
- Monitor for cyanotoxins in raw water and treatment adjustments;
- Monitor for toxins in raw and finished water and treatment adjustments; and
- Monitor for toxins in finished water, treatment adjustments/additions, and public communications.
The advance materials, which include a presentation on?the health advisories?(PDF) and a presentation on?ways to prepare for and respond to cyanotoxins?(PDF), also include a “traffic light” approached guide to communications, monitoring, and treatment as cyanotoxin concentrations increase in raw and/or finished water. It is expected that EPA will issue the full health advisories in June. Health advisories are not regulations, but rather provide information and guidance from EPA to states and water utilities on contaminants of concern.
