Availability of Health Effects Support Documents and Drinking Water Health Advisories for Cyanobacterial Toxins; and a Support Document Containing Recommendations for Managing Cyanotoxins in Drinking Water

The Environmental Protection Agency (EPA) announces the release of Ten-Day Health Advisories (HAs) for two cyanobacterial toxins, microcystins and cylindrospermopsin. EPA also announces the release of Health Effect Support Documents (HESDs) for three cyanobacterial toxins: Microcystins, cylindrospermopsin, and anatoxin- a. The HESDs constitute a comprehensive review of the published literature on the chemical and physical properties of these toxins, the toxin synthesis and environmental fate, occurrence and exposure information, and health effects. The HESDs are used to develop HAs. Based on the reported occurrence, toxicology, and epidemiology data, EPA found there are adequate data to develop HAs for microcystins and cylindrospermopsin, but inadequate data to develop an HA for anatoxin- a. EPA's HAs provide states, drinking water utilities and the public with information on health effects of microcystins and cylindrospermopsin, analytical methods to test for cyanotoxins in water samples, and treatment technologies to remove cyanobacterial toxins in drinking water. Additionally, EPA announces a support document for states and utilities to assist them as they consider whether and how to manage cyanobacterial toxins in drinking water. The recommendations in this document are intended to assist public drinking water systems (PWSs) manage the risks from cyanobacterial toxins in drinking water, including information and a framework that PWSs can consider in their cyanotoxin risk management efforts.