Microcystin-LR is one of the cyanobacterial toxins associated with blue-green algae.
Not all green scum is an algal bloom, and not all algal blooms contain microcystins.
Drinking water:
(1) Do not drink water from a lake during or after the occurrence of an algal bloom.
(2) Boiling water does not remove or destroy the toxin.
(3) Test water for microcystin after an algal bloom. Water is safe if the toxin level is less than 0.1 parts per billion.
(4) Water from a water treatment facility is generally free of toxic levels of microcystin.
Recommendations for a fisherman:
(1) Avoid fishing in an affected water for at least 2 weeks after an algal bloom.
(2) Discard the guts of fish caught from lakes with an active algal bloom.
Skin contact with contaminated water:
(1) Do not swim or bathe in affected water during or shortly after a bloom.
(2) Keep pets away from affected water.
(3) Wash thoroughly following skin contact with contaminated water, using clean water.
