Published: Jun 16, 2011 6:42 PM EDT
Updated: Jun 15, 2011 7:13 PM EDT

FORT MYERS, Fla. - The Lee County Health Department is maintaining its warning for people, pets and livestock to avoid contact with the Caloosahatchee River water despite toxicity test results showing low concentrations not associated with health risks.

“Although we cannot confirm unhealthy concentrations of algae toxins in the river at the one test site, the situation can change quickly,” said Charles Walther, director of Environmental Engineering for the Health Department. “The blue-green algae bloom continues. It can move, and it can even change bacteria types.”

These conditions will most likely remain until there is sufficient rainfall to flush out the river, said Walther. Adverse health symptoms reported so far are burning eyes and respiratory conditions.

Environmental scientists will continue to monitor the river for the development of different types of bacteria. The currently identified strain is Cyanobacteria, known to produce toxins which cause harm to fish, animals and people. It is also known to reduce oxygen levels when the bacterium decomposes, resulting in fish kills.

The Health Department is recommending residents and visitors avoid eating fish from the river especially, if caught near floating dead fish. The Health Department also recommends avoiding swimming to prevent accidental ingestion of river water, and allowing pets and livestock to drink from the river. The river is posted with warning signs where the bloom is most dense.

The World Health Organization reports humans are affected with a range of symptoms including skin irritation, stomach cramps, vomiting, nausea, diarrhea, fever, sore throat, headache, muscle and joint pain, blisters of the mouth and liver damage. Swimmers in water containing cyanobacterial toxins may suffer allergic reactions, such as asthma, eye irritation, rashes, and blisters around the mouth and nose. The toxins can also affect the kidneys.