Boston health officials issue warning after toxic algae found in Charles River

Boston public health officials issued a warning for a section of the Charles River after discovering a toxic cyanobacteria algae bloom that exceeds state guidelines for recreational water. The Boston Public Health Commission advised residents to avoid contact with the water and areas of algae concentration, as the bloom poses significant health risks. Affected areas include Broad Canal and North Point Park, which are closed to all water activities, including swimming and fishing. Symptoms of exposure can range from skin irritation to severe gastrointestinal issues, with pets also at risk of death from ingestion. The algae can create murky water resembling pea soup and can last for days or weeks during warm weather.

The Department of Public Health will conduct ongoing testing, lifting the advisory only when two consecutive samples show algae levels below 70,000 cells/mL. Residents can direct inquiries to the Mayor’s Health Line. Health officials emphasize the importance of rinsing off immediately after contact with affected water.