Health Advisory Cyanobacteria Bloom Expands in the Charles River

The Boston Public Health Commission (BPHC) has expanded its cyanobacteria advisory for the Charles River, now covering all areas downstream of the Cambridge Street Bridge. Recent testing by the Massachusetts Department of Public Health (DPH) detected cyanobacteria levels surpassing safety thresholds for recreational water. Residents are strongly advised against swimming, fishing, or engaging in any activities that involve contact with the water, as the toxins can pose serious health risks. Dogs are particularly vulnerable, with potential symptoms including vomiting and seizures if they ingest contaminated water. Algal blooms can last for weeks, and the DPH will continue monitoring the situation, requiring two rounds of safe testing before lifting the advisory.

The presence of toxins may cause gastrointestinal issues and more severe health effects, especially in children and small pets. Residents can find a detailed map of the affected areas and are encouraged to rinse off immediately if they come in contact with the water. For further inquiries, the BPHC's Environmental and Occupational Health Division is available for assistance.