BOSTON ~ Boston Public Health Commission Issues Advisory for Cyanobacteria in Charles River

The Boston Public Health Commission (BPHC) has issued a public health advisory for the Charles River, alerting residents to the presence of cyanobacteria in the water. The advisory, which was first shared on August 1, 2025, has now been expanded to include all areas downstream of the Cambridge Street bridge.

According to the Massachusetts Department of Public Health (DPH), cyanobacteria cells have been found in this part of the river at levels that exceed DPH guidelines for recreational waterbodies. Cyanobacteria, also known as blue-green algae, can produce toxins that can make people and pets sick.

Residents are being urged to avoid contact with the water and any areas where algae concentration is present, including on shore. This includes activities such as swimming, fishing, paddleboarding, kayaking, and canoeing. Additionally, dogs should not be allowed to swim in or drink from the river.

More on Boston Chron

• Winzele: A Trusted Isolation Transformer Manufacturer
• Luxury Mediterranean Estate in Gotha Sells for $1.52 Million, Closing $45,000 Over Asking
• ZEELOOL's Black Friday Sale Starts Early with Up to 80% Off Frames
• UV Weathering Test Chamber vs Xenon Arc Test Chamber: What's the Right Solution for Your Products
• Emeritus Addresses Hospital Bed Shortages with Smart Storage Solutions

A map with the precise location of the advisory can be found at the bottom of this press release. In case of contact with the water, it is advised to rinse off immediately.

Blue-green algae blooms can make water murky and give it a pea soup or paint-like appearance. These blooms can produce toxins that may cause health issues if ingested while swimming or through direct skin contact or inhalation of water droplets containing toxins.

For humans, ingestion is the primary concern while direct skin contact and inhalation are secondary concerns. Symptoms may include skin and eye irritation as well as respiratory issues and gastrointestinal symptoms such as vomiting and diarrhea. In severe cases where toxins are present in high levels, children and small pets may experience more serious health effects such as liver or kidney problems or neurological issues. In some cases, these toxins can even result in death.

More on Boston Chron

• Fulton County & Grow Your World Amplify Atlanta Youth Through the Youth Audio Collective
• 2026 Oscars Betting Odds: One Battle After Another Favored for Best Picture
• City of Boston and Northeastern University Announce New Five-Year PILOT Agreement and New Ten-Year Institutional Master Plan, which include Historic Commitments on Housing and Community Benefits
• Allen Field Co., Inc. Components Selected for Esko ArtiosCAD 3D Component Library
• Boston: Winners Announced For Icons of Franklin Park Poster Competition

If your dog has been exposed to an algae bloom and shows symptoms such as vomiting, staggering, drooling, or convulsions, it is important to contact a veterinarian immediately. Dogs are at risk of ingesting the algae or licking it off their fur, which can lead to serious health complications and even death.

The BPHC and DPH will continue to monitor cyanobacteria levels in the Charles River and conduct sampling for laboratory analysis once the bloom has dissipated. The DPH requires two rounds of samples collected a week apart that are below the threshold of 70,000 cells/milliliter of water before lifting the advisory.

Residents with questions or concerns can contact the Boston Public Health Commission's Environmental and Occupational Health Division at (617) 534-5965 for more information.

The advisory serves as a reminder to always be cautious when swimming or participating in water activities in natural bodies of water. It is important to pay attention to any posted advisories and avoid contact with water that appears discolored or has an unusual odor. By taking these precautions, we can help keep ourselves and our pets safe from potential health risks.

---

Show All News | Report Violation