For the majority of the summer, Newton’s Crystal Lake has not been so crystalline. Cyanobacteria, a kind of algae bloom, was detected in the Charles River in Waltham and Weston at the end of July. In addition, two mosquitos were discovered with cases of West Nile Virus in Crystal Lake.
Both are dangerous to humans.
While most algal blooms are not harmful, cyanobacteria is toxic to people and animals. The state’s Department of Public Health has warned swimmers to stay out of the water.
In a publication from the Center for Disease Control and Prevention, “Contact with high levels of cyanobacteria has been found to contribute to eye, ear and skin irritation. Ingestion can lead to more serious health effects such as muscle cramps or twitching.”
Prolonged exposure may lead to serious liver damage. At the beginning of August, levels were nearly twice the safe limit and Crystal Lake was closed. It will remain closed for the rest of the season. Incidents of algae have occurred with increasing frequency over the past decade. Currently in the area around Brandeis, the Charles River near the Moody St. Dam, Waltham and Lasell College Boathouse, Newton Dean Pond and Crystal Lake are all closed to algal blooms. It is linked to waters that are high in nutrient-filled run off like septic tank overflows and fertilizer.
While most people have only mild flu-like symptoms, or no symptoms at all, West Nile is dangerous to children and the elderly. There have been four recent West Nile-related deaths in Massachusetts. This year, 119 mosquito pools in Massachusetts have tested positive for West Nile.
The Massachusetts Department of Public Health on Aug. 23 raised the Boston-area threat level for the virus to “high.” The designation signifies that the presence of West Nile-carrying mosquitoes is very likely.
At least five neighborhoods in Boston have seen mosquitoes afflicted with disease, while the second human case was reported this week. The high-threat rating applies also to the cities of Somerville, Cambridge, Arlington, Belmont, Brookline and Watertown.
Nationally, there have been 1,118 cases of West Nile, 41 of them resulting in death this year. Authorities are not clear on cause of the recent increase.
