Bathing with caution Thesinian authorities warn against blue algae in Lake Maggiore

Authorities in Ticino have issued warnings about blue-green algae, also known as cyanobacteria, detected in Lake Maggiore. The first instances were identified on Thursday near Muralto, according to the Department of Health and Social Affairs in Ticino. These microorganisms can pose health risks, especially when they form dense colonies in the water. Officials have urged caution among swimmers and advised against contact with visible clusters of these organisms.

The warning comes amid concerns over potential contamination of other shore areas along the lake. People are being asked to swim only in clear water and avoid any direct contact with the algae. Children under the age of five and individuals with sensitive skin are particularly discouraged from entering the water. Additionally, pets such as dogs should remain away from the lake to prevent exposure to potentially harmful substances.

Cyanobacteria, despite their name, are not true algae but rather bacteria. This classification stems from historical misidentification due to their bluish-green appearance. According to the Water Research Institute Eawag, these organisms typically thrive during summer and autumn months. Their growth is favored by prolonged warm conditions and poor water mixing, which prevents them from sinking to the bottom of the lake.

Health effects associated with exposure to cyanobacterial blooms range from mild symptoms like skin rashes and red eyes to more severe issues such as flu-like symptoms and gastrointestinal distress. The World Health Organization has established guidelines indicating that mild symptoms can occur at concentrations of up to 20,000 cyanobacteria cells per milliliter of water. At higher levels—around 100,000 cells per milliliter—the toxin concentration becomes critical, leading to respiratory difficulties and flu-like symptoms. Ingestion of water containing between 10 to 100 million cells per milliliter could result in poisoning symptoms including nausea and diarrhea. However, at this level of contamination, the water tends to be so murky that swimming would likely not be appealing anyway.

Swimming advisories have been put in place following recent findings of cyanobacteria in Lake Maggiore. Authorities emphasize the importance of monitoring water clarity before engaging in aquatic activities. While not all cyanobacterial blooms produce toxins, the presence of these organisms necessitates vigilance and adherence to safety recommendations. Public awareness campaigns aim to inform residents and visitors about the potential dangers and appropriate precautions to take when using the lake's waters.

Residents and tourists alike are encouraged to stay informed about current conditions and follow official guidance regarding safe recreational use of Lake Maggiore. Continued monitoring will help determine the extent of the bloom and whether additional measures need to be implemented to protect public health. As the situation develops, further updates from local authorities will provide necessary information to ensure the well-being of those who frequent the area.