Warmer weather means Nova Scotians should watch for blue-green algae blooms in lakes and rivers. "While the risk to health is fairly low, people should avoid contact with algae blooms and the water where they occur until the bloom has dissipated," said Gary O'Toole, director of environmental health. "If you come in contact with a bloom and develop symptoms that persist for a few days, you should consult a physician." Also known as pond scum, the algae can be spotted by its blueish green, grassy or soupy appearance and sometimes, gives off a distinct odour. It can naturally form on any lake or river in the right conditions. Many types of blue-green algae are harmless, but some can produce toxins that pose a health risk to people and animals. People should not swim in, drink from, or eat fish from water sources where blue-green algae is present. Water contaminated by the algae should not be used to prepare or cook food, and boiling the water will not eliminate the toxins. If water containing the algae is swallowed, symptoms may include stomach ache, diarrhea, vomiting and nausea. Direct contact with skin from swimming may cause skin, nose, throat or eye irritations. Nova Scotians who suspect they see an algae bloom can call and report it to their local Department of Environment office. For more information, visit the departments of Environment and Health and Wellness websites at www.novascotia.ca/nse/water/docs/BlueGreenAlgae.pdf and www.novascotia.ca/hpp/environmental/ .