Swimming in Natural Water: Beware of Blue-green algae
As soon as it gets warmer, people seek coolness in lakes and ponds. While this can be wonderfully refreshing, a danger lurks in the form of blue-green algae. In fact, swimming in water contaminated with blue-green algae can lead to unpleasant health problems.
There are millions of tiny organisms in natural water, which is quite normal. Most are harmless, but that is not true of blue-green algae. Despite the name, blue-green algae are not true algae, but bacteria, also known as cyanobacteria.
What is Blue-green algae?
Blue-green algae occur mainly in freshwater. During warm periods, they can multiply rapidly. Excessive growth of blue-green algae indicates deteriorated water quality. The recent drought and high temperatures have greatly increased the growth of blue-green algae.
These bacteria form a blue-green (sometimes reddish-brown) floating layer on the water, often giving off a strong odor of sulfur or sewage. This is because many blue-green algae die at the bottom of the floating layer, releasing toxins into the water. These toxins are harmful to both humans and animals. So don't let your dog swim in contaminated water.
How do you check for Blue-green algae?
How do you know if there is blue-green algae in the water? Before you go swimming, check the map on zwemwater.nl. Here you can see exactly where blue-green algae has been found and where it is better not to swim. The water quality is measured regularly and the website is continuously updated, so check it regularly. There are often warning signs at lakes or other natural waters where blue-green algae has been detected.
Health Problems Due to Blue-green Algae
Should you swim in contaminated water or accidentally swallow water despite precautions, health issues may arise.
Swam in Blue-green algae? If you swam in water with blue-green algae but did not swallow, take a shower as soon as possible and rinse yourself with tap water (soap is not necessary). Within 12 hours of swimming, skin irritation, itching or burning may occur. Red, irritated and itchy eyes are also common. People with asthma may become stuffy from inhaling small water droplets.
Swallowed water?
If you have gotten water in your mouth or nose while swimming, you may experience stomach cramps, diarrhea and vomiting. Severe symptoms due to large amounts of toxins are rare, because this would require you to drink a lot of contaminated water. Swallowing usually involves small amounts. Other possible symptoms include allergic reactions with fever, a sore throat, earache, runny nose or swollen lips.
How long the symptoms last varies from person to person. Most people feel better within three to five days. If you have ingested a lot of blue-green algae, have trouble breathing or have other serious symptoms, contact your doctor.
