What does "blue bath" mean?

Since the summer of last year, the water level in Taihu Lake has been the lowest in 50 years. Coupled with continuous high temperature and little rain, Taihu Lake is seriously eutrophic. Many factors lead to the early outbreak of cyanobacteria, which leads to natural disasters and affects the water quality of tap water sources to some extent. This year, Wuxi entered the summer one month ahead of schedule, with a high altitude. The water level in Taihu Lake was low, and blue bath broke out, which caused the tap water to stink and was too serious to drink. It is said that even tap water can't be used for bathing and laundry. Recently, all the supermarkets in Wuxi have run out of clean water and the shelves are empty!

Cyanobacteria are called blue toxins)

(There are blue toxins in specific areas inside cyanobacteria)

There are many kinds of blue toxins, one of which is classified as hepatotoxin and neurotoxin, which is known to attack the liver and nerves, and the other is irritating to the skin. When blue toxin cells rupture or die, the toxins classified above will be released into water. )

When exposed to lake water containing cyanobacteria toxin, although some people will get sick, drinking water containing polluted algae may not necessarily lead to death. Long-term exposure to water containing cyanobacteria hepatotoxin, even if the content is low, may have long-term or chronic adverse effects on human body)

If you continuously ingest water, fish or other aquatic products containing cyanobacteria, you may have headache, fever, diarrhea, abdominal pain, nausea or vomiting. If you swim in polluted water, your skin may be itchy or your eyes/skin may be irritated. If you suspect that you have been in direct contact with polluted water and your body has adverse reactions, rinse your body with clean water and contact your doctor immediately.

Boiled water will not remove the toxins from cyanobacteria, because you can't detect the presence of toxins by the appearance, smell or taste of water, only chemical tests can.

If possible, don't wash clothes and tableware with contaminated water. If there is no other water source, rubber gloves must be worn when using water at home. Bathing with contaminated water should be avoided, because direct contact with the skin will cause skin irritation and rash. )

Microcystins have water solubility and heat resistance. Soluble in water, methanol or acetone, non-volatile, resistant to pH change. The molecular formula of MC-LR is C49H74N 10O 12, and its molecular weight is 995.2 (often calculated as 1000).

Its solubility in water is greater than 1g/L, and its chemical properties are quite stable. The natural degradation process of microcystins in water is very slow. When the content of microcystins in water is 5ug/L, only 10% is absorbed by particles in water after three days, and 7% is precipitated with sediment. Microcystins have high heat resistance and cannot be destroyed or removed by heating and boiling. Coagulation, sedimentation, filtration and chlorination of tap water can not remove it. A survey showed that low concentration of microcystins (128 ~ 1400 ng/L) were detected in the effluent of three water plants around the lake. The results showed that the microcystins in drinking water could not be completely removed by conventional disinfection treatment.

It is a hepatotoxin and a strong promoter of liver cancer.

After drinking water containing microcystins, domestic animals and wild animals will have symptoms such as diarrhea, fatigue, anorexia, vomiting, drowsiness, increased mouth and eye secretions, and even death. Pathological changes include liver enlargement, congestion or necrosis, enteritis bleeding, pulmonary edema and so on.

Microcystins are also very harmful to human health. The LD50 of MC-LR is about 50~ 100 ug/kg. When people take a bath, swim and do other water recreation, skin contact with water containing microcystins will cause sensitive parts (such as eyes) and skin allergies; A small amount of drinking can cause acute gastroenteritis; Long-term drinking may lead to liver cancer. Medical departments found that microcystins in drinking water have a great correlation with the incidence of primary liver cancer in the population. 1996 caused acute liver failure in Brazil 100, and at least 50 people died within 7 months due to the acute effect of microcystins, which attracted worldwide attention.