Microcystin

Microcystin-containing 'blooms' are a problem worldwide, including China, Brazil, Australia, South Africa,[9][10][11][12][13][14][15][16] the United States and much of Europe.

[4] Of these, several are uncommon non-proteinogenic amino acids:[17] Microcystins covalently bond to and inhibit protein phosphatases PP1 and PP2A and can thus cause pansteatitis.

[26] A wide range of other factors such as pH may also affect MC production, but comparison is complicated due to a lack of standard testing conditions.

One of the fatal cases for microcystic intoxication through hemodialysis was studied in Brazil where 48% of patients that received the surgery in a specific period of time died because the water used in the procedure was found to be contaminated.

[32][33] In 2011, a record outbreak of blooming microcystis occurred in Lake Erie, in part related to the wettest spring on record, and expanded lake bottom dead zones, reduced fish populations, fouled beaches, and damaged the local tourism industry, which generates more than $10 billion in revenue annually.

[21] In 2016, microcystin had been found in San Francisco Bay Area shellfish in seawater, apparently from freshwater runoff, exacerbated by drought.

[38] Microcystins cannot be broken down by standard proteases like pepsin, trypsin, collagenase, and chymotrypsin due to their cyclic chemical nature.

Once ingested, microcystin travels to the liver via the bile acid transport system, where most is stored, though some remains in the blood stream and may contaminate tissue.

[40][41][page needed] Acute health effects of Microcystin-LR are abdominal pain, vomiting and nausea, diarrhea, headache, blistering around the mouth, and after inhalation sore throat, dry cough, and pneumonia.

A few studies suggest a relationship may exist between liver and colorectral cancers and the occurrence of cyanobacteria in drinking water in China.