Endemic fluorosis is a chronic systemic disease characterized by skeletal fluorosis and dental fluorosis, which is caused by excessive fluorine in the environment in a certain area, and residents living in the environment take in excessive fluorine for a long time through drinking water, food and air, and is also called endemic fluorosis.

1. Endemic fluorosis is a worldwide endemic disease closely related to the abundance of fluorine in geographical environment. Its basic symptoms are dental fluorosis and skeletal fluorosis. It is caused by the high fluorine content in local rocks and soil, which leads to the increase of fluorine content in drinking water and food. Excessive fluoride intake destroys the metabolic balance of calcium and phosphorus in human body. It is widely distributed, mainly in India, the Soviet Union, Poland, Czech Republic, Szladek, Germany, Italy, Britain, the United States, Argentina, Mexico, Morocco, Japan, Malaysia and other countries; In China, it is mainly popular in Guizhou, Shaanxi, Gansu, Shanxi, Shandong, Hebei, Liaoning, Jilin and Heilongjiang. In addition, when the fluoride emitted by phosphate fertilizer, copper, iron, aluminum production, brick and tile, ceramics, glass and other industries and industrial and domestic coal exceeds the purification capacity of nature, it will do harm to crops and livestock, and human beings will also cause chronic fluoride poisoning if they eat food and vegetables with high fluorine content for a long time. The prevention method is to reduce the fluorine content in water.

2. Chronic toxic diseases caused by the fluoride content in drinking water exceeding the normal needs of human body (the standard fluoride content is less than 1 mg/L). This is due to the excessive fluorine content in the geological environment of some areas. Endemic fluorosis is mainly characterized by the formation of mottled enamel teeth and skeletal fluorosis, which can lead to paralysis in severe cases. This disease is very popular in the world, and there are more than a dozen provinces and cities in China with high fluorine content, and its distribution is related to the regional geological environment. Therefore, it is one of the important tasks for environmental geologists to find out the regional environmental geological conditions and the geochemical characteristics of fluorine, find good water according to local conditions and improve water for disease prevention. There are many methods to reduce the fluorine content in drinking water, such as activated aluminum fluoride filtration, basic aluminum fluoride adsorption and electrodialysis, which are suitable for residential areas and factories and mines with centralized water supply. The method of adding alum into water and filtering with slag is economical and convenient, which is most suitable for scattered residents and rural areas.