Читать книгу Groundwater Geochemistry - Группа авторов - Страница 45

The quantity of fluoride in drinking water varies around the world as well as region to region depending on the geographical location. Contamination of fluoride ions has been largely illustrated in the groundwater of mainly humid, tropical parts of the world. The countries having this type of climatic condition include China, countries in South Asia, and countries in Africa (Ayoob and Gupta 2006). According to WHO 2002, the recommended fluoride concentration of drinking water is 1.5 mg/L. However, estimations show that 200 million or more people are consuming fluoride‐contaminated drinking water worldwide. According to some studies, it has been revealed that over 5 million people are exposed to fluoride‐contaminated groundwater in Mexico (Ayoob and Gupta 2006).