Environmental and Sustainability Indicators (Dec 2023)
Recent advancements in fluoride impact on human health: A critical review
Abstract
In groundwater, excessive fluoride concentration has been evidenced in more than 20 developing and developed countries including India, wherein 19 states are confronting serious problems owing to fluorosis. A total 71% of earth's surface constitutes water however, only some amount is drinkable and suitable for household activities. Groundwater present below the earth's surface is a vital source of water for human intake. Numerous scientists have reported that a small amount of fluoride is beneficiary for strengthening the bone and preventing dental caries, instead, its high dose causes severe effects on human health such as skeletal fluorosis, dental fluorosis, increase in bone fracture, decrease in birth rates, impaired thyroid functions, increased rates of Urolithiasis and lower IQ in children. Fluoride exposure may lead to high frequency of chronic irritative respiratory disease, chronic bronchitis in particular. Due to high intake of sodium fluoride pesticides and dental products, severe fluoride toxicity and death have also been witnessed. Although fluorine is present in all four spheres of earth i.e., lithosphere, atmosphere, hydrosphere and biosphere, however the volcanic rocks are also one of major sources of large quantity of fluorine. Through numerous natural processes like rock dissolution, volcanic eruptions and man-induced activities (ore processing, coal burning, use of industrial plants and fertilizers), fluorine enters to the environment. Fluoride is a highly reactive chemical entity naturally found as CaF2 being a vital component in minerals (fluorite, topaz, cryolite, fluorapatite, theorapatite and phosphorite etc.). Entrance of fluoride in the soil occurs through rocks weathering, precipitation or waste runoff. In cases where water is not polluted by external sources, the surface water does not constitute more than 0.3 Mg/l of fluoride. Drinking water is the foremost supplier (75–90% of day-to-day consumption) of fluoride whereas, other sources are intoxication like food, drugs, cosmetics and industrial exposure etc.
