Question

What is currently known about fluoride in drinking water supplies?

a) All bottled water contains fluoride added as part of the bottling process.
b) Scientific evidence has shown that communities with fluoridated water have higher cancer rates.
c) Very few communities in the U.S. have fluoridated water.
d) In communities where fluoride is lacking in the water there is a high dental decay rate.
e) Where the water supply contains too little fluoride, discoloration of the teeth occurs due to fluorosis.

Answer 1

Fluoride in drinking water is crucial for preventing tooth decay by making teeth more resistant to acid; 75% of the U.S. has fluoride-added water, though not all communities have access. While beneficial in correct amounts, excessive fluoride can lead to fluorosis, affecting both teeth and bones.

Step-by-step explanation:

Fluoride plays a crucial role in preventing tooth decay by transforming hydroxyapatite in teeth into fluorapatite, thereby making the teeth more acid-resistant and less soluble. As of 2012, 75% of the U.S. population received water with sufficient fluoride for this protective effect, but around 100 million Americans still lacked access to fluoridated water. The process of adjusting the fluoride content in water to optimal levels is known as community water fluoridation, considered the most cost-effective method for fluoride delivery. However, natural variations can lead to excessive fluoride, known as fluorosis. Dental fluorosis can occur with slight overexposure, resulting in teeth discoloration, while skeletal fluorosis, which affects bones and joints, arises from significant overexposure. The U.S. Environmental Protection Agency sets a maximum allowable level of 4 ppm (4 mg/L) to prevent these conditions.