Approximately 4.2 trillion gallons of water is seen in the United States each year, but about 90% evaporates immediately or ends up in the ocean (McCuen, 1986) . In 1974, Congress passed the Safe Drinking Water Act after a national debate over the amount of organic chemicals such as chloroform and benzene in drinking water in the United States (McCuen, 1986). One of the other groundwater contaminants is fluoride. There is not much fluoride in its elemental state due to its high level of radioactivity and it exists as fluorides in minerals and water (WHO, 2004). Fluoride was introduced into water during the last half of the twentieth century and was one of the two most recent developments affecting drinking water (Barzilay, 1999). Fluoride is used to protect against tooth decay and other dental decay and binds to tooth enamel (Barzilay, 1999). Fluoridation is a beneficial outcome for public health, and the initiation of experiments with it has established that fluoride is an effective and cost-effective method of aiding public health. This cost-effective method of fluoridation costs citizens, on average, only 30 cents to $2 per year (Walker, 1978). However, only a small amount of the fluoridated water pumped each year reaches people's mouths; because most water ends up being used for personal tasks like washing dishes. A fluoride concentration of 1 milligram per liter is the perfect amount of fluoride to prevent tooth decay, although some of the side effects that fluoride has on people can be dangerous if consumed in too high concentrations. Is your water fluoridated? By the end of the 20th century, more than 60% of the US population was using fluoridated water. Approximately...... middle of paper ......lower and where the climate is generally humid and humid, the concentration of fluoride in the water is generally higher. Fluoride, when consumed properly, can be a health benefit, but failure to do so can cause serious health problems and even death. Works Cited Barzilay, J. I. (1999). The water we drink. New Brunswick, New Jersey: Rutgers University Press. Langwith, J. (2010). Waterfall. Farmington Hills, MI: Greenhaven Press.McCuen, G. E. (1986). Protect water quality. Hudson, Wisconsin: GEM Publications. Walker, R. (1978). Water supply, treatment and distribution. Englewood Cliffs, New Jersey: Prentice-Hall, Inc. WHO. (2000). Chapter 6.5 Fluorides, World Health Organization (WHO), Regional Office for Europe, Copenhagen, Denmark.WHO. (2004). Fluoride in drinking water. Retrieved from http://www.who.int/water_sanitation_health/dwq/chemicals/fluoride.pdf