January 25 marks the anniversary of the first time a United States city began fluoridating their water supply.
The US National Institutes of Health began a study to test the relationship of fluoride and tooth decay and public health. They added fluoride to the water supply in Grand Rapids, Michigan beginning in 1945. Their results were published in 1950 showing after the addition of 1 mg/L concentration of fluoride there was a significant reduction in the number of cavities. This was enough for them to recommend adding fluoride to municipal water supplies. Fluoridation became the accepted policy of the US Public Health service in 1951. Today, about two-thirds of the US population is receiving fluoridated water.
This policy has continuously caused controversy, mainly because fluoride is a known toxic substance. Excessive exposure causes dental fluorosis which darkens and weakens tooth enamel, the exact opposite of its intended purpose. Opponents point to changes in personal dental care in the past sixty years may have had more of an impact on the reduction of cavities than any fluoride added to the water.
The Centers for Disease Control list fluoridation as one of the 10 great public health achievements of the 20th Century. The American Dental Association, American Academy of Pediatrics, US Public Health Service, and World Health Organization all endorse water fluoridation. On the other end of the spectrum, Europeans do not fluoridate their water and have also seen a decline in cavities. Several scientists at the Environmental Protection Agency believe it is an unreasonable risk. Several communities in the United States have voted to stop adding fluoride to their water supply.
Overall, January 25, 1945, is either a day of celebration or a day of infamy.
Notable Science History Events for January 25
1945 – First Water Supply Fluoridated
1923 – Arvid Carlsson was born.
Carlsson is a Swedish chemist and pharmacologist who investigated the neurotransmitter dopamine and its effects on people suffering from Parkinson’s disease. He found a way to measure dopamine levels in brain tissue. He also found the levels in the area of the brain controlling movement were higher than other areas of the brain. When he gave the animals a drug to lower dopamine levels, they showed motion control loss similar to the symptoms of Parkinson’s. He could return function to the animals by injecting the dopamine precursor L-dopa. The same treatment helps people alleviate the symptoms of Parkinson’s. This discovery earned him a third of the 2000 Nobel Prize in Medicine.
1917 – Ilya Prigogine is born.
Prigogine was awarded the Nobel Prize in Chemistry for his work in the thermodynamics of irreversible processes. He defined what is meant by a dissipative system in physical chemistry. Dissipative systems are open systems operating far outside thermodynamic equilibrium. He showed systems in dissipative systems have greatly different behaviors from systems involving the same components near thermal equilibrium.
1627 – Robert Boyle is born.
Boyle was an Irish chemist who made a significant contribution away from the alchemical idea of Aristotle’s four elements to the atomic model of elements. He argued elements consisted of ‘corpuscles’ (atoms) instead of the four traditional elements of earth, air, fire, and water. He also proposed nature could be broken down and described as a set of simple mathematical laws. He outlined his arguments in the form of a narrative of a group discussion in his book The Sceptical Chymist.
He also worked extensively with gases, especially with low pressure or ‘rarefied airs’ and vacuums. He demonstrated that vacuum can exist in nature, sound cannot travel through it, and animals cannot live without air. These experiments led to Boyle’s ideal gas law where a gas at constant temperature will have changes in pressure inversely proportional to changes in the volume containing the gas.
Boyle was also one of the founding members of the Royal Society that formed from a group of science and mathematically inclined people who met on a weekly basis in London and Oxford. He was elected president of the Society in 1680 but turned them down because the oath of office disagreed with his religious principles. Boyle’s religious contributions included financing an Irish translation of the Bible, funding missionaries to travel with the East India Company and a series of public lectures relating science and Christianity.
Boyle’s The Sceptical Chymist is available free online (it’s 400 years past the Copyright limits after all). The Internet Archive has a scan of an original printing containing all the 1600s English ∫pellings and printer errors. Project Gutenberg has a version with a font that is easier on the eyes. It’s not the easiest read, but it is a great look at 17th Century scientific discourse.