Written by Tatjana Djakovic, Staff Writer. This study analyzes the risk of excessive fluoride consumption which leads to bone deformations and teeth discoloration. It was analyzed in skeletons from an ancient population that were very well preserved due to their sudden death during a volcanic eruption.

Chronic exposure to fluoride known as fluorosis contributes to deterioration of bones, mottling and discoloration of tooth enamel (1). It has been estimated that 25–30 million people are at risk of developing fluorosis, and half a million are suffering from it (2). Fluorosis is prevalent in many parts of India; however fluorosis has also been known to occur in western countries, but in very low amounts (3). The prevalence of dental fluorosis was less than one-quarter of people aged 6 to 49 in United States (4).

Fluorine is an element found in earth’s crust and it is present in its ionic form of fluoride in minerals, soil, water, plants and food. Fluoride is very important for preventing tooth decay at low concentrations of less than 1mg/L. This is according to the World Health Organization, based on an extensive review of dental surveys conducted in the United States over 60 years ago. Several studies have shown dental decay reduction of up to 60% after fluoridation (5). When it is present in saliva, fluoride increases the process of remineralization (enhancing the return of mineral to the teeth) as well as interfering with the bacterial process to metabolize sugars to produce acid. (6)

Even though flouride is beneficial in low concentrations, excessive fluoride consumption leads to health problems. Sources of fluoride that may contribute to overexposure include: consumption from drinking water, inhalation of fluoride dusts/fumes, use of coal as an indoor fuel source, fluoridated mouth rinse (which young children may swallow), bottled waters not tested for their fluoride content, and most commonly; addition of fluoride to public water which attributes to 40% of all fluorosis (7).

Fluoride is retained in the bones and induces hardening of all the bones, including the spine. In addition, there is a degeneration and enlargement of the joints and bones, similar to osteoarthritis. The clinical condition exhibits bone, joint and muscle pain due to early restrictions in spine movements and at a later stage progressive stiffness of the vertebral joints, induced by calcification of ligaments (8).

In the current study, researchers analyzed 76 human skeletons aged 0 to 52 years (mean age 30.2 years) that were victims of the 79 AD Vesuvius volcanic eruption. The skeletons were recently excavated on the ancient beach of Herculaneum and comprehensively analyzed for signs of fluorosis. The area of Herculaneum was known to be high in concentration of fluoride due to the release of volcanic gases that contained hydrogen flouride gas.

The skeletons were very well preserved as a result of the instant death caused by volcanic hot surge (500 degrees Celsius) followed by rapid vaporization of their tissues and organs. The researchers made sure to discriminate the flouride concentration in the bodies at the time of their death and after they have been excavated, because bones buried for long periods absorb and accumulate fluoride from the soil (8).

The researchers performed an extensive analysis of every joint of each individual that was involved in the tragic accident for signs of bone deformities indicative of fluorosis. Enamel fluorosis was scored according to a four value scoring system. The chest bones, spine, pelvis and long bones of each individual were examined for the calcification of ligaments, cartilage and tendons, as well as the presence of healed fractures.  A 0 to 3 score (0=absent, 1= moderate, 2=severe, 3= ankylosis) was assigned to each joint of individuals aged 15 years old.

The authors of this momentous study state, “At Herculaneum, the majority of the individuals more than 15 years old (73.5%) show evidence of intense calcification of the ligaments, tendons, cartilage and interosseous membranes (5).” The outer surface of bones also showed resorption (release of minerals and calcium from bone to the blood), increased spaces between bones, heavier in weight and  a marble-like appearance.

Also there was no evidence of bone change by microorganisms that were observed, which can be predicted due to type of burial environment of the skeletons.

After a large, thorough analysis, the researchers have determined the prevalence of each of the conditions among the skeletal remains.

Condition Description Prevalence
Hypertrophic Osteosclerosis Bony growth formed on normal bone limits joint movement 27.6%
Spondyloarthritis toward lower spine Inflammatory disease that causes bone destruction resulting in deformities of the spine 18.5%
Ankylosis (affecting mainly the spine, joints, and sternum) Stiffness of a joint due to abnormal adhesion and rigidity of the bones of the joint, which may be the result of injury or disease. 14.9%
Severe ankylosis major lesions Severe form of ankylosis. 39.2%
Spine ankylosis joints Ankylosis of the spine. 18.% (males)17.6% (females)
Osteoarthritic-like lesion Imbalance between the production and the destruction of cartilage resulting in loss of cushioning between joints. 47.2%
Fractures Partial or complete break in the bone. 32.1%
Osteomalacia Softening of the bones due to a lack of vitamin D or a problem with the body’s ability to break down and use this vitamin. 8.2%
Spondylolysis Condition in which a bone (vertebra) in the spine slips out of the proper position onto the bone below it. 8.9%
Susceptibility to bone fractures Susceptibility to partial or complete breaks in bone 35.7%.
Defects of the teeth Accounts for dental defects 96.1%
Enamel alteration Changes in enamel appearance 34.4%
Carious lesions Tooth decay 78.6%

The results also indicated that 90% of the osteoarthritic-like lesions index is age related (p<0.0001).There was also a significant correlation between the number of bone fractures per individual and age (p<0.003) (8).

The analysis of this ancient population suggests that fluorosis in this area was already present in Roman times. The researchers calculated a fluoride intake of 10.8 to 18.0 mg/day per person at the time of the AD 79 eruption, which is associated with crippling skeletal disorders (10) and an increased susceptibility to bone fractures (9).

Maximum Contaminant Level for fluoride set by Environmental Protection Agency in drinking water is 4.0 mg/L, which does not protect against adverse health effects, particularly in children whose bones more susceptible to absorbing fluoride. The Health and Human Services Department lowered its recommended levels to 0.7 milligrams of fluoride per liter of water (11). The tragic incidence that occurred during the Vesuvius volcanic eruption serves as an example that excessive intakes of fluoride can be damaging to the body even today and should be safely monitored to prevent dental and skeletal deformities.

Source: Petrone, Pierpaolo, et al. “Enduring fluoride health hazard for the Vesuvius area population: the case of AD 79 Herculaneum.” PloS one 6.6 (2011): e21085.

Copyright: © 2011 Petrone et al. Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Click here to read the full text study.

Posted June 25, 2013.

References:

  1. D.R Reddy, R.D Srikanth et al.,  “Fluorosis”, Surgical Neurology, Volume 49, Issue 6, June 1998, Pages 635-636,
  2. S Chandra, VP Thergaonkar, R Sharma. “Water quality and dental fluorosis.” Indian J Public Health, 25 (1981), pp. 47–51
  3. Kokueisei Gakkai Zasshi et al., “Relationship between fluoride concentration in drinking water and dental caries in Japan”22 (1972), pp. 144–196
  4. Beltrán-Aguilar ED, Barker L, Dye BA. Prevalence and severity of dental fluorosis in the United States, 1999-2004. NCHS data brief, no 53. Hyattsville, MD: NationalCenter for Health Statistics. 2010
  5. World Health Organization(WHO). Environmental Health Criteria. 227. Fluoride: Geneva: World Health Organization; 2002.
  6. Ayoob G., Fluoride in drinking water: a review of the status and stress effects. (2006). Crit Rev Environ Sci Technol 36: 433-487.
  7. United States Environmental Protection Agency (2010). Comment-Response Summary Report for the Peer Review of the Fluoride: Dose-Response Analysis for Non-Cancer Effects Document
  8. Petrone, Pierpaolo, et al. “Enduring Fluoride Health Hazard for the Vesuvius Area Population: The Case of AD 79 Herculaneum.” PloS one 6.6 (2011): e21085
  9. U.S. Environmetnal Protection Agency.  (2002) National Primary Drinking Water Regulations, Drinking Water Contaminants, Fluoride. Pp 56-80.
  10. George, Caroline. “Battle renewed over value of fluoridation.” Canadian Medical Association Journal 183.9 (2011): E531-E532.
  11. U.S. DHHS2000a. Oral Health in America: A Report of the Surgeon General. Rockville, MD:National Institute of Dental and Craniofacial Research, National Institutes of Health, U.S. Department of Health and Human Services.