Key Findings - Water Fluoride/Skeletal Fluorosis:

1) In India and China, surveys have consistently found clinical skeletal fluorosis to occur in in communities with 1.0 - 1.5 ppm fluoride in water, and crippling fluorosis to occur in communities wtih 3 ppm fluoride.

2) Case reports from India have documented crippling fluorosis among some individuals drinking as little as 1.2 - 1.3 ppm fluoride in water.

3) In the United States, case reports have documented skeletal fluorosis among people with kidney disease at water fluoride levels as low as 1.7 ppm, and among heavy tea drinkers, at water fluoride levels as low as 2.2 to 3.5 ppm.

4) There have been no systematic studies in the United States to assess the prevalence of skeletal fluorosis among susceptible subsets of the population.

Published Data - Water Fluoride/Skeletal Fluorosis in India & China: (back to top)

"Skeletal fluorosis in India and China has been reported to occur when the fluoride concentration in water exceeds 1 ppm, and has been found to occur in communities with only 0.7 ppm. The Chinese government now considers any water supply
containing over 1 ppm fluoride a risk for skeletal fluorosis."
SOURCE: Gupta R, Kumar AN, Bandhu S, Gupta S. (2007) Skeletal fluorosis mimicking seronegative arthritis. Scandanavian Journal of Rheumatology 36(2):154-5.

"It is also generally stated that a dose of 10–20 mg/day (equivalent to 5–10 ppm in the water, for a person who ingests 2 L/day) for at least 10 years is necessary to develop crippling skeletal fluorosis. But, the research in India provides credible evidence for a striking contrast to these perceptions as most of the information relating to endemic fluorosis has originated from India where skeletal fluorosis has been associated with water-borne fluoride concentrations of 2 to 3 ppm or lower and even at 0.7 ppm. It is observed that in many populations of India, skeletal fluorosis can occur at a minimum fluoride level of 1.35 ppm and crippling form of skeletal fluorosis at or above 2.8 ppm, given the presence of predisposing factors."
SOURCE: Ayoob S, Gupta AK. (2006). Fluoride in Drinking Water: A Review on the Status and Stress Effects. Critical Reviews in Environmental Science and Technology 36:433–487

"Endemic fluorosis in rural India occurs because of prolonged ingestion of water with excess fluoride (water F > l ppm) resulting in significant skeletal morbidity."
SOURCE: Tiwari S, et al. (2004). Simultaneous exposure of excess fluoride and calcium deficiency alters VDR, CaR, and calbindin D 9 k mRNA levels in rat duodenal mucosa. Calcified Tissue International 75: 313-20

"High fluoride (>1.0 mg/L) in drinking water resulted in dental and skeletal fluorosis in local residents (children and pregnant women)... It has been determined that fluoride concentration in excess of 1 mg/L exposes residents to high health risks based on risk identification."
SOURCE: Bo Z, et al. (2003). Distribution and risk assessment of fluoride in drinking water in the west plain region of Jilin province, China. Environmental Geochemistry and Health 25: 421-31.

"confirmed cases of human skeletal fluorosis were reported where, in 6 of 22 communities studied, the fluoride content of drinking water was between 1.2 and 1.9 ppm; whether this represents the sole source of fluoride ingested is not known."
SOURCE: Marier JR, et al. (1963). Accumulation of skeletal fluoride and its implications. Archives of Environmental Health 664-671.

"At this 1.5 ppm F concentration, 6.1, 6.8, and 9.5% of adults in villages of Banswara, Udaipur, and Dungarpur districts, respectively, showed evidence of skeletal fluorosis."
SOURCE: Choubisa SL. (2001). Endemic fluorosis in Southern Rajasthan, India. Fluoride 34: 61-70.

"The reports outside of the United States, taking everything into consideration, do get clinically observable adverse effects certainly at 4 (ppm) or above. There are plenty of papers." -
SOURCE: Kleerekoper M. (1983). Surgeon General's Ad Hoc Committee on 'Non-Dental Health Effects of Fluoride." Transcript of Proceedings, National Institutes of Health, Bethesda, Maryland, April 19.

Water Fluoride & Skeletal Fluorosis - Inner Mongolia, CHINA SOURCE: Xu RQ, Wu DQ, Xu RY. (1997). Fluoride 30: 26-28.
	Skeletal Fluorosis
Fluoride content of water (Villages in Inner Mongolia, China)	Individuals Examined	Cases	% with Skeletal Fluorosis
0.4	1,046	0	0
0.65	941	2	0.21
1.4	1204	93	7.72
1.6	889	109	12.26
3.2	798	101	12.66
3.4	866	132	15.24
4.7	214	42	19.63
6.9	834	166	19.9

---

Water Fluoride & Skeletal Fluorosis - INDIA SOURCE: Susheela AK, Kumar A, Bhatnagar M, Bahadur R. (1993). Fluoride 26: 97-104..
			Skeletal Fluorosis
Village	Fluoride Content of Water (Mean)	Fluoride Content of Water (Range)	Individuals Examined	Cases	% with Skeletal fluorosis
Bhanakpur	1	0.7 - 1.6	837	141	16.8%
Sikrona	2.5	0.3 - 5.4	518	94	18%
Karnera	3.7	0.3 - 7	315	135	42.8%
Samaypur	3.2	0.25 - 8	288	163	58.6%

---

Water Fluoride & Skeletal Fluorosis/Crippling Fluorosis - Rajasthan, INDIA SOURCE: Choubisa SL. (2001). Fluoride 34: 61-70.
	Fluoride Content of Water (ppm)		Skeletal Fluorosis
Districts & villages	Mean	Range	Individuals Examined (>21 yrs)	Cases	% with Skeletal Fluorosis	Crippling Fluorosis
Banswara
Isarwada	1.6	1.2-2.1	108	7	6.1%	--
Gangertalai	1.9	1.2 - 3.0	102	15	14.7%	--
Vassioda	2.6	2.2-2.9	122	23	18.9%	--
Mangala	3.3	2.7-4.1	126	31	24.6%	+
Borda	3.5	2.6-4.2	120	36	30%	+
Chhotipadel	3.7	2.9-4.6	116	38	32.8%	+
Dungarpur
Mewadi	1.6	1.1-1.8	112	10	8.9%	--
Jhariyana	1.8	1.7-2.0	104	20	19.2%	--
Indora	2.4	1.1-3.1	105	27	25.7%	--
Deotalab	2.8	1.5-4.1	98	39	39.8%	+
Dad	3.1	2.8-3.9	96	41	42.7%	+
Bokedsal	3.2	2.9-3.5	102	40	39.2%	+
Udaipur
Matasula	1.5	1.2-1.7	103	7	6.8%	--
Amlu	1.6	1.3-1.6	94	8	8.5%	--
Dagar	1.9	0.2-3.0	90	14	15.6%	--
Thada	2.6	0.2-5.1	102	20	19.6%	--
Bhabrana	3.0	2.6-3.5	114	24	21.1%	+
Dhamodar	3.8	3.0-4.7	110	37	33.6%	+
Jhalara	4.0	3.5-4.7	142	52	36.6%	+

---

Water Fluoride & Skeletal Fluorosis/Crippling Fluorosis - Punjab, INDIA SOURCE: Jolly SS. (1968). Fluoride 1: 65-75.
	Fluoride Content of Water		Skeletal Fluorosis
Village	Mean	Range	Individuals Examined	Cases	% with Skeletal Fluorosis	Crippling Fluorosis
Gharachon	1.4	0.9-2.5	82	2	2.4%	--
Laluwala	2.4	1.0-5.5	74	17	23.0%	--
Dhapai	3.0	1.1-5.5	107	21	19.6%	--
Bhodipura	3.0	1.3-5.2	64	27	42.2%	+
Rajthai	3.3	0.5-6.5	160	16	10%	--
Bhikti	3.3	1.0-5.9	160	73	45.6 %	+
Sanghera	3.6	1.1-5.8	154	51	33.1 %	+
Ramuana/ Ganjigulab	5.0	1.5-11.5	90	54	60%	+
Singh	8.5	3.7-14.0	56	33	58.9%	+
Khara	9.7	6.0-16.2	232	164	70.7%	+

---

Published Data - Water Fluoride /Skeletal Fluorosis in the U.S.: (back to top)

See also: Fluoridation, Dialysis, & Osteomalacia

Water Fluoride & Skeletal Fluorosis - UNITED STATES
Study	Fluoride Content of Water
Linsman 1943	1.2 - 5.7
Sauerbrunn 1965	2.2 - 3.5
Morris 1965	1.0 - 9.2
Goldman 1971	4.0 - 7.8
Juncos 1972	1.7, 2.6
Johnson 1979	1.7, 1.7, 1.9, 2.0
Felsenfield 1991	7.2 - 8.2
Whyte 2005	2.8

"3 ppm wouldn't protect the individual with renal insufficiency..."
SOURCE: Wallach S. (1983). Surgeon General's Ad Hoc Committee on 'Non-Dental Health Effects of Fluoride." Transcript of Proceedings, National Institutes of Health, Bethesda, Maryland, April 19.

"The finding of adverse effects (skeletal fluorosis) in (kidney) patients drinking water with 2 ppm of fluoride suggests that a few similar cases may be found in patients imbibing 1 ppm, especially if large volumes are consumed, or in heavy tea drinkers and if fluoride is indeed the cause."
SOURCE: Johnson W, et al. (1979). Fluoridation and bone disease in renal patients. In: E Johansen, DR Taves, TO Olsen, Eds. Continuing Evaluation of the Use of Fluorides. AAAS Selected Symposium. Westview Press, Boulder, Colorado. pp. 275-293.

"It seems probable that some people with severe or long-term renal disease, which might not be advanced enough to require hemodialysis, can still experience reduced fluoride excretion to an extent that can lead to fluorosis, or aggravate skeletal complications associated with kidney disease."
SOURCE: Groth, E. (1973), Two Issues of Science and Public Policy: Air Pollution Control in the San Francisco Bay Area, and Fluoridation of Community Water Supplies. Ph.D. Dissertation, Department of Biological Sciences, Stanford University, May 1973.

"It is generally agreed that water fluoridation is safe for persons with normal kidneys. Systemic fluorosis in patients with diminished renal function, however, seems a reasonable possibility."
SOURCE: Juncos LI, Donadio JV. (1972). Renal failure and fluorosis. Journal of the American Medical Association 222:783-5.

"All patients with dental fluorosis and anemia and/or signs of renal impairment should have radiographic examinations of the skeletal systems to rule out the existence of fluoride osteosclerosis."
SOURCE: Linsman JF, McMurray CA. (1943). Fluoride osteosclerosis from drinking water. Radiology 40: 474-484; erratum 497.

Research Gaps - No Systematic Studies Investigating Skeletal Fluorosis in U.S. among Susceptible Subsets: (back to top)

"a fairly substantial body of research indicates that people with kidney dysfunction are at increased risk of developing some degree of skeletal fluorosis... However, there has been no systematic survey of people with impaired kidney function to determine how many actually suffer a degree of skeletal fluorosis that is clearly detrimental to their health."
SOURCE: Hileman B. (1988). Fluoridation of water.Questions about health risks and benefits remain after more than 40 years. Chemical and Engineering News August 1, 1988, 26-42.

"In the United States, there have been no reported cases of skeletal fluorosis in persons who drink water containing only one part per million (ppm) of fluoride. However, since no systematic studies have been carried out in patients with renal insufficiency, this possibility cannot be excluded with certainty."
SOURCE: Johnson W, et al. (1979). Fluoridation and bone disease in renal patients. In: E Johansen, DR Taves, TO Olsen, Eds. Continuing Evaluation of the Use of Fluorides. AAAS Selected Symposium. Westview Press, Boulder, Colorado. pp. 275-293.

"It seems probable that some people with severe or long-term renal disease, which might not be advanced enough to require hemodialysis, can still experience reduced fluoride excretion to an extent that can lead to fluorosis, or aggravate skeletal complications associated with kidney disease... It has been estimated that one in every 25 Americans may have some form of kidney disease; it would seem imperative that the magnitude of risk to such a large sub-segment of the population be determined through extensive and careful study. To date, however, no studies of this sort have been carried out, and none is planned."
SOURCE: Groth, E. (1973), Two Issues of Science and Public Policy: Air Pollution Control in the San Francisco Bay Area, and Fluoridation of Community Water Supplies. Ph.D. Dissertation, Department of Biological Sciences, Stanford University, May 1973.

Back to top