NRC: Altitude

How the NRC reviewed the matter of "altitude"
© 2006 PFPC

QUOTE: (from Page 91; "Diagnostic issues")

"Some studies in the international literature have reported severe mottling of the teeth that could not be attributed to fluoride exposure. For example, Whitford (1996) was unable to explain a high prevalence of severe lesions resembling fluorosis in Morococha, Peru on the basis of exposure to fluoride in water, food, or dental
products. Yoder et al. (1998) found severe dental mottling in a population in Tanzania with negligible fluoride in the water
(>0.2 ppm). They noted that urinary fluoride concentrations in affected subjects from that area were not consistent with concentrations found in subjects from a high fluoride area who had severe enamel fluorosis. Mottling unrelated to fluoride exposure has been suggested to be due to malnutrition, metabolic disorders, exposure to certain dietary trace elements, widespread introduction of tea drinking among children at very early ages, or physical trauma to the tooth (Curzon and Spector 1977; Cutress and Suckling
1990)." (NRC 2006; Page 91)

COMMENTS:

1) This paragraph is entirely misleading and the reader is given the impression that the mottling observed by Yoder et al (1998), or as observed from drinking tea, etc., is "unrelated to fluoride". The cited studies are misinterpreted. Yoder et al. (1998) found very high concentrations of fluoride in the magadi which the Tanzanian subjects were consuming. In addition the authors found that altitude was a significant risk factor.

NOTE: High altitude has been established as a significant risk factor for dental fluorosis. The higher the altitude, the less fluoride is required to cause enamel fluorosis. At high altitudes, even small amounts of fluoride in water may cause severe dental fluorosis.

There are many studies conducted in the last 10 years documenting this (Angmar-Mansson & Whitford, 1990; Cao et al., 2003; Mabelya et al., 1992; 1997; Manji et al., 1986; Martinez-Mier et al., 2004; Soto-Rojas et al., 2004; Molina et
al., 1999; Rwenyonyi et al., 1999; Yoder et al., 1998; Whitford, 1997; etc.).

NOTE: Whitford’s Morococha, Peru - a polluted mining village of 6000 inhabitants - is located at 4540m...

See: Reference Set - Altitude

The NRC addressed this risk factor only "in passing", and only the study by Rweneyonyi is later cited (page 92):

QUOTE:

"More recently, Rweneyonyi et al. (1999) reported higher prevalences of severe enamel fluorosis at higher altitudes than at lower altitudes in Uganadan populations with the same water fluoride levels."
(NRC 2006; Page 92)

One other important aspect in evaluating "altitude" is the fact that, not only do humans seem to retain more fluoride at higher altitudes (Angmar-Mansson & Whitford , 1990), food sources also tend to accumulate more fluoride at such altitudes (Mabelya et al., 1997; Yoder et al., 1998). Of course it has been known for centuries that at high altitudes iodine deficiency and goiter occurrence is much more severe. Iodine deficiency potentiates the toxic effects of fluoride (Zhao et al, 1998).

The NRC failed entirely to address this matter appropriately and in a scientifically sound manner.

2) Considering the sentence:

"Mottling unrelated to fluoride exposure has been suggested to be due to malnutrition, metabolic disorders, exposure to certain dietary trace elements, widespread introduction of tea drinking among children at very early ages, or physical trauma to the tooth (Curzon and Spector 1977; Cutress and Suckling 1990)."

How can anyone state that mottling from tea drinking is NOT related to fluoride exposure?? Perhaps the NRC should be made aware of the many studies from all over the world clearly identifying the fluoride in tea as the source of dental fluorosis...

SEE: Tea & Fluorosis

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REFERENCES

Angmar-Mansson B, Whitford GM - "Environmental and physiological factors affecting dental fluorosis." J Dent Res 69 Spec No:706-13; discussion 721 (1990)

Mabelya L, Konig KG, van Palenstein Helderman WH - "Dental fluorosis, altitude, and associated dietary factors (short communication)" Caries Res 1992;26(1):65-7 (1992)

Yoder KM, Mabelya L, Robison VA, Dunipace AJ, Brizendine EJ, Stookey GK - "Severe dental fluorosis in a Tanzanian population consuming water with negligible fluoride concentration" Community Dent Oral Epidemiol 26(6):382-93 (1998)

Angmar-Mansson B, Whitford GM - "Environmental and physiological factors affecting dental fluorosis." J Dent Res 69 Spec No:706-13; discussion 721 (1990)

Cao J, Zhao Y, Liu J, Xirao R, Danzeng S - "Varied ecological environment and fluorosis in Tibetan children in the nature reserve of Mount Qomolangma" Ecotoxicol Environ Saf 48(1):62-5 (2001)

Mabelya L, van Palenstein Helderman WH, van't Hof MA, Konig - "KG.Dental fluorosis and the use of a high fluoride-containing trona tenderizer
(magadi). Community Dent Oral Epidemiol.25(2):170-6 (1997)

Mabelya L, Konig KG, van Palenstein Helderman WH - "Dental fluorosis, altitude, and associated dietary factors (short communication)" Caries Res 1992;26(1):65-7 (1992)

Manji F, Baelum V, Fejerskov O - "Fluoride, altitude and dental fluorosis" Caries Res 20(5):473-80 (1986)

Martinez-Mier EA, Soto-Rojas AE, Urena-Cirett JL, Katz BP, Stookey GK, Dunipace AJ- "Dental fluorosis and altitude: a preliminary study" Oral Health Prev Dent. 2(1):39-48 (2004)

Molina Frechero N, Mendez Ramirez I, Hernandez Guerrero JC, Bologna Molina R- "Dental fluorosis and altitude in Mexican and Uruguayan schoolchildren ", ABSTRACTS from 3nd EADPH Congress, September 8-9, 1999, Strasbourg, France; Originally Published in Community Dental Health Volume 16 Number 3 Div. Est Postgrado Facultad de Odontologia UNAM, UAM-X, IMAS-UNAM, Mexico , Study was supported by UAM an CONACyt #27615/M

Rwenyonyi C, Bjorvatn K, Birkeland J, Haugejorden O - "Altitude as a risk indicator of dental fluorosis in children residing in areas with 0.5 and 2.5 mg fluoride per litre in drinking water."Caries Res 33(4):267-74 (1999)

Soto-Rojas AE, Urena-Cirett JL, Martinez-Mier Ede L - "A review of the prevalence of dental fluorosis in Mexico" Rev Panam Salud Publica. 15(1):9-18 (2004)

Whitford GM - "Determinants and mechanisms of enamel fluorosis" Ciba Found Symp 205:226-41; discussion 241-5 (1997)