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2 Measures of Exposure to Fluoride in the United States
Pages 23-88

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From page 23...
... 1993 review of the health effects of ingested fluoride reported estimates of average daily fluoride intake from the diet of 0.04-0.07 milligrams per kilogram (mg/kg) of body weight for young children in an area with fluoridated water (fluoride concentration in drinking water, 0.7-1.2 mg per liter [L]
From page 24...
... sourCes oF Fluoride exPosure Drinking Water General Population The major dietary source of fluoride for most people in the United States is fluoridated municipal (community) drinking water, including water consumed directly, food and beverages prepared at home or in restaurants from municipal drinking water, and commercial beverages and processed foods originating from fluoridated municipalities.
From page 25...
... limits the fluoride that can be present in public drinking-water supplies to 4 mg/L (maximum contaminant level, or MCL) to protect against crippling skeletal fluorosis, with a secondary maximum contaminant level (SMCL)
From page 26...
... . Of the 237 counties, 84 have median groundwater fluoride concentrations exceeding 1 mg/L; of these, 25 counties exceed 2 mg/L and five exceed 4 mg/L.
From page 27...
... . Typical fluoride concentrations in various types of drinking water in the United States are summarized in Table 2-1.
From page 28...
... Table 2-2 provides examples of fluoride intake by typical and high consumers of municipal water by age group. The estimates of water consumption described in Appendix B are in keeping with recently published "adequate intake" values for total water consumption (including drinking water, all beverages, and moisture in food; IOM 2004; see Appendix B, Table B-10)
From page 29...
... 2 nigniviLelpoePybreta 41.0-480.0 d ekatnIediroulF yad/gk/gm 040.0-320.0 460.0-730.0 450.0-230.0 040.0-320.0 130.0-810.0 830.0-220.0 830.0-220.0 830.0-220.0 yad/gm 5.2-5.1 1.1-76.0 48.0-94.0 1.1-66.0 2.1-7.0 0.2-2.1 6.2-5.1 8.2-6.1 5.2-4.1 W) lapicinu c M(ytinummoCfonoitpmusnoC sremusnoChgiH noitpmusnoCreta yad/gk/Lm 33 021 35 54 33 62 23 23 23 W yad/Lm 001,2 059 007 049 000,1 007,1 002,2 003,2 050,2 d 020.0-210.0 270.0-240.0 130.0-810.0 820.0-610.0 910.0-110.0 910.0-110.0 020.0-210.0 810.0-110.0 .)
From page 30...
... A number of authors have pointed out the difficulty doctors and dentists face in ascertaining individual fluoride intakes, just from drinking water (from all sources) , for the purpose of prescribing appropriate fluoride supplementation (Nowak and Nowak 1989; Chan et al.
From page 31...
... . The Army's planning factor for individual tap water consumption ranges from 1.5 gallons/day (5.7 L/day)
From page 32...
... . Diabetes mellitus and diabetes insipidus are both characterized by high water intakes and urine volumes, among other things (Beers and Berkow 1999; Eisenbarth et al.
From page 33...
... (1979) ; most of the patients had urine volumes exceeding 3 L/day and drinking water with fluoride concentrations around 1.7-3 mg/L.
From page 34...
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From page 35...
... 3 gniviLspuorgbuSnoitalupoPdetceleSfosrebme d ekatnIediroulF yad/gk/gm 480.0-940.0 480.0-940.0 480.0-940.0 480.0-940.0 21.0-70.0 480.0-940.0 81.0-11.0 81.0-11.0 yad/gm 2.4-5.2 9.5-4.3 4.8-9.4 01-9.5 4.2-4.1 9.5-4.3 6.3-1.2 31-4.7 c sremusnoChgiH noitpmusnoCreta yad/gk/Lm 07 07 07 07 001 07 051 051 W yad/Lm 005,3 009,4 000,7 004,8 000,2 009,4 000,3 005,01 Mybreta d WgniknirD ekatnIediroulF yad/gk/gm 60.0-530.0 60.0-530.0 60.0-530.0 60.0-530.0 60.0-530.0 60.0-530.0 60.0-530.0 60.0-530.0 yad/gm 0.3-8.1 2.4-5.2 0.6-5.3 2.7-2.4 2.1-7.0 2.4-5.2 2.1-7.0 2.4-5.2 b morfekatnIediroulFfoselpmaxE sremusnoClacipyT noitpmusnoCreta yad/gk/Lm 05 05 05 05 05 05 05 05 W yad/Lm 005,2 005,3 000,5 000,6 000,1 005,3 000,1 005,3 .secruos) lapicinum(ytinummocdetadiroufl a 4-2 ELBAT saerAdetadiroulFni )
From page 36...
... . Cows' milk likewise contains very low fluoride concentrations, compared with other dietary sources such as drinking water.
From page 37...
... Measured fluoride concentrations in tea leaves range from 170 to 878 mg/kg in different types of tea, with brick tea generally having 2-4 times as much fluoride as leaf tea (Wong et al.
From page 38...
... . In practice, fluoride content in tea or coffee as consumed will be higher if the beverage is made with fluoridated water; however, for the present purposes, the contribution from water for beverages prepared at home is included in the estimated intakes from drinking water, discussed earlier.
From page 39...
... varied from 0.35 mg/day for children aged 1-4 to 3.0 mg/day for 40- to 64-year-old males. Over all ages and both sexes, the esti TABLE 2-5 Examples of Fluoride Intakes by Heavy Drinkers from Alcoholic Beverages Alone Fluoride Fluoride Intake, mg/day Beverage Concentration, mg/L 8 drinks per day 12 drinks per day Beer (12-oz.
From page 40...
... Apart from drinking water (direct and indirect consumption, as described earlier) , the most important foods in terms of potential contribution to individual fluoride exposures are infant formula, commercial beverages such as juice and soft drinks, grapes and grape products, teas, and processed chicken (Table 2-6)
From page 41...
... . Several authors also point out the difficulty in evaluating individual fluoride intake, given the wide variability of fluoride content among similar items (depending on point of origin, etc.)
From page 42...
... A number of papers have suggested approaches to decreasing children's intake of fluoride from toothpaste, including decreasing the fluoride content in TABLE 2-7 Estimated Typical Fluoride Intakes from Toothpastea Age Group, years Fluoride Intake, mg/day Age Group, years Fluoride Intake, mg/day Infants < 0.5b 0 Youth 13-19 0.2 Infants 0.5-1 0.1 Adults 20-49 0.1 Children 1-2 0.15 Adults 50+ 0.1 Children 3-5 0.25 Females 13-49c 0.1 Children 6-12 0.3 aBased on information reviewed by Levy et al.
From page 43...
... The authors recommended that the effectiveness of professionally applied topical fluoride products in modern clinical practice be evaluated. Exposures from topical fluorides during professional treatment are unlikely to be significant contributors to chronic fluoride exposures because they are used only a few times per year.
From page 44...
... is released to the atmosphere by natural sources such as volcanoes11 and by a number of anthropogenic sources. In North America, anthropogenic sources of airborne fluoride include coal combustion by electrical utilities and other entities, aluminum production plants, phosphate fertilizer plants, chemical production facilities, steel mills, magnesium plants, and manufacturers of brick and structural clay (reviewed by ATSDR 2003)
From page 45...
... , and as such, its emissions are subject to control based on "maximum achievable control technology" emission standards. Such standards are already in effect for fluoride emissions from primary and secondary aluminum production, phosphoric acid manufacture and phosphate fertilizer production, and hydrogen fluoride production (ATSDR 2003)
From page 46...
... In their estimates, fluoride intake from soil was 5-9 times lower than that from fluoridated drinking water. For children with pica (a condition characterized by consumption of nonfood items such as dirt or clay)
From page 47...
... . The respective fluoride ion concentrations from a 200 ppm aqueous synthetic cryolite (97.3% pure)
From page 48...
... Fluoride exposures from a total of 543 forms of foods (e.g., plantbased, bovine, poultry, egg, tea) containing fluoride were also estimated as the background food exposure.
From page 49...
... for many foods also indicates that the total background food exposure would not be significantly different from the analysis by EPA, except for the fluoride intake from tea. A closer examination of the residue profile used by EPA (2004)
From page 50...
... in their drinking water. Other fluoride-containing organic chemicals go through more extensive metabolism that results in greater increased bioavailability of fluoride ion.
From page 51...
... . Aluminum in drinking water comes both from the alum used as a flocculant or coagulant in water treatment and from leaching of aluminum into natural water by acid rain (ATSDR 1999; Li 2003)
From page 52...
... Fluorosilicates Most fluoride in drinking water is added in the form of fluosilicic acid (fluorosilicic acid, H2SiF6) or the sodium salt (sodium fluosilicate, Na2SiF6)
From page 53...
... . In drinking water at approximately neutral pH and typical fluoride concentrations, all the silicofluoride appears to be dissociated entirely to silicic acid [Si(OH)
From page 54...
... 2001b) , mean fluoride intakes from water, supplements, and dentifrice combined ranged from 0.360 mg/day (12 months old)
From page 55...
... total exPosure to Fluoride A systematic estimation of fluoride exposure from pesticides, background food, air, toothpaste, fluoride supplement, and drinking water is presented in this section. The estimated typical or average chronic exposures to inorganic fluoride from nonwater sources are presented in Table 2-9.
From page 56...
... 6 FLUORIDE IN DRINKING WATER TABLE 2-9 Total Estimated Chronic Inorganic Fluoride Exposure from Nonwater Sources Average Inorganic Fluoride Exposure, mg/kg/day BackPopulation Sulfuryl ground Tooth- Total Subgroups Fluoridea Cryolitea Fooda pasteb Aira Nonwater Supplementc All infants (<1 0.0005 0.0009 0.0096 0 0.0019 0.0129 0.0357 year) Nursing 0.0003 0.0004 0.0046 0 0.0019 0.0078d 0.0357 Nonnursing 0.0006 0.0012 0.0114 0 0.0019 0.0151 0.0357 Children 1-2 0.0013 0.0031 0.0210 0.0115 0.0020 0.0389 0.0192 years Children 3-5 0.0012 0.0020 0.0181 0.0114 0.0012 0.0339 0.0227 years Children 6-12 0.0007 0.0008 0.0123 0.0075 0.0007 0.0219 0.0250 years Youth 13-19 0.0004 0.0003 0.0097 0.0033 0.0007 0.0144 0.0167 years Adults 20-49 0.0003 0.0004 0.0114 0.0014 0.0006 0.0141 0 years Adults 50+ 0.0003 0.0005 0.0102 0.0014 0.0006 0.0130 0 years Females 13-49 0.0003 0.0005 0.0107 0.0016 0.0006 0.0137 0 yearse aBased on the exposure assessment by EPA (2004)
From page 57...
... from Drinking Water (All Sources) a Fluoride Concentrations in Tap Water (fixed nontap water at 0.5 mg/L)
From page 58...
... . The assumption for nontap water concentration is based on the most recent 6-year national public water system compliance monitoring from a 16-state cross section that represents approximately 41,000 public water systems, showing average fluoride concentrations of 0.482 mg/L in groundwater and 0.506 mg/L in surface water (EPA 2003a)
From page 59...
... , the contribution from toothpaste is reduced to approximately 5% at 1 mg/ L, 3-4% at 2 mg/L, and 2% at 4 mg/L. Correspondingly, the contribution from drinking water increases to approximately 57% at 1 mg/L, 70% at 2 mg/L, and 82% at 4 mg/L.
From page 60...
... For example, at an average fluoride concentration of 3.3 mg/L for brewed tea and 0.86 mg/L for iced tea (USDA 2004) , the tea component in the background food presented in Table 2-9 represents an average daily consumption of one-half cup of brewed tea or 2 cups of iced tea.
From page 61...
... Other groups of people who are expected to have exposures higher than those calculated here include infants given fluoride toothpaste before age 1, anyone who uses toothpaste more than twice per day or who swallows excessive amounts of toothpaste, children inappropriately given fluoride supplements in a fluoridated area, children in an area with high fluoride concentrations in soil, and children with pica who consume large amounts of soil. The exposure estimates presented in this chapter for non-drinking-water routes are based on the potential profile of fluoride residue concentrations
From page 62...
... . Any new and significant source of fluoride exposure, such as commodities approved for sulfuryl fluoride fumigation application beyond April 2005, is expected to alter the percentage of drinking water contribution as presented in this chapter.
From page 63...
... that all sources of drinking water (both tap and nontap water) contain the same specified fluoride concentration.
From page 64...
... summary oF exPosure assessment The estimated aggregated total fluoride exposures from pesticides, background food, air, toothpaste, and drinking water are summarized for drinking water fluoride concentrations of 1 mg/L (Table 2-13) , 2 mg/L (Table 2-14)
From page 65...
... 0.164 0.8 6.9 0.9 91.4 aWomen of childbearing age. ABBREVIATIONS: DM, diabetes mellitus; NDI, nephrogenic diabetes insipidus.
From page 66...
... 0.314 0.4 3.6 0.5 95.5 aWomen of childbearing age. ABBREVIATIONS: DM, diabetes mellitus; NDI, nephrogenic diabetes insipidus.
From page 67...
... By holding the exposure from drinking water at a constant with the EPA default water intake rates, children 1-2 years old have slightly higher total exposure than the nonnursing infants, reflecting the higher exposure from nonwater sources (Table 2-9)
From page 68...
... The estimated total exposure for children 1-2 years old and adults at 4 mg/L fluoride in drinking water is approximately two times the exposure at 2 mg/L and three times the exposure at 1 mg/L. The estimated total daily fluoride exposures for three population subgroups with significantly high water intake rates are included in Tables 2-13, 2-14, and 2-15.
From page 69...
... are probably most suitable for evaluating recent or current fluoride exposures or fluoride balance (intake minus excretion) , although some sources indicate that samples obtained from fasting persons may be useful for estimating chronic fluoride intake or bone fluoride concentrations (e.g., Ericsson et al.
From page 70...
... drinking water 1985 (Figure 2-6) 0.82 (range, 0.5-1.1)
From page 71...
... drinking water 1985 0.82 (range, 0.5-1.1)
From page 72...
... 2004 0.7-1.0 mg/L in drinking water, 10 9.2 mg/kg (peak) with fluoride dentifrice (after 4 months)
From page 73...
... drinking water 1985 0.82 (range, 0.5-1.1)
From page 74...
... (1999b) found that wholesaliva fluoride concentrations in 5- to 10-year-old children were not signifi 14 For example, following defluoridation of a town's water supply from 8 mg/L to around 1.3 mg/L (mean daily fluoride content over 113 weeks)
From page 75...
... Measured fluoride concentrations in human breast milk have been correlated with the2-4 mother's fluoride intake in some studies (Dabeka et al.
From page 76...
... (1999a) found a direct relationship between fluoride concentrations in drinking water and fluoride concentrations in fingernail 0.6 clippings0.03 0.4 0.02 from 6-0.05 7-year-old children with no known fluoride exposure 0.04 to 0.06 0.07 0.08 0.09 other than fromintake F drinking water.
From page 77...
... and serum (right) fluoride concentrations as 1.8 functions of estimated daily fluoride intake (data from Gupta et al.
From page 78...
... . Measuring the fluoride content of teeth and bones can give an indication of chronic or cumulative fluoride exposure, although after cessation of fluoride exposure, bone fluoride concentrations slowly decrease because of resorption of bone.
From page 79...
... for adults in areas of various fluoride concentrations in drinking water. However, the ranges (Table 2-16; see also Chapter 3, Figure 3-1)
From page 80...
... is characterized by increased bone mass, increased radiographic density of the bones, and a range of skeletal and joint symptoms; preclinical skeletal fluorosis is associated with fluoride concentrations of 3,500-5,500 ppm in bone ash and clinical stages I, II, and III with concentrations of 6,000-7,000, 7,500-9,000, and >8,400, respectively (PHS 1991) , although other sources indicate lower concentrations of bone fluoride in some cases of skeletal fluoride (see Chapter 5)
From page 81...
... These reports indicate that a fluoride concentration of 7-8 mg/L for 7 years is sufficient to bring about skeletal fluorosis (Felsenfeld and Roberts 1991) , but skeletal fluorosis may occur at much lower fluoride concentrations in cases of renal insufficiency (Juncos and Donadio 1972; Johnson et al.
From page 82...
... 82 ecnerefeR dnasocnuJ oidanoD 2791 .latenosnhoJ 9791 dlefnesleF streboRdna 1991 .lateetyh W 5002 stnemmoC cihpargonegtneordnasisoroufllemanE cimetsys"htiwtnetsisnocsegnahcenob noitanibmocehtotdetubirtta",sisoroufl eht(aispidylopdnaycneicfifusnilanerfo ;) esaesidlanereht enolaretawllew morfgnitluserrettal cinilCoya Mehtybdetroper foesuacehtneebevahyam"ediroulF cihpargonegtneordnalacinilcelbatceted "stceffe foesaesidlanerdahstneitapehtfoeviF latelekserofebnoitarudsraey51tsaelta enilakla depolevedsmotpmys muresdetavele,sisorelcsoetsO spihdnaseenkfossenffits,esatahpsohp sisohpyk,)
From page 83...
... 1999, 2000 0.05-0.07 "Useful upper limit for fluoride intake in children" Burt 1992 0.057-0.071 "Health hazard" for adults (4-5 mg/day) c McClure et al.
From page 84...
... , with 1 mg/L in drinking water; Figure 2-9 shows the average intake of fluoride from drinking water alone (Table 2-10) , given a fluoride concentration at the MCLG/MCL (4 mg/L)
From page 85...
... No other age groups have that intake at ordinary fluoride concentrations; all age groups reach or exceed that intake with water at 4 mg/L. For individuals with higherthan-average intake of community water, intakes for the youngest children (<1 year)
From page 86...
... ry1<(stnafnillA gnisruN· gnisrun-noN· ry2-1nerdlihC ry5-3nerdlihC yr 6-12 Children ry91-31htuoY ry94-02stludA yr 50+ Adults ry94-31sela meF FIGURE 2-9 Estimated average intake of fluoride from drinking water alone, based on a fluoride concentration of 4 mg/L (MCLGl/MCL; based on Table 2-10)
From page 87...
... Additional information on fluoride concentrations in soils in residential and recreational areas near industrial fluoride sources also should be obtained. · Additional studies on the relationship between individual fluoride exposures and measurements of fluoride in tissues (especially bone and nails)
From page 88...
... Important exposure aspects of such studies would include the following: ­ collecting data on general dietary status and dietary factors that could influence exposure or effects, such as calcium, iodine, and aluminum intakes ­ characterizing and grouping individuals by estimated (total) exposure, rather than by source of exposure, location of residence, fluoride concentration in drinking water, or other surrogates ­ reporting intakes or exposures with and without normalization for body weight (e.g., mg/day and mg/kg/day)


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