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OCR for page 416
Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
APPENDIX B
Measures of Exposure to Fluoride in the United States: Supplementary Information
U.S. DATA ON ARTIFICIAL AND NATURAL FLUORIDE IN DRINKING WATER
The recommended “optimal” fluoride concentrations for community public water supply systems and school public water supply systems are shown in Table B-1. Both sets of recommendations are based on the “annual average of maximum daily air temperatures” (CDC 1995, based on two studies in the 1950s). Table B-2 provides the approximate number of persons receiving artificially fluoridated public water in 1992, by fluoride concentration. In practice, most states seem to use a single fluoride concentration for the whole state. Figure B-1 shows the fluoride concentration by state with respect to annual average temperature for that state over the period 1971-2000. Table B-3 presents the approximate number of persons receiving naturally fluoridated public water in 1992, by fluoride concentration.
The number of persons served with public water supplies exceeding 4 milligrams (mg) of fluoride per liter (L) is expected to be substantially lower now than in 1992. For example, South Carolina, which had more than half of the persons in that category in 1992 (Table B-3), now has only occasional violations of the maximum contaminant level (MCL) (e.g., two water systems with 10 violations in calendar year 2003; SCDHEC 20041). On the other hand, a recent news article indicates that some areas in Virginia
1
See also local drinking water information by state at http://www.epa.gov/safewater/dwinfo.htm.
OCR for page 417
Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
TABLE B-1 Recommended Optimal Fluoride Concentrations for Public Water Supply Systems
Annual Average of Maximum Daily Air Temperaturesa
Recommended Fluoride Concentrations, mg/L
°F
°C
Community Water Systems
School Water Systemsb
50.0-53.7
10.0-12.0
1.2
5.4
53.8-58.3
12.1-14.6
1.1
5.0
58.4-63.8
14.7-17.7
1.0
4.5
63.9-70.6
17.8-21.4
0.9
4.1
70.7-79.2
21.5-26.2
0.8
3.6
79.3-90.5
26.3-32.5
0.7
3.2
aBased on temperature data obtained for a minimum of 5 years.
bBased on 4.5 times the optimal fluoride level for communities. School water fluoridation is recommended only when the school has its own source of water and is not connected to a community water system. Several other criteria are also considered; for example, if >25% of the children attending the school already receive optimally fluoridated water at home, the school’s water should not be fluoridated.
SOURCE: CDC 1995.
are still served by water systems with fluoride exceeding 4 mg/L (Hirschauer 2004).
Miller-Ihli et al. (2003) reported on fluoride concentrations in water samples collected in 1999 from 24 locations nationwide; these locations were expected to provide nationally representative samples for the National Food and Nutrient Analysis Program.2 Not unexpectedly, their findings indicate a bimodal distribution of fluoride concentrations in public drinking water: either water was fluoridated at approximately 1 mg/L or it was not fluoridated, with concentrations bordering on undetectable.
WATER INGESTION AND FLUORIDE INTAKES
Tables B-4 to B-7 summarize recent estimates by the U.S. Environmental Protection Agency (EPA) of the mean and selected percentiles of water ingestion by source (community supplies, bottled water, “other” sources, and all sources combined) and subpopulation (EPA 2000a); Tables B-8 and B-9
2
Miller-Ihli et al. (2003) reported that 40% of the samples were fluoridated and suggested that, rather than using an average fluoride concentration for the country, an individual should be assumed to have a 40% probability of ingesting fluoridated water and a 60% probability of ingesting nonfluoridated water. However, CDC (2002a) estimates that about two-thirds of the U.S. population served by public water supplies receives fluoridated water. Thus, the sampling reported by Miller-Ihli et al. was probably not sufficiently representative on a population-weighted basis.
OCR for page 418
Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
TABLE B-2 Population Sizes by Level of Artificial Fluoridation in 1992
Fluoride, mg/L
Number of Statesa
Population
Percentage
States
0.7
1
149,290
0.11
Hawaii
0.7-0.9
1
8,014,583
5.88
Texas
0.7-1.0
1
1,282,425
0.94
Arizona
0.8
4
12,886,396
9.46
Florida, Louisiana, Oklahoma, South Carolina
0.8-1.0
1
432,700
0.32
Delaware
0.9
2
7,177,525
5.27
Kentucky,b Virginiac
0.9-1.2
1
1,921,525
1.41
Colorado
1.0
29
93,060,026
68.30
Alabama, California, Connecticut, District of Columbia, Georgia, Idaho, Illinois, Indiana,c Kansas, Maryland, Massachusetts, Michigan, Mississippi, Missouri, Nebraska, Nevada, New Jersey, New Mexico, New York, North Carolina,c Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, Utah, Washington, West Virginia,c Wisconsin
1.0-1.1
2
1,931,337
1.42
Iowa, Wyoming
1.0-1.2
2
214,865
0.16
Montana, New Hampshire
1.1
1
233,447
0.17
Vermontd
1.2
5
5,026,243
3.69
Alaska, Maine, Minnesota,e North Dakota, South Dakota
No dataf
2
3,911,884
2.87
Arkansas, Puerto Rico
Total
52
136,242,246
100
aIncludes the 50 states, the District of Columbia, and Puerto Rico.
bA few small water supplies have artificial fluoride concentrations of 4.0 mg/L.
cA few small water supplies have artificial fluoride concentrations of 4.5 mg/L.
dA few small water supplies have artificial fluoride concentrations of 4.9 mg/L.
eA few small water supplies have artificial fluoride concentrations of 5.4 mg/L.
fData for Arkansas were not provided (the table for Arkansas contained a duplication of the Alaska data). The water fluoridation data were not provided for Puerto Rico.
SOURCE: CDC 1993.
give the corresponding estimates for consumption of community water or all water as a function of body weight. The data in Tables B-4 through B-9 are for those persons who actually consume water from the indicated source, rather than per capita estimates for the entire population. Estimates include plain (noncarbonated) drinking water and indirect water (water added to foods and beverages during preparation at home or by local food service establishments). Water in processed foods (commercial water) or naturally contained in foods (biological water) was not included.
OCR for page 419
Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
FIGURE B-1 Level of artificial fluoridation in 1992 by state (Table B-2; CDC 1993) versus area-weighted annual average temperature (°F) for that state over the period 1971-2000 (NCDC 2002a). Temperature for the District of Columbia is for Climate District 4 of the state of Maryland (NCDC 2002b). States with a range of artificial fluoride levels (Arizona, Colorado, Delaware, Iowa, Montana, New Hampshire, Texas, and Wyoming) are included at each relevant fluoride level. Arkansas and Puerto Rico are not included because of the lack of information on fluoride levels. Thin line indicates the “recommended optimal fluoride levels” for the given range of “annual average of maximum daily air temperatures” (emphasis added; Table B-1; CDC 1995).
EPA’s estimates are based on U.S. Department of Agriculture surveys taken in 1994, 1995, and 1996 of food ingestion data for two nonconsecutive days for a sample of more than 15,000 individuals in the 50 states and the District of Columbia selected to represent the entire U.S. population based on 1990 census data (EPA 2000a). (An additional survey of children in 1998 was included in the estimates used in Chapter 2.) Because these estimates were developed for the purpose of estimating people’s exposures to substances in drinking water and also are based on relatively recent data,
OCR for page 420
Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
TABLE B-3 Population Sizes by Level of Natural Fluoridation in 1992
Reported Level of Natural Fluoride, mg/L
Statea
Reported Range, mg/L
≤1.2
1.3-1.9
2.0-3.9
≥4.0
Not givenb
Reported Totalc
Alabama
0.7-3.6
27,368
25,195
6,827
0
—
54,283
Arizona
0.7-7.4
242,309
63,132
39,259
516
—
345,266
Arkansas
NAd
—
—
—
—
—
17,239
California
0.7-3.5
389,715
24,583
500
0
—
414,798
Colorado
0.1-11.2
363,905
75,755
361,969
1,926
—
801,224
Connecticut
0.7-1.9
870
160
0
0
—
1,030
Delaware
0.6-0.9
7,171
0
0
0
—
7,171
Florida
0.5-3.6
890,443
37,435
1,227
0
—
929,105
Georgia
0.7-2.0
16,039
878
1,200
0
7,475
25,592
Hawaii
0.7
354
0
0
0
—
354
Idaho
0.6-15.9
293,127
8,275
2,650
500
—
304,552
Illinois
0.7-4.0
291,600
91,237
56,481
500
6,658
446,050
Indiana
0.7-4.4
177,890
36,254
5,541
5,790
31,928
264,233
Iowa
0.7-7.0
186,936
90,182
28,484
1,445
—
302,652
Kansas
0.5-2.6
81,884
14,958
22,846
0
41,558
161,515
Kentucky
NAe
0
0
0
0
1,899
1,899
Louisiana
0.7-3.8
302,520
44,787
12,599
0
—
357,210
Maryland
0.3-5.1
36,583
11,705
100
225
—
48,613
Massachusetts
1.0-1.1
122
0
0
0
—
122
Michigan
0.7-1.9
114,605
9,968
0
0
—
124,623
Minnesota
0.7-3.2
2,386
908
367
0
—
4,000
Mississippi
0.8-3.5
93,120
9,965
1,560
0
—
104,645
Missouri
0.7-5.0
74,412
58,168
16,906
180
—
143,603
Montana
0.1-7.3
85,452
3,923
7,171
1,814
492
82,985
Nebraska
0.3-1.4
31,246
4,352
0
0
—
35,598
Nevada
0.5-2.6
16,440
3,628
5,187
0
—
25,255
New Hampshire
1.0-3.9
12,612
3,749
11,190
0
—
27,551
OCR for page 421
Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
New Jersey
0.7-2.5
32,344
56,450
24,651
0
—
113,445
New Mexico
0.7-13
178,754
45,619
58,556
4,295
261
287,485
New York
NAe
0
0
0
0
1,536
1,216
North Carolina
0.0-2.7
0
7,200
325
0
183,076
190,601
North Dakota
0.5-7.0
5,205
6,002
6,024
3,793
—
20,421
Ohio
0.8-2.8
131,963
104,558
13,450
0
1,010
249,755
Oklahoma
0.7-12.0
62,353
20,803
8,966
18,895
—
111,017
Oregon
0.7-2.4
39,865
2,320
680
0
—
42,865
South Carolina
0.1-5.9
62,924
27,968
190,430
105,618
—
378,995
South Dakota
0.7-6.0
10,097
14,053
41,038
692
—
37,758
Texas
0.7-8.8
2,234,504
426,341
233,326
36,863
25,200
2,955,395
Utah
0.7-2.0
8,240
2,560
0
0
—
10,800
Virginia
0.7-6.3
8,418
11,423
207,924
18,726
408
246,694
Washington
0.7-2.7
54,460
3,117
4,916
0
—
62,493
West Virginia
1.2
659
0
0
0
—
659
Wisconsin
0.7-2.7
90,713
36,570
50,140
0
—
174,850
Wyoming
0.7-4.5
14,694
21,984
2,144
120
—
38,942
Totals
6,674,302
1,406,165
1,424,634
201,898
301,501
9,954,559
aAlaska, the District of Columbia, Maine, Pennsylvania, Rhode Island, Tennessee, and Vermont reported no water systems with natural fluoridation.
bReported as 0.0 or some other number suspected to be a misprint.
cTotal given in the summary table for each state. Because of apparent internal inconsistencies, the numbers in the preceding columns do not necessarily give the same total.
dData for Arkansas were not provided (the table for Arkansas contained a duplication of the Alaska data).
eReported as 0.0 for all systems with natural fluoride.
SOURCE: CDC 1993.
OCR for page 422
Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
TABLE B-4 Estimated Average Daily Water Ingestion (mL/day) from Community Sources During 1994-1996, by People Who Consume Water from Community Sources
Population
Mean
50th Percentile
90th Percentile
95th Percentile
99th Percentile
Sample Size
Population
All consumers
1,000
785
2,069
2,600
4,273
14,012
242,641,675
<0.5 year
529
543
943
1,064
1,366
111
1,062,136
0.5-0.9 year
502
465
950
1,122
1,529
135
1,449,698
1-3 years
351
267
719
952
1,387
1,625
10,934,001
4-6 years
454
363
940
1,213
1,985
1,110
11,586,632
7-10 years
485
377
995
1,241
1,999
884
14,347,058
11-14 years
641
473
1,415
1,742
2,564
759
14,437,898
15-19 years
817
603
1,669
2,159
3,863
777
16,735,467
20-24 years
1,033
711
2,175
3,082
5,356
644
17,658,027
25-54 years
1,171
965
2,326
2,926
4,735
4,599
106,779,569
55-64 years
1,242
1,111
2,297
2,721
4,222
1,410
19,484,112
≥ 65 years
1,242
1,149
2,190
2,604
3,668
1,958
28,167,077
Males (all)
1,052
814
2,164
2,733
4,616
7,082
118,665,763
<1 year
462
441
881
1,121
1,281
118
1,191,526
1-10 years
444
355
934
1,155
1,731
1,812
18,847,070
11-19 years
828
595
1,673
2,058
3,984
768
15,923,625
≥ 20 years
1,242
1,038
2,387
3,016
4,939
4,384
82,703,542
Females (all)
951
747
2,005
2,482
3,863
6,930
123,975,912
<1 year
560
542
967
1,122
1,584
128
1,320,308
1-10 years
426
329
940
1,109
2,014
1,807
18,020,621
11-19 years
638
457
1,382
1,774
2,598
768
15,249,740
≥ 20 years
1,116
943
2,165
2,711
4,268
4,227
89,385,243
Lactating women
1,665
1,646
2,959
3,588
4,098
34
971,057
Pregnant women
872
553
1,844
2,588
3,448
65
1,645,565
Women aged 15-44 years
984
756
2,044
2,722
4,397
2,176
55,251,477
SOURCE: EPA 2000a.
OCR for page 423
Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
TABLE B-5 Estimated Average Daily Water Ingestion (mL/day) from Bottled Water During 1994-1996, by People Who Consume Bottled Water
Population
Mean
50th Percentile
90th Percentile
95th Percentile
99th Percentile
Sample Size
Population
All consumers
737
532
1,568
1,967
3,316
3,078
57,316,806
<0.5 year
411
349
896
951
1,193
51
538,267
0.5-0.9 year
437
361
802
808
1,578
37
456,103
1-3 years
302
232
649
819
1,175
368
2,532,201
4-6 years
390
315
794
922
1,319
213
2,336,873
7-10 years
416
323
828
985
1,767
164
2,808,756
11-14 years
538
361
1,099
1,420
2,192
148
2,896,893
15-19 years
665
468
1,503
1,777
3,149
163
3,528,434
20-24 years
786
532
1,640
2,343
3,126
179
5,089,216
25-54 years
822
621
1,773
1,981
3,786
1,174
28,487,354
55-64 years
860
685
1,833
2,306
2,839
279
3,987,578
≥ 65 years
910
785
1,766
2,074
2,548
302
4,655,131
Males (all)
749
523
1,626
2,097
3,781
1,505
26,298,392
<1 year
414
317
805
1,012
1,397
48
575,019
1-10 years
365
266
767
847
1,685
376
3,755,220
11-19 years
682
464
1,423
1,822
2,802
144
2,969,950
≥ 20 years
845
592
1,774
2,303
3,855
937
18,998,203
Females (all)
727
532
1,542
1,893
3,031
1,573
31,018,414
<1 year
436
428
895
896
1,301
40
419,351
1-10 years
375
289
765
993
1,347
369
3,922,610
11-19 years
544
357
1,116
1,537
3,143
167
3,455,377
≥ 20 years
819
690
1,747
1,975
3,060
997
23,221,076
Lactating women
749
608
1,144
1,223
1,286
7
278,308
Pregnant women
891
683
1,910
1,957
2,198
27
698,645
Women aged 15-44 years
766
592
1,598
1,922
3,093
611
16,279,438
SOURCE: EPA 2000a.
OCR for page 424
Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
TABLE B-6 Estimated Average Daily Water Ingestion (mL/day) from Other Sources (e.g., Wells and Cisterns) During 1994-1996, by People Who Consume Water from Those Sources
Population
Mean
50th Percentile
90th Percentile
95th Percentile
99th Percentile
Sample Size
Population
All consumers
965
739
1,971
2,475
3,820
2,129
34,693,744
<0.5 year
306
188
637
754
878
15
117,444
0.5-0.9 year
265
172
552
560
567
14
198,639
1-3 years
347
291
710
761
1,190
206
1,243,498
4-6 years
390
285
778
1,057
1,332
137
1,382,002
7-10 years
485
399
992
1,093
1,623
134
2,121,832
11-14 years
733
553
1,561
1,884
3,086
121
2,243,452
15-19 years
587
395
1,221
1,721
2,409
109
2,372,842
20-24 years
640
472
1,305
1,648
1,937
67
1,809,825
25-54 years
1,124
917
2,175
2,834
4,728
731
15,480,754
55-64 years
1,276
1,110
2,365
2,916
5,152
272
3,504,576
≥65 years
1,259
1,188
2,136
2,470
3,707
323
4,218,880
Males (all)
1,031
785
2,107
2,821
4,734
1,155
17,880,530
<1 year
243
148
554
567
773
16
198,829
1-10 years
426
320
884
1,077
1,630
259
2,566,652
11-19 years
702
564
1,366
1,753
2,787
103
2,011,715
≥20 years
1,212
1,001
2,286
3,017
4,883
777
13,103,334
Females (all)
894
710
1,826
2,225
3,035
974
16,813,214
<1 year
344
256
537
579
759
13
117,254
1-10 years
416
352
865
1,039
1,165
218
2,180,680
11-19 years
624
406
1,394
1,873
2,489
127
2,604,579
≥ 20 years
1,046
941
1,925
2,371
3,123
616
11,910,701
Lactating women
1,248
915
2,148
2,410
2,620
7
182,414
Pregnant women
1,066
660
1,676
1,807
3,374
7
168,433
Women aged 15-44 years
904
666
1,863
2,319
3,056
283
6,759,992
SOURCE: EPA 2000a.
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Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
TABLE B-7 Estimated Average Daily Water Ingestion (mL/day) from All Sources During 1994-1996 by Consumers of Water
Population
Mean
50th Percentile
90th Percentile
95th Percentile
99th Percentile
Sample Size
Population
All consumers
1,241
1,045
2,345
2,922
4,808
15,172
259,972,235
<0.5 year
544
545
947
1,078
1,365
156
1,507,727
0.5-0.9 year
580
563
1,130
1,273
1,672
154
1,732,993
1-3 years
422
351
807
993
1,393
1,814
12,143,483
4-6 years
548
468
1,019
1,268
2,031
1,193
12,438,322
7-10 years
608
514
1,131
1,425
2,172
937
15,248,676
11-14 years
815
651
1,625
1,962
3,033
812
15,504,627
15-19 years
1,006
776
1,897
2,414
4,027
814
17,697,092
20-24 years
1,283
1,013
2,508
3,632
5,801
678
18,544,787
25-54 years
1,486
1,273
2,638
3,337
5,259
4,906
113,011,204
55-64 years
1,532
1,378
2,557
2,999
4,395
1,541
21,145,387
≥65 years
1,453
1,345
2,324
2,708
3,750
2,167
30,997,937
Males (all)
1,300
1,070
2,483
3,149
5,212
7,689
126,998,276
<1 year
549
538
1,121
1,278
1,567
151
1,560,310
1-10 years
536
451
1,024
1,254
1,817
1,993
20,495,833
11-19 years
1,001
761
1,898
2,434
4,011
809
16,887,932
≥ 20 years
1,549
1,331
2,740
3,524
5,526
4,736
88,054,201
Females (all)
1,185
1,021
2,221
2,703
4,252
7,483
132,973,959
<1 year
577
559
950
1,131
1,654
159
1,680,410
1-10 years
528
445
993
1,226
2,035
1,951
19,334,648
11-19 years
830
664
1,652
1,955
3,083
817
16,313,787
≥20 years
1,389
1,221
2,416
2,928
4,512
4,556
95,645,114
Lactating women
1,806
1,498
3,021
3,767
4,024
41
1,171,868
Pregnant women
1,318
1,228
2,339
2,674
3,557
70
1,751,888
Women aged 15-44 years
1,265
1,065
2,366
2,952
4,821
2,314
58,549,659
SOURCE: EPA 2000a.
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Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
TABLE B-8 Estimated Average Daily Water Ingestion (mL/kg of Body Weight per Day) from Community Sources during 1994-1996, by People Who Consume Water from Community Sources
Population
Mean
50th Percentile
90th Percentile
95th Percentile
99th Percentile
Sample Size
Population
All consumers
17
13
33
44
79
13,593
236,742,834
<0.5 year
88
85
169
204
240
106
1,034,566
0.5-0.9 year
56
52
116
127
170
128
1,405,128
1-3 years
26
20
53
68
112
1,548
10,417,368
4-6 years
23
18
45
65
95
1,025
10,751,616
7-10 years
16
12
33
39
60
820
13,427,986
11-14 years
13
10
27
36
54
736
14,102,256
15-19 years
12
9
26
32
62
771
16,646,551
20-24 years
15
11
31
39
80
637
17,426,127
25-54 years
16
13
32
40
65
4,512
104,816,948
55-64 years
17
14
32
38
58
1,383
19,011,778
≥65 years
18
16
32
37
53
1,927
27,702,510
Males (all)
16
13
32
43
81
6,935
117,076,195
<1 year
66
60
139
175
235
115
1,180,289
1-10 years
21
16
43
55
87
1,705
17,865,064
11-19 years
14
10
27
38
67
755
15,717,364
≥ 20 years
15
13
30
38
62
4,360
82,313,478
Females (all)
17
14
35
45
77
6,658
119,666,639
<1 year
72
69
139
169
203
119
1,259,405
1-10 years
21
17
45
61
98
1,688
16,731,906
11-19 years
12
9
26
32
48
752
15,031,443
≥20 years
17
14
33
41
63
4,099
86,643,885
Lactating women
26
20
54
55
57
33
940,375
Pregnant women
14
9
43
47
65
1,645,565
Women aged 15-44 years
15
12
32
39
66
2,126
54,000,618
SOURCE: EPA 2000a.
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Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
they are appropriate for the present purpose of estimating the range of current exposures to fluoride. These estimates are based on a 2-day average, whereas for fluoride exposure, long-term averages of intake are usually more important. However, given the size of the population sampled, the likelihood that the entire sample represents days of unusually high or unusually low water intake is small. Thus, these values are considered reasonable indicators both of typical water consumption and of the likely range of water consumption from various sources on a long-term basis. However, they should not be used by themselves to estimate the number of individuals or percentage of the population that consumes a given amount of water on a long-term basis, especially not at the extremes of the range. Water intakes at the low end are not of major importance for the present report, and water intakes at the high end are considered separately (Chapter 2), with additional information beyond what is provided by EPA.
It may be helpful to compare the water intakes (all sources, Table B-7) with values for adequate intake3 (AI) of water recently published by the Institute of Medicine (IOM 2004; Table B-10). The AI for total water (drinking water, other beverages, and moisture contained in food) is set “to prevent deleterious, primarily acute, effects of dehydration, which include metabolic and functional abnormalities” (IOM 2004). “Given the extreme variability in water needs which are not solely based on differences in metabolism, but also in environmental conditions and activity, there is not a single level of water intake that would ensure adequate hydration and optimal health for half4 of all apparently healthy persons in all environmental conditions” (IOM 2004). The AI for total water is based on the median total water intake from U.S. survey data (NHANES III, 1988-1994; described by IOM 2004). Daily consumption below the AI is not necessarily a concern “because a wide range of intakes is compatible with normal hydration. Higher intakes of total water will be required for those who are physically active or who are exposed to [a] hot environment” (IOM 2004). For the intake values shown in Table B-10, approximately 80% of the intake comes from drinking water and other beverages (including caffeinated and alcoholic beverages).
Use of bottled water in the United States has at least doubled since 1990 (Grossman 2002), suggesting that more people use bottled water now than in 1994-1996 and/or that individuals use more bottled water per person.
3
“Adequate intake” is defined as “the recommended average daily intake level based on observed or experimentally determined approximations or estimates of nutrient intake by a group (or groups) of apparently healthy people that are assumed to be adequate—used when an RDA [recommended dietary allowance] cannot be determined” (IOM 2004).
4
The estimated average requirement (EAR) on which a recommended dietary allowance is based is defined as “the average daily nutrient intake level estimated to meet the requirement of half the healthy individuals in a particular life stage and gender group” (IOM 2004).
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Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
TABLE B-10 Adequate Intake Values (L/day) for Total Water
Males
Females
Group
From Foods
From Beverages
Total Water
From Foods
From Beverages
Total Water
0-6 months
0
0.7
0.7
0
0.7
0.7
7-12 months
0.2
0.6
0.8
0.2
0.6
0.8
1-3 years
0.4
0.9
1.3
0.4
0.9
1.3
4-8 years
0.5
1.2
1.7
0.5
1.2
1.7
9-13 years
0.6
1.8
2.4
0.5
1.6
2.1
14-18 years
0.7
2.6
3.3
0.5
1.8
2.3
>19 years
0.7
3.0
3.7
0.5
2.2
2.7
Pregnancya
—
—
—
0.7
2.3
3.0
Lactationa
—
—
—
0.7
3.1
3.8
aWomen aged 14-50 years.
SOURCE: IOM 2004.
However, total water consumption per person from all sources combined probably has not changed substantially. Information for a few groups in the tables (children < 1 year of age, pregnant and lactating women) is based on relatively small sample sizes, and the confidence to be placed in specific percentile values is therefore lower. Sample sizes for some other population subgroups of potential interest (e.g., Native Americans with traditional lifestyles, people in hot climates, people with high physical activity, people with certain medical conditions) were not large enough to evaluate intake by members of the subgroup, although some people from those groups are included in the overall sample (EPA 2000a).
Tables B-11 to B-14 summarize fluoride intakes that would result from ingestion of community water (for the mean, 90th, 95th, and 99th percentiles of consumption estimated by EPA) at various levels of water fluoride (“optimal” fluoridation levels of 0.7, 1.0, or 1.2 mg/L, and the present secondary MCL [SMCL] and MCL of 2 and 4 mg/L, respectively). The SMCL and MCL are included for purposes of comparison; most people in the Unites States do not drink water with those fluoride levels. An average consumer below the age of 6 months would have an intake of 0.06-0.1 mg/kg/day from fluoridated water (0.7-1.2 mg/L), whereas an adult would ingest approximately 0.01-0.02 mg/kg/day. Individuals at the upper levels of water intake from EPA’s estimates (Table B-14) could have fluoride intakes in excess of 1 mg/day at the lowest levels of fluoridation up to about 6 mg/day for some adults, depending on age and level of water fluoridation. Persons in the high-water-intake groups described above could have even higher intakes.
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Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
TABLE B-11 Estimated Intake of Fluoride from Community Water for Average Consumersa
Fluoride Level
Water Intake, mL/day
0.7 mg/L
1 mg/L
1.2 mg/L
2 mg/L
4 mg/L
Population
Intake, mg/day
All consumers
1,000
0.70
1.00
1.20
2.00
4.00
<0.5 year
529
0.37
0.53
0.63
1.06
2.12
0.5-0.9 year
502
0.35
0.50
0.60
1.00
2.01
1-3 years
351
0.25
0.35
0.42
0.70
1.40
4-6 years
454
0.32
0.45
0.54
0.91
1.82
7-10 years
485
0.34
0.49
0.58
0.97
1.94
11-14 years
641
0.45
0.64
0.77
1.28
2.56
15-19 years
817
0.57
0.82
0.98
1.63
3.27
20-24 years
1,033
0.72
1.03
1.24
2.07
4.13
25-54 years
1,171
0.82
1.17
1.41
2.34
4.68
55-64 years
1,242
0.87
1.24
1.49
2.48
4.97
≥65 years
1,242
0.87
1.24
1.49
2.48
4.97
Water Intake, mL/kg/day
Intake, mg per kg body weight/day
All consumers
17
0.012
0.017
0.020
0.034
0.068
<0.5 year
88
0.062
0.088
0.106
0.176
0.352
0.5-0.9 year
56
0.039
0.056
0.067
0.112
0.224
1-3 years
26
0.018
0.026
0.031
0.052
0.104
4-6 years
23
0.016
0.023
0.028
0.046
0.092
7-10 years
16
0.011
0.016
0.019
0.032
0.064
11-14 years
13
0.009
0.013
0.016
0.026
0.052
15-19 years
12
0.008
0.012
0.014
0.024
0.048
20-24 years
15
0.011
0.015
0.018
0.030
0.060
25-54 years
16
0.011
0.016
0.019
0.032
0.064
55-64 years
17
0.012
0.017
0.020
0.034
0.068
≥65 years
18
0.013
0.018
0.022
0.036
0.072
aBased on water consumption rates estimated by EPA (2000a).
EXPOSURES FROM FLUORINATED ANESTHETICS
The sampled data in Table B-15 illustrate wide ranges of reported mean peak serum fluoride concentrations from the use of fluorinated anesthetics under various surgical conditions and for different age groups ranging from 22-day-old infants to people > 70 years old. These data are collected from studies conducted in many countries, including Australia, France, Finland, Germany, Ireland, Japan, the United Kingdom, and the United States. The
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Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
TABLE B-12 Estimated Intake of Fluoride from Community Water for 90th Percentile Consumersa
Fluoride Level
Water Intake, mL/day
0.7 mg/L
1 mg/L
1.2 mg/L
2 mg/L
4 mg/L
Population
Intake, mg/day
All consumers
2,069
1.45
2.07
2.48
4.14
8.28
<0.5 year
943
0.66
0.94
1.13
1.89
3.77
0.5-0.9 year
950
0.67
0.95
1.14
1.90
3.80
1-3 years
719
0.50
0.72
0.86
1.44
2.88
4-6 years
940
0.66
0.94
1.13
1.88
3.76
7-10 years
995
0.70
1.00
1.19
1.99
3.98
11-14 years
1,415
0.99
1.42
1.70
2.83
5.66
15-19 years
1,669
1.17
1.67
2.00
3.34
6.68
20-24 years
2,175
1.52
2.18
2.61
4.35
8.70
25-54 years
2,326
1.63
2.33
2.79
4.65
9.30
55-64 years
2,297
1.61
2.30
2.76
4.59
9.19
≥65 years
2,190
1.53
2.19
2.63
4.38
8.76
Water Intake, mL/kg/day
Intake, mg per kg body weight/day
All consumers
33
0.023
0.033
0.040
0.066
0.132
<0.5 year
169
0.118
0.169
0.203
0.338
0.676
0.5-0.9 year
116
0.081
0.116
0.139
0.232
0.464
1-3 years
53
0.037
0.053
0.064
0.106
0.212
4-6 years
45
0.032
0.045
0.054
0.090
0.180
7-10 years
33
0.023
0.033
0.040
0.066
0.132
11-14 years
27
0.019
0.027
0.032
0.054
0.108
15-19 years
26
0.018
0.026
0.031
0.052
0.104
20-24 years
31
0.022
0.031
0.037
0.062
0.124
25-54 years
32
0.022
0.032
0.038
0.064
0.128
55-64 years
32
0.022
0.032
0.038
0.064
0.128
≥65 years
32
0.022
0.032
0.038
0.064
0.128
aBased on water consumption rates estimated by EPA (2000a).
minimum alveolar concentration per hour (MAC-hr) ranged from short-term (e.g., for cesarean section as reported by Abboud et al. 1989) to prolonged (e.g., >10 hours as reported by Murray et al. 1992 and Obata et al. 2000) surgery and up to 7 days of continuous exposure for critically ill patients (e.g., as reported by Osborne et al. 1996). Test subjects included healthy males who underwent 3-9 hours of anesthesia (Munday et al. 1995), female smokers (Laisalmi et al. 2003), infants and children (age as indicated
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Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
TABLE B-13 Estimated Intake of Fluoride from Community Water for 95th Percentile Consumersa
Fluoride Level
Water Intake, mL/day
0.7 mg/L
1 mg/L
1.2 mg/L
2 mg/L
4 mg/L
Population
Intake, mg/day
All consumers
2,600
1.82
2.60
3.12
5.20
10.40
<0.5 year
1,064
0.74
1.06
1.28
2.13
4.26
0.5-0.9 year
1,122
0.79
1.12
1.35
2.24
4.49
1-3 years
952
0.67
0.95
1.14
1.90
3.81
4-6 years
1,213
0.85
1.21
1.46
2.43
4.85
7-10 years
1,241
0.87
1.24
1.49
2.48
4.96
11-14 years
1,742
1.22
1.74
2.09
3.48
6.97
15-19 years
2,159
1.51
2.16
2.59
4.32
8.64
20-24 years
3,082
2.16
3.08
3.70
6.16
12.33
25-54 years
2,926
2.05
2.93
3.51
5.85
11.70
55-64 years
2,721
1.90
2.72
3.27
5.44
10.88
≥65 years
2,604
1.82
2.60
3.12
5.21
10.42
Water Intake, mL/kg/day
Intake, mg per kg body weight/day
All consumers
44
0.031
0.044
0.053
0.088
0.176
<0.5 year
204
0.143
0.204
0.245
0.408
0.816
0.5-0.9 year
127
0.089
0.127
0.152
0.254
0.508
1-3 years
68
0.048
0.068
0.082
0.136
0.272
4-6 years
65
0.046
0.065
0.078
0.130
0.260
7-10 years
39
0.027
0.039
0.047
0.078
0.156
11-14 years
36
0.025
0.036
0.043
0.072
0.144
15-19 years
32
0.022
0.032
0.038
0.064
0.128
20-24 years
39
0.027
0.039
0.047
0.078
0.156
25-54 years
40
0.028
0.040
0.048
0.080
0.160
55-64 years
38
0.027
0.038
0.046
0.076
0.152
≥65 years
37
0.026
0.037
0.044
0.074
0.148
aBased on water consumption rates estimated by EPA (2000a).
in Table B-15), and patients with renal insufficiency (Conzen et al. 1995). In general, higher MAC-hr resulted in higher peak serum inorganic fluoride concentration. None of the studies presented in Table B-15 shows clear evidence of renal impairment as a result of the increased serum fluoride concentration, except transient reduction in renal function among the elderly (>70 years) reported by Hase et al. (2000). Higher peak serum concentration
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Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
TABLE B-14 Estimated Intake of Fluoride from Community Water for 99th Percentile Consumersa
Population
Water Intake, mL/day
Fluoride Level.
0.7 mg/L
1 mg/L
1.2 mg/L
2 mg/L
4 mg/L
Intake, mg/day
All consumers
4,273
2.99
4.27
5.13
8.55
17.09
<0.5 year
1,366
0.96
1.37
1.64
2.73
5.46
0.5-0.9 year
1,529
1.07
1.53
1.83
3.06
6.12
1-3 years
1,387
0.97
1.39
1.66
2.77
5.55
4-6 years
1,985
1.39
1.99
2.38
3.97
7.94
7-10 years
1,999
1.40
2.00
2.40
4.00
8.00
11-14 years
2,564
1.79
2.56
3.08
5.13
10.26
15-19 years
3,863
2.70
3.86
4.64
7.73
15.45
20-24 years
5,356
3.75
5.36
6.43
10.71
21.42
25-54 years
4,735
3.31
4.74
5.68
9.47
18.94
55-64 years
4,222
2.96
4.22
5.07
8.44
16.89
≥65 years
3,668
2.57
3.67
4.40
7.34
14.67
Water Intake, mL/kg/day
Intake, mg per kg body weight/day
All consumers
79
0.055
0.079
0.095
0.158
0.316
<0.5 year
240
0.168
0.240
0.288
0.480
0.960
0.5-0.9 year
170
0.119
0.170
0.204
0.340
0.680
1-3 years
112
0.078
0.112
0.134
0.224
0.448
4-6 years
95
0.067
0.095
0.114
0.190
0.380
7-10 years
60
0.042
0.060
0.072
0.120
0.240
11-14 years
54
0.038
0.054
0.065
0.108
0.216
15-19 years
62
0.043
0.062
0.074
0.124
0.248
20-24 years
80
0.056
0.080
0.096
0.160
0.320
25-54 years
65
0.046
0.065
0.078
0.130
0.260
55-64 years
58
0.041
0.058
0.070
0.116
0.232
≥65 years
53
0.037
0.053
0.064
0.106
0.212
aBased on water consumption rates estimated by EPA (2000a).
was reported for smokers (Cousins et al. 1976; Laisalmi et al. 2003) and is associated with alcohol, obesity, and multiple drug use (Cousins et al. 1976). Because the reference point for the potential nephrotoxicity in these studies was the peak serum fluoride concentration, data are generally not available for an estimation of the total fluoride load or the area under the curve from the use of these anesthetics.
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Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
TABLE B-15 Serum Inorganic Fluoride Concentration from Fluorinated Anesthetic Agents
Mean Serum Inorganic Fluoride, μM
Age (range)
No. of Subjects
MAC-houra
Baseline
Peak
References
Isoflurane
51 years
13
NA
NA
No change
Hara et al. 1998
NA
90
NA
NA
3
Groudine et al. 1999
>70 years
6
3.7
NA
4
Hase et al. 2000
55.5 years
26
NA
about 2.5
5
Goldberg et al. 1996
57 years
24
1.1
3.8
5.4
Newman et al. 1994
28 years
11
9.2
<2
5.5
Higuchi et al. 1995
28 yearsb
20
0.06
5.6
5.6
Abboud et al. 1989
27.7 yearsb
20
0.14
5.9
5.6
Abboud et al. 1989
48.5 years
20
15.9
NA
7.4
Obata et al. 2000
53.7 years
7
4.8
NA
8
Matsumura et al. 1994
26-54 years
5
NAc
2.1-2.4
8.4-27.9
Osborne et al. 1996
20-75 years
9
19.2
3.5-3.8
43.2
Murray et al. 1992
Enflurane
22 days to 11 years
40
0.3-0.7
NA
2-8
Oikkonen and Meretoja 1989
0.7-1.5
NA
4-10
Oikkonen and Meretoja 1989
1.5-3.3
NA
6-10
Oikkonen and Meretoja 1989
22 day
1
0.6
NA
3
Oikkonen and Meretoja 1989
29 day
1
1.5
NA
7
Oikkonen and Meretoja 1989
3 months
1
1.6
NA
11
Oikkonen and Meretoja 1989
4 months
1
1.6
NA
11
Oikkonen and Meretoja 1989
9 months
1
2.0
NA
7
Oikkonen and Meretoja 1989
1-9 years
8
NA
1.7
10.5
Hinkle 1989
47-60 years
5
4-6.8
about 2-3
7
Sakai and Takaori 1978
63.9 years
20
1.07
NA
13.3
Conzen et al. 1995
48 years(27-58 years)
16
1
NA
13.8
Laisalmi et al. 2003
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Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
44 years (35-39 years)d
17
1
NA
18.7
Laisalmi et al. 2003
59.3 years
40
2.8
1.2
16.75
Blanco et al. 1995
47.8 years
8
1.24
2-2.5
18
Cousins et al. 1987
40.2 years
10
2.7
1.8
22.2
Cousins et al. 1976
18-35 years
5
6
28.1
Munday et al. 1995
18-35 years
5
NA
27.5
Munday et al. 1995
Halothane
41.5 years
10
4.9
1.9
1.6
Cousins et al. 1976
6.2 years (1-12 years)
40
2.6
NA
1.8
Sarner et al. 1995
42-57 years
5
2.9-4.9
2-3
3
Sakai and Takaori 1978
50 years
8
2.5
2-2.5
4
Cousins et al. 1987
28.9 years
20
0.07
5.9
5.6
Abboud et al. 1989
9.2 years (5-12 years)
25
2.2
NA
6
Taivainen et al. 1994
20-75 years
10
19.5
3.8
12.6
Murray et al. 1992
Sevoflurane
12 months (7.7-25 months)
41
4.7
NA
13.8
Lejus et al. 2002
6.2 years (1-12 years)
40
2.6
NA
14.7
Sarner et al. 1995
>70 years
7
5.1
NA
18
Hase et al. 2000
8.8 years
25
2.2
NA
21
Taivainen et al. 1994
50 years
25
0.8
3.8
23
Newman et al. 1994
67.4 years
21
1.01
NA
25
Conzen et al. 1995
60.5 years
40
2.9
1.2
27.7
Blanco et al. 1995
52.7 years
24
NA
about 2.5
28
Goldberg et al. 1996
18-35 years
5
3
NA
30.5
Munday et al. 1995
5
6
31-34
5
9
36.6
29 years
15
9.9
<2
36.8
Higuchi et al. 1995
53 years
13
3.7
NA
about 31
Hara at al. 1998
NA
98
2.9
NA
40
Groudine et al. 1999
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Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
Mean Serum Inorganic Fluoride, μM
Age (range)
No. of Subjects
MAC-houra
Baseline
Peak
References
26.6 years (19-49 years)
11
10.6
NA
41.9
Higuchi et al. 1994
56.8 years
10
18.0 high flow
NA
47.1
Obata et al. 2000
62.0 years
10
16.7 low flow
NA
53.5
Obata et al. 2000
54.9 years
8
6.1
NA
54
Matsumura et al. 1994
24 years
8
14.0
<2
57.5
Higuchi et al. 1995
aMAC is the minimum alveolar concentration, or the mean end-tidal anesthetic concentration. When MAC-hr is not reported, it is estimated as MAC-hr = (mean percent concentration) x (anesthesia time).
bCesarean section patients with induction to delivery time of 7.4-8.4 minutes.
cCritically ill patients under anesthesia for 5-7 days at 0.6-1.2% isoflurane.
dSmoking > 10 cigarettes a day.
ABBREVIATION: NA, not applicable.
OCR for page 437
Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
TABLE B-16 Summary of Estimated Safe and Adequate Daily Dietary Intakesa of Fluoride
Age, years
Weight, kgb
Range, mg/day
Range, mg/kg/dayc
0-0.5
6
0.1
0.5
0.017
0.083
0.5-1
9
0.2
1.0
0.022
0.11
1-3
13
0.5
1.5
0.038
0.12
4-6
20
1.0
2.5
0.050
0.13
7-10
28
1.5
2.5
0.054
0.089
Males
11-14
45
1.5
2.5
0.033
0.056
15-18
66
1.5
2.5d
0.023
0.038
19-24
72
1.5
4.0e
0.021
0.056
25-50
79
1.5
4.0
0.019
0.051
51+
77
1.5
4.0
0.019
0.052
Females
11-14
46
1.5
2.5
0.033
0.054
15-18
55
1.5
2.5d
0.027
0.045
19-24
58
1.5
4.0e
0.026
0.069
25-50
63
1.5
4.0
0.024
0.063
51+
65
1.5
4.0
0.023
0.062
aThe term “safe and adequate daily dietary intake” was used by the NRC (1989b) “when data were sufficient to estimate a range of requirements, but insufficient for developing [a Recommended Dietary Allowance].” This category was to be accompanied by “the caution that upper levels in the safe and adequate range should not be habitually exceeded because the toxic level for many trace elements may be only several times usual intakes.” Use of this term should not be taken to imply that the present committee considers these intakes to be safe or adequate.
bMedian for age group.
cCalculated from range (mg/day) and weight (kg) given for age groups.
dUpper limit for children and adolescents (upper age not specified).
eUpper limit for adults.
SOURCE: NRC 1989b.
REFERENCE INTAKES OF FLUORIDE
Table B-16 provides the median weight and range of fluoride intake (mg/day; safe and adequate daily dietary intake5), by age group, from the National Research Council (NRC 1989b). Table B-17 provides the reference
5
The term “safe and adequate daily dietary intake” was used by the NRC (1989b) “when data were sufficient to estimate a range of requirements, but insufficient for developing [a Recommended Dietary Allowance].” This category was to be accompanied by “the caution that upper levels in the safe and adequate range should not be habitually exceeded because the toxic level for many trace elements may be only several times usual intakes.” Use of this
OCR for page 438
Fluoride in Drinking Water: A Scientific Review of EPA’S Standards
TABLE B-17 Summary of Dietary Reference Intakes of Fluoride
Reference Weight, kg
Adequate Intake
Tolerable Upper Intake
Age, years
mg/d
mg/kg/daya
mg/d
mg/kg/daya
0-0.5
7
0.01
0.0014
0.7
0.10
0.5-1
9
0.5
0.056
0.9
0.10
1-3
13
0.7
0.054
1.3
0.10
4-8
22
1
0.045
2.2
0.10
9-13
40
2
0.050
10
0.25
Boys 14-18
64
3
0.047
10
0.16
Girls 14-18
57
3
0.053
10
0.18
Males 19+
76
4
0.053
10
0.13
Females 19+
61
3
0.049
10
0.16
aCalculated from intake (mg/day) and weight (kg) given for age groups by IOM (1997) and ADA (2005).
SOURCES: IOM 1997; ADA 2005.
weight and range of fluoride intake (mg/day; dietary reference intake), by age group, from the Institute of Medicine (IOM 1997) and the American Dental Association (ADA 2005). In both tables, the intakes in terms of mg/ kg/day were calculated from the cited information as indicated.
term should not be taken to imply that the present committee considers these intakes to be safe or adequate.
Representative terms from entire chapter:
table stud
