Breast Milk Iodine and Perchlorate Concentrations in Lactating Boston-Area Women

0021-972X/07/$15.00/0
The Journal of Clinical Endocrinology & Metabolism 92(5):1673–1677
Printed in U.S.A.
Copyright © 2007 by The Endocrine Society
doi: 10.1210/jc.2006-2738
Breast Milk Iodine and Perchlorate Concentrations in
Lactating Boston-Area Women
Elizabeth N. Pearce, Angela M. Leung, Benjamin C. Blount, Hamid R. Bazrafshan, Xuemei He,
Sam Pino, Liza Valentin-Blasini, and Lewis E. Braverman
Section of Endocrinology, Diabetes, and Nutrition (E.N.P., A.M.L., X.H., S.P., L.E.B.), Boston Medical Center and Boston
University School of Medicine, Boston, Massachusetts 02118; Division of Laboratory Sciences (B.C.B., L.V.-B.), National
Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia 30333; and Department of
Medicine (H.R.B.), Golestan University Medical School, Golestan, Islamic Republic of Iran
Context: Breastfed infants rely on adequate maternal dietary iodine
(range, 25–920 ?g/liter). Perchlorate was detectable in all 49 breast milk
intake.
samples (range, 1.3– 411 ?g/liter), all 56 urine samples (range, 0.37–127
?g/liter), and all 17 infant formula samples (range, 0.22–4.1 ?g/liter)
Objective: Our objective was to measure breast milk iodine and
measured. Breast milk iodine content was significantly correlated with
perchlorate, an inhibitor of iodide transport into the thyroid and
urinary iodine per gram creatinine and urinary cotinine but was not
potentially into breast milk, in Boston-area women.
significantly correlated with breast milk or urinary perchlorate.
Participants: The study included 57 lactating healthy volunteers in
Conclusions: Perchlorate exposure was not significantly correlated
the Boston area.
with breast milk iodine concentrations. Perchlorate was detectable in
infant formula but at lower levels than in breast milk. Forty-seven
Measurements: Breast milk iodine and perchlorate concentrations
percent of women sampled may have been providing breast milk with
and urine iodine, perchlorate, and cotinine concentrations were mea-
insufficient iodine to meet infants’ requirements. (J Clin Endocri-
sured. For comparison, iodine and perchlorate levels in infant for-
nol Metab 92: 1673–1677, 2007)
mulae were also measured.
Results: Median breast milk iodine content in 57 samples was 155
?g/liter (range, 2.7–1968 ?g/liter). Median urine iodine was 114 ?g/liter
THYROID HORMONE, REQUIRING adequate iodine in- takeintheperinatalperiod,theNationalAcademyofSciences
take, is critical for neurodevelopment in utero and in early
recently recommended that consideration be given to adding
life. Worldwide, iodine deficiency remains the leading cause of
iodine to all prenatal vitamins (7). The American Thyroid As-
preventable mental retardation (1). Since the 1920s, U.S. dietary
sociation has also recently recommended that all women re-
iodine has generally been adequate. However, among U.S.
ceive 150 ?g iodine supplements daily during pregnancy and
women of childbearing age (15–44 yr), median urinary iodine
lactation and that all prenatal vitamins contain 150 ?g iodine (8).
levels, a biomarker for dietary iodine, decreased by over 50%
Perchlorate is an anion that decreases the uptake of iodine
from 1971–1994 according to data from the National Health and
into the thyroid gland and potentially into milk ducts in the
Nutrition Examination Survey (NHANES) (2). More recent
lactating breast by competitively inhibiting the sodium/iodide
NHANES data indicate that urinary iodine levels have stabi-
symporter (NIS) on the basolateral surface of thyroid cells and
lized (3). Although the latest NHANES study demonstrated an
on lactating breast cells. Perchlorate is a component of solid
adequate median urinary iodine level of 167.8 ?g/liter in U.S.
rocket fuel, is found in Chilean nitrate fertilizers used in the
adults, 16.8% of U.S. women of childbearing age had urinary
United States, and is an environmental contaminant from nat-
iodine concentrations of less than 50 ?g/liter (3). In our pop-
ural processes in many regions of the United States. Perchlorate
ulation at Boston Medical Center, we have reported that 9% of
has been detected in the drinking water of communities around
100 women sampled had urinary iodine levels below 50 ?g/
the United States (9), including Massachusetts (10). It has also
liter, and 49% had values below that recommended for preg-
been detected in foods such as lettuce and wheat (11, 12). Per-
nant women (4). Breastfed infants are reliant on adequate ma-
chlorate exposure appears to be ubiquitous in the U.S. popu-
ternal dietary iodine intake (5). The Institute of Medicine’s
lation (13). A recent study measured perchlorate in the breast
recommended dietary allowance for lactating women is 290 ?g
iodine daily (6). Based on concerns about adequate iodine in-
milk of 36 women from 18 states and found detectable levels in
all of the samples (range, 0.6–2.2 ?g/liter) (14). Breast milk
iodide and perchlorate concentrations were inversely corre-
First Published Online February 20, 2007
lated in the six samples with perchlorate concentrations of at
Abbreviations: NHANES, National Health and Nutrition Examina-
least 10 ?g/liter, although there were no correlations between
tion Survey; NIS, sodium/iodide symporter.
breast milk iodide and perchlorate in the full data set (14).
JCEM is published monthly by The Endocrine Society (http://www.
Another recent study concluded that cigarette smoking
endo-society.org), the foremost professional society serving the en-
docrine community.
decreases breast milk iodine concentrations (15). Cigarette
1673
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J Clin Endocrinol Metab, May 2007, 92(5):1673–1677
Pearce et al. • Breast Milk Iodine and Perchlorate
smoke contains significant levels of cyanide that is metab-
subjects whose breast milk was measured sequentially was assessed
olized to thiocyanate, a known competitive inhibitor of the
using repeated-measures ANOVA. Differences in breast milk and urine
NIS. Elevated serum thiocyanate levels may inhibit NIS-
iodine values between smokers and nonsmokers and differences in
measured and labeled infant formula iodine content were assessed using
mediated transport of iodide in the lactating breast, leading
an independent t test. Differences in mean values across subject groups
to reduced breast milk iodine levels.
were assessed by ANOVA. Differences in median iodine and perchlorate
The objective of the present study was to determine
values in breast milk compared with infant formula were assessed using
whether breast milk iodine concentrations in Boston-area
the Wilcoxon rank sum test.
women are adequate for infant nutrition and whether breast
milk iodine concentrations may be associated with environ-
Results
mental perchlorate or cigarette smoke exposure. Levels of
Median iodine content in the 57 breast milk samples was
iodine and perchlorate in breast milk were compared with
155 ?g/liter [range, 2.7–1968 ?g/liter; mean (? sd), 205 ?
those measured in 17 brands of infant formulae.
271 ?g/liter]. There was no significant intrafeed variation in
the iodine content of the subjects whose breast milk was
assessed sequentially during a single feed. Breast milk iodine
Subjects and Methods
concentrations in the three women who reported using io-
We obtained breast milk and urine samples from 57 healthy Boston-
dine-containing multivitamins were 28, 68, and 187 ?g/liter.
area volunteers (range, 19 – 45 yr; mean age, 30 ? 6 yr), at 10 –250
In a subset of 27 women whose use of iodized table salt was
(median, 48) days postpartum, between July 2002 and April 2006. The
local Institutional Review Board approved the protocol, and informed
determined, there was no significant difference in breast milk
consent was obtained from all participants. Volunteers were recruited
iodine levels between the subjects who reported regular,
through various means, including a community-based new mothers’
occasional, or no use of iodized salt (P ? 0.16). There was a
group, routine postpartum visits at a hospital-based inner-city obstetric
slight but significant positive correlation between breast milk
clinic, and flyers posted in a hospital lobby. Of the women studied, 72%
iodine content and maternal age (r2 ? 0.08; P ? 0.04) but not
reported taking prenatal multivitamins, but only three were using io-
dine-containing multivitamin preparations.
infant age (P ? 0.4). Median urine iodine content was 114
Twenty-seven women completed a questionnaire regarding their de-
?g/liter (range, 25–920 ?g/liter; mean, 155 ? 142).
mographics and intake of dietary iodine and iodine-containing multi-
Perchlorate was detectable in all 49 breast milk samples (me-
vitamins. Spot urinary iodine measurements were obtained from all
dian, 9.1 ?g/liter; range, 1.3–411; mean, 33 ? 77) and 56 urine
subjects. Urine perchlorate, creatinine, and cotinine (a metabolite of
nicotine in cigarette smoke) concentrations were also measured. Samples
samples tested (median, 3.0 ?g/liter; range, 0.37–127; mean,
of breast milk (approximately 10 ml) were collected at the start of a feed
8.2 ? 19). Cotinine was detected in the urine of 32 (57%) of 56
using either hand expression or a breast pump in 27 of the women.
urine samples tested (range, 1.5–1575 ng/ml), with six (19%) of
Samples of breast milk were collected in 5-ml increments sequentially
these likely to be smokers (urinary cotinine ?500 ng/ml). Mean
using a breast pump in the other 30 women. In this subset of 30 subjects,
breast milk iodine was 62 ? 35 ?g/liter in the smokers and
we measured breast milk iodine concentrations both at the start of a feed
and sequentially throughout a single feed to assess any potential in-
221 ? 285 ?g/liter in the nonsmokers (P ? 0.0005), whereas
trafeed variation. In the women whose breast milk was collected in
urinary iodine did not differ between these groups (P ? 1.0).
sequential increments, the mean breast milk iodine concentration is
There were significant differences in the mean breast milk per-
reported. Enough breast milk was available in 49 (86%) and enough
chlorate concentrations between the women recruited from the
urine was available in 56 (98%) of the samples for the measurement of
perchlorate. Enough urine was available in 56 (98%) of the samples for
mothers seen at routine postpartum visits at a hospital-based
the measurement of cotinine. All breast milk and urine samples were
inner-city obstetric clinic (n ? 10; 88.0 ? 150.0 ?g/liter), those
obtained within the same hour.
from the community-based new mothers’ group (n ? 9; 50.0 ?
Seventeen brands of infant formulae were also assessed for iodine and
62.5 ?g/liter), and those recruited by the hospital postings (n ?
perchlorate levels. A single sample of each different type of liquid
30; 10.3 ? 13.8 ?g/liter) (P for difference across the three groups
formula available at a local supermarket was purchased for testing. Nine
brands were sold in concentrated form and designed to be diluted by
was 0.01). There were no significant differences between breast
half before use. Iodine and perchlorate levels were measured directly in
milk iodine, urinary iodine, urinary perchlorate, and urinary
these samples, and the results were divided by half to reflect the con-
cotinine across these subject groups.
centration intended for infant use. The other eight brands were sold
Breast milk and urine iodine content in micrograms per
ready for use.
Breast milk, infant formulae, and urine iodine concentrations were
liter were not significantly correlated (r2 ? 0.06; P ? 0.08). A
measured spectrophotometrically by a modification of the method of
significant positive correlation between breast milk iodine
Benotti et al. (16). Iodine concentrations were measured at least twice; in
and urine iodine content per gram creatinine was observed
95% of the samples, the initial two measurements were within 15% of
(r2 ? 0.27; P ? 0.0001). There was a significant positive
each other, and the two values were averaged. In the case where the
correlation between breast milk perchlorate and urine per-
initial two measurements were not within 15% of each other, a third
measurement was obtained, and the average of all measurements was
chlorate concentrations (r2 ? 0.11; P ? 0.02). There were no
reported. Cotinine measurements were performed by immunoassay
significant correlations between breast milk iodine and per-
(Immulite 2000 Nicotine Metabolite Assay; Diagnostic Products Corp.,
chlorate concentrations (n ? 49; r2 ? 0.05; P ? 0.1) (Fig. 1),
Los Angeles, CA). Urine creatinine measurements were performed us-
including the 23 women whose breast milk perchlorate val-
ing Jaffe’s alkaline picrate method. The perchlorate content of breast
milk, infant formulae, and urine samples was measured at the Centers
ues were 10 ?g/liter or higher (r2 ? 0.002; P ? 0.8). Breast
for Disease Control and Prevention laboratories in Atlanta, GA, using
milk iodine and urine perchlorate concentrations (r2 ? 0.004;
ion chromatography-mass spectrometry (17).
P ? 0.7) were not significantly correlated. There was a slight
All statistical analyses were carried out using SAS version 9.1 (SAS
but significant inverse correlation between breast milk iodine
Institute, Cary, NC). Spearman’s rank correlation coefficient was used
and urine cotinine concentrations (r2 ? 0.13; P ? 0.006) (Fig.
to determine whether linear associations were present, and multivariate
linear regression was used to determine significant predictors of breast
2). In multivariate models, breast milk perchlorate (P ? 0.9),
milk iodine concentration. Intrafeed variation in the iodine content of the
urine perchlorate (P ? 0.4), urine cotinine (P ? 0.2), and baby
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Pearce et al. • Breast Milk Iodine and Perchlorate
J Clin Endocrinol Metab, May 2007, 92(5):1673–1677
1675
2500
500
(n = 49, r2 = 0.05, p = 0.1)
2000
)
/L)
400
g
c
1500
e (mcg/L
300
i
n
I
odine (m

Iod
1000
i
lk
t

M
s
a
200
500
Breast Milk
ean Bre
100
0
M
0
0
100
200
300
400
500
0
1
2
3
4
Breast Milk Perchlorate (mcg/L)
SD: 14.6
20.5
18.1
441.3
FIG. 1. Correlation between breast milk iodine and perchlorate con-
Quartile
centrations.
FIG. 3. Mean breast milk iodine content by quartile, with SD shown
numerically. Dotted line corresponds to approximate breast milk io-
age (P ? 0.6) did not predict breast milk iodine levels. As-
dine content required to achieve adequate intake (110 –130 ?g/liter)
suming an average daily infant intake of 0.78 liters breast
for an infant age 0 – 6 months.
milk (1) and that these breast milk samples are representa-
tive, 27 of the 57 samples (47%) did not contain sufficient
iodine levels are highest in transitional milk (2–5 d postpar-
iodine to meet infants’ adequate intake of 110 –130 ?g/d, as
tum) and decrease to stable levels by 10 d postpartum (18).
recommended by the Institute of Medicine (Fig. 3).
We report that among the 30 subjects whose breast milk was
In the 17 brands of infant formulae, the median measured
sampled sequentially, there were no significant intrafeed
iodine concentration was 145 ?g/liter (range, 84–224 ?g/liter),
variations in iodine concentration. A recent study suggests,
and the median perchlorate concentration was 1.50 ?g/liter
however, that there is a substantial amount of day-to-day
(range, 0.22–4.1 ?g/liter) (Table 1). Measured infant formula
and diurnal variation in breast milk iodine excretion (19).
iodine concentrations were significantly higher than labeled
The median breast milk iodide level in a 1984 sample of 37
amounts (P ? 0.0001). There was no significant difference be-
U.S. women was 178 ?g/liter (20), which is similar to the
tween the median breast milk and infant formula iodine con-
median iodine value of 155 ?g/liter observed in our study.
centrations (P ? 1.0), whereas the median breast milk perchlor-
However, the median breast milk iodine value in our study
ate concentration was significantly higher than the median
was far higher than the median values of breast milk iodide
infant formula perchlorate concentration (P ? 0.0001).
(33.5 and 55.2 ?g/liter) observed recently by Kirk et al. (14,
19) in two samples of U.S. women. Some, but not all, of this
Discussion
difference may be due to our method of measuring total
Iodine is avidly concentrated in the lactating breast, due to
iodine in contrast to Kirk et al. (14, 19), who measured only
increased expression of NIS during lactation (18). Breast milk
ionic iodine (iodide); however, approximately 80 –90% of
iodine in human milk is in the form of iodide (S. Pino,
2500
unpublished data). The median breast milk iodine concen-
tration observed in our study was also far higher than the
(n = 56, r2 = 0.13, p = 0.006)
mean value of 38.5 ?g/liter reported in 55 Chilean women
2000
(21); the iodine content of breast milk from the Chilean
/L)
women was measured by the same method as reported in the
1500
current manuscript (16). Tellez et al. (21) in the Chilean study
(mcg
and Chan et al. (22) in an Australian study reported that
1000
breast milk iodine levels correlate with urinary iodine per
Iodine
i
lk
gram creatinine but not with unadjusted urinary iodine val-
ues, as seen in the present study.
st M
500
Assuming breast milk intake of 0.78 liter/d (6) as the only
Brea
source of breastfed infant iodine nutrition, and that single
0
samples are representative of daily breast milk iodine con-
tent, which may not be correct due to the day-to-day and
-500
diurnal variation in breast milk iodine content noted by Kirk
0
200
400
600
800
1000
1200
1400
1600
1800
et al. (19), 47% of women sampled may have been providing
Urinary Cotinine (ng/mL)
breast milk with insufficient iodine to meet infants’ daily
FIG. 2. Correlation between breast milk iodine and urine cotinine
requirements. The difference between median breast milk
concentrations.
and measured infant formula iodine levels was not signifi-
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J Clin Endocrinol Metab, May 2007, 92(5):1673–1677
Pearce et al. • Breast Milk Iodine and Perchlorate
TABLE 1. Iodine and perchlorate concentrations in 17 brands of infant formulae
Labeled iodine
Measured iodine
Measured perchlorate
Liquid infant formula brand
(?g/liter)
(?g/liter)
(?g/liter)
Milk-based
Enfamil A.R. Lipil (thickened with rice starch, iron-fortified)
67
224
4.1
Enfamil LactoFree Lipil (lactose-free, iron-fortified)a
100
120
0.4
Enfamil Lipil Low Iron
67
158
2.1
Enfamil Lipil with Iron (infant formula)a
67
102
1.7
Enfamil with Iron (milk-based)a
67
162
2.0
Nestle Good Start with Iron (Supreme, with easy to digest
80
145
0.3
Comfort Proteins)a
Nestle Good Start with Iron (Supreme, with easy to digest
80
178
0.2
Comfort Proteins)
Nutramigen Lipil (lactose-free, hypoallergenic, iron-fortified)
100
193
1.5
Similac Advanced Infant Formula with Irona
40
122
1.5
Similac Alimentum Advance with Iron (protein hydrolysate
100
158
2.0
formula with iron, hypoallergenic)
Similac Infant Formula Low Iron
40
153
2.1
Similac Infant Formula with Irona
40
142
1.6
Similac Lactose Free Infant Formula with Iron
60
143
1.4
Similac Neosure Advance with Iron
100
178
2.5
Soy-based
Enfamil Prosobee Lipil (milk-free, lactose-free, iron-fortified)a
100
112
0.3
Enfamil Prosobee Soy Infant Formula (milk-free, lactose-free,
100
122
0.6
iron-fortified)a
Similac Isomil Soy Formula with Iron (milk-free, lactose-free)a
100
84
0.4
All of the iodine and perchlorate levels reported here reflect the concentration intended for infant use.
a The nine brands of infant formula that were sold in concentrated form and designed to be diluted by half before use.
cant (P ? 1.0); however, there was a significant difference
significant difference in the perchlorate levels among the
between the labeled and measured mean infant formula io-
subjects when grouped by method of recruitment, which
dine concentrations (P ? 0.0001). Assuming an average in-
may be attributable to the relatively small sample size as well
fant formula intake of 0.86 liter/d (for infants 2 months of
as the demographic differences of the study population. In
age) (23), the labeled iodine concentrations in all 17 (100%)
data from NHANES 2001–2002, non-Hispanic Blacks had
infant formula brands were insufficient to meet the Institute
lower levels of urinary perchlorate than non-Hispanic
of Medicine’s recommended adequate intake of 110 ?g/d,
Whites (13). Perchlorate was also detectable in all 56 human
whereas 35% of the measured infant formula iodine concen-
urine samples tested, with median levels (2.90 ?g/liter, and
trations contained insufficient iodine levels. Although clin-
2.94 ?g/g creatinine) consistent with previously published
ically apparent iodine deficiency disorders are vanishingly
data (17). The source of this perchlorate exposure is unknown
rare in U.S. infants, it is possible that breast-fed infants whose
and merits further investigation.
mothers’ milk is iodine deficient, as well as some formula-fed
Kirk et al. (14) previously speculated that milk perchlorate
infants, might experience subtle neurodevelopmental abnor-
of 10 ?g/liter or higher may lead to reduced milk iodide
malities. An upper limit for iodine tolerability has not been
levels. Despite the fact that 47% of our samples contained
established in infants.
perchlorate at concentrations of at least 10 ?g/liter, we found
The question of whether low-level environmental per-
no correlations between milk perchlorate and milk iodine
chlorate exposure has clinical consequences has been ex-
content. Our results are consistent with the results of Lenge-
tremely controversial (24) and has been the topic of a recent
mann (26), who found dairy cattle milk iodine excretion
National Academy of Sciences review (7). Median urine per-
unaffected by perchlorate doses less than 0.1 mg/kg?d. A
chlorate was 3.6 ?g/liter in 2820 spot urine specimens in the
recent study of pregnant and lactating Chilean women con-
most recent NHANES survey (2001–2002) (13), and there was
suming tap water known to contain naturally occurring per-
a small positive correlation with serum TSH and a small
chlorate (?110 ?g/liter) also found no correlation between
inverse correlation with serum T4 values among women, but
perchlorate exposure and breast milk iodine or newborn
not men, with urinary iodine values less than 100 ?g/liter
thyroid function tests (21). One possible reason for the lack
(25). The developing fetus and infant are likely to be most
of correlation in these studies might be the diurnal and day-
vulnerable to the adverse effects of perchlorate on thyroid
to-day variation in breast milk concentrations of both iodine
function because they have the highest rate of thyroidal
and perchlorate (19).
iodine turnover and they require adequate thyroid hormone
Thiocyanate, as a metabolite of cigarette smoking, is also
for normal neurodevelopment. In this study, we found mea-
a known inhibitor of the NIS. Laurberg et al. (15) reported that
surable perchlorate levels in 100% of 49 human milk samples
although both smokers and nonsmokers had stable levels of
tested, with a median value of 9.1 ?g/liter. This is higher than
urinary iodine postpartum, smokers (defined as those with
the levels reported by Kirk et al. (14, 19) in two recent studies
urinary cotinine ?500 ng/ml) had lower concentrations of
(medians, 3.3 and 4.0 ?g/liter) and in the infant formulae
breast milk iodine, and their infants had lower concentra-
currently measured (median, 1.50 ?g/liter). There was a
tions of urinary iodine. Similarly, we found a small but
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Pearce et al. • Breast Milk Iodine and Perchlorate
J Clin Endocrinol Metab, May 2007, 92(5):1673–1677
1677
significant inverse correlation between breast milk iodine
United States National Health And Nutrition Examination Survey 2001–2002.
and urine cotinine concentrations and found that smokers
Thyroid 15:692– 699
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had significantly lower breast milk iodine levels than non-
in pregnant women from the Boston, Massachusetts area. Thyroid 14:327–328
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against smoking for this and many other reasons.
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6. Food and Nutrition Board, Institute of Medicine 2006 Dietary reference
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tional Research Council 2005 Health implications of perchlorate ingestion.
iodine nutrition is warranted in U.S. women. Although in the
Washington DC: National Academies Press
present study we found no correlation between breast milk
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iodine and perchlorate concentrations, the relatively low lev-
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human milk do raise concerns. One limitation of the study
9. Environmental Protection Agency 2004 Unregulated contaminant monitoring
was that we do not know the impact of breast milk per-
regulation (UCMR) data from public water systems. http://www.epa.gov/
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the occurrence of sources of perchlorate in Massachusetts. www.mass.gov/
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dep/cleanup/sites/percsour.pdf. (accessed 9/5/2006)
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that there should be more public awareness of the impor-
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2017
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studies consistently point to the value of human milk as the
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Acknowledgments
iodine content of human breast milks. Early Hum Dev 13:81– 85
19. Kirk AB, Dyke JV, Martin CF, Dasgupta PK 2006 Temporal patterns in
perchlorate, thiocyanate and iodide excretion in human milk. Environ Health
Received December 12, 2006. Accepted February 8, 2007.
Perspect 10.1289/ehp. 9558
Address all correspondence and requests for reprints to: Elizabeth N.
20. Gushurst CA, Mueller JA, Green JA, Sedor F 1984 Breast milk iodine reas-
Pearce, M.D., M.Sc., Boston Medical Center, 88 East Newton Street, Evans 201,
sessment in the 19890s. Pediatrics 73:354 –357
Boston, Massachusetts 02118. E-mail: elizabeth.pearce@bmc.org.
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We acknowledge support from the General Clinical Research Grant
CB, Crump KS, Gibbs JP 2005 Long-term environmental exposure to per-
M01 RR00533.
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The role of the Centers for Disease Control (CDC) in this study dealt
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conclusions in this report are those of the authors and do not necessarily
13:873– 876
represent the views of CDC.
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by on August 14, 2009
jcem.endojournals.org
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