Grantee Research Project Results
2012 Progress Report: An Epidemiologic Study of Time Trends and Health Effects of Persistent Organic Pollutants, Mercury and Micronutrients
EPA Grant Number: R833705Title: An Epidemiologic Study of Time Trends and Health Effects of Persistent Organic Pollutants, Mercury and Micronutrients
Investigators: Berner, James E.
Institution: Alaska Native Tribal Health Consortium
EPA Project Officer: Aja, Hayley
Project Period: June 1, 2009 through May 31, 2013 (Extended to May 31, 2015)
Project Period Covered by this Report: June 1, 2012 through May 31,2013
Project Amount: $948,121
RFA: Issues in Tribal Environmental Research and Health Promotion: Novel Approaches for Assessing and Managing Cumulative Risks and Impacts of Global Climate Change (2007) RFA Text | Recipients Lists
Research Category: Environmental Justice , Climate Change , Tribal Environmental Health Research , Human Health
Objective:
Objectives of Research:
- Determine current maternal blood levels of persistent organic pollutants (POP), heavy metals and micronutrients, and compare these levels to previous cohorts of pregnant women in 1999-2002, 2004-2006.
- Look for associations between levels of POPs, heavy metals and micronutrients and positive and negative health outcomes in mothers and infants.
- Measure blood pressure in children born to mothers recruited in 1999-2004 to determine the relationship of prenatal Hg exposure of childhood blood pressure.
- Measure tissue levels of POPs, heavy metal in Pacific salmon caught in the Yukon and Kuskokwim Rivers to compare at time trends in the Bering Sea and the North Pacific Ocean contaminant levels, by comparison with a study in 2001. Climate regime change associated with Himalayan glaciers melting and resultant increasing Asian river output, may have increased industrial and agricultural chemical levels in the Western Pacific Boundary current flowing into the North Pacific Ocean and Bering Sea.
Progress Summary:
Research Objective 1
Recruitment reached 160 Yupik women and has stopped. Rising costs of travel for recruitment, and costs of human blood analysis, since the original grant budget was approved, mean that the MOM Study cohort size will be limited to 160 women and their infants. The last pregnant woman to enter the cohort delivered in February of 2013, and her infant will reach 12 months of age in February of 2014.
The prior two cohorts, 1999-2002, and 2004-2006, have undergone additional data review, review of most of the charts that were missing from earlier reviews have been done, preliminary data are included in this report and will be discussed in this section and in Research Objective 2. Late data, including brominated flame retardants and fluorinated compounds, have had preliminary descriptive statistical analyses performed. Brominated and fluorinated compound levels are now available, and are included in this report. Salmon tissue levels have been returned to the USFWS from the contract laboratory. The USFWS official collaborating with ANTHC will release the results, in October of 2013, after they complete data review with their staff. Only 95 fatty acid analyses had been performed on maternal blood from the first two cohorts, and comparative data with a cohort of Inupiat mothers are presented in the last report. Additional samples from the first two cohorts are now undergoing analysis, with results to be made available in October of 2013.
Correlative data from legacy POPs, O-3FAs and Hg are presented in Table 3. The remainder of the fatty acid specimens will be processed and returned with POPs and Hg results from the current cohort. These results are also to be returned in October 2013 from the CDC NCEH DLS. The metals data on the most recent MOM Study cohort of 160 women has just been received (9/13), but has not yet been statistically evaluated. The complete data set of analytes described above will be available for final statistical analysis to be completed and reported by May 21, 2014.
Results:
The demographic data from the initial two cohorts of Yupik pregnant women are shown in Table 1 below.
Table 1 - Maternal Demographics; Cohort I, 1999-2002 and Cohort II, 2004-2007
Data for all moms N=418 |
||
Age Group* |
n |
% |
14-18 |
31 |
7.6% |
19-25 |
180 |
43.9% |
26-35 |
160 |
39.0% |
36-45 |
38 |
9.3% |
45+ |
1 |
0.2% |
Location |
|
|
A - Bethel |
354 |
84.7% |
B - Barrow |
57 |
13.6% |
C – A/P Islands |
7 |
1.7% |
Medical Abstracts |
|
|
Y |
371 |
88.8% |
N |
47 |
11.2% |
Data below is for moms with medical abstracts N=371 |
||
Birth Outcomes |
|
|
Live Birth |
332 |
89.5% |
Missing/Unknown |
23 |
6.2% |
Spontaneous Abortion |
13 |
3.5% |
Stillborn |
3 |
0.8% |
Breastfeeding |
|
|
Not Available |
93 |
25.1% |
No |
48 |
12.9% |
Yes |
230 |
62.0% |
Alcohol use |
|
|
Not Available |
57 |
15.4% |
No |
258 |
69.5% |
Yes |
56 |
15.1% |
Smoke at home |
|
|
Don’t know |
154 |
41.5% |
No |
95 |
25.6% |
Yes |
122 |
32.9% |
Pregnancy abnormality |
|
|
Not Available |
29 |
7.8% |
No |
136 |
36.7% |
Yes |
206 |
55.5% |
Delivery abnormality |
|
|
Not Available |
62 |
16.5% |
No |
197 |
53.2% |
Yes |
112 |
30.3% |
Illicit drugs |
|
|
Not Available |
71 |
19.1% |
No |
271 |
73.0% |
Yes |
29 |
7.8% |
Therapeutic Drugs |
|
|
Not Available |
60 |
16.2% |
No |
173 |
46.6% |
Yes |
138 |
37.2% |
*Age data not available for eight (8) of the mothers
Initial data from this cohort on risk factors, including tobacco and alcohol are shown, but at this time, data on underlying disease and pregnancy associated conditions, have not been added, as that has not yet been reviewed. This will be completed by May 21, 2014, the end of the no-cost extension of the funding agreement for the MOM Study. Compared to the U.S. all races population data, the Yupik women are younger and have more children.
Comparisons of geometric mean blood levels of legacy POPs between the first two Yupik cohorts are shown in Table 2.
Table 2
Geometric mean levels (lipid adjusted) selected persistent organic pollutants (POP) detected in at least 60% of the serum samples collected from a population of Alaska Native women – 1999 - 2006, residing in the Yukon-Kuskokwim Delta.
Analyte |
Total |
Cohort 1 1999 - 2202 |
Cohort 2 2003 -2006 |
|||
|
N |
Geo Mean |
N |
Geo Mean |
N |
Geo Mean |
Persistent pesticides
|
|
|
|
|
|
|
p,p’,-DDE |
339 |
125.97 |
136 |
129.66 |
203 |
123.56 |
Hexachlorobenzene |
329 |
20.52 |
127 |
|
202 |
21.91 |
Mirex |
339 |
|
136 |
|
203 |
|
Oxychlordane |
329 |
13.40 |
133 |
14.82 |
196 |
12.51 |
B-Hexachlorocyclohexane |
332 |
7.64 |
133 |
10.51 |
199 |
6.17 |
y-Hexachlorocyclohexane |
332 |
|
133 |
|
199 |
|
o,p’-DDT |
341 |
|
136 |
|
205 |
|
p,p’-DDT |
337 |
|
133 |
|
204 |
|
trans-Nonachlor |
335 |
20.55 |
133 |
19.30 |
202 |
21.42 |
Polychlorinated biphenyls |
|
|
|
|
|
|
138/158 |
344 |
15.30 |
142 |
17.08 |
202 |
14.16 |
153 |
345 |
27.86 |
142 |
33.92 |
203 |
24.15 |
180 |
345 |
11.24 |
142 |
13.18 |
203 |
10.06 |
Care in interpreting any differences between the two groups should be exercised, as there appear to be differences between residents of coastal villages, compared to riverine villages, which may reflect the greater intake of top predator sea mammals in coastal communities, and thus higher levels of both POPs and Hg. Further analysis will be carried out on these two categories of residents when the currently recruited cohort data are available.
Comparisons of Yupik women from the first two cohorts and other pregnant circumpolar populations in the AMAP Maternal Blood Monitoring Program are shown in Figure 1.
As can be seen, Yupik women are very similar in blood levels of legacy POPs to most other populations, and are most similar to western Canadian Inuit women.
Results of the preliminary correlations between POPs, bromated compounds, fluorinated compounds, O-3 FAs, and blood levels of Hg are shown in Table 3 below.
Table 3
Pearson Correlation Coefficients for Maternal Contaminant and micronutrient values Cohorts I and II
Prob>[r] under H0: Rho=0
Number of Observations
*Pregnant Alaska NativeYupikWomen
Pearson Correlation Coefficients
Data collected 1999-2006
Analyte |
Hg |
HCB |
Oxy |
PCB 153 |
PBDE 47 |
PFOS |
C205w3 |
Hg |
|
.039060 <.0001 314 |
0.49139 <.0001 320 |
0.49875 <.0001 329 |
0.01875 0.7953 194 |
0.14546 0.0584 170 |
0.66351 <.0001 100 |
HCB |
0.39060 <.0001 314 |
|
0.78391 <.0001 332 |
0.71032 <.0001 334 |
0.04901 0.4831 207 |
0.27017 0.0003 179 |
0.38395 0.0003 83 |
Oxy |
0.49139 <.0001 320 |
0.78391 <0001 332 |
|
0.83602 <.0001 340 |
-0.05834 0.4037 207 |
0.19282 0.0097 179 |
0.44021 <.0001 87 |
PCB 153 |
0.49875 <.0001 320 |
0.71032 <.0001 334 |
0.83602 <.0001 340 |
|
-0.05004 0.4740 207 |
0.24320 0.0010 179 |
0.29763 0.0036 94 |
PBDE 47 |
-0.01875 0.7953 194 |
-0.04901 0.4831 207 |
-0.05834 0.4037 207 |
-0.05004 0.4740 207 |
|
0.03284 0.6634 178 |
|
PFOS |
0.14546 0.0584 170 |
0.27017 0.0003 179 |
0.19282 0.0097 179 |
0.24320 0.0010 179 |
0.03284 0.6634 178 |
|
|
C205w3 |
0.66351 <.0001 100 |
0.38395 0.0003 83 |
0.44021 <.0001 87 |
0.29763 0.0036 94 |
|
|
|
*Hg –Mercury (total) HCB – Hexachlorolbenzene, Oxy – Oxychlordane, PCB153 – Polychlorinated biphenyl,
PBDE47 – Polybrominateddiphenyl ether, PFOS – PolyfluorinatedOctaineSulfanate, C205w3 – EicosapentanoicAcid*Data collected was supported by an EPA Interagency Agreement with the Office of International Activities #IAGDW7593818701
These data demonstrate several interesting findings: (1) There is a strong positive correlation between the blood levels of legacy POPs, indicating that exposure is from a common source, in this case, marine fish (mostly salmon) and marine mammals. (2) There is a similarly strong positive correlation between blood Hg level and legacy POPs, indicating that Hg exposure is from the same source as POPs. (3) There is a strong positive correlation between O3-FAs, Hg, and POPs, indicative of this valuable micronutrient being found in the same subsistence food sources as Hg and POPs.
The data for correlations of brominated flame retardants (BFRs) and polyfluorinated compounds have now been statistically examined, and, as can be seen in the table, fluorinated compounds are well-correlated with the legacy POPs and Hg, and with O-3 FAs, but brominated compounds do not appear to be associated with POPs, Hg, or O-3FAs. Specimens from the first two cohorts show levels of BFRs similar to U.S. NHANES data in pregnant women, and far higher than levels in Europe. These are shown in Figure 2 below.
This analysis will be completed the end of 2013. Since these compounds are also found in most residences, exposure to these may, or may not, be related to subsistence foods. Data from the salmon tissue will also provide evidence for, or against, marine sources for these compounds.
Research Objective 2
An analysis of prenatal and neonatal health metrics have been tentatively selected based on prevalence in the first two cohorts. At present, these include spontaneous abortion, preterm delivery, length of pregnancy, birth weight, hypertensive disorders in pregnancy, results of oral glucose challenge screening, Hgb A1C levels and congenital anomalies. Neonatal metrics include hospitalizations due to infection, growth abnormalities, and developmental abnormalities. Other metrics and outcomes will also be examined, such as associations with micronutrient levels, and possibly added to the analysis, depending on the statistical power required.
Of interest is a significant negative association of urine Hg levels in mothers, with infant birth weight, and head circumference. These data are not included in Table 3, but will be a part of the MOM Study paper that is in preparation. This association has never been previously observed, and it will be important to add the current cohort numbers to those already analyzed to see if the association persists. This analysis will be completed by May 21, 2013, the end of the no-cost extension of the funding agreement for the MOM Study.
Research Objective 3
This objective will be accomplished in the final 6 months of the grant, as the youngest children in Cohort 2 will have reached the age of 7 years, and BP obtained at that age, or older, will replicate the ages of the Faroe Island cohort of children in whom the association between BP and prenatal mercury exposure was first documented. This will entail chart reviews, as travel to the small villages in the Yukon-Kuskokwim Delta has become very expensive. The review of charts will be complete by May 21, 2014, the end of the no-cost extension funding agreement for the MOM Study.
Research Objective 4
Salmon tissue samples for this objective have been analyzed, and results are now at the USFWS office in Fairbanks. The results will be available in October of 2013, according to the USFWS, to allow time for the relults to be reviewed by their staff. These results will be examined for any significant changes from the 2001 samples, from the same species, from the same rivers, at the same locations, and by the same laboratory. The salmon results will be compared to human tissue levels, for organochlorines, brominated and fluorinated compounds, and metals. The comparison of the salmon tissue data, and the determination of any significant differences in the two cohorts, will be complete by May 21, 2014, the end of the no-cost extension of the MOM Study funding agreement.
Future Activities:
Year 5 will concentrate on completion of infant and maternal medical record abstraction, data entry from the current cohort analysis results of the fatty acid and micronutrient analyses, and the persistent organic pollutant and heavy metal analyses. Presentations to tribal groups in Alaska on the initial results of both human and salmon tissue analyses, IRB, agency and tribal approval of papers from the analyses, and submission to journals will take place after data analysis. Collaborators at the NIH Diabetes Unit on the Phoenix Indian Medical Center Campus will work with the PI to determine if any single contaminant, or group of contaminants, is associated with the risk of an abnormal response to the prenatal oral glucose challenge. This would indicate that exposure to organohalogens and Hg at the levels seen in the Yupik women presents a risk factor for development of insulin resistence in pregnancy, and thus the development of gestational diabetes mellitus. The salmon tissue levels of brominated flame retardants and fluorinated compounds will be examined for any evidence that they are related to human tissue levels of those compounds, as both are found in indoor environments as well. The analysis of cord blood data will undergo evaluation for association with infant outcomes.
Journal Articles:
No journal articles submitted with this report: View all 54 publications for this projectSupplemental Keywords:
Micronutrients, salmon, gestational diabetes mellitus, persistent organic pollutants, heavy metalsRelevant Websites:
Relevant Websites: Community Environment and Safety
http://www.anthc.org/chs/ces/ Exit
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.