Progress 10/01/05 to 09/30/08
Outputs
OUTPUTS: A summary of the outputs of this project are: research training of 1 PhD, 1 MS and 6 undergraduate students; presentations at 6 regional, national and international conferences/venues; development of a biomonitoring educational pamphlet; and dissemination of knowledge to area lactation consultants, the NH State Department of Public Health, the New Hampshire Breast Feeding Task Force, and the 40 participants in the research study. PARTICIPANTS: Gale Carey, PI from the University of New Hampshire. Dr. Carey directed the project and oversaw its implementation. Rebecca Dunn, Ph.D. This research served as the PhD project for Dr. Dunn, who recruited and educated participants, procured breast milk samples, prepared samples for analysis, developed and/or administered surveys, conducted data analyses, and is preparing work for publication. Andrea Arel Hoppe, M.S. This work served as a MS project for Ms. Hoppe (formerly Arel), conducted animal experiments and metabolic analyses. Janice Huwe, PhD., Collaborator from USDA, Fargo, ND. Dr. Huwe was responsible for breast milk and adipose tissue PBDE analyses via GC-MS. TARGET AUDIENCES: Target Audience: scientists in the environmental sciences, lactation consultants, lactating women. Efforts: undergraduate students in my classes at the University of New Hampshire. PROJECT MODIFICATIONS: Objective (3) was not met. This objective was to occur in collaboration with the NH Public Health Laboratories who possessed equipment for conducting this work. However, their limited resources prevented them from being available to conduct this work with us.
Impacts
One goal of this project was to determine the levels of PBDEs in breast milk of lactating women from New Hampshire and to examine potential relationships between PBDE levels in breast milk and stage of lactation, maternal characteristics, living environment and dietary intake. Forty women, ages 22 to 40, provided up to three breast milk samples at the end of their first, second and third month of breastfeeding for evaluation of day-to-day and month-to-month variation in PBDE levels. Participants were asked to complete four questionnaires, which provided maternal, living environment, and diet information. The sum of PBDE congeners found in breast milk was defined as: BDE-28/33, 47, 85, 99, 100, 153, 154, and 183. The sum of PBDE concentrations in breast milk over the three-month collection period ranged from 6.5 to 166.7 ng/g lipid. The median for the three-month period was 29.7 ng/g. BDE-47 was the predominant congener; however, BDE-153 predominated in 20% of the participants' samples from each month. Day-to-day variation in the sum of PBDE congeners was negligible; there was no significant difference in mean PBDE levels from month-to-month. Regression analysis revealed relationships between log-transformed PBDE levels in breast milk and questionnaire data. Positive associations were seen between BDE-153 and age (r = 0.36 p = 0.02), saturated fat consumption (r = 0.31 p = 0.05), and home model (r = 0.51 p = 0.004). There was a negative association between PBDE levels (both the sume of PBDE congeners and BDE-47) and fruit consumption (r = 0.36 p = 0.02, for the sume of PBDE congeners). Our results indicate that PBDE levels in breast milk from the state of New Hampshire are within the range that has been reported in the U.S., and that levels are stable during the first three-months of lactation. Our findings revealed a higher predominance pattern with BDE-153 compared to other studies, and indicate that PBDE levels are influenced by age, diet, and the home environment. The association between fruit consumption and PBDE (both the sum of PBDE congeners and BDE-47) levels during the last trimester was surprising, and suggests that plant-based foods reduce the PBDE body burden by an unknown mechanism. A second goal of this project was to explore the endocrine-disrupting potential of PBDEs using a rat model. One month of PBDE treatment of rats caused a 77% reduction in plasma thyroid hormone levels, a 61% reduction in insulin-stimulated glucose oxidation in fat cells, and a 26% increase in epinephrine-stimulated fat breakdown in fat cells, compared to controls. These data suggest that PBDEs could provoke the development of metabolic obesity in rats; the effects in humans remains unknown. The impact of these findings is that increased awareness and additional information are available to environmental health researchers and policy makers whose focus is the potential for environmental chemicals to disrupt normal hormonal and physiological balance in mammals.
Publications
- Hoppe, A.A. and Carey, G.B. 2007. Polybrominated diphenyl ethers (PBDEs) as endocrine disruptors of adipocyte metabolism. Obesity 15:2942-2950.
- Dunn, R. 2008. "Biomonitoring polybrominated diphenyl ethers in breast milk of lactating women in the Seacoast area of New Hampshire", Ph.D Thesis, University of New Hampshire, Durham, NH, 203 pages.
- Dunn, R.L., Huwe, J.K, and Carey, G.B. 2008. Biomonitoring polybrominated diphenyl ethers in lactating women. 10th Annual Workshop on Brominated Flame Retardants, Abstract No. 45.
- Dunn, R.L. and Carey, G.B. 2008. Developing a biomonitoring communication pamphlet for potential participants. 10th Annual Workshop on Brominated Flame Retardants. Abstract No. 46.
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Progress 10/01/06 to 09/30/07
Outputs
OUTPUTS: This work was disseminated in 2 presentations: the first was at the annual meeting of the USDA regional project NCCC097 in Washington, DC, April 2007 "Biomonitoring PBDEs in Lactating Women", and the second was to scientists at the USDA-ARS Biosciences Research Laboratory in Fargo, ND, May 2007, "PBDEs and Obesity: Is there a connection?". One publication is in-press. One PhD student (anticipated graduation is May 2008) continues her work on this project.
PARTICIPANTS: Gale Carey, PhD., PI from University of New Hampshire. Dr. Carey directs the project and oversees its implementation. Rebecca Dunn, PhD candidate from University of New Hampshire. Ms. Dunn is responsible for recruiting and educating participants, procuring breast milk samples, preparing samples for analyses, and analyzing data. Janice Huwe, PhD., Collaborator from USDA, Fargo ND. Dr. Huwe is responsible for breast milk PBDE analyses. New Hampshire Breast Feeding Task Force. This organization provides valuable feedback on our communication with participants. Professional Development: -Ms. Dunn co-presented a seminar at the USDA in Fargo, NH with Dr. Carey. -Ms. Dunn presented a seminar about PBDEs and breast milk at the 18th Annual Conference on Promoting, Protecting and Supporting Breastfeeding in New Hamsphire.
TARGET AUDIENCES: Target audience: scientists in the environmental sciences. Efforts: Three undergraduate students from a Technical Writing class at the University of New Hampshire learned about our work with PBDEs as they designed a web site for us that highlights this research.
Impacts
Forty women from the Seacoast area of New Hampshire have completed their participation in this study. The participants were of limited diversity. Thirty-nine of the forty women were Caucasian, and 80% of the participants had completed a 4-year college degree or higher. The average age was 31 years (range 22 to 40), 78% were first-time mothers, and average BMI was 27.3 at three weeks post-partum and 26.5 at twelve weeks post-partum. Because data from the first five participants, from whom breast milk samples were collected on three successive days of three successive months, demonstrated that day-to-day variation in PBDE levels was minimal, only one sample was collected per month from the remaining participants. Three breast milk samples (at weeks four, eight and twelve post-partum) from each participant have been collected and analyzed for eight PBDE congeners: BDE 28/33, 47, 100, 99, 154, 85, 153 and 183. Because BDE-209 is a variable yet ubiquitous contaminant, it is
not included in these analyses. Results show that the mean sum of eight PBDEs over the three month collection period range from 7.3 to 139.6 ng/g lipid. Overall, the dominant congeners are BDE-47, followed by BDE-153, followed by BDE-100. However, BDE-153 is the dominant congener in 20% of the participants, a trend that has been reported by other researchers. Month-to-month variation in the mean level of PBDEs shows a downward trend, from 37.3 ng/g lipid at month one, to 35.1 ng/g lipid at month two, to 34.2 ng/g lipid at month three. Except for PBDE-99, there is a downward trend in the concentration of each congener from months one to three. This is paralleled by a downward trend in the percent lipid content of the milk from months one to three. Forty maternal characteristics surveys and forty maternal environmental surveys have been coded and entered into spreadsheets. Eighty food frequency questionnaires (two per participant - one examining food intake for the last three months of
pregnancy, and the second examining food intake for the first three months of lactation) have been analyzed by the Fred Hutchinson Cancer Research Center. Selected nutrient data of interest have been entered into spreadsheets. All spreadsheets have been merged into one SPSS file, with 320 variables coded and labeled. Preliminary examination of the data suggests that monthly PBDE means will require log transformation; currently potential associations are being examined via scatter plots and regression models are being considered. These findings demonstrate that PBDE levels in breast milk of New Hampshire women are similar to levels reported elsewhere in the United States, but are significantly higher than levels reported elsewhere around the world. The impact of these findings is that increased awareness and additional information are now available to environmental health researchers and policy makers whose focus is the potential for PBDEs to disrupt normal hormonal balance in the
human body.
Publications
- No publications reported this period
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Progress 10/01/05 to 09/30/06
Outputs
Four goals have been accomplished over the past year on our research project. Our first goal was educating prospective subjects. Before recruiting lactating women into our research project, we developed an educational pamphlet called "Steps to a Healthy Future". The pamphlet informs women about the goal of our research and educates them about environmental chemicals, "body burden" and polybrominated diphenyl ethers (PBDEs). The New Hampshire Breastfeeding Task Force, and a focus group of 8 lactating women, provided valuable feedback during the development of the pamphlet. Once the pamphlet was optimized, it was placed in the offices of local pediatricians, obstetricians, and lactation consultants. Our second goal was recruiting subjects and collecting breast milk samples. Forty lactating women from the Seacoast area of New Hampshire provided us with breast milk samples from months one, two and three of lactation. Each woman completed a validated maternal
characteristics survey, two food frequency questionnaires to probe for dietary fat intake from animal products which are a primary source of PBDEs, and a validated environmental survey. In order to examine for day-to-day variability in PBDE levels, a subset of five women each provided nine breast milk samples, expressed on three successive days of months one, two and three of lactation. Our third goal was preliminary sample analysis. The forty-five, day-to-day variability samples have been analyzed for 12 PBDE congeners. The average range for the sum of PBDEs at one month was 9.58 to 93.20 ng/g milk fat, at two months was 8.14 to 88.07 ng/g milk fat, and at 3 months was 9.16 to 75.30 ng/g milk fat. The dominant congener was BDE-47, and visual inspection of the data reveals that the day-to-day variation is less than 20%. Because methodological variation is 20%, we conclude that day-to-day variation is minimal and are proceeding with analysis of the remaining 105 samples. Our fourth
goal was exploring the endocrine-disrupting potential of PBDEs using the rat model. Six-week old Sprague-Dawley rats were treated with either 18 mg PBDE/kg body weight/day or corn oil vehicle (n=12 per treatment). After one month of PBDE treatment, plasma thyroid hormone levels were reduced by 77%, adipocyte insulin-stimulated glucose oxidation was reduced by 61%, and adipocyte epinephrine-stimulated lipolysis was increased by 26%, compared to control. Despite the lack of a difference in rat body weight or adipocyte size between the treated and control rats, these data suggest PBDE treatment could provoke the development of metabolic obesity in rats.
Impacts
To date, our work shows that PBDE levels in breast milk of New Hampshire women are similar to levels reported in women's milk from other areas of the U.S. However, these levels are significantly higher than levels reported from other countries of the world. PBDEs can disrupt normal hormone balance of the body, therefore careful examination of the biological effects of PBDEs in humans is called for.
Publications
- Arel, A.C. and Carey, G.B. 2006. The effects of polybrominated diphenylethers (PBDEs) on adipocyte functionality in vitro and in vivo. FASEB J. 20:A164.
- Arel, Andrea C. 2006. The effects of polybrominated diphenyl ethers (PBDEs) on adipocyte functionality in vitro and in vivo. MS Thesis, University of New Hampshire, Durham, NH, 83 pages.
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