Polybrominated Biphenyl Human Epidemiology Paper Review

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Assessing inter-generational transfer of a brominated flame retardant

Authors: Avenel D. Joseph, Metrecia L. Terrell, Chanley M. Small, Lorraine L. Cameron, and Michele Marcus.

Name of Source: Journal of Environmental Monitoring

Year: 2009

Full Citation Information: Journal, Issue, Publisher, etc.: J Environ Monit. 11(4):802-807. The Royal Society of Chemistry

Scientific Discipline/Field: Exposure assessment

Focus of Article (specific exposure pathways, animal tox, epi, etc.): The purpose of this study was to examine the inter-generational transfer of PBB from mother to child and whether this association was modified by maternal breast-feeding patterns. One 145 mother-child pairs that were participants of the Michigan Long-Term PBB Study were included in this analysis.

Summary of Findings in Article:
-Maternal serum PBB equal to or above 8 mg/L was associated with the child having detectable serum PBB, this was the most important predictor.
-Mothers who breast-fed for 5.5 months or more were 6 times more likely to have a child with a detectable serum PBB concentration compared to a non-breast-fed child.
-Maternal age of 28 years or older was associated with the child having detectable serum PBB
-Children born during the PBB exposure period more likely to have detectable serum PBB
Study shows that the inter-generational transfer of PBB is similar to that of other related lipophilic compounds such as PCB and PBDE.

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: No

Maternal Exposure to a Brominated Flame Retardant and Genitourinary Conditions in Male Offspring

Authors: Authors: Chanley M. Small, John J. DeCaro, Metrecia L. Terrell, Celia Dominguez, Lorraine L. Cameron, Julie Wirth, and Michele Marcus

Name of Source: Children’s Health

Year: 2009

Full Citation Information: Journal, Issue, Publisher, etc.: Children's Health 117: 1175-1179

Scientific Discipline/Field: Epidemiology, Children’s Health

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Authors hypothesize that the upward trend in industrial nations in the incidence of male genitourinary conditions may be attributed to increased exposure to endocrine disruptors such as PBB. Investigated the relationship between maternal serum levels of PBBs and genitourinary conditions among male offspring exposed in utero in the Michigan cohort.

Summary of Findings in Article:
-After adjustment for gestational age at birth, sons of highly exposed women were twice as likely to report any genitourinary condition compared with sons of the least exposed women. This risk was increased when sons born after the exposure but before the mother’s serum PBB measurement were excluded.
-There was a threefold increase in reported hernia or hydrocele among sons with higher PBB exposure.
-There was no individual association between PBB exposure and cryptorchidism or with hypospadias.
The finding of increased reports of hernia or hydrocele among the most exposed may be explained by an antiandrogenic effect of PBB--animal data suggests antiandrogenic effects of perinatal PBB exposure through increased metabolism of testosterone and decreased responsiveness to testosterone.

Any policy implications discussed in article: "The increasing occurrence of male GU anomalies in industrialized countries warrants further study to guide public health efforts".

Any response to the article in OpEds, News coverage: Summarized by Jonathan Chevrier and Wendy Hessler in May 19, 2009 issue of Environmental Health News.

A cohort study of the association between secondary sex ratio and parental exposure to polybrominated biphenyl (PBB) and polychlorinated biphenyl (PCB)

Authors: Metrecia L. Terrell, Alissa K. Berzen, Chanley M. Small, Lorraine I. Cameron, Julie J. Wirth, and Michele Marcus

Name of Source: Environmental Health

Year: 2009

Full Citation Information: Journal, Issue, Publisher, etc.:
Environ Health. 8:35
doi:10.1186/1476-069X-8-35

Scientific Discipline/Field: Environmental Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Identified offspring of female PBB Michigan cohort participants and linked sex ratio of this population to parental serum PBB and PCB concentrations to investigate the association between parental exposures to PBB and offspring sex ratio. Explored confounders including parental age and education at offspring’s birth, parental BMI at cohort enrollment, birth order, gestational age, and year of offspring’s birth.

Summary of Findings in Article:
-Proportion of male offspring births to cohort mothers was higher than in the US population (0.542 vs. 0.514) and higher than in the state of Michigan (0.511-0.516) during the same time period.
-When both parents were in the cohort there were increased odds of a male birth when combined parents’ enrollment PBB exposure was at or above the median concentrations for mothers and fathers (this was not statistically significant).
-In models where only one parent’s exposure was considered, there was a suggestion of increased odds of a male birth for paternal PBB exposure only, but not for maternal PBB exposure only.
-Similar results found for PCBs
-Covariates: Increased odds of male birth for high paternal BMI, increased odds of male birth for offspring born prior to 37 weeks of gestation

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: Summarized in Natural Standard News, September 2009.

A decay model for assessing polybrominated biphenyl exposure among women in the Michigan Long-Term PBB Study

Authors: Metercia L. Terrell, Amita K. Manatunga, Chanley M. Small, Lorraine L. Cameron, Julie Wirth, Heidi Michels Blanck, Robert H. Lyles, and Michele Marcus.

Name of Source: Journal of Exposure Science and Environmental Epidemiology

Year: 2008

Full Citation Information: Journal, Issue, Publisher, etc.: J Expo Sci Environ Epidemiol. 18(4)410-420, Nature Publishing Group

Scientific Discipline/Field: Exposure Assessment, Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Estimated serum PBB decay and investigated the effects of covariates on serum PBB decay rates among 406 female Michigan cohort members. Age at exposure and body mass index (BMI) at the initial measurement were time-independent covariates. Time since exposure, smoking history, pregnancy status, and breast-feeding status were time-dependent covariates.

Summary of Findings in Article:
-Higher BMI was associated with a slower decay rate
-Smokers had a faster decay rate than nonsmokers
-Increasing age at exposure was marginally associated with a slower decay rate
-Suggestion of faster serum PBB decay rate for women who breast-fed during the interval between serum PBB measurements.

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: No

Maternal Exposure to Polybrominated and Polychlorinated Biphenyls: Infant Birth Weight and Gestational Age

Authors: Marjory L. Givens, Chanley M. Small, Metrecia L. Terrell, Lorraine L. Cameron, Heidi Michels Blanck, Paige E. Tolbert, Carol Rubin, Alden K. Henderson, and Michele Marcus

Name of Source: Chemosphere

Year: 2007

Full Citation Information: Journal, Issue, Publisher, etc.: Chemosphere 69(8):1295-1304
Elsevier

Scientific Discipline/Field: Environmental Epidemiology, Maternal Exposure

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Given the temporal trends in premature births, the ubiquitous presence of halogenated organics, the present study examines the potential association between exposure to PBB and PCB in utero and infant birth weight and gestational age. Study population, drawn from the Michigan cohort, consisted of 444 mothers and their 899 infants born between 1975 and 1997 (retrospective analysis).

Summary of Findings in Article:
-Did not observe a consistent association between maternal exposure to PBB and infant birth weight or gestational age
-There was a significant, negative relationship between a high level of maternal enrollment PBB and infant birth weight—but this result not supported by analyses using estimated maternal PBB at conception nor in GEE models to assess the tails of the outcome distributions
-No association found for PCB levels with gestational age or infant birth weight
-No significant association with birth weight and gestational age found among women with highest (10%) PBB or PCB exposure

Any policy implications discussed in article: No, only say that because brominated compounds are currently used in consumer products additional research is needed.

Any response to the article in OpEds, News coverage: No

Endometriosis among women exposed to polybrominated biphenyls

Authors: Caroline S. Hoffman, Chanley M. Small, Heidi Michels Blanck, Paige Tolbert, Carol Rubin, and Michele Marcus

Name of Source: Annals of Epidemiology

Year: 2007

Full Citation Information: Journal, Issue, Publisher, etc.: Ann Epidemiol. 17(7):503-510
Elsevier

Scientific Discipline/Field: Environmental Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Examines the association between endometriosis and exposure to PBBs and PCBs among women of the Michigan cohort. Constructed Cox models to estimate the relative incidence of endometriosis in relation to PBB and PCB levels.

Summary of Findings in Article:
-Compared to women with low PBB exposure, women with moderate and high PBB exposure did not have increased incidence of endometriosis.
-Increased incidence of endometriosis was suggested among women exposed to moderate PCB and high PCB levels compared to low PCB exposure.

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: No

Risk of spontaneous abortion among women exposed to polybrominated biphenyls

Authors: Chanley M. Small, Keely Cheslack-Postava, Metrecia Terrell, Heidi Michels Blanck, Paige Tolbert, Carol Rubin, Alden Henderson, Michele Marcus

Name of Source: Environmental Research

Year: 2007

Full Citation Information: Journal, Issue, Publisher, etc.:
Environ Res. 105(2): 247-255
Elsevier

Scientific Discipline/Field: Environmental Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Investigates the association between PBB and PCB exposures and pregnancy loss prior to 20 weeks gestation. Using generalized estimating equations to account for correlated outcomes within the same woman, the authors assessed the risk of spontaneous abortion among 529 women of the Michigan cohort with 1344 potentially exposed pregnancies.

Summary of Findings in Article:
- Compared to pregnancies with PBB exposure below the limit of detection, those with levels above 2.9 ppb had a non-significant reduced odds of spontaneous abortion
- Compared to pregnancies with PCB exposure below the limit of detection, those with levels above 6.5 ppb had little difference in risk
- Maternal age at conception above 34 years was significantly associated with elevated risk of spontaneous abortion
-Older age at menarche was associated with decreased risk of spontaneous abortion
Results do not support PBB and PCB exposure association with risk of spontaneous abortion after adjusting for maternal age at conception, age at menarche, and prior infertility.

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: No

The influence of age at exposure to PBBs on birth outcomes

Authors: Anne M. Sweeney and Elaine Symanski

Name of Source: Environmental Research

Year: 2007

Full Citation Information: Journal, Issue, Publisher, etc.:
Environ Res 105(3):370–9.
Elsevier Inc

Scientific Discipline/Field: Environmental Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Examined the association between early age at exposure to PBBs and subsequent birth weight and gestational length in offspring among females in the Michigan cohort. Hypothesized that younger ages at exposure to PBBs among females would be associated with an increased risk of higher birth weight infants among offspring.

Summary of Findings in Article:
-Relative to the oldest age group, age <10 years at exposure was the most important predictor of increased birth weight.
-Infant birth weight increased approximately 16 g for every 10 ppb increase in serum PBBs
-No association between initial PBB levels and gestational age
-No evidence of an interaction between PCBs and PBBs and birth weight
The results of the analysis supported the hypothesis that maternal age at exposure to PBBs occurring at age 10 years or younger (peripubertal) increases the risk of higher birth weight among infants. The explanation for this is not known but it may indicate that the time period preceding onset of puberty reflects a more vulnerable time for exposure to these endocrine active chemicals.

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: Comment in Environ Res. 2008 September; 108(1): 117–126 by Terrell et al. who say that the conclusion of a maternal age at exposure effect does not appear to be substantiated from the data because 1) maternal age at enrollment was erroneously used as a proxy for maternal age at exposure, 2) substantial proportion of the population did not have detectable serum PBB which wasn’t accounted for in the model, and 3) the maternal age at exposure effect appears to be an artifact from methodological issues.

Polybrominated biphenyls, polychlorinated biphenyls, body weight, and incidence of adult-onset diabetes mellitus

Authors: Oana Vasilu, Lorraine Cameron, Joseph Gardiner, Peter DeGuire, Wilfried Karmaus

Name of Source: Epidemiology

Year: 2006

Full Citation Information: Journal, Issue, Publisher, etc.:
Epidemiol. 17(4):352-359.
Lippincott Williams & Wilkins, Inc.

Scientific Discipline/Field: Environmental Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): To determine the incidence of adult-onset diabetes, they analyzed Michigan cohort members without diabetes at enrollment, ages 20 years and older, with known PBB and PCB levels, who participated in at least 1 follow-up survey. Using Poisson regression, they determined the incidence density ratio (IDR) of diabetes for different serum levels of PBB and PCB, controlling for age, body mass index, smoking, and alcohol consumption at enrollment. Hypothesize that exposure to PBBs and PCBs are risk factors for the subsequent development of adult-onset diabetes in this Michigan cohort.

Summary of Findings in Article:
-Analyzing 25 years of follow-up data, they did not find that higher PBB serum levels were a risk factor for the incidence of diabetes mellitus.
-However, in women, but not in men, higher PCB serum levels were associated with increased incidence of diabetes (IDR = 2.33; 95% confidence interval = 1.25–4.34 in the highest PCB group compared with the lowest).
-In both men and women, overweight and obesity increased the diabetes incidence.

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: Response in same issue of Epidemiology by Longnecker stating that PCB levels were low and that a great proportion of variation in measured levels among subjects may be accounted for by differences in metabolism and excretion—the measurements are not sufficient for showing causality and clinical significance.

Menstrual function among women exposed to polybrominated biphenyls: a follow-up prevalence study

Authors: Stephanie I Davis, Heidi Michels Blanck, Vicki S Hertzberg, Paige E Tolbert, Carol Rubin, Lorraine Cameron, Alden K Henderson, and Michele Marcus

Name of Source: Environmental Health

Year: 2005

Full Citation Information: Journal, Issue, Publisher, etc.:
Environ Health 4:15.
BioMed Central Ltd.

Scientific Discipline/Field: Environmental Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Association of serum PBB levels with menstrual cycle and bleed length which are markers for the reproductive status of women

Summary of Findings in Article:
Follow-up prevalence study drawing from the Michigan Female Health Study was conducted during 1997–1998 among women in a cohort exposed to PBBs in 1973. Current PBB levels were estimated by exponential decay modeling of serum PBB levels collected from 1976–1987 during enrollment in the Michigan PBB cohort.
-No overall association was found between PBB exposure and menstrual cycle characteristics, but a significant interaction between PBB exposures with past year weight loss was found. Longer bleed length and shorter cycle length were associated with higher PBB exposure among women with past year weight loss.
-Found that women who were 6–13 years old at the time of the Michigan incident (now 24–31
years) in the highest tertile and decile of current estimated PBBs had shorter bleed length relative to 36–38 year old women in the low tertile. The age interaction may indicate that women who
were orally exposed before they reached menarche may have been affected during developmental maturation toward menses.

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: No

Time to menopause in relation to PBBs, PCBs, and smoking

Authors: Heidi Michels Blanck, Michele Marcus, Paige E. Tolbert, Cheryl Schuch, Carol Rubin, Alden K. Henderson, Rebecca H. Zhang, and Vicki S. Hertzberg

Name of Source: Maturitas

Year: 2004

Full Citation Information: Journal, Issue, Publisher, etc.:
Maturitas 49(2):97–106.
Elsevier Ireland Ltd.

Scientific Discipline/Field: Environmental Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Examine the relation between self-reported age at menopause obtained from the health survey and serum PBB exposure in women in the Michigan PBB cohort. Also examined self-reported age at menopause and two other environmental exposures for which data were available: PCBs and smoking. Hypothesize that polyhalogenated biphenyl exposure could alter reported age at menopause by alteration of endocrine feedback loops and alteration of circulating hormone levels.

Summary of Findings in Article:
To define menopausal status, women were interviewed in 1997 and asked whether they had had any menstrual periods in the previous year, why their menstrual periods had stopped (e.g. surgery), and age at their last menstrual period. Serum PBB and PCB taken at enrollment (1976–1978) into the Michigan PBB registry.
-Did not find an association between PBB or PCB exposure and time to menopause in women currently active in the Michigan PBB cohort
-State that further studies of menopause age in women exposed to ubiquitous chemaical exposures are warranted because of the uncertainty between exposure and latent effects

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: No

Polybrominated biphenyl exposure and benign breast disease in a cohort of US women

Authors: Reinhard Kaiser, Michele Marcus, Heidi Michels Blanck, Mary Naughton, Rebecca H. Zhang, Alden K. Henderson, Paige E. Tolbert, Carol H. Rubin, and Vicki S. Hertzberg

Name of Source: Annals of Epidemiology

Year: 2003

Full Citation Information: Journal, Issue, Publisher, etc.:
Ann Epidemiol. 13(1):16-23
Elsevier

Scientific Discipline/Field: Environmental Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Examined the relationship between serum polybrominated biphenyl (PBB) levels and the risk of benign breast disease in the Michigan cohort women. Used extended Cox models to generate adjusted hazard ratios; models included PCBs and risk factors for benign breast disease reported in the literature.

Summary of Findings in Article:
-Compared with women with low PBB exposure, benign breast disease was not reported more frequently among those with moderate or high PBB exposure.
-Age, smoking, and annual number of health-care provider visits were significantly associated with benign breast disease.

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: No

Growth in girls exposed in utero and postnatally to polybrominated biphenyls and polychlorinated biphenyls

biphenyls
Authors: Heidi Michels Blanck, Michele Marcus,Carol Rubin, Paige E. Tolbert, Vicki S. Hertzberg, Alden K. Henderson, and Rebecca H. Zhang

Name of Source: Epidemiology

Year: 2002

Full Citation Information: Journal, Issue, Publisher, etc.:
Epidemiology 13(2):205–10.
Lippincott Williams & Wilkins, Inc

Scientific Discipline/Field: Environmental Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Evaluated the association of prenatal and lactational PBB exposure with current height and weight adjusted for height in daughters 5–24 years of age born to exposed mothers enrolled in the Michigan PBB Registry. Hypothesized that exposure to PBBs during gestation and early infancy may disrupt normal growth.

Summary of Findings in Article:
-No relation was observed between either estimated prenatal PBB or PCB exposure and height.
- Although moderate prenatal PBB exposure did appear to be related to increased weight for height, no effect was observed for high prenatal PBB exposure.

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: Letter in September 2002 issue of Epidemiology by Wilfried Karmaus who notes that determining growth, a trend over time, requires at least three height or weight measurements (Blanck et al. did single measurement). Also notes that the authors did not take into consideration the exposure of their cohort to DDE.

Breast-feeding among women exposed to polybrominated biphenyls in Michigan

Authors: Ann R. Thomas, Michele Marcus, Rebecca H. Zhang, Heidi Michels Blanck, Paige E. Tolbert, Vicki Hertzberg, Alden K. Henderson, and Carol Rubin

Name of Source: Environmental Health Perspectives

Year: 2001

Full Citation Information: Journal, Issue, Publisher, etc.:
Environ Health Perspect. 109(11):1133-1137
EBSCO Publishing

Scientific Discipline/Field: Environmental Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Examine the relationship between serum measurements of PBBs and the frequency and duration of lactation in women of Michigan cohort. Three outcomes of interest: whether or not subject chose to breast-feed, duration of breast-feeding as main source of nutrition, and duration of breast-feeding.

Summary of Findings in Article:
-None of the three outcomes were associated with serum PBB levels, even after controlling for maternal age, previous history of breast-feeding, BMI, maternal education, household income, history of smoking in year before pregnancy, consumption of alcohol during first trimester, history of thyroid disorder, gestational age of infant, time to pregnancy, and year of birth.
Despite having an adequate sample size and minimal potential for selection or recall bias, this analysis did not demonstrate a link between serum PBB level and the decision to breast-feed or measures of duration of lactation.

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: Environ Health Perspect. 2002 Sep;110(9):A503-4; author reply A504 by Walter Rogan and William Weil. Note that Weil found that unexposed women breast-fed about twice as long as exposed women which might have been because of the warnings about breast-feeding with PBB-contaminated milk , which they recall as being more ominous than reported by Thomas or because of some biological effect of PBB. State that the presence of the finding then and its absence now causes us to speculation that there may be poor recall or other reasons why duration of lactation does not work well as a recalled outcome.

Age at menarche and tanner stage in girls exposed in utero and postnatally to polybrominated biphenyl

Authors: Heidi Michels Blanck, Michele Marcus, Paige E. Tolbert, Carol Rubin, Alden K. Henderson, Vicki Stover Hertzberg, Rebecca H. Zhang, and Lorraine Cameron

Name of Source: Epidemiology

Year: 2000

Full Citation Information: Journal, Issue, Publisher, etc.:
Epidemiology 11(6):641–7
Lippincott Williams & Wilkins, Inc

Scientific Discipline/Field: Environmental Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Association between perinatal PBB exposure and age at menarche and current breast and pubic hair Tanner stage in daughters of women exposed to PBBs

Summary of Findings in Article:
Invited all female offspring at least 5 years of age in 1997, born during or after the Michigan PBB incident to participating mothers in the Michigan PBB registry, to take part in this study.
-Girls exposed to relatively high estimated amounts of PBB in utero and in early infancy through breastfeeding had an earlier age at menarche. Breastfed daughters of mothers with a high estimated serum PBB level at the time of pregnancy were found to have an earlier menarche than non-breastfed daughters of mothers with a low estimated serum PBB level at the time of pregnancy.
-There was a suggestion of earlier breast development for breastfed girls with moderate in utero PBB exposure, but not for breastfed girls with high exposure.
-The odds of being in a pubic hair stage of 2 or above increased with increasing PBB exposure among girls who were breastfed.
Authors note that possible mechanisms for the action of PBBs in relation to puberty include alteration of endocrine feedback loops and alteration of circulating hormone levels.

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: Highlighted in book Our Stolen Future by Theo Colborn, Dianne Dumanoski, and John Peterson Myers. Presented at American Academy of Pediatrics Grand Rounds by Ruth Etzel in 2001.

Determinants of polybrominated diphenyl serum decay among women in the Michigan PBB cohort

Authors: Heidi M. Blanck, Michele Marcus, Vicki Hertzberg, Paige E. Tolbert, Carol Rubin, Alden Henderson, Rebecca Zhang

Name of Source: Environmental Health Perspectives

Year: 2000

Full Citation Information: Journal, Issue, Publisher, etc.:
Environ Health Persp. 108(2):147-52

Scientific Discipline/Field: Environmental Epidemiology, Pharmacokinetics

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Used archived PBB serum data from Michigan cohort to study the elimination of PBB in serum over time and to identify factors associated with elimination including age, BMI, smoking history, pregnancy, and breastfeeding duration. The study sample consisted of 380 women over 16 with initial levels of 2 ppb.

Summary of Findings in Article:
-PBB decay was significantly slower (had longer half-life) among women with an initial BMI at or above the median, suggests there is greater retention ofPBBs in women with greater amounts of adipose tissue.
-A borderline significant effect was observed for the number of pregnancies—PBB decay was slower and inversely related to number of pregnancies.
-No significant change in the decay estimate was observed with age, smoking history, or breastfeeding duration.
-Longer half-lives were found with higher initial PBB levels suggesting that PBB elimination may be a saturable process at higher exposures resulting in different distribution patterns or, more likely, that there are unmeasured sources of variability.

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: No

Cancer among a Michigan Cohort Exposed to Polybrominated Biphenyls in 1973

Authors: Ashraful Hoque, Alice J. Sigurdson, Keith D. Burau, Harold E. B. Humphrey, Kenneth R. Hess, Anne M. Sweeney

Name of Source: Epidemiology

Year: 1998

Full Citation Information: Journal, Issue, Publisher, etc.:
Epidemiology, Vol. 9, No. 4, (Jul., 1998), pp. 373-378
Lippincott Williams & Wilkins

Scientific Discipline/Field: Environmental Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Association between site-specific cancer risk and serum polybrominated biphenyl level. Nested case-control study of Michigan cohort accidentally exposed to PBBs in 1973, study population followed for 20 years. Controls were randomly selected cancer-free individuals who were frequency matched to cases by sex and age.

Summary of Findings in Article:
-No strong relation between baseline serum PBB levels and excess cancer risk for all sites combined
-Observed an increasing dose-response relation for digestive system cancer risk with higher serum PBB
category (4-20, 21-50, and >50 ppb) after adjustment for family cancer history, cigarette smoking, alcohol drinking, and baseline serum PCB level
-Observed an increasing dose-response relation for risk of lymphoma and increasing serum PBB category
-Found a threefold increased risk for breast cancer at PBB levels greater than 2 ppb and 2.4-fold increased risk for PBB levels between 4 and 20 pbb

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage:
Editorial in same issue of Epidemiology by Pier Alberto Bertazzi who says the study is small and needs extension and replication but that it is nevertheless a step forward in identifying environmental components in the combination of events underlying cancer occurrence in a population.

Breast cancer among women exposed to polybrominated biphenyls

Authors: Alden K. Henderson, Daniel Rosen, Gayle L. Miller, Larry W. Figgs, Sheila Hoar Zahm, Shelia Hoar Zahm, Susan M. Sieber, Nathaniel Rothman, Harold E. B. Humphrey, Thomas Sinks

Name of Source: Epidemiology

Year: 1995

Full Citation Information: Journal, Issue, Publisher, etc.:
Epidemiology 6(5):544-546
Lippincott Williams &Wilkins

Scientific Discipline/Field: Environmental Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Conducted a nested case-control study with 1,925 women enrolled in a polybrominated biphenyl (PBB) registry to examine the association between breast cancer and serum PBBs. Twenty women who developed breast cancer were matched to 290 control subjects on sex, race, and age

Summary of Findings in Article:
-Women with serum PBB levels of 2-3 ppb or 4 ppb or greater had a higher estimated risk for breast cancer than women with less than 2 ppb. The odds ratios were unchanged when available breast cancer risk factors were included in the analysis.
-Did not observe a dose-response relation between exposure and disease risk
-Excess risk with exposure was not limited to cases diagnosed 10 or more years after exposure

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: No

Effect of polybrominated biphenyls (PBB) on developmental abilities in young children

Authors: Edward M. Schwartz and William A. Rae

Name of Source: American Journal of Public Health

Year: 1983

Full Citation Information: Journal, Issue, Publisher, etc.:
Am J Public Health 73: 277-281.
American Public Health Association

Scientific Discipline/Field: Environmental Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Eighteen children, ages 4 to 6 years, with known exposure to PBBs in utero and/or through breast milk were administered developmental tests (McCarthy Scales of Children’s Abilities and Wechsler Preschool and Primary Intelligence). These same children had exhibited low scores on a partial developmental assessment two years earlier (Seagull 1983, see above). Current results were compared to normative test data.

Summary of Findings in Article:
-Cognitive indices and overall IQs as well as composite and subtest scores from the PBB cohort revealed means to be within the average or normal range in all areas.
-There were no differences in scores between the PBB cohort and the norm group for both tests and the PBB cohort actually scored higher than expected from the standardization data.
-Mean WPPSI and MSCA scores are generally found to be higher in the low exposure group compared to the high exposure group.
-inverse relationship of borderline statistical significance on the perceptual scales of both tests.

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: Discussed by Nebert et al. in the American Journal of Public Health 73(3):286-289. Note that testing is more complete and under more ordinary circumstances compared to earlier Seagull study. Say that intraindividual variation in gas chromatographic analysis of PBB levels in fat samples should have been mentioned as variance of 20% between samples from the same person is not uncommon.

Developmental Abilities of Children Exposed to Polybrominated Biphenyls (PBB)

Authors: Elizabeth Ann Walker Seagull

Name of Source: American Journal of Public Health

Year: 1983

Full Citation Information: Journal, Issue, Publisher, etc.:
Am J Public Health 73:281-285
The American Public Health Association

Scientific Discipline/Field: Environmental Epidemiology, Neurotoxicology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): To investigate whether ingestion of
polybrominated biphenyls has an adverse effect on the neuropsychological development of young children exposed in utero and in infancy, five tests of the McCarthy Scales of Children's Abilities (block building, puzzle solving, word knowledge, draw-a-design, and draw-a-child) were administered to a group of 19 PBB-exposed Michigan children.

Summary of Findings in Article:
-Performance on all 5 tests had a negative relationship to the natural logarithm of the fat PBB level. As PBB level increased, standardized scores decreased. This was statistically significant for 4 of the 5 tests
-Multivariate analysis of covariance (including parental education, socioeconomic status, gender) confirmed the existence of a significant main effect for fat PBB level, with parental education held constant.
-Children with higher body burdens of PBB scored significantly lower than exposed children with lower body burdens on the same 4 tests, and on a composite score representing overall performance.
These results suggest the existence of an inverse relationship between body levels of PBB and some developmental abilities in young children.

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: Critiqued by Nebert et al. in the American Journal of Public Health 73(3):286-289. State that the arbitrary division of high and low exposed groups was not justified. Also note that only 5 tests from the whole battery of the McCarthy Scales of Children's Abilities were selected and therefore were given out of context of the entire battery
under circumstances in which the test would not ordinarily be given, viz in the midst of an array of physical and medical tests. The results of this screen' thus called attention to an aspect of these young children's health that needed confirmation.

Cutaneous effects of exposure to polybrominated biphenyls (PBBs): The Michigan PBB incident

Authors: Joseph J. Chanda, Henry A. Anderson, Roman W. Glamb, Diane L. Lomatch, Mary S. Wolff, John J. Voorhees, and Irving J. Selikoff

Name of Source: Environmental Research

Year: 1982

Full Citation Information: Journal, Issue, Publisher, etc.:
Environmental Research 29: 97-108
Academic Press, Inc.

Scientific Discipline/Field:

Focus of Article (specific exposure pathways, animal tox, epi, etc.): Investigated the Michigan farming population (quarantined and nonquarantined) 3 years after exposure accident detecting cutaneous abnormalities (acne, hair loss, skin redness, skin peeling, and scaling, itching, increased sweating, and increased growth of fingernails and toenails). Michigan Chemical Company workers also examined.

Summary of Findings in Article:
-Quarantined and Nonquarantined farm adults reported more peeling and scaling, erythema, hair loss, increased nail growth, increased sweating, itching, and dryness than controls (Subjective)
-Quarantined, Nonquarantined, and Michigan Chemical Company workers all reported to physicians significantly increased prevalence of the conditions above compared to control group (Subjective)
-Quarantined and nonquarantined individuals were examined to have more diffuse alopecia and halogen acne than controls. Michigan Chemical Company workers had more halogen acne and folliculitis than both farm residents and control groups.
“On the basis of the findings it is reasonable to conclude that polybrominated biphenyls probably have significant cutaneous toxicity”

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: No

The human health effects of exposure to polybrominated biphenyls

Authors: Jeoffrey K. Stross, Irving A. Smokler, John Isbister, and Kenneth R. Wilcox

Name of Source: Toxicology and Applied Pharmacology

Year: 1981

Full Citation Information: Journal, Issue, Publisher, etc.:
Toxicol Appl Pharmacol. 58:145-150.
Academic Press, Inc.

Scientific Discipline/Field: Environmental Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): To determine if high risk groups suffered adverse effects from their known exposure to PBB, 51 people with known exposure to PBB were studied: 23 farmers with disabling health complaints and 28 chemical workers involved in
the PBB manufacturing process were systematically evaluated.

Summary of Findings in Article:
-The farmers had a high frequency of constitutional symptoms, hepatomegaly and skin rashes, findings not commonly noted in the chemical workers.
-Biochemical and hematologic testing revealed few abnormalities, and electromyograms, nerve conduction velocities, endocrine studies, and lymphocyte transformation studies provided no objective findings that correlated with subjective complaints.
-There was no relationship between PBB levels and physical or laboratory abnormalities.
Their evidence suggests that people exposed to PBB have few objective findings at the time, and reactive depression may be responsible for the high prevalence of constitutional symptoms.

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: No

The effect of polybrominated biphenyl on infants and young children

Authors: William B. Weil, Martha Spencer, David Benjamin, Elizabeth Seagull

Name of Source: The Journal of Pediatrics

Year: 1981

Full Citation Information: Journal, Issue, Publisher, etc.:
J Pediatr. 98(1):47-51.
The C.V. Mosby Co.

Scientific Discipline/Field: Environmental Epidemiology, Developmental Toxicology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): The effects of PBB on 33 children born between September 1, 1973, and December 31, 1975, were evaluated in September, 1977. These children, born to families who lived on quarantined farms, were compared to 20 children who were not exposed to PBB. The birthdate interval was selected to obtain children who were exposed in utero or in early infancy or both, the two time periods when damage to developing tissues and organ systems should have been maximal.

Summary of Findings in Article:
-No effects of PBB identified in relation to physical growth, physical examination, or neurologic assessment
-Parents reported the exposed children having more respiratory disease, urninary tract infection, more fever of unknown origin, and increased clumsiness compared to controls. PBB-exposed children were also reported to have had significant loss of appetite and slow weight gain, but by actual measurement their weight was similar to that of controls.
-There were some indications of an inverse relationship between PBB fat level and performance on selected developmental tests.
“However, the powerful social and psychological factors do have impact on the parents, and their anxieties may be transmitted to the children. Alternatively, the parents' perceptions of the health of
their children may be distorted by the anxieties, fears, and pressures generated by the occurrence. Some of the discrepancies between the historical information and physical findings in this study are consistent with the differences between the direct and indirect effects of an acute environmental pollution.”

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: No

Exposure to polybrominated biphenyls: Some effects on personality and cognitive functioning

Authors: Gregory G. Brown and Robert Nixon

Name of Source: Journal of the American Medical Association

Year: 1979

Full Citation Information: Journal, Issue, Publisher, etc.:
JAMA 242(6):523-527.

Scientific Discipline/Field: Environmental Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): To investigate further the effects of PBB exposure on neuropsychological function, 21 persons exposed to polybrominated biphenyls (PBB) were compared with hospital volunteers on a battery of tests measuring memory, motor strength and coordination, cortical-sensory perception, personality, and higher cognitive functioning.

Summary of Findings in Article:
-The PBB adipose levels did not correlate with performance on any test in the battery.
-The two groups did differ on the Minnesota Multiphasic Personality Inventory, suggesting an adjustment reaction with depressive symptoms and somatizing defenses.
-Persons exposed to PBB were also impaired relative to control subjects on tests of prose recall, short-term memory, concentration, and cognitive flexibility. However, these differences vanished when group differences on education and personality were statistically held constant.

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: No

Pediatric health aspects of PBBs

Authors: Mason Barr, Jr.

Name of Source: Environmental Health Perspectives

Year: 1978

Full Citation Information: Journal, Issue, Publisher, etc.:
Environ Health Persp. 23:291-294
National Institute of Environmental Health Sciences

Scientific Discipline/Field: Environmental Epidemiology

Focus of Article (specific exposure pathways, animal tox, epi, etc.): There is a suggestion that Michigan farm children who had multiple symptoms during the 1973-76 period are getting better. A discrete syndrome of il health has not been identified among Michigan farm children. The symptoms complained of indicate a disruption of various physiological functions, including neurobehavioral, gastrointestinal and immunological. Michigan children from quarantined and nonquarantined farms were examined and conditions were compared to a control group of children from Wisconsin with no known exposure to PBBs.

Summary of Findings in Article:
-Comparison of all Michigan children with the Wisconsin children showed that there were statistically
significant differences between the two for 35 of the 65 symptoms studied
-Except in the case of dental caries, the Michigan sample had a higher prevalence of each symptom.
-Comparison of the symptomatic (with 10 or more reported symptoms) and nonsymptomatic groups
showed that, except for 5 symptoms, the prevalence of each symptom was significantly higher in the symptomatic group. The 5 exceptions were dental caries, "hay fever," acne vulgaris, fractures, and
tachycardia.
-When the symptomatic Michigan group was compared to the Wisconsin group all symptoms, except nine, were found to be significantly more prevalent in the symptomatic group. The nine exceptions were dental caries, vision problems, otitis media, "hay fever," enuresis, bronchitis, pneumonitis, convulsions, and tachycardia.
- Statistically significant differences between the nonsymptomatic Michigan group and the Wisconsin group were found for only four symptoms: fatigue, anorexia and diarrhea were more prevalent in the
Nonsymtpomatic Michigan group and dental caries were more prevalent in the Wisconsin group.
-Those children from quarantined farms were less likely to have multiple symptoms (29%) than were those from nonquarantined farms (34%)

Any policy implications discussed in article: No

Any response to the article in OpEds, News coverage: No

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