Serum Polybrominated Biphenyls (PBBs) and Polychlorinated Biphenyls (PCBs) and Thyroid Function among Michigan Adults Several Decades after the 1973–1974 PBB Contamination of Livestock Feed

Abstract

Background:In 1973–1974, Michigan residents were exposed to polybrominated biphenyls (PBBs) through an accidental contamination of the food supply. Residents were enrolled in a registry assembled after the incident, and they and their children participated in follow-up studies to assess subsequent health outcomes.Objectives:We evaluated associations between serum PBBs and polychlorinated biphenyls (PCBs) and markers of thyroid function among Michigan adults.Methods:Serum concentrations of four PBB and four PCB congeners were measured at least once in 753 adults, including 79 women who participated in a 2004–2006 study and 683 women and men with follow-up during 2012–2015. Participants completed questionnaires on health conditions (including physician-diagnosed thyroid disease), behaviors, and demographics. Thyroid hormones were measured in a subset without thyroid disease (n=551). In multivariable linear regression models, PBB and PCB congener concentrations, on both the volume (nanogram/milliliter) and lipid (nanogram/gram lipid) basis, were assessed in relation to thyroid hormones. Logistic regression models were used to estimate associations between serum PBBs and PCBs and thyroid disease.Results:Thyroid disease was common (18% overall; 25% among women). Among women, all odds ratios (ORs) for PBB-153 and thyroid disease were positive for quintiles above the reference level, but estimates were imprecise and were without a monotonic increase. For an interquartile range (IQR) increase in PBB-153 (0.43 ng/mL), the OR (any thyroid disease)=1.12; (95% CI: 0.83, 1.52) (n=105 cases); for hypothyroidism, OR=1.35 (95% CI: 0.86, 2.13) (n=49 cases). There were 21 cases of thyroid disease in men [OR=0.69 (95% CI: 0.33); 1.44 for an IQR increase (0.75 ng/mL) in serum PBB-153]. PCB congeners were statistically significantly associated with greater total and free thyroxine and total triiodothyronine among women and with total and free triiodothyronine among men in lipid-standardized models.Conclusions:We found some evidence to support associations of PBBs and PCBs with thyroid disease and thyroid hormone levels. https://doi.org/10.1289/EHP1302

Exposure to polybrominated biphenyl (PBB) associates with genome-wide DNA methylation differences in peripheral blood

“…This is consistent with early studies that that showed that 35-40% of Michigan farmers who had eaten PBB-contaminated food had a significant reduction in in vitro immune function [69]. While no studies have looked at PBB's association with the development of autoimmune disorders, studies in this cohort have found PBB exposure is associated with the development of hypothyroidism (which is commonly caused by an autoimmune disorder) in both men and women, although neither of these analyzed hypothyroidism by type [24,25]. Additionally, when the signal for the CpGs associated with low grade inflammation was compared to the signal from PBB, they were correlated, and PBB was associated with the proportion of B cells, even after controlling for age, sex, and lipid levels.…”

“…Total lipid level was calculated in this cohort as part of previous studies [25]. A Triglyceride Quantification Assay Kit (Abnova Corporation) was used to measure the total triglyceride content in serum, and a Cholesterol Assay Kit (Caymen Chemical Company) was used to measure total cholesterol content in serum.…”

“…Additionally, because PBB can pass through the placental barrier and is present in breast milk, children born to exposed women are also exposed [23]. This cohort has reported many endocrine-related and reproductive health concerns, such as thyroid disease, spontaneous abortions, earlier age of menarche, and genitourinary conditions in male offspring, as well as breast cancer, digestive cancer, and lymphomas [24][25][26][27][28][29][30][31][32][33]. In general, the people who were exposed in utero or in childhood were found to be particularly susceptible to endocrine-related conditions [34].…”

Examining Reproductive Health Outcomes in Females Exposed to Polychlorinated Biphenyl and Polybrominated Biphenyl

“…As part of continued effort to enroll members and inform the community of research findings, members of the PBB registry were mailed invitations to attend community meetings held throughout the state where recruitment was conducted between 2012 and 2015. Community meetings were also advertised in the local press; thus, individuals from the original registry as well as others who had lived in the state of Michigan during the time of contamination (1973)(1974) or were offspring of those who lived in the state during that time 41 attended and subsequently participated. For this study, participants had to be women between the ages of 18 and 59, had to have completed a detailed reproductive health questionnaire, and had to have a blood draw with recent PCB and PBB concentrations.…”

Separation of halogenated benzenes enabled by investigation of halogen–π interactions with carbon materials

“…The separation of halogenated benzenes in oil samples is a major issue in the eld of environmental chemistry, since many halogenated benzenes are in waste oil and are highly toxic. [73][74][75] Therefore, the LC separation of halogenated benzenes has great importance in environmental chemistry and shows its potential for separating toxic aromatic halogens, such as polychlorinated biphenyls and polybrominated biphenyls.…”