We spend 90% of our time inside buildings, where we are exposed to many semi-volatile organic chemicals harmful to human health. Polybrominated diphenyl ethers (PBDEs), organophosphate esters (OPEs), per- and polyfluoroalkyl substances (PFAS), and polychlorinated biphenyls (PCBs) are four classes of persistent chemicals that have been commonly found in building materials, migrate out into air and dust, and have been detected in the blood or urine of over 90% of Americans. With a focus on these chemical classes in office buildings, the aims of this dissertation were to assess 1) global differences in chemical exposures, 2) the hormonal activity of indoor dust due to its chemical components, and 3) the impact of a “healthier” materials intervention on levels of chemicals in dust. First, we evaluated exposures of 130 office workers in the USA, UK, China, and India to PBDEs, OPEs, and PCBs using silicone wristbands to sample chemical exposures during work hours. Our findings showed substantial differences across the four countries, which have varying regulations for each chemical class. Some office workers were exposed to legacy PCBs and PBDEs decades after chemical phase-outs due to the long lifespans of building materials. We also found frequent exposures to PCB-11, a contemporary, unintentional byproduct (not banned) in pigments. Exposures to DecaBDE were higher than PentaBDE due to either later phase-outs or restriction exemptions in all four countries. Seven OPEs were detected in nearly all wristbands. Participants in the USA and UK often had higher BFR and OPE exposures, at least partially due to the older and more strict flammability regulations compared to China and India.Second, we quantified hormonal activities of 46 university building dust samples in novel cell-based assays and evaluated associations with measured concentrations of PFAS, PBDEs, and OPEs. We assayed estrogen receptor activation, androgen receptor suppression, peroxisome proliferator-activated receptor suppression, thyroid hormone receptor suppression, and thyroid hormone transport interference. All dust samples were hormonally active, and every assay endpoint had significant or suggestive associations with at least one chemical class. Third, in the same buildings, we evaluated the impact of “healthier” furniture and carpet materials on the chemical concentrations in dust. Rooms with full “healthier” materials interventions were associated with substantially lower dust levels of PFAS and OPEs and suggestive evidence of lower PBDE levels compared to rooms with no intervention or a partial intervention. We found that old buildings continued to contaminate dust with legacy chemicals, even if the chemicals had since been phased out. We also identified electronics and exposed insulation as two other important product categories to address next. In summary, we found that global office buildings influence worker exposures to both legacy and contemporary chemicals, that these chemicals contribute to hormonally active dust in buildings, and that “healthier” materials can reduce the chemicals in building dust. There are actionable solutions to reduce these chemicals indoors and prevent future legacy chemicals. The decisions we make today on healthier materials in buildings will influence the health of generations to come.
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Healthier Materials in Buildings: Assessments of Global Chemical Exposures, Hormonally Active Dust, and Product Interventions
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