Elevated house dust and serum concentrations of PBDEs in California: unintended consequences of furniture flammability standards?

An applied environmental justice framework for exposure science

On the 30th anniversary of the Principles of Environmental Justice established at the First National People of Color Environmental Leadership Summit in 1991 (Principles of Environmental Justice), we continue to call for these principles to be more widely adopted. We propose an environmental justice framework for exposure science to be implemented by all researchers. This framework should be the standard and not an afterthought or trend dismissed by those who believe that science should not be politicized. Most notably, this framework should be centered on the community it seeks to serve. Researchers should meet with community members and stakeholders to learn more about the community, involve them in the research process, collectively determine the environmental exposure issues of highest concern for the community, and develop sustainable interventions and implementation strategies to address them. Incorporating community "funds of knowledge" will also inform the study design by incorporating the knowledge about the issue that community members have based on their lived experiences. Institutional and funding agency funds should also be directed to supporting community needs both during the "active" research phase and at the conclusion of the research, such as mechanisms for dissemination, capacity building, and engagement with policymakers. This multidirectional framework for exposure science will increase the sustainability of the research and its impact for long-term success.

Semivolatile organic compounds in homes: strategies for efficient and systematic exposure measurement based on empirical and theoretical factors

Residential exposure can dominate total exposure for commercial chemicals of health concern; however, despite the importance of consumer exposures, methods for estimating household exposures remain limited. We collected house dust and indoor air samples in 49 California homes and analyzed for 76 semivolatile organic compounds (SVOCs)--phthalates, polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and pesticides. Sixty chemicals were detected in either dust or air and here we report 58 SVOCs detected in dust for the first time. In dust, phthalates (bis(2-ethylhexyl) phthalate, benzyl butyl phthalate, di-n-butyl phthalate) and flame retardants (PBDE 99, PBDE 47) were detected at the highest concentrations relative to other chemicals at the 95th percentile, while phthalates were highest at the median. Because SVOCs are found in both gas and condensed phases and redistribute from their original source over time, partitioning models can clarify their fate indoors. We use empirical data to validate air-dust partitioning models and use these results, combined with experience in SVOC exposure assessment, to recommend residential exposure measurement strategies. We can predict dust concentrations reasonably well from measured air concentrations (R(2) = 0.80). Partitioning models and knowledge of chemical Koa elucidate exposure pathways and suggest priorities for chemical regulation. These findings also inform study design by allowing researchers to select sampling approaches optimized for their chemicals of interest and study goals. While surface wipes are commonly used in epidemiology studies because of ease of implementation, passive air sampling may be more standardized between homes and also relatively simple to deploy. Validation of passive air sampling methods for SVOCs is a priority.

After the PBDE phase-out: a broad suite of flame retardants in repeat house dust samples from California

Higher house dust levels of PBDE flame retardants (FRs) have been reported in California than other parts of the world, due to the state's furniture flammability standard. However, changing levels of these and other FRs have not been evaluated following the 2004 U.S. phase-out of PentaBDE and OctaBDE. We analyzed dust collected in 16 California homes in 2006 and again in 2011 for 62 FRs and organohalogens, which represents the broadest investigation of FRs in homes. Fifty-five compounds were detected in at least one sample; 41 in at least 50% of samples. Concentrations of chlorinated OPFRs, including two (TCEP and TDCIPP) listed as carcinogens under California's Proposition 65, were found up to 0.01% in dust, higher than previously reported in the U.S. In 75% of the homes, we detected TDBPP, or brominated "Tris," which was banned in children's sleepwear because of carcinogenicity. To our knowledge, this is the first report on TDBPP in house dust. Concentrations of Firemaster 550 components (EH-TBB, BEH-TEBP, and TPHP) were higher in 2011 than 2006, consistent with its use as a PentaBDE replacement. Results highlight the evolving nature of FR exposures and suggest that manufacturers continue to use hazardous chemicals and replace chemicals of concern with chemicals with uncharacterized toxicity.

Toxics Use Reduction in the Home: Lessons Learned from Household Exposure Studies

Workers and fence-line communities have been the first to benefit from the substantial reductions in toxic chemical use and byproducts in industrial production resulting from the Massachusetts Toxics Use Reduction Act (TURA). As TURA motivates reformulation of products as well as retooling of production processes, benefits could extend more broadly to large-scale reductions in everyday exposures for the general population. Household exposure studies, including those conducted by Silent Spring Institute, show that people are exposed to complex mixtures of indoor toxics from building materials and a myriad of consumer products. Pollutants in homes are likely to have multiple health effects because many are classified as endocrine disrupting compounds (EDCs), with the ability to interfere with the body's hormone system. Product-related EDCs measured in homes include phthalates, halogenated flame retardants, and alkylphenols. Silent Spring Institute's chemical analysis of personal care and cleaning products confirms many are potential sources of EDCs, highlighting the need for a more comprehensive toxics use reduction (TUR) approach to reduce those exposures. Toxics use reduction targeted at EDCs in consumer products has the potential to substantially reduce occupational and residential exposures. The lessons that have emerged from household exposure research can inform improved chemicals management policies at the state and national levels, leading to safer products and widespread health and environmental benefits.