Modern indoor environments contain a vast array of manufactured products, many of which emit toxic contaminants that can harm children. Of special concern are crib mattresses, as infants spend most of their time sleeping, with their breathing zone and skin in close proximity to, or touching, the source, and thus are likely to be exposed to elevated concentrations of released chemicals, including organophosphates and phthalates. Although the adverse health effects associated with exposure to these semi-volatile organic compounds have been extensively demonstrated, accurate evaluation of infants' exposure and the subsequent health effect remain hamstrung by a poor understanding of the emission and fate of these semi-volatile organic compounds in sleep microenvironments. The goal of this research is to explicitly elucidate the fundamental mechanisms governing emission, transport, and infants' exposure associated with organophosphates and phthalates in sleep microenvironments.
This project will elucidate the fundamental mechanisms that govern the release of organophosphates and phthalates from crib mattresses and incorporate these mechanisms into a new transport and exposure model. The PI will be the first to develop a general and rapid method for measuring key parameters that control semi-volatile organic emissions, which is urgently needed for rapid screening of products for semi-volatile organic additives that are most harmful to children's health. The PI will also accurately measure semi-volatile organic gas/particle partitioning using an innovative direct approach. This research will, for the first time, connect the mechanistic understanding of emissions to the previously-overlooked strong sorption by airborne particles, bedding materials, and skin, and to the subsequent impacts on inhalation and dermal exposures. It will significantly advance the ability to predict emission, fate and transport, and exposures for a range of chemicals in sleep microenvironments and other similar microenvironments (e.g., infants' incubators), which have not been extensively researched with respect to exposure to toxic chemicals. The specific research objectives are to: 1) develop a novel, rapid method to characterize the emissions of organophosphates and phthalates from crib mattresses; 2) determine the sorptive interactions of the target semi-volatile organic compounds with particles and surfaces (e.g., bedding and clothing) through systematic laboratory studies; 3) develop an innovative combined emission, transport, and exposure model to predict the spatial and temporal distributions of pollutants in the vicinity of sleeping infants and subsequent exposures; and 4) conduct a series of controlled tests in a room-sized chamber with a breathing, thermal manikin of an infant to validate the model and to investigate the influences of various environmental factors on infants' exposures. The project will benefit from collaboration with the Children's Environmental Health Institute, with commitment for co-organizing a symposium that will involve the transfer of the project findings to a large base of health researchers and practitioners.
