New Faculty Colloquium - Has your Home Become a Toxic Factory? Plastic Emissions and Human Exposures
Wed, November 18, 2009 • 4:45 PM • GAR 2.112
Dr. Ying Xu (Civil Engineering)
Has your Home Become a Toxic Factory? Plastic Emissions and Human Exposures
Phthalates, a group of chemicals made from petroleum, are mainly used as plasticizers to enhance product flexibility. Recent studies indicate that phthalates may result in profound and irreversible changes in development of human reproductive tract. As they are not chemically bound in materials, slow emissions from products to air usually occurs and may result a substantial exposure. Importantly, about 5 million school-aged children attend school in Texas classrooms that consist of large area of vinyl flooring, where phthalates are typically present at concentrations of 40% (w/w), and are thus exposed to phthalates from this significant source at least 30 hr/week. Therefore, it is critically important to evaluate human exposures and health risks associated with phthalate emissions from consumer products.
Because of the difficulties associated with sampling and analysis of semi-volatile organic compounds, only a few chamber studies quantifying their emissions from building materials and consumer products are available. However, Dr. Xu successfully developed and validated the first mechanistic model to predict the emissions of phthalates from polymeric materials. She designed a special chamber which is able to shorten the test period from 1 year to only 1 month. In the following studies, Dr. Xu have developed a state-of- the-art model that can be used to identify the most important sources of phthalate exposure, and can explain differences in susceptibility to phthalates based on age, species, and exposure routes (inhalation, dermal absorption and oral ingestion). She discovered that the material source characteristics have a significant effect on all the exposure pathways.
Dr. Xu’s research represents the first attempt to explicitly elucidate the fundamental mechanisms governing the release of phthalates from polymeric building materials as well as their subsequent interaction with interior surfaces. The results will be of value to architects, governments, manufacturers, and engineers who wish to specify low-emitting green materials for healthy buildings. It will permit health professionals to identify and control health risks associated with many of the semi-volatile organic compounds used in indoor materials and consumer products in a relatively inexpensive way.