Children at Risk for Ingestion of PAHs from Pavement Sealant, Study Finds

Feb. 13, 2012

Follow us on Twitter:@BaylorUMediaCom

Media Contact: Frank Raczkiewicz, (254) 710-1964

WACO, Texas (Feb. 13, 2012) - Children living near coal-tar-sealed pavement are likely to receive a far higher dose of carcinogenic polycyclic aromatic hydrocarbons (PAHs) from incidental ingestion of house dust than do children living near unsealed pavement, and that dose is more than two times higher than the PAH dose children are estimated to receive from food.

In a paper published in the journal Environmental Pollution, researchers at Baylor University in Waco, Texas, and the U.S. Geological Survey (USGS) in Austin, Texas, reported that the calculated non-dietary dose of B2 (carcinogenic) PAHs for children in residences adjacent to coal-tar-sealed pavement is 14 times that for children in residences adjacent to unsealed pavement.

Access the full study through this link:

http://www.sciencedirect.com/science/article/pii/S0269749112000279

The results are an important step in evaluating the human-health risk associated with use of coal-tar-sealcoat products.

"Our study indicates that house dust in residences adjacent to coal-tar-sealed pavement might represent a primary and biologically relevant exposure to B2 PAHs, especially in young children. This is of particular interest because of the widespread use of coal-tar-based sealant on parking lots and residential driveways in the U.S.," said E. Spencer Williams., Ph.D., principal author of the study and Baylor University assistant research scientist at the Center for Reservoir and Aquatic Systems Research in the College of Arts & Sciences.

Coal-tar-based pavement sealant, a product applied to many parking lots, driveways, and even playgrounds primarily in the Central, Southern, and Eastern U.S., has PAH concentrations 100 to1,000 times greater than most other PAH sources. An earlier study documented that house dust in residences adjacent to coal-tar-sealed parking lots had PAH concentrations 25 times higher than in house dust in residences adjacent to parking lots with other types of surfaces.

Humans regularly are exposed to PAHs through ingestion of cooked and uncooked foods, incidental ingestion of soil and dust, inhalation of ambient air and absorption through skin. While some previous studies have indicated that diet is the most important source of PAHs to humans, those studies did not consider house dust contaminated with PAHs from coal-tar-based sealcoat.

"Until now, common knowledge held that dietary ingestion was the most important way that children are exposed to PAHs, but these dose calculations challenge that assumption for some settings," added Barbara Mahler, also an author of the exposure study and a researcher with the USGS.

About Baylor University

Baylor University is a private Christian university and a nationally ranked research institution, classified as such with "high research activity" by the Carnegie Foundation for the Advancement of Teaching. The university provides a vibrant campus community for approximately 15,000 students by blending interdisciplinary research with an international reputation for educational excellence and a faculty commitment to teaching and scholarship. Chartered in 1845 by the Republic of Texas through the efforts of Baptist pioneers, Baylor is the oldest continually operating university in Texas. Located in Waco, Baylor welcomes students from all 50 states and more than 80 countries to study a broad range of degrees among its 11 nationally recognized academic divisions.

About Baylor College of Arts & Sciences

The College of Arts & Sciences is Baylor University's oldest and largest academic division, consisting of 27 academic departments and 13 academic centers and institutes. The more than 5,000 courses taught in the College span topics from art and theatre to religion, philosophy, sociology and the natural sciences. Faculty conduct research around the world, and research on the undergraduate and graduate level is prevalent throughout all disciplines. Visit www.baylor.edu/artsandsciences

Looking for more news from Baylor University?