Featured Research

from universities, journals, and other organizations

Proximity to coal-tar-sealed pavement raises risk of cancer, study finds

Date:
March 28, 2013
Source:
Baylor University
Summary:
People living near asphalt pavement sealed with coal tar have an elevated risk of cancer, according to a new study. Much of this calculated excess risk results from exposures in children, age six or younger, to polycyclic aromatic hydrocarbons from the sealant.

People living near asphalt pavement sealed with coal tar have an elevated risk of cancer, according to a study in the journal Environmental Science and Technology. Much of this calculated excess risk results from exposures in children, age six or younger, to polycyclic aromatic hydrocarbons (PAHs) from the sealant.

"The increased cancer risk associated with coal-tar-sealed asphalt (CSA) likely affects a large number of people in the U.S. Our results indicate that the presence of coal-tar-based pavement sealants is associated with significant increases in estimated excess lifetime cancer risk for nearby residents," 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 Baylor's College of Arts & Sciences.

Researchers from Baylor University in Waco, Texas, and the in Austin, Texas, are the first to report on the potential human health effects of PAHs in settled house dust and soil in living spaces and soil adjacent to parking lots sealed with coal-tar-based products.

"Exposure to these compounds in settled house dust is a particularly important source of risk for children younger than six years of age, as they are expected to ingest this material at higher rates," Williams said. "This indicates that the use of coal-tar-based pavement sealants magnifies aggregate exposures to PAHs in children and adults in residences adjacent to where these products are used and is associated with human health risks in excess of widely accepted standards."

Data on PAHs in settled house dust used for this analysis were published previously by the same authors. In that study, settled house dust and parking lot dust were sampled for 23 ground-floor apartments in Austin, Texas. The parking lot surfaces adjacent to the apartments were coal-tar-sealed asphalt, asphalt-based sealant over asphalt pavement, or unsealed concrete. Concentrations of PAHs were 25 times higher in house dust in residences adjacent to coal-tar-sealed pavement compared to those with other pavement types. "This study was the first to find a strong association between a product or a behavior and PAHs in house dust," said Barbara Mahler, the USGS research hydrologist who oversaw the study.

For this study, doses and risk associated with residences adjacent to unsealed asphalt lots were considered relative to those adjacent to (CSA) parking lots. Benzo(a)pyrene concentrations in CSA-affected settled house dust were high relative to those reported in most parts of the U.S. where coal-tar-based sealcoat is not used (California and Arizona). Data for PAHs in coal-tar-sealed asphalt-affected soils and unsealed asphalt-affected soils are available from samples from New Hampshire and suburban Chicago.

The analysis did not consider exposure to the dust on the pavement itself, which has PAH concentrations 10s to 100s of times higher than those in house dust or soil, or inhalation of air over sealed pavement. "Over time, about half of the PAHs in the sealcoat are released into the air, and concentrations in air are extremely high, particularly in the hours to days after application," said Peter Van Metre, USGS research hydrologist and author of two papers on volatilization of PAHs from sealcoat.

Sealcoat is a black, shiny substance sprayed or painted on the asphalt pavement of parking lots, driveways, and playgrounds to improve appearance and protect the underlying asphalt. An estimated 85 million gallons of coal-tar-based sealant are applied to pavement each year, primarily east of the Continental Divide in the U.S. and parts of Canada. Coal-tar-based pavement sealants are 15 to 35 percent coal-tar pitch, which has been classified as a human carcinogen by the International Agency for Research on Cancer. Over time, the dried sealant is worn away from pavement surfaces, and the resulting mobile dust particles can be transported into nearby homes.

"Although the analysis presented here is based on a limited dataset, the results indicate that biomonitoring might be warranted to characterize the exposure of children and adults to PAHs associated with coal-tar-based pavement sealant," Williams said. "Further investigation is also needed into the impacts of coal-tar-based pavement sealants on PAH concentrations in indoor and outdoor environments."


Story Source:

The above story is based on materials provided by Baylor University. Note: Materials may be edited for content and length.


Journal Reference:

  1. E. Spencer Williams, Barbara J. Mahler, Peter C. Van Metre. Cancer Risk from Incidental Ingestion Exposures to PAHs Associated with Coal-Tar-Sealed Pavement. Environmental Science & Technology, 2013; 47 (2): 1101 DOI: 10.1021/es303371t

Cite This Page:

Baylor University. "Proximity to coal-tar-sealed pavement raises risk of cancer, study finds." ScienceDaily. ScienceDaily, 28 March 2013. <www.sciencedaily.com/releases/2013/03/130328125236.htm>.
Baylor University. (2013, March 28). Proximity to coal-tar-sealed pavement raises risk of cancer, study finds. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2013/03/130328125236.htm
Baylor University. "Proximity to coal-tar-sealed pavement raises risk of cancer, study finds." ScienceDaily. www.sciencedaily.com/releases/2013/03/130328125236.htm (accessed October 20, 2014).

Share This



More Health & Medicine News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How Nigeria Beat Its Ebola Outbreak

How Nigeria Beat Its Ebola Outbreak

Newsy (Oct. 20, 2014) The World Health Organization has declared Nigeria free of Ebola. Health experts credit a bit of luck and the government's initial response. Video provided by Newsy
Powered by NewsLook.com
Another Study Suggests Viagra Is Good For The Heart

Another Study Suggests Viagra Is Good For The Heart

Newsy (Oct. 20, 2014) An ingredient in erectile-dysfunction medications such as Viagra could improve heart function. Perhaps not surprising, given Viagra's history. Video provided by Newsy
Powered by NewsLook.com
Ebola Worries End for Dozens on U.S. Watch Lists

Ebola Worries End for Dozens on U.S. Watch Lists

Reuters - US Online Video (Oct. 20, 2014) Forty-three people who had contact with Thomas Eric Duncan, the first person diagnosed with Ebola in the U.S., were cleared overnight of twice-daily monitoring after 21 days of showing no symptoms. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Fauci: Ebola Protocols to Focus on Training

Fauci: Ebola Protocols to Focus on Training

AP (Oct. 20, 2014) Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, says he expects revised CDC protocols on Ebola to focus on training, observation and ensuring health care workers are more protected. (Oct. 20) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins