(Press-News.org) WACO, Texas (March 28, 2013)- 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.
To watch video comments by Dr. Williams, click here: http://www.baylor.edu/mediacommunications/news.php?action=story&story=128514
Follow this link to read the complete study: http://pubs.acs.org/doi/abs/10.1021/es303371t
Researchers from Baylor University in Waco, Texas, and the U.S. Geological Survey 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."
INFORMATION:
ABOUT BAYLOR UNIVERSITY
Baylor University is a private Christian university and a nationally ranked research institution, characterized as having "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. Baylor sponsors 19 varsity athletic teams and is a founding member of the Big 12 Conference.
ABOUT BAYLOR COLLEGE OF ARTS & SCIENCES
The College of Arts & Sciences is Baylor University's oldest and largest academic division, consisting of 26 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 http://www.baylor.edu/artsandsciences
Philadelphia, PA, March 28, 2013 – Antidepressants are commonly prescribed for the treatment of depression, but many individuals do not experience symptom relief from treatment. The National Institute of Mental Health's STAR*D study, the largest and longest study ever conducted to evaluate depression treatment, found that only approximately one-third of patients responded within their initial medication trial and approximately one-third of patients did not have an adequate clinical response after being treated with several different medications. Thus, identifying predictors ...
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"After 'does this program work?', the question ...
ALBUQUERQUE, NM and DURHAM, NC--A new study conducted by The Mind Research Network in Albuquerque, N.M., shows that neuroimaging data can predict the likelihood of whether a criminal will reoffend following release from prison.
The paper, which is to be published in the Proceedings of the National Academy of Sciences, studied impulsive and antisocial behavior and centered on the anterior cingulate cortex (ACC), a portion of the brain that deals with regulating behavior and impulsivity.
You can view the paper by clicking here: http://www.pnas.org/cgi/doi/10.1073/pnas.1219302110.
The ...
PHILADELPHIA — During embryonic development, animals generate many different types of cells, each with a distinct function and identity.
"Although the identities of these cells remain stable under normal conditions, some cells can be persuaded to take on new identities, through reprogramming," says Ben Stanger, MD, PhD, assistant professor of Medicine in the Division of Gastroenterology at the Perelman School of Medicine, University of Pennsylvania.
Researchers have been able to reprogram cells experimentally, but few have shown that cells can change their identities ...
The union of theory and practice makes broadband, low-loss optical devices practical, which is why two groups of Penn State engineers collaborated to design optical metamaterials that have custom applications that are easily manufactured.
Metamaterials are manufactured materials that derive their unusual properties from structure rather than only composition, and possess exotic properties not usually found in nature. Nanostructured metamaterials appear different for signals of different frequencies. They are dispersive, so that if researchers manipulate this material ...
Women who abruptly and prematurely lose estrogen from surgical menopause have a two-fold increase in cognitive decline and dementia.
"This is what the clinical studies indicate and our animal studies looking at the underlying mechanisms back this up," said Brann, corresponding author of the study in the journal Brain. "We wanted to find out why that is occurring. We suspect it's due to the premature loss of estrogen."
In an effort to mimic what occurs in women, Brann and his colleagues looked at rats 10 weeks after removal of their estrogen-producing ovaries that were ...
Swarms of robots acting together to carry out jobs could provide new opportunities for humans to harness the power of machines.
Researchers in the Sheffield Centre for Robotics, jointly established by the University of Sheffield and Sheffield Hallam University, have been working to program a group of 40 robots, and say the ability to control robot swarms could prove hugely beneficial in a range of contexts, from military to medical.
The researchers have demonstrated that the swarm can carry out simple fetching and carrying tasks, by grouping around an object and working ...
Considerable opportunity exists to improve interventions and outcomes of traumatic brain injury (TBI) in older adults, according to three studies published in the recent online issue of NeuroRehabilitation by researchers from the Icahn School of Medicine at Mount Sinai.
An Exploration of Clinical Dementia Phenotypes Among Individuals With and Without Traumatic Brain Injury
Some evidence suggests that a history of TBI is associated with an increased risk of dementia later in life, but the clinical features of dementia associated with TBI have not been well investigated. ...
(Edmonton) Researchers from the University of Alberta are teaming up with child-care providers and day-home operators to ensure they have adequate training and support needed to offer inclusive spaces for children with disabilities.
Lesley Wiart was the lead author of a new study that identified challenges in providing inclusive spaces for children with physical disabilities, cognitive impairments and behavioural issues. The research showed that many Alberta child-care centres and day homes support inclusion but sometimes lack training and support.
"Even though providers ...
This press release is available in German.
Mate choice is a key factor in the evolution of new animal species. The choice of a specific mate can decisively influence the evolutionary development of a species. In mice, the attractiveness of a potential mate is conveyed by scent cues and ultrasonic vocalizations. Researchers from the Max Planck Institute for Evolutionary Biology in Plön investigated whether house mice (Mus musculus) would mate with each other even if they were from two populations which had been separated from each other for a long time period. To do this, ...
