"Asphalt Institute Study on "Differences Between Asphalt & Coal Tar"
The Asphalt Institute is the voice of the Asphalt Industry, conducting ongoing research and development on the latest technologies in the paving industry.
As the experts the paving industry they point would be sealcoating projects away from coal tar towards petroleum based products. The reason is simple, Report RR-78-1 is a
highly technical report on the chemistry of petroleum asphalt compared to coal tar pitch and road tars and sheds light on the reason for this stance, and why
coal tar coatings are not as effective as petroleum base treatments. For more information click on the following PDF file.
Differences Between Asphalt & Coal Tar.pdf
"Alarming Levels of Coal Tar Dust From Seal Coatings showing up in homes..." MSNBC News Jan 2010
Chemicals in a cancer-causing substance used to seal pavement, parking lots and driveways across the U.S. are showing up at alarming levels in dust in homes, prompting
concerns about the potential health effects of long-term exposure, a new study shows.
The substance is coal tar sealant, a waste product of steel manufacturing that is used to protect pavement and asphalt against cracking and water damage, and to impart
a nice dark sheen. It is applied most heavily east of the Rockies but is used in all 50 states.
But scientists with the U.S. Geological Survey say the sealant — one of two types commonly used in the U.S. — doesn’t stay put. It slowly wears off and is tracked into
homes on the shoes of residents. For More info go to http://www.msnbc.msn.com/id/34809699/ns/us_news-environment
USGS RESEARCH Parking Lot Sealcoat: A Major Source of Polycyclic Aromatic Hydrocarbons (PAHs) in Urban and Suburban Environments
Collaborative studies by the City of Austin and the U. S. Geological Survey (USGS) have identified coal-tar based sealcoat—the black, shiny emulsion painted or sprayed on
asphalt pavement such as parking lots—as a major and previously unrecognized source of polycyclic aromatic hydrocarbon (PAH) contamination. Several PAHs are suspected human
carcinogens and are toxic to aquatic life. Studies in Austin, Texas, showed that particles in runoff from coal-tar based sealcoated parking lots had concentrations of PAHs
that were about 65 times higher than concentrations in particles washed off parking lots that had not been sealcoated. Biological studies, conducted by the City of Austin
in the field and in the laboratory, indicated that PAH levels in sediment contaminated with abraded sealcoat were toxic to aquatic life and were degrading aquatic communities
, as indicated by loss of species and decreased numbers of organisms. Identification of this source of PAHs may help to improve future strategies for controlling these
compounds in urban water bodies across the Nation where parking lot sealcoat is used. http://www.msnbc.msn.com/id/34809699//
COAL TAR COATINGS UNSAFE FOR THE ECOSYSTEM
As coal tar coatings age and abrade from tires, snow plows, and normal oxidation, the toxic chemicals in the abraded particles of coal tar coatings collect and accumulate
in runoff into our streams, waterways, lakes, and underground water table. Scientists are concerned. As of now, they do not know the long-term effects of exposure to the
public from release of these highly toxic PAHs into waterways and soils. For more info go to:
USGS data displayed that coal tar coatings release up to 1000 times greater toxins into the water shed than those released by asphalt pavement or asphalt based coatings. It is true that many sources of PAHs exist, however, USGS data shows that up to 93% of toxic PAHs in water shed runoff can be eliminated by removing one source from public use–coal tar seal coatings!
The question? Where has the sharp increase in toxic PAHs found in our national urban water shed during the last twenty years come from? The answer was uncovered in June of 2005 in Austin, Texas in the Barton Springs watershed study co-authored by the City of Austin and the USGS. The study found extremely high concentrations of PAHs (double the concentrations found in a Federal Superfund Cleanup site in Ohio) in Austin's pristine Barton Springs spring-fed natural aquatic playground.
The June 2005 study identifies Polycyclic Aromatic Hydrocarbons (PAHs) found in coal tar seal coatings as a primary watershed pollutant threatening aquatic life as well as the potential threat to human health. One ingredient in significant quantities is included in The U.S. Environmental Protection Agency's (EPA) list of twelve persistent Bioaccumulative and Toxic Chemicals (PBTs). According to the EPA, "PBTs are highly toxic and long-lasting substances that can build up in the food chain and become harmful to human and ecosystem health."
WHAT IS OUR RESPONSIBILITY?
Should we conduct a national debate while these carcinogens and toxins continue to rise in our lakes, streams, rivers, aquifers and soils? The fact is, no one really knows just how significant the effect of these lethal carcinogens will be to human, animal, and plant life over time.
WHAT CAN I DO NOW TO HELP?
You can can choose to eliminate over 90% of PAHs released into our ecosystem and make a positive impact on the environment! Choose safer asphalt based treatments. There are many safe and low level PAHs preservation processes that will protect your asphalt investment and our environment, all at the same time. Read the MSDS information on the coatings you consider before making a buying decision. If it contains any coal tar derivatives, just say NO!
More on environmental hazards of coal tar coatings can be found at:
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