Some Driveway Coatings Contain Carcinogens

Household maintenance is almost always a chore. It’s a surprise that anyone ever really gets around to it. But for those that do, some of it, especially that concerning driveway maintenance, might be doing more harm than good.

Protecting driveways with special coatings has been a popular way to keep them in good shape for years. In addition to prolonging their lifespans, these coatings also make them look newer and protect them from the elements. However, recent research has shown that a very popular driveway coating, a coal-tar pavement sealant, is loaded up with carcinogens. Worse still, small, yet harmful, amounts of this coating can stick to your feet and be tracked into the house where it can potentially wreak even more havoc.

Fuel Burning Findings

The study, performed by scientists with the United States Geological Survey, has shown that these coal-tar pavement sealants contain over 1,000 times more polycyclic aromatic hydrocarbons (PAHs) than their asphalt-based counterparts. The PAHs, which are byproducts of fuel burning, are known to cause cancer.

Two things are especially interesting about this study: A) the pavement sealants are used much more commonly east of the Continental Divide. West of the Continental Divide, far less harmful asphalt-based equivalents are the norm. B) The coatings may not even be necessary. Studies have shown that the coatings do little to prevent driveway wear and tear.

Coal-Tar Pavement Sealant

But you’re not quite in the clear if you don’t use a coal-tar pavement sealant on your driveway. The U.S. Geological Survey further concluded that the insane amounts of PAHs in these sealants could be affecting the house dust in homes up to 25 feet (or farther) away from driveways coated with it. This means that if your neighbor uses it, or even a business down the street, then your home might not be safe. In particular danger from this cancer-causing chemical are infants, children, and pets that are close to the floor where the dust containing PAHs collects.

In addition to being dangerous for people to ingest, PAHs and the pavement sealant also are cause for environmental concern. Because they are not firmly rooted to the surface they are put on, they have been shown to drain in rainwater runoff thus entering the water supply.

Costly Solutions

U.S. Geological Survey team member Nancy McClintock considers the recent findings of coal-tar sealant to be “a nation-wide problem.” But what can you do? There are few environmentally and health-friendly alternatives on the market today but most of those that are cost a pretty penny. For instance, a Texas-based company produces an asphalt sealant that is the only safe alternative to coal tar but it costs nearly 15 times more.

Researchers are compiling more and more evidence on the dangers of coal-tar sealant and you’re sure to hear more about the issue soon if you keep your ears open. For now, your best bet is to just leave your driveway unprotected. Scientific studies have shown that while sealants improve the look of a driveway, they do little, if nothing, to improve its life span. And, hey, what do you care more about? The look of your driveway or the lifespan of your family?

Aaron Trussell is an environmental engineering student at a major U.S. university. His passion is writing about subjects related to his future career.