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Hidden Passengers: toxic chemicals invading your life and what you can do about it

Ohio Environmental Council, July 14, 2015

At the Ohio Environmental Council, we are working hard day in and day out to make a healthier state for all who call Ohio home. This work includes not only protecting our streams, lakes and rivers and advocating for clean energy and healthy outdoor air, but also reducing our exposure to environmental toxins in our homes and communities.

Many of us assume that the products we use in and around our homes on a daily basis are generally safe. We believe that we have adequate systems in place to provide protection from unsafe chemicals in products such as the carpet or paint in our homes, the furniture we sit on, or even the shampoo we use to wash our young babies’ hair. Unfortunately this is not so.

Today we are facing a serious public health and environmental crisis from chemical exposures in our homes, in products we use daily, and in our air, soil and water. We are seeing marked increases in chronic health problems linked to chemical exposures, such as learning disabilities, infertility, and cancer.

The reason: the federal law intended to deal with evaluating the risks from chemicals before they enter the market is broken. The Toxic Substances Control Act or TSCA has been seriously flawed since it was passed in 1976. Of an estimated 84,000 chemicals on the market, the EPA has been able to require little to no health and safety information and to restrict only five of these chemicals.

Today mark’s the first blog in a series that I will write covering toxic chemicals in our homes and every day environment. I will cover where they are found, why they are used, the health problems and risks associated with them, and sometimes even how I, myself, have come into contact with them. Being a mother of a young child and working as an advocate for safer chemicals, I have become especially aware of reducing toxic chemical exposures in my own home. The goal of this blog series is to help you gain awareness and reduce household chemical exposures, too.   

Introducing coal tar sealants:

Ever heard of coal tar-based sealants (aka blacktop sealant)? Okay, well maybe you haven’t heard of them, but you have likely seen or smelled the toxic fumes from a shiny blacktop on a hot summer day. This is from a newly sealed driveway or parking lot, and in most cases in Ohio, this sealant is made of “coal tar.” Coal tar is a thick, black or brown liquid. While its use on roads is extremely rare, it is commonly used on private driveways, parking lots, and playgrounds. The sealant is used to make blacktop more resistant to weathering.

There are two widely used types of sealant: coal tar-based and asphalt-based. Coal tar is a byproduct of coal distilling. Asphalt is a byproduct of petroleum refining. Asphalt-based sealant is popular west of the Continental Divide, while coal tar is popular in the east because there is more coal industry and it is more convenient to transport. 

Our own driveways may be raising our risk of getting cancer. Wait, say what?

Coal tar sealants are a serious, although seldom recognized , public health problem. This is because coal tar sealants contain more than 200 different polycyclic aromatic hydrocarbons or PAHs. PAHs are a group of chemical compounds that form whenever anything with a carbon base is burned. Seven PAHs found in coal tar sealants are classified as likely human carcinogens by the EPA.

To put this in perspective, those seven compounds are the same carcinogens found in cigarette smoke.

The USGS and Baylor University recently conducted a study which found that a person who spends her whole life living next to a coal tar sealed black top driveway is 38 times more likely to get cancer compared to someone who did not.

The study also found that 80% of a person’s lifetime dosage of PAH’s happens before the age of 18. Half of a persons total exposure happens between ages 0 to 6. This means that children are at a disproportionate risk to the health impacts of coal tar. Young children are the most at risk because they play directly on and around black tops and because they put their hands in their mouth more often than adults, typically without washing them first.

How do the PAHs from coal tar enter our bodies?

  • Inhalation of wind-blown particles and fumes that volatilize from sealed parking lots
  • Ingestion of abraded particles from driveways, parking lots or play grounds, or ingestion soil which contains coal tar through it’s leaching  into the ground around the black top. Children in particular are at higher risk because they are more likely to play on these surfaces.
  • Ingestion of house dust which contains coal tar particles. This is an important source of exposure, again, for small children who spend time on the floor and put hands and objects into their mouths.

Many of the health problems associated with coal tar could be avoided by using asphalt sealant instead. Product analyses indicate that coal tar sealcoats contain about 1,000 times more PAHs than sealcoat products with an asphalt base. 

Harmful effects of coal tar to our water & wildlife:

PAHs from coal tar sealants move from a coated surface and into our environment through storm water runoff, adhesion to tires, wind, foot traffic and volatilization. Some PAHs are toxic to mammals (including humans), birds, fish, amphibians such as frogs and salamanders, and plants. Aquatic insects and other small creatures that live in streams and lakes are particularly susceptible to PAH contamination. These aquatic critters are often monitored as indicators of stream quality, the “canary in the coal mine” so to speak.

Scientific studies have shown a relationship between coal tar sealant contamination and harmful effects on aquatic life, including:

  • Salamanders and newts had stunted growth, difficulty swimming and liver problems.
  • Frogs had stunted growth and developed more slowly than usual.
  • Bullhead catfish from the Anacostia River (Washington DC) had tumors believed to be related to elevated PAH concentrations.

Reducing your exposure & improving water quality:

Decide against using coal tar sealants on your own driveway or on your business parking lot. Instead, simply substitute an asphalt based sealant or use an altogether different material such as concrete, gravel, bricks, or stones. Find out if it is used on the playground at your child’s school or daycare and advocate for its use to stop.  You can determine if a product has a coal-tar base by looking for the words “coal tar,” “refined tar,” “refined coal-tar pitch,” or other similar terms that may be listed on the product container. You can also ask your contractor to review the products Material Safety Data Sheet (MSDS) for the Chemical Abstracts Services (CAS) number 65996-93-2 or the words from above. 

My story:

The impetus for kicking off this blog series with coal tar sealants was the fact that my daughter’s daycare recently sealed its main walkway (which doubles as a children’s play area) with a coal tar based sealant. It’s use was obvious from the “mothball” smell and the skin irritation that occurred to my student intern who was touching the material to investigate it with me. Can you imagine my dismay (and that of my poor intern!)?

As unfortunate as the exposure was for the many children and parents served by the center (just think of all those shoes carrying coal tar particles into homes), it also opened up an opportunity for affecting change at my daughter’s daycare. After providing an overview of the toxicity and health impacts of coal tar sealant, I am happy to report that my daughter’s daycare owner has agreed to cease using the material and to come up with an alternative!

You can have a victory too!

Talk to folks about this issue: talk to your neighbors, your family members, and your child’s day care owner. And don’t stop there; talk to your local, state, and federal lawmakers too. Progress can be made. Several jurisdictions including Austin, Texas; Washington, DC; Dane County, Wisconsin; and several suburbs of Minneapolis, Minnesota have banned the use of coal tar based sealants. Similar bans are under consideration in other jurisdictions. 

Additional resources to provide talking points for these conversations can be found here.

Finally, spread the word about the public health risk associated with coal tar sealants by sharing this blog on Twitter and Facebook.