In a just released study with the USGS, a Baylor toxicologist has shown that cancer risks to children (ages 0 to 6) with exposures to dust and soil contaminated with coal tar sealants are significant. As stated below, soil is the "primary driver of risk," a medium that has been ignored by many to date. In other words, it just isn't good enough to remove sealant from long-standing, coal-tar sealed surfaces, but adjacent soils must also be considered and remediated.
Also important in the paper was that while the primary risk is soil, indoor dust exposure is nearly as significant. In other words, keeping your kids from playing on a coal tar sealed surface outside is not a big improvement over playing inside a house with a coal tar sealed surface outside.
How can we compare this risk to other things we are familiar with? The risk is similar to a woman living with a smoker or working in a smoke-filled environment. The link for this study is in the post below, Thank You for Not Sealing.
The results of this study show the wisdom of the State of Minnesota's earlier recommendation that schools cease the application of coal tar sealants at schools and the Austin Independent School District's decision to remove remnant coal tar sealants from all paved school surfaces. Let's hope that more schools, and parents take this study to heart and make similar efforts.
We've had a lot to say about health and coal tar sealants on this site. Some related posts are:
Cancer Risks of Coal Tar Sealants Exposed
Our Babies Are Exposed to Tar At Unsafe Levels at School
A link to the abstract and a way to order the complete article is found here.
Recent studies documented significantly higher concentrations of polycyclic aromatic hydrocarbons (PAHs) in settled house dust in living spaces adjacent to parking lots sealed with coal-tar-based products, as well as in nearby soil. To date, no studies have examined the potential human health effects of PAHs from these products in dust and soil. Here we present the results of an analysis of potential cancer risk associated with incidental ingestion exposures to PAHs in settings near coal-tar-sealed pavement. Exposures to benzo[a]pyrene equivalents were characterized across five scenarios. Deterministic and probabilistic methods were used to calculate excess lifetime cancer risk arising from exposures to PAHs in house dust, soil, and both media. The central tendency estimate of excess cancer risk resulting from lifetime exposures to soil and dust via non-dietary ingestion in these settings exceeded 1 * 10-4 in both deterministic and probabilistic estimates. Soil was the primary driver of risk, but according to probabilistic calculations, reasonable maximum exposure to affected house dust in the first 6 years of life was sufficient to generate risk in excess of 1 * 10-4. 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. Much of this calculated excess risk arises from exposures to PAHs in childhood (i.e., ages 0-6).