Rob Vance, vice president of sales for Vance Brothers Inc., a producer of both asphalt-based and refined coal tar-based sealers, says the results and conclusions of both Austin studies are open to interpretation.
"As far as we're concerned, the studies and conclusions we're arguing about are based on interpretation," Vance says. "These people clearly attempt to single-source refined coal tar as responsible for all the PAHs they found and there's just no evidence to suggest that. We're asking our customers to contact us before jumping to any conclusions, and we're telling them to realize that PAHs are everywhere in the environment. A focus on just refined coal tar-based sealants won't reduce the amount of PAHs.
"One has to wonder whether the agenda of the people in Austin is to reduce PAHs in the environment or ban a product that, for whatever reason, they don't like," Vance says. "Maybe the agenda is that refined coal tar-based sealer is a small industry group, more easily attacked than a large industry. Like asphalt sealer, coal tar-based sealers contain PAHs - but if they can eliminate the easiest target they can claim 'Look what I've done' whether or not what they've done addresses the problem. I think they need to take the blinders off and look at the whole picture. This product's been around a long time."
LeHuray agrees. "Look at it in the context of the body of work done in the Austin area, where all this was started and remains focused," she says. "A reasonable question to ask is whether they have an agenda. It certainly appears that their agenda is to directly identify refined coal tar as 'the source' of PAHs. Not 'a' source or 'a minor source,' as we believe it is, but 'the source' - a conclusion that is clearly not supported even by their own data."
Girish Dubey, president of Star Inc. which produces asphalt-based and refined coal tar-based sealers, says that even after concerns were raised about PAHs originating from refined coal tar sealers, the U.S. EPA and the Texas Commission on Environmental Quality have concluded that Barton Creek was safe for swimming. "It has been concluded through independent evaluations that the U.S.G.S. Austin studies are flawed and grossly extrapolated," Dubey says.
But Vance says most people in the industry are finally recognizing the importance of this issue. "This is not a coal tar issue, it's a pavement sealer issue," Vance says. "There are PAHs in refined coal tar-based sealers and there are PAHs in asphalt-based sealers. And if they start eliminating one because they can, that's the first step in eliminating the other one. This is not just a one-product specific issue we're going to be dealing with."
Surface Coatings' Lee Lowis agrees. "It needs to be understood that this is an industry-wide situation. The people who initiated the coal tar ban in Austin made it very clear that their intent was to ban asphalt next," Lowis says.
"It is hard to make a case that this has become an issue based on science when a variety of past studies, including one by the Texas Department of Transportation, have shown that the PAHs contained in products such as refined coal tar generally do not "leach" out. Therefore they are not a contamination hazard. In fact coal tar is actually considered a recycled material."
"PAHs are ubiquitous," she says. "Many are listed as 'possible human carcinogens' but none in the U.S. are listed as 'known human carcinogens.' That's a difficult distinction to make - between 'known' and 'possible' human carcinogens - but it's an important distinction. Typically a 'known' human carcinogen has been shown to cause cancer in humans based on epidemiology studies which review the health experience of individuals in a particular industry compared to the general population. 'Possible' human carcinogens are listed that way because they cause cancer in laboratory animals exposed at high doses for about two years."
LeHuray says neither the initial Austin Barton Creek study nor the recent Austin apartment dust study take into account any other possible sources for PAHs, instead citing refined coal tar sealer as the single dominant PAH source.