javascript:; More Repetition Than Revelation in Coal Tar Sealer Industry's New Bias Claims | Coal Tar Free America

A few weeks ago, representatives of the coal tar sealer industry came out with new claims of bias by USGS researchers.  Press releases, presentations and insider editorials were coordinated to push back on recent research by the USGS and Baylor University, which found high lifetime cancer risks when living near a coal tar sealed parking lot.  Industry has now even glommed onto a new catch-phrase called "white hat bias."  However, a review of one of the cornerstone reports of this effort reveals little more than the usual distortions by industry, just dressed up with toxicology jargon.

One of the sources of these claims is a new, industry-funded research paper entitled, Peer Review of Coal-Tar-Sealed Pavement Risk Assessment.  While the content has changed, the tactics are similar to what has come from the industry: dodges, and distortions.  Even the title is a distortion, which will be explained later.

If you do read the report, what is most interesting is what you won't find in it.  Does this industry that pumps 85 million gallons of the most potent source of polycyclic aromatic hydrocarbons (PAH) around our nation even have any idea how bioavailable* or toxic it is?  Have they published any research that addresses this?  Has the coal tar industry analyzed what happens to these known human carcinogens after they wear off or evaporate from a parking lot?  Do they know what other effects of this product there are on the unborn?  "No" to all four questions.  This is a fundamental regulatory problem.  How can we allow a potent source to be cast to the environment in this way?  How can the EPA allow an industry to take a hazardous material and say it is no longer hazardous if it is reused as a product?

In general we felt comfortable as a decent readers of science and with our knowledge of this subject to evaluate 9 out of the 11 comments. There is nothing in those 9 comments that would reasonably be expected to change the results.  One of the comments would require understanding "why" the researchers used data in certain manners.  This was not apparent in the paper or the supplemental materials.  

The other that we did not answer was about detailed toxicological risk procedures.

Below is a summary table in which the first 3 columns are verbatim from the study with the exception that we replaced their bullets in column 3 with a numbered list.  We added the fourth column as our evaluation of the Industry Review (Arcadis).  The numbers in column 3 and 4 correspond to each other.  Just click on the table to enlarge it.

Some of the main points made by the authors are merely repeated statements made by the Baylor/USGS team as to the limits of the study.  In other words, the Baylor/USGS paper acknowledges limitations of their work and Arcadis' comments appear as if they uncovered a heretofore unknown fact.  

One of these was the topic of bioavailability, which you can read in the Baylor/USGS paper was acknowledged to be difficult to put a firm number to.  However we know that coal tar sealants are bioavailable to aquatic species through laboratory experiments and to bacteria via the Ames Test.

Click on this table for an enlarged view.

Another problem with the paper is in the title and the use of the term "peer review."  It has the connotation that it is independent and unbiased; both of which are untrue by a normal meaning.  Here is one definition that seeks to manage or reveal bias on the part of the reviewer in a truly peer-reviewed article:

"Reviewers' comments and conclusions should be based on a consideration of the facts, exclusive of personal or professional bias. To the extent possible, the system of review should be designed to minimize actual or perceived bias on the reviewers' part. If reviewers have any interest that might interfere with an objective review, then they should either decline a role as reviewer or declare the conflict of interest..." Office of Research Integrity, University of Alaska

So at best this report should be titled and referred to as a "Review" and nothing more.

A more robust response to this will be required by the USGS sometime in the future because it was officially lodged invoking the "Data Quality Act."  When it comes out, we'll be sure to let you know.

*bioavailability: the amount of a substance which can be absorbed into a living thing

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