The City of Springfield, MO conducted a broad study on the environmental effects of PAH from coal tar sealants. This web page links to lots of resources and reports on their findings.
The United States Geological Survey is a scientific research agency of the Federal Government. They study the natural hazards, natural resources, and utilize scientific disciplines spanning geography, hydrology, biology, and geology.
This section of the website displays the latest features produced by the USGS relating to Coal Tar Sealant.
They keep up-to-date on the latest research and news on actions against CTS and new alternatives. Articles span across the United States and as far back as 2010. Their site's mission statement:
Dedicated to researching, educating, and advocating for the ban and elimination of toxic coal tar sealants (CTS) from our parking lots, homes, and environment.