In a somewhat related item, Environment Canada (the nation of course) and the University of Toronto have completed an analysis of coal tar sealant use in Ontario. Findings include:
- coal tar sealants (CTS) are available for commerical and retail users
- CTS coverage in the greater Toronto area is nearly 6 square miles (14 km2)!
- sealant scraping concentrations were somewhat lower than published data from Mahler et al. at the USGS (perhaps due to both mislabeling in Canada and non-coal tar lot contamination in the USGS sampling)
- large loss of PAH's due to volatization during drying/curing (see graph below)
- the average annual, estimated PAH load to surface water and soil is more than 7,000 pounds per year in Toronto
- a presentation of these finds can be found at this link: http://www.epa.gov/greatlakes/bns/integration/Jun2011/Li_6152011.pdf