USGS Video of Congressional Briefing Now Online


PAHs Increasing in Urban U.S. Lakes from Laura Parsons on Vimeo.

In mid-April the United States Geological Survey presented the science of coal tar sealant pollution to Congress.  Earlier we summarized the presentation in a blog posted later that day entitled, “USGS Shines as PCTC Whines in DC”.  As you can see above, the video of this presentation is now available.  It is a clear, layman’s perspective of the science and development of the studies done by the USGS to date.

Here are some of the highlights selected from the Environmental and Energy Study Institute (EESI)’s summary:

  • Seven different PAHs are qualified as probable human carcinogens by the Environmental Protection Agency (EPA) and have been linked to harmful effects on sperm in men, and on umbilical cords in pregnant women, with connections to slower cognitive development in young children.
  • The City of Austin received funding from the EPA to study sediment profiles near residential and light commercial areas for PAH concentrations greater than 1,500 mg/kg, numbers normally associated with coking of coal or tire manufacturing. U.S. Geological Survey (USGS) found that the only product with PAH concentrations higher than 1,500 mg/kg amongst motor oil, diesel engine emissions, asphalt, etc. was coal tar-based sealcoat.
  • Asphalt-based sealants have PAH concentrations of 50 mg/kg, while coal tar-based sealants have PAH concentrations of 100,000 mg/kg.
  • Lesions, liver abnormalities, tumors, decreased juvenile growth, and increased mortality found in fish populations have been connected with PAHs in the water. While these types of PAHs are insoluble and do not affect our drinking water, they affect humans through inhalation, ingestion, and dermal exposure.
  • USGS analyzed house dust in several apartments in Austin. PAH concentrations in dust in apartments next to parking lots with coal tar sealants were 25 times higher than in dust in apartments next to parking lots with asphalt-based or no sealants.
  • On April 13, 2011 Washington State Senate passed what is likely to become the first statewide ban on the use and sale of coal tar sealants. The bill is currently awaiting a signature from the governor.