American urban lake pollution traced to parking lot seal coat

[unhappycamper]

American urban lake pollution traced to parking lot seal coat
By Renee Schoof | McClatchy Newspapers
Posted on Sunday, December 5, 2010

WASHINGTON — A black sealant sprayed on parking lots, driveways and playgrounds turns out to be the largest contributor to the rise of a toxic pollutant in urban lakes and reservoirs across America, according to a new U.S. Geological Survey study.

Scientists saw concentrations of polycyclic aromatic hydrocarbons (PAHs) going up rapidly in the 1990s in areas of urban sprawl. PAHs have been known as a probable human carcinogen since the 19th century, when cancer struck chimney sweeps, said Peter Van Metre, a USGS scientist and a principal author of the report. PAHs also are toxic to fish and other aquatic plant and animal life.

The research was based on sampling of sediments from the bottom of 40 lakes and reservoirs in commercial and residential areas in cities and suburbs typical of where most Americans live — not near old industrial sites. Among the cities tested were Anchorage, Alaska; Fort Worth, Texas; Portland, Ore.; Seattle; Orlando, Fla.; Raleigh, N.C., Chicago, Newark, N.J., Detroit; Milwaukee and Boston.

What was striking about the findings was that lakes that had high levels of PAHs also had a large fraction of those PAHs coming from coal-tar-based sealants. The opposite also was true — lakes that had low PAH levels also had a very low fraction of them from the sealant.

For example, Middle Tanasbrook Pond in suburban Portland had very low levels of PAHs, but Palmer Lake, in suburban Minneapolis, had PAH levels 25 times higher. Both communities have major highways and about the same population density.

[eppur_se_muova]

1. Sure it's toxic, but it's cheap! Get your priorities straight! nt

[L. Coyote]

3. Petroleum products are exempt from worker protection laws too.

Gasoline is about as poisonous as anything we deal with regularly. Gasoline is very high in volatile organic solvents, causes cancers and brain damage.

Maybe the effects of gasoline are coming to fruition--as we all become brain-damaged, we start to not worry about things like this.

[hunter]

2. Yet another reason automobiles are loathsome.

:(

[pschoeb]

4. Some places overuse cheap sealants

For protecting the asphalt you only need to seal at most, every three years, most sealants last 6 years, some up to 10 years. But many places seal their lots every year for purely cosmetic reasons.