[acn-l] aquatic news of interest

Bruce Bernard (gaiafusion at yahoo.com)
Tue, 03 Oct 2000 16:08:25 -0700 (PDT)

Source: American Chemical Society
(http://www.acs.org/)Date: Posted 9/29/2000

Pollution From Urban Sprawl Threatens Aquatic Life In
Major U.S. Cities

Pollution from traffic congestion is getting into
waterways, where it can poison animal and other
aquatic life, according to research presented in the
current (October 1) issue of Environmental Science &
Technology, a peer-reviewed journal of the American
Chemical Society, the world's largest scientific
society.

The study blames increased traffic from urban sprawl
for high levels of polycyclic aromatic hydrocarbons,
or PAHs, in lakes and reservoirs around six
metropolitan areas, including Washington, D.C., New
York, Newark, N.J., Minneapolis, Dallas and Seattle.
Effects due to vehicle traffic included PAH
concentrations in reservoir sediments up to 100 times
greater than pre-urban conditions, said Peter Van
Metre, lead author of the study from the U.S.
Geological Survey in Austin, Texas.

The compounds are unlikely to get into the drinking
water supply and adversely affect human health because
they stick to the sediments in water supplies, he
said. In addition, it is safe to eat fish or crabs -
because the substance does not accumulate in animals -
but the substances can kill aquatic life due to their
toxicity and mutagenic effects, the researchers noted.
PAHs are comprised of a multitude of substances that
are considered both known and suspected human
carcinogens.

Though water pollution from PAHs is thought to have
little effect on humans, it may pose a bigger threat
to aquatic life in urban waterways than other more
well-known contaminants, such as lead, the pesticide
DDT or PCBs, Van Metre said.

"People realize that cars and traffic cause air
pollution, but they are not aware that they also cause
water pollution," Van Metre said. "Increased traffic
is frequently linked to degraded air quality, but its
effect on aquatic sediment is not as recognized."

The researchers examined sediment samples from 10
lakes in selected older and newly developed urban
areas. Using sediment core samples that recorded
contaminant concentrations over the past 30 years,
they found high - and rising - PAH concentrations, Van
Metre continued. Testing revealed that the PAH levels
exceeded sediment guidelines at all the sites, in some
cases by several orders of magnitude.

The results were somewhat surprising since previous
studies showed decreasing levels of the materials
after reaching highs in the 1950s, he said. The
researchers, however, were unable to speculate on a
direct correlation between air quality and water
quality.

Sources of PAHs from traffic include, soot, asphalt,
motor oil, tire and exhaust emissions. The
contaminants can also come from industrial plants or
other sources, but the researchers determined the
increase was almost exclusively due to more cars on
the roadways. The compounds are typically carried to
the waterways by stormwater.

The research cited above was part of the U.S.
Geological Survey's National Water Quality Assessment
Reconstructed Trends program.

------------------------------------------------------------------------
Note: This story has been adapted from a news release
issued by American Chemical Society for journalists
and other members of the public. If you wish to quote
from any part of this story, please credit American
Chemical Society as the original source. You may also
wish to include the following link in any citation:
http://www.sciencedaily.com/releases/2000/09/000929073033.htm

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