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August 15, 2006


[Rachel's introduction: Septic systems do not effectively remove
hormone-disrupting chemicals, which can leach into groundwater.]

By Megan Rauscher

NEW YORK (Reuters Health) -- Septic systems may not remove natural
hormone-disrupting chemicals -- like estrogen excreted in women's
urine -- from wastewater before it gets into groundwater, which feeds
many drinking water supplies, according to tests conducted in Cape
Cod, Massachusetts.

In Cape Cod, more than 85 percent of residential and commercial
properties use septic systems.

In a telephone interview, Dr. Chris Swartz said: "We did find both
natural estrogen and alkyl phenols from detergents entering
groundwater at concentrations very similar to concentrations that have
been documented in the literature to show adverse reproductive effects
in fish swimming in rivers downstream of wastewater treatment

Other chemicals detected in groundwater near the tested septic system
include caffeine and detergent brightening compounds.

Swartz, senior scientist at the Silent Spring Institute in Newton,
Massachusetts, said there is still "hot debate" in the Environmental
Protection Agency and among scientists in general as to whether the
concentrations of these and other chemicals that are being found in
the environment have human health implications.

"The biggest concern is for prenatal exposures, because fetuses are
exquisitely sensitive to any type of hormonal imbalances during their
development," he explained.

Swartz hopes publication of his team's findings in the August 15 issue
of Environmental Science and Technology will fuel dialogue among land
use planners and policy makers about what septic systems are and are
not removing.

"It's important to understand this if we are going to rely on septic
systems," said Swartz.

Currently about 25 percent of US households and probably a larger
amount globally, Swartz noted, use on-site septic systems for
household waste treatment as opposed to public sewage treatment

"And there is a US and global trend toward decentralized wastewater
treatment," Swartz said.

Prior research on septic systems have dealt only with nutrients such
as nitrogen and phosphorus that may leach from septic tanks, get into
groundwater, and eventually make it to surface body waters that the
groundwater feeds.

The current tests, Swartz said, clearly show that other chemicals,
like natural estrogens, known to interfere with human hormonal
regulation, are also getting away from septic system treatment. Future
studies, he concludes, are needed to determine the extent and
potential effects of drinking water contamination with hormone-
disrupting chemicals and other potentially harmful chemicals.

SOURCE: Environmental and Science Technology August 15, 2006.

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