Sludge Watch ==> Evidence for the migration of steroidal estrogens through riverbed sediments

[Maureen Reilly]

Labadie P, AB Cundy, K Stone, M Andrews, S Valbonesi and EM Hill. 2007.
*Evidence for the migration of steroidal estrogens through riverbed
sediments*.

Environmental Science and Technology 41: 4299 -4304
<http://pubs.acs.org/cgi-bin/abstract.cgi/esthag/2007/41/i12/abs/es063062j.html>

(Synopsis of study found at:
http://www.environmentalhealthnews.org/newscience/2007/2007-1008labadieetal.html)

New research confirms that estrogenic contaminants can contaminate
groundwater after being carried by sewage into rivers. Standard water
treatment doesn't remove them from waste water effluent, so they pass
from treatment plants into rivers. Once in river waters, this new
research shows they can seep through river sediments and from there
potentially into groundwater. Some types of sediment, for example, those
rich in clay, will slow the process considerably.

*What does it mean? *Estrogens and estrogenic compounds released into
the environment with wastewater effluent can migrate out of the water
and down into riverbed sediments. The findings are important because
they demonstrates that hormones and chemicals can reach and may
contaminate shallow groundwater. People can be exposed to the pollutants
by drinking the water or irrigating with it.

This is the first field evidence that estrogens from WWTP's can move
down into the sediment under effluent receiving waters. The results
challenge prior beliefs about the life and transport of estrogenic
substances. One is that estrogen concentrations in WWTP effluent are so
low they are of little ecological consequence. Another is that estrogens
are rendered harmless either by dilution in large water bodies or by
clinging to suspended particles.

Estrogen movement through the water bottom depended on if it was sand or
clay. In this study, estrogens traveled through sediment, especially the
sandy sediment, to at least 20 cm. It is not known how deep estrogens
would go if the sediment was mostly sand, as is found in Florida and
other geologically similar areas.

Other unknown estrogenic substances from the sewage effluent appear to
be moving through clay sediment. Although they were not identified,
these compounds may include surfactants, for example nonylphenol and
octylphenol, which are ubiquitous components of industrial and
residential detergents.

It is both fair and important to realize that the current WWTP
technology was not designed to remove nutrients, estrogenic compounds,
pharmaceuticals and personal care products. It is fair, because the
outdated wastewater treatment methods should not shoulder the blame; it
is important, because it is clear that current technologies are creating
risks of unknown magnitude for public health.