Fish Study Raises Red Flag on Water Supply
Fish caught in the rivers
near Allegheny County's
storm sewer overflow pipes contain almost twice as much of certain estrogenic
chemicals that can cause cancer, a University
of Pittsburgh study has
found.
The link between sewage
plant discharges and fish contaminated with those chemicals has been
established by studies in other urban areas around the world, but the finding
is particularly significant in Allegheny
County, which has more
than 400 sanitary and combined sewer overflows.
The findings are a concern
for public health because of the region's dependency on the rivers for its
drinking water. Dr. Conrad Dan Volz, head of the study, said a number of
reports have shown a link between high ingestion of estrogens and hormone
problems and some cancers, including testicular cancer.
Estrogenic chemicals,
called xenoestrogens or estrogen-mimicking chemicals, come from garden
pesticides, plasticizers, glues, cosmetics and products that dissolve
detergents. Pharmaceutical estrogens from female hormone replacement drugs and
birth control pills are also found in sewage discharges.
"Pittsburgh
has more combined sewer overflows than any other city in the United States,"
said Dr. Volz, an assistant professor in Pitt's Graduate School of Public
Health. "During the summer such discharges can occur on as much as 75
percent of the days, and the raw sewage has more estrogenic chemicals that do
not get broken down at all by the waste treatment process."
The latest results of the
ongoing study by Dr. Volz, who is also a co-director of the Pitt Cancer
Institute's Center for Environmental Oncology, will be discussed today at an
institute retreat in Greensburg.
Earlier reports of study
results showed that it was difficult to identify the gender of 85 percent of
the channel catfish caught on the Allegheny, Monongahela and Ohio rivers near
the Point, and also that chemicals extracted from all 25 randomly sampled fish
caused growth of estrogen-sensitive breast cancer cells cultured in a laboratory.
Eleven of those samples produced very aggressive cancer growth.
Dr. Volz has called those
fish the "canary in the coal mine" for public health related to
drinking water, most of which comes from th
