By Hilary White
ST. JOHN, New Brunswick, February
18, 2008 (LifeSiteNews.com) - A study by Dr. Karen Kidd, of the University of
New Brunswick and the Canadian Rivers Institute, found that estrogen from birth
control pills flooding into the water system through sewage adversely affects
fish populations.
The researchers added estrogen to an
experimental lake at a level commonly found in the treated wastewater from
cities with about 200,000 people. The researchers discovered that one
consequence is that exposed male fish become feminized, producing a protein
normally found in females. Chronic exposure to estrogen led to the near
extinction of the lake's fathead minnow population, as well as significant
declines in larger fish, such as pearl dace and lake trout.
"We've known for some time that
estrogen can adversely affect the reproductive health of fish, but ours was the
first study to show the long-term impact on the sustainability of wild fish
populations," explains Kidd.
"What we demonstrated is that
estrogen can wipe out entire populations of small fish - a key food source for
larger fish whose survival could in turn be threatened over the longer
term."
Kidd also noted that once the
estrogen levels in the water were lowered, fish populations rebounded after
three years. "Once you take the stressor out the system, we now have ample
evidence that suggests affected fish populations will recover," she said.
Kidd is preparing a report for the
American Association for the Advancement of Science (AAAS) titled, "From
Kitchen Sinks to Ocean Basins: Emerging Chemical Contaminants and Human
Health".
In the 1980's and 90's,
municipalities in Canada and elsewhere began stencilling pictures of fish next
to storm drains to remind citizens that toxic chemicals - such as paint and
motor oil - poured into the sewers would harm the environment and wildlife. In
1998, a trendy industrial designer in San Francisco won an award for creating
storm drain grates shaped like fish.
Health authorities estimate that 100
million women worldwide take some form of hormonal contraceptives; but there is
still little media attention given to the growing concerns of scientists about
its environmental impact. However, studies are leaking out into the mainstream
press more frequently as public interest in the environment grows.
The Pill, along with numerous other
commonly used chemicals, end up in the water system as estrogen. At a
conference on breast cancer in Toronto in 1998, author and cancer surgeon Dr.
Susan Love said, "Pollutants are metabolized in our bodies as estrogen. And
it is lifetime exposure to estrogen that has increased world cancer rates by
26% since 1980....We live in a toxic soup of chemicals".
Studies are also showing significant
evidence for a link between environmental estrogens and estrogen-like chemical
pollutants and the earlier onset of puberty in girls.
The phenomenon of early-onset
puberty in American girls is so pervasive, that the Lawson Wilkins Pediatric
Endocrine Society urged changing the definition of abnormal development. Ten
years ago, breast development at age 8 was considered abnormally early, but a
study in 1997 said that among 17,000 girls in North Carolina, almost half of
blacks and 15 percent of whites had begun breast development by age 8. Studies
from the United Kingdom, Canada, and New Zealand have shown similar results.
The new definition for abnormally early
breast development ought to be, the society says, 7 for white girls and 6 for
black girls. Marcia Herman-Giddens, adjunct professor at the School of Public
Health at the University of North Carolina, said, "My fear is that medical
groups could take the data and say 'This is normal. We don't have to worry
about it.' My feeling is that it is not normal. It's a response to an abnormal
environment."
Conclusive studies are difficult to
conduct, however, because of the all-pervasive nature of the environmental
contamination. With all the estrogen-like elements in the environment,
Herman-Giddens said, "it's virtually impossible to study. There's no place
to find an unexposed population."