Study finds human medicines altering marine biology
- Turns out there's more to treated sewage than just high nutrients...
related link for Ventura wastewater: http://venturaecosystem.blogspot.com/2007/12/ventura-wastewater-treatment-plant.html
Study finds human medicines altering marine biology
Southern California toxicology researchers find chemicals from
wastewater are ending up in coastal oceans -- and affecting the
hormone levels of fish.
By Kenneth R. Weiss, Los Angeles Times Staff Writer
BOSTON -- Sewage-treatment plants in Southern California are failing
to remove hormones and hormone-altering chemicals from water that gets
flushed into coastal ocean waters, according to the results of a study
The preliminary findings were part of the most ambitious study to date
on the effect of emerging chemical contaminants in coastal oceans. It
confirms the findings of smaller pilot studies from 2005 that
discovered male fish in the ocean were developing female
characteristics, and broadened the scope of the earlier studies by
looking at an array of man-made contaminants in widespread tests of
seawater, seafloor sediment and hundreds of fish caught off Los
Angeles, Orange and San Diego counties.
The results, outlined by a Southern California toxicologist at a
conference in Boston, reveal that a veritable drugstore of
pharmaceuticals and beauty products, flame retardants and plastic
additives are ending up in the ocean and appear to be working their
way up the marine food chain.
Flame retardants used in upholstery and plastic additives are showing
up in fish tissues at levels as high or higher than lingering residue
of the banned pesticide DDT and another stubborn industrial pollutant,
polychlorinated biphenyls, or PCBs.
The study also showed that male flatfish contain unusually high levels
of the female hormone estrogen, possibly in reaction to one or more of
these hormone-altering chemicals.
As many as 90% of these male fish were found to have produced egg yolk
proteins, and one had actually produced eggs, indicating that the
feminizing of fish seen in freshwater streams and lakes can happen in
the open ocean as well. This evidence, scientists said, suggests that
diluting pollution with a vast amount of seawater may not be an
effective way to dispose of these new and little-understood
"Dilution is not the solution for some of these newer compounds," said
Steven Bay, a toxicologist with the Southern California Coastal Water
Research Project in Costa Mesa. He expects the study to raise policy
debates over upgrading sewage-treatment plants.
Although some of these contaminants may be in urban runoff, the main
source appears to be the 1 billion gallons of partially treated sewage
that flows into the ocean every day from the region's four major
Women taking birth control pills excrete estrogen in their urine,
which is flushed down the toilet and ends up in the ocean. The same is
true of antidepressants, tranquilizers, anti-inflammatory medicine and
other drugs, as well as musk fragrances, sunscreens, soaps and
additives to plastics -- compounds known to mimic or disrupt hormones.
"Sewage-treatment plants only remove 50% to 70% of these chemicals,"
Bay sketched out the preliminary results in a special session at the
annual meeting of the American Assn. for the Advancement of Science.
Much of Saturday's discussion focused on sex-changing chemicals in
municipal wastewater. "It doesn't take much of the pill to stop fish
from reproducing," said Karen Kidd, a biology professor at the
University of New Brunswick in Canada.
Kidd said sewage plants could remove virtually all estrogen with more
advanced forms of treatment.
Primary treatment, the type used in San Diego, doesn't take out as
much estrogen as secondary treatment, used by Los Angeles' Hyperion
plant in El Segundo. Those plants, if upgraded to tertiary treatment,
could remove nearly all of the estrogen, Kidd said.
Another study looked at how compounds used as fabric stain repellents,
nonstick pan coatings and coatings in microwave popcorn bags have
accumulated in the blood and tissue of loggerhead sea turtles. They
are suppressing the immune systems of these turtles, which are
officially designated as threatened with extinction.
The sea turtles pick up these compounds through what they eat, said
Jennifer M. Keller, a researcher with the National Institute of
Standards and Technology. "They eat crabs and clams and other
shellfish -- a diet they share with humans."
The study in Southern California waters looked at contaminants in
wastewater, surrounding ocean waters, sediments and in the flesh of
600 flatfish called hornyhead turbot.
These bottom-dwelling fish were selected because they reside near
The results showed that the chemicals and responses from the fish were
widespread and not confined to areas near sewage outfalls, showing how
easily the chemicals get dispersed.
Besides elevated estrogen levels in male fish, test results showed
altered thyroid hormone levels in the turbot. They also had depressed
cortisol levels, an indication that the fish were worn out and are
vulnerable to disease.
So far, Bay said, no evidence has emerged that the chemicals are
threatening their survival or ability to reproduce.