Loading ...
Sorry, an error occurred while loading the content.

Study finds human medicines altering marine biology

Expand Messages
  • Paul Jenkin
    Turns out there s more to treated sewage than just high nutrients... related link for Ventura wastewater:
    Message 1 of 1 , Feb 18, 2008
      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
      released Saturday.

      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
      sewage outfalls.

      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 said.

      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
      sewage outfalls.

      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.

    Your message has been successfully submitted and would be delivered to recipients shortly.