HeadsUp Newsletter - Vol 3.10: October 2006

Recent reports concerning emergent contaminants in water such as: antibiotics, vitamins, human and veterinary pharmaceuticals, and other supplements have raised concerns for many environmentalists.  Research proves that a substantial amount (up to 60%) of the antibiotics, drugs and medications consumed are excreted from the body through urine and discharged into sewer systems.

Recently, researchers have found medium to high levels of pharmaceuticals in water bodies and waste streams in Europe and the United States. In fact, sulfonamides (a family of antibiotics used to treat a wide range of bacterial infections) have been detected in leachate (liquid formed within a landfill site that seeps into groundwater) from a Danish landfill, and in Berlin drinking water wells. Studies in the U.S. have identified antibiotics, sulfonamides and trimethoprim (used to treat infections of the urinary tract), in groundwater from a landfill containing hospital waste in Washington and in the water supply wells in a Nebraska filtration site.

In addition to human excretion of medications, antibiotics for veterinary purposes and aquacultures are also discharged into soils, sediments, surface waters and even groundwater. In the aquatic environment, these substances can be bio-transformed or mineralized, riveted to sludge, or remain in the wastewater and reach ambient surface waters.

The advancement of wastewater treatment in the past century has relieved most developed nations from concern over industrial chemicals in water supplies.  Nevertheless, many people in these regions demand increasingly cleaner water, a demand resulting from the popular perception that anything added to the water supply is harmful.  Which leads us to the question: “how clean is too clean?”  Are the emergent contaminants in our water supply worth attention?  What happens when this waste is reintroduced to water ways?

One study holds residuals released from women’s hormone replacement therapy responsible for the occurrence of more female than male frogs, as well as hormone imbalances in fish causing the feminization of male fish.  A Southern Illinois University found that antibiotics in water killed off blue-green algae.  Seeing that some researchers believe there is risk of people developing antibiotic resistance as antibiotics and medications become more prevalent in our aquatic ecosystems- humans are at risk too! What’s more, environmentalists are becoming increasingly concerned with the massive amount of anti-depressants prescribed in the United States. If we are drinking tap water tainted with these drugs, are we all getting a little Prozac?

Although many reports on the repercussions have been recently published on this topic, very little information on the long-term effects of medications and antibiotics in effluent are available since these studies are relatively new. Dr. Ninad Gujarathi from Colorado State University’s Department of Chemical and Biological Engineering provides the following four solutions to counter antibiotic pollution:

1. Conventional Methods:
   Methodologies that treat wastewater through absorption on hydrophobic beds, coagulation and softening.
2. Reverse Osmosis:
   Treatment process whereby dissolved salts and organic materials may be separated from water by forcing the water through a semi-permeable membrane under high pressure.
3. Chemical & Electrochemical Oxidation:
   A treatment using chemicals and oxidation processes to remove all types of substances from water.
4. Phytoremediation:
   Biological techniques that fix environmental problems using plants. Dr. Gujarathi’s research focused on the testing of two specific antibiotics: tetracycline and oxytetracycline. While difficult to remove through wastewater treatment plants, success was achieved via oxidation by reactive oxygen species (ROS) through the Phytoremediation method. This method proved to be the best and most efficient way to remove antibiotics from wastewater.

Phytoremediation uses vegetation to contain, degrade, modify and remove pollutants from soil and water. The pollutants are not necessarily absorbed by the roots. The ROS are secreted from the roots and the antibiotics in the water are then degraded and detoxified. Dr. Gujarathi further examined three types of vegetations most suited for removing antibiotics: parrot feathers, sunflower hairy roots and water lettuce. His research concluded that the greatest removal rates can be attributed to water lettuce.

While we must still wait on further research to fully know the long term effects of antibiotics, vitamins, human and veterinary pharmaceuticals, and other supplements in our water supply, it may be worth taking a preventative approach in order to guarantee the safety of our water supply for future generations.

For more information please log on to:
http://cals.arizona.edu/AZWATER/awr/july00/feature1.htm

http://www.whp-apsf.ca/en/documents/pharmWater.html

http://www.washingtonpost.com/wp-dyn/content/article/2005/06/22/AR2005062201988_pf.html

http://www.cvmbs.colostate.edu/mip/people/faculty/linden.htm