The Changing Face of Water Pollution

If asked to name types of water pollution, the average person would probably mention things like bacteria, pesticides, trash and oil. More knowledgeable lake users would also include nutrients and sediment on the list. The aforementioned categories have made up much of what we know of as water pollution, but there are new types of contaminants that are making headlines; pharmaceuticals and personal-care products! These contaminants, along with cleaning products, make up what is known as Organic Wastewater Contaminants (OWC’s).

Pharmaceuticals include antibiotics, estrogen (natural and synthetic), steroids, and prescription drugs. The personal-care products are items such as sun-block, perfumes and insect repellents. In a way these items are not really “new” pollutants, as they have probably existed in the environment ever since we started to use them. What has changed is our ability to measure them in small concentrations (also, an increased population means more of these materials are making their way into our environment).

How prevalent are they? A recent study by the U.S. Geological Survey found trace amounts of at least one OWC in 80% of the 139 streams monitored. The streams were located throughout the country and the findings suggest that these pollutants are widespread. This may lead to the question - How do they get into the environment? Often the answer is through sewage treatment plant effluent. Any medication that is not totally used by the body is past out as waste, while personal-care products are constantly being washed down the drain when we bathe. Treatment plants are not set up to remove pharmaceuticals and personal-care products from the effluent. These contaminants may also move through septic systems or come from improperly disposed of chemicals (cleaners dumped down storm drains). Humans may not be the only source of OWC’s. Antibiotic and hormones used on livestock may also contribute to the problem.

Right now these materials do not occur in the environment in concentrations that are deemed harmful to humans (though knowledge of affects due to long-term, low dose exposure is not always known). A greater worry is what impact these contaminants may have on the aquatic life which live in constant contact with OWC’s. Some recent findings are cause for concern.

- Scientist at the Battelle Marine Sciences Laboratory in Washington state have found that synthetic estrogen can negatively impact the reproductive ability of male rainbow trout. This may mean more obstacles for already struggling native salmon (a cousin to the rainbow trout).

- Canadian scientists added estrogen to a lake and found that the flathead minnow population had greatly decreased over a three year period and would disappear in year four. The estrogen interfered with the minnows ability to reproduce. Flathead minnows only have a life expectancy of 2-3 years, so they were the first species to display a drastic reduction in population. Three other species of fish that take longer to reach sexual maturity are being monitored.

- Baylor University toxicologist have found fluoxetine, the active ingredient in Prozac, in the tissue of bluegill. The repercussions of this are still under investigation, but it does bring up the question of chemicals building up in fish tissue and causing the need for advisories against consumption.

Another issue of concern is the number of OWC’s that are making their way into the environment. In the
U.S.G.S. study, stream samples were analyzed for 95 different OWC’s. All told, 82 different contaminants showed up at least once, with a full third of the streams containing at least 10 different OWC’s. It should be noted that the streams chosen for the study were all considered susceptible to contamination based on their location near intense urbanization or livestock production (Because little is known about OWC’s in the environment, the goal of this study was to determine if they were out there in measurable levels).
As the study of OWC’s continues we will hear more about these types of contamination. Hopefully future studies will give us both a better idea of how much is already in the environment as well as some idea of what the negatives impacts of these contaminants might be.

Until we know more, the only thing that we can do is try to limit our personal contribution to the problem. Some of the things we can do with pharmaceuticals includes: taking all of our prescriptions so there won’t be a need to flush any down the toilet, check to see if the pharmacy will take back and destroy any leftover medications or see if local household hazardous-waste collection programs will accept expired medicines. Household cleaners should be used as directed and disposed of, if need be, through hazardous -waste programs. Personal care products can be used, but we need to be aware of more natural alternatives and use them when possible (e.g. citronella instead of DEET in bug repellant).

We have come a long way in the battle against water pollution, but we still have more work to do. It is up to each of us to educate ourselves on how we, as individuals, contribute to the polluting of our environment. And more importantly, educate ourselves on how we can minimize our impacts. Technological advances will continue to improve our abilities to monitor what is in the environment and we must stay alert to the changing face of water pollution.

Dan Obrecht

Brought to you by the Lakes of Missouri Volunteer Program