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Emerging Contaminants


Frequently Asked Questions:

What are Emerging Contaminants?

Emerging Contaminants are often referred to by a myriad of titles including microconstituents, trace organic compounds, pharmaceuticals in the environment, or pharmaceuticals and personal care products. The titles refer to a diverse collection of thousands of chemical substances that range from prescription, veterinary, and over-the-counter therapeutic drugs to cosmetics, sunscreens, and fragrances.

What are Endocrine Disruptors?

Endocrine disruptors are a subset of this collection of compounds and are agents that affect the endocrine system. The endocrine system is a complex network of organs which secrete hormones into the bloodstream to target cell receptors in other organs or tissues to regulate many of the body’s functions. Endocrine disrupting compounds are suspected to cause negative reproductive and developmental health effects in humans, animals and the aquatic environment by mimicking or blocking hormones and therefore disrupting the body’s normal functions. Some examples of endocrine disrupting compounds include pesticides, plasticizers and flame retardants.

How do Emerging Contaminants enter the environment?

These compounds enter our environment though various passageways. The following human activities contribute pharmaceuticals and personal care products to the aquatic environment:

  • Medications that are not metabolized completely by the body and are excreted into the sewer system;
  • Unused or expired medications that are flushed or placed in the trash;
  • Externally applied personal care products are washed down the drain.

Are these compounds new to the environment?

No. We have to believe that these compounds have existed in the environment for as long as they have been used commercially. Therefore the existence of these compounds in our waters is not a new phenomenon. It has only become more widely evident in the last decade because of continually improving chemical analysis methodologies that have lowered the limits of detection to the level of parts per trillion.

Are there treatment options available to remove Emerging Contaminants at drinking water and waste water plants?

At this time, reverse osmosis membranes and nanofiltration membranes have exhibited great success in removing target analytes in several published studies. Still, no single drinking water or wastewater treatment technology is currently available to remove all of these compounds. The removal efficiency of the treatment technology is related to the structure and concentration of the compound. Each technology has varying success rates at removing emerging contaminants from the water.

At what concentration are these compounds being detected?

To date, concentrations of analyzed compounds have been detected in the range of parts per billion (ppb) and parts per trillion (ppt). A part per billion can be compared to less than a teaspoon of water in an Olympic-sized swimming pool.

Are these concentrations detrimental to human health?

Research has not proved these concentrations to be detrimental to human health, although some of these compounds have been linked to negative effects in fish and aquatic health.

Is Pennsylvania involved with researching Emerging Contaminants?

Yes. In 2006, the PA Department of Environmental Protection (DEP) entered into a cooperative agreement with the U.S. Geological Survey (USGS) Water Science Center in New Cumberland, PA to conduct a reconnaissance study to screen for pharmaceuticals and antibiotic compounds in surface and well waters in South Central Pennsylvania.

  • Phase I: Samples were collected at upstream and downstream locations in the vicinity of six agricultural operations and five wastewater treatment plants. Samples were also collected at six groundwater stock wells in agricultural areas. Four samples were collected at each site March through September of 2006. Analyses were completed on 120 environmental samples and 21 quality control samples. Samples were analyzed for 15 pharmaceutical and 31 antibiotic compounds. The report for Phase I titled Concentrations of Selected Pharmaceuticals and Antibiotics in South-Central Pennsylvania Waters, March through September 2006 and is available through the USGS.
  • Phase II: In 2007, the PADEP commenced a three year cooperative agreement with the USGS titled; “Characterization of Emerging Contaminants and Fish Health in Pennsylvania Surface Waters.” The focus for Phase II is now statewide instead of centralized and will evaluate the presence of emerging contaminants in our sourcewater and will conduct a comprehensive fish health assessment.

    A final report will characterize the distribution and occurrence of emerging contaminants, pathogens and bacteria, as well as the identification of pathogenic and fecal source markers. This formal USGS peer-reviewed report, published in the Scientific Investigations Report series, will be available in June of 2010. A final report evaluating the fish health in PA source water is anticipated in 2009 and will assess whether impacts to fish are occurring that may be associated with the occurrence of emerging contaminants.

    Even though these compounds are not new to our environment, scientists have raised sufficient concern about emerging contaminants in recent years. Therefore DEP has dedicated funding to advance our knowledge and address the issue in Pennsylvania.

What can the public do to reduce the amount of pharmaceuticals found in Pennsylvania waters?

Unused or expired medications should never be flushed or disposed of down the drain. We encourage participation in community pharmaceutical return programs. The White House Office of National Drug Control Policy published the Federal Guidelines for the Proper Disposal of Prescription Drugs (PDF) in February of 2007. If community returns programs are not available, the Guidelines advise citizens to mix their unused or expired medications with an undesirable substance such as kitty litter or coffee grounds and place them in the trash and avoid flushing and diversion.

Environmental Forums on Emerging Contaminants:




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