Navigation
 

Medicine in the Water

Are medicines in the water?

Medicines have been found in many surface waters throughout the U.S. and internationally. The U.S. Geological Survey tested 139 streams throughout the U.S. for the presence of 95 chemicals in 1999 – 2000 and found:

  • 80% of streams contained 1+ of these chemicals

  • 50% of streams contained 7+ chemicals

  • 34% of streams contained 10+ chemicals

    Of these 95 chemicals:

  • 33 are known or suspected to be hormonally active

  • 46 are pharmaceutically active (have the ability to affect living matter) 

Northwest studies have found pharmaceuticals in surface water, ground water, and marine waters, as well as soils and sediments.

  • Studies of Columbia River water quality and sediments found a number of pharmaceuticals, including: acetaminophen, diphenhydramine (a widely used antihistamine), and trimethoprim (an antibiotic), fluoxetine (the medicine in Proxac), carbamazapine (a mood-stabilizer), codeine (a narcotic), and other medicines.
  • A Washington State Department of Ecology 2004 study in the Sequim-Dungeness region of the Olympic Peninsula detected medicines in effluent from tertiary wastewater treatment plants, including: acetaminophen, codeine, metformin (a diabetes medicine), sulfamethoxazole (an antibiotic), salbutamol (a bronchodilator), carbamazepine (a mood stabilizer), ranitidine (Zantac), estrone (hormone replacement therapy), trimethoprim (antibiotic), and ketoprofen (NSAID). Metformin was also found in groundwater and wells.

These medicines have been detected at very low levels, but many studies indicate there can be harmful impacts on aquatic organisms from low level exposures to some medicines, or combinations of medicines.

Medicines in drinking water

Public drinking water supplies are not commonly tested for pharmaceuticals, but recent sampling has found widespread presence of medicines in public drinking water at very low levels. Water supplies downstream from wastewater treatment discharges may be impacted because wastewater treatment systems cannot remove or destroy all pharmaceuticals. The concentrations of pharmaceuticals in drinking water are very low and are not likely to be an immediate human health concern.

  • A 2008 Associated Press series published the results of a nationwide study that found medicines in the drinking water of 24 major metropolitan areas serving 41 million Americans.
  • Some frequently detected compounds found in drinking water were atenolol (heart medication), carbamazepine (mood-stabilizer), gemfibrozil (anti-cholesterol), meprobamate (tranquilizer), naproxen (pain-killer), phenytoin (anti-seizure medication), sulfamethoxazole and trimethoprinm (antibiotics).

How do medicines get into the water?

Medicines enter our waterways and environment in two ways:

1. Excretion of medicines and their metabolites from our bodies. Humans and animals pass drugs or drug metabolites through their bodies and these chemicals pass through septic systems or wastewater treatment plants. Wastewater treatment systems cannot effectively remove all medicines, and many are discharged to surface waters or are collected in biosolids that are often applied to land. 

2. Disposal of waste medicines to sewers or trash: A significant amount of medicines go unused. When flushed down toilets or sinks, medicines can enter the environment because they are not removed or degraded by septic systems or wastewater treatment processes. Disposal of active pharmaceutical compounds in the garbage is an environmental concern because medicines may still be released into the environment.  In addition many are concerned of misuse and poisoning associated with throwing narcotics and other medicines in the garbage, which may not be secure at the curb. 

No one knows how much of the medicines in our environment comes from either of these routes, but the simplest approach to reducing the amounts is to adopt better disposal practices for waste medicines. 

Does wastewater treatment remove medicines?

Conventional wastewater treatment systems were not designed to remove or destroy pharmaceuticals and other organic compounds. Currently, it is not known what treatment processes would be needed to completely remove all of the thousands of different pharmaceutical compounds from wastewater, or what the cost of these new technologies will be.

Septic systems treat and clean wastewater, but they do not effectively remove medicines and other organic compounds.

Properly disposing of waste medicines through medicine take-back programs is an action that can be taken now to reduce the amount of medicines entering the environment, and is more economical that trying to capture these waste medicines through wastewater treatment or environmental clean-up.

Can medicines in our waters create problems? 

The environmental concentrations of pharmaceuticals are low; less than the recommended therapeutic doses for humans. A number of studies are looking at these low levels of medicines, or combinations of medicines, and the impacts on aquatic organisms. Researchers have found changes in reproductive function, behavior, growth, and increased mortality from exposure to some medicines or combinations of medicines at concentrations found in the environment.

Additional Information: