# data[].attributes.body
The presence of pharmaceuticals in water supplies is a growing concern worldwide. Medicines have been found in the drinking water supplies of about 41 million Americans. The concentrations of these medications are very small and will likely not impact anyone

# data[].attributes.body
Medicines get into the water supply by human excretion, drugs being flushed down the toilet or going down the sink. The disposal of unused or expired medications by flushing them down the toilet or pouring them down the sink contributes to pharmaceutical contamination of water supplies. The wastewater is treated before it is released into water but pharmaceuticals can pass through water treatments.

# data[].attributes.body
There is no evidence showing that the drugs in the water supply are affecting humans, the presence of the medication is extremely low. While the focus has primarily been on human health impacts, the presence of pharmaceuticals in water supplies can also have ecological consequences.

# data[].attributes.attachment_link.readable_text
A prescription drug may begin its life as a pretty little pill, but after a brief detour through a human digestive tract and miles of plumbing, some of it ends up in drinking water. Though the levels of pharmaceuticals in drinking water are minuscule, in the parts per trillion, some researchers are concerned that long-term exposure to this low-dose cocktail could prove harmful.

"If you were to drink two litres of water a day for 70 years, at the end of those 70 years, you would have taken 1% of the normal daily dose of someone taking that prescribed medication. For a variety of standard medications, the concentrations are exceedingly low," says Sébastien Sauvé, associate professor of environmental chemistry at the Université de Montréal in Quebec. "The question we don't have the answer to is: What is the impact of chronic exposure to a very low exposure to a mixture of drugs?"

Researchers have detected all sorts of drugs in drinking water - antibiotics, antidepressants, contraceptives and on down the list. The presence of endocrine disruptors, found in drugs such as steroids, has been shown to seriously mess with hormones in fish, decreasing fertility and even causing sex change. Sauvé contributed to one study that found the presence of six antidepressants in brook trout (concentrated in the liver and brain) exposed to municipal effluent ( Chemosphere 2011; 83:564-71).

The presence of certain drugs in water may have a cumulative effect, warns Sauvé. If antibiotics accumulate in the environment and work their way back into the human population, for instance, it could contribute to antibiotic resistance. Another concern is that exposure to even trace amounts of drugs could have a negative impact on the health of more vulnerable members of the population, such as babies who drink formula mixed with tap water.

One step that countries could take, and likely will in the future as research in this area grows, is to establish guidelines that limit the amount of drugs permitted to enter the water supply, suggests Sauvé.

"There is a total absence of thresholds. There are no guidelines," he says, adding that "there is not enough literature or data to derive good-quality guidelines."

Still, there are enough data to convince some experts that chronic exposure to even small amounts of drugs is best avoided, suggests Chris Metcalfe, professor of environmental and resource studies at Trent University in Peterborough, Ontario, who led a study that found traces of six antidepressants downstream from waste water treatment plants on the Grand River in southern Ontario ( Environ Toxicol Chem 2010;29:79-89).

"The only way to fix the problem is to invest in better wastewater treatment to remove the pharmaceuticals before discharge," Metcalfe writes in an email. "Of course, this focuses on the issue of effects on humans. What about aquatic organisms that are exposed?"

For its part, Health Canada is conducting a two-year national survey, to be published in 2012, of disinfection by-products and other contaminants in drinking water. The survey is looking for the presence of a number of pharmaceuticals, including atorvastatin, carbamazepine, diclofenac and gemfibrozil.

"The results of the study will help the department determine if new or emerging disinfection by-products and other emerging contaminants (e.g., pharmaceuticals) identified in the scientific literature are present in Canadian drinking water supplies and establish the priorities for guideline development. The survey will help determine the need for any action to minimize risk to human health from pharmaceuticals in drinking water," Stéphane Shank, a senior media relations advisor, writes in an email. "While there are no known adverse human health effects attributed to the extremely low presence of pharmaceuticals in drinking water, research continues to focus on detection and removal from drinking water."

Provincial governments are also responsible for keeping drinking water drinkable and several have made efforts to monitor the levels of pharmaceuticals in the water supply. In Ontario, for example, the Ministry of the Environment has tested water for pharmaceuticals and personal care products (PPCPs) in the past, and has found contaminants, such as bisphenol A, but only at very low levels. The province takes a "source-to-tap" approach to testing water and plans to continue its efforts, according to ministry spokesperson Kate Jordan.

"We are continuing to study PPCPs in water to help us better understand the potential environmental and health effects of these products," Jordan writes in an email. "Studies are underway to continue to investigate the effectiveness of water treatment technologies to reduce pharmaceuticals and other emerging contaminants in source water."

In the United States, government agencies are ramping up their efforts to monitor drugs in drinking water. "There is enough information to suggest there is potential for concern," says David Trimble, a director in the natural resources and environment group of the US Government Accountability Office, which recently released a report calling for various government agencies, including the Drug Enforcement Administration, the Environmental Protection Agency and the Food and Drug Administration, to collaborate on monitoring drug levels in drinking water ( www.gao.gov/new.items/d11346.pdf).

"These interagency efforts have been largely informal. We have made recommendations to establish a formal mechanism to coordinate this research," says Trimble. "You have to do that to get the data to decide if you need to regulate or not. You need the data first."

# data[].attributes.attachment_link.description
A prescription drug may begin its life as a pretty little pill, but after a brief detour through a human digestive tract and miles of plumbing, some of it ends up in drinking water. Though the levels of pharmaceuticals in drinking water are minuscule, in the parts per trillion, some researchers are concerned that long-term exposure to this low-dose cocktail could prove harmful.

# data[].attributes.body
Aquatic organisms living in contaminated water bodies may be exposed to these substances, leading to bioaccumulation and potential disruptions to aquatic ecosystems. As predators consume prey that have accumulated pharmaceuticals, the concentrations of these substances can become magnified, leading to potentially harmful levels in top predators.

# data[].attributes.body
Increasing public awareness about the pharmaceuticals in the water supply and promoting responsible medication disposal methods can help prevent the improper disposal of medications and upgrading wastewater treatment will clean out all medicines and other waste that is in water

# data[].attributes.attachment_link.title
The Drugs We Wash Away: Pharmaceuticals, Drinking Water and the Environment