Have you ever wondered how clean your drinking water really is? Or maybe it's something you've never given a second thought. A recent investigation by the Associated Press has uncovered the disturbing reality of municipal water supplies.

Would you willingly drink water laced with antibiotics, anti-convulsants, mood stabilizers and sex hormones? According to the AP at least 41

million Americans from Los Angeles to Detroit are unknowingly doing just that as the five month investigation reveals that pharmaceuticals such as these are commonly detected in drinking water supplies across the country. 

Evidence suggests the same is also true around the world with studies finding pharmaceuticals in drinking water throughout Asia, Australia, Canada and Europe.    

Although the concentrations of these drugs are tiny, measured in quantities of parts per billion or trillion, scientists are worrying more and more about the long-term consequences of consuming this chemical cocktail on a daily basis.

The levels detected are far below the levels of a medical dose, and water companies insist their water is safe, but there are growing concerns both for human health and for the environment as new research shows that even such tiny amounts of pharmaceutical contaminants can have devastating effects.

The AP found that water companies are not eager to reveal results of pharmaceutical screenings. The MetroWest Daily News quotes the head of a group representing major California suppliers as saying the public "doesn't know how to interpret the information" and might be unduly alarmed.

This doesn't sound like a wholly unreasonable position but the companies may also be concerned about research demonstrating just how dangerous low level contamination of the water supply can be.

Even some pharmaceutical company employees have voiced concerns about the human health impacts of contaminated water.  Mary Buzby director of environmental technology for drug maker Merck & Co. Inc. said at a conference last summer: "There's no doubt about it, pharmaceuticals are being detected in the environment and there is genuine concern that these compounds, in the small concentrations that they're at, could be causing impacts to human health or to aquatic organisms."

During its investigation the AP discovered that recent laboratory research has found that effects from small concentrations of pharmaceuticals include faster proliferation of cancer cells, kidney cells growing too slowly, and blood cells showing biological activity associated with inflammation.

Additionally there are concerns that chroline added to drinking water to kill any organisms present may have the unexpected effect of enhancing the toxicity of pharmaceutical residues that may also be present.

When presented with findings like these from the AP, there are those who like to repeat the principle of toxicology which says that "dose determines toxicity." This principal implies that below a certain dose a substance is harmless. But this is an extremely simplistic way of looking at a complex issue.

In vulnerable individuals such as children, the elderly, and those with exisiting illness, even quantities of pharmaceuticals way below the toxic dose may cause problems. Recent research has also revealed that many chemicals do not display a linear association between dose and toxicity. As strange as it sounds, very low doses of a chemical may be more toxic than a moderate dose before becoming toxic again at higher levels.

In addition, problems are not likely to arise from a single pharmaceutical or other chemical contaminant, but rather from the cumulative affect of many. The AP investigation revealed that some water samples across the US contained as many as 56 different pharmaceuticals or byproducts.

How do pharmaceuticals end up in the water supply?

When people take take medication some of the drug is absorbed and metabolised but not all of it. Some unchanged drug will be excreted along with metabolised forms which may be equally or even more toxic. Then there are the unused medications which people routinely flush down the toilet after coming off a drug midway through a pack or after deciding they don't want to take the drug after all. With 3.7 billion prescriptions fullfilled and 3.3 billion over the counter medications purchased last year in the US, this is no small matter.

In addition industrial farming methods involve the routine feeding of antibiotics, growth hormones, and other drugs to cattle and other livestock. Again, drugs and their metabolites are excreted by the animals and enter the water supply.

How can you make sure you're drinking clean water?

Purchasing bottled mineral water may be an option since it is in the companies best interest to sell the purest water possible. It is what they base their business on. Of course bottled water is something of a thorny environmental issue in itself as it is coming to be seen as wasteful and polluting with bottles being transported all over the world by polluting ships, trains, and trucks.

A better option may be a home water filter. A process called reverse osmosis removes virtually all traces of pharmaceuticals from drinking water. Unfortunately it is very expensive to implement on the large scale required by local water companies.

Luckily reverse osmosis water filters are available for the home and are becoming more affordable all the time. They can be plumbed in to the main household water supply meaning that pure water is delivered from every tap in the house. This is a job that any plumber can take care of in very little time. The only problem with reverse osmosis is that it is so effective at purifying water that it removes beneficial minerals along with the less desirable substances. It is therefore a good idea to add mineral supplements directly to the filtered water or take a multi-mineral tablet every day when using a reverse osmosis system.

Learn more about water filters for the home