More than 50 million Americans (and God knows how many Canadians) drink water with traces of a variety of prescription drugs, from antibiotics to sex hormones to mood stabilizers.

According to a just-released Associated Press (AP) investigation, revealing that the drugs were detected in the drinking water supplies of 24 metropolitan areas, including Southern California, Northern New Jersey, Detroit, Washington, D.C., Philadelphia, PA, and Louisville, KY.

There's no reason to think that Canadian water supply is any healthier.

When we ingest medication, our bodies absorb most of it and the rest eventually passes through our system. It is then flushed down the toilet, treated, and eventually winds up in lakes, rivers, or reservoirs. And before that water hits our tap, it is cleansed once more at treatment plants. But many plants do not test or treat for drug residue, which is why there may be traces of antibiotics and other drugs in your ice water.

Before you swear off your tap for good, drink in this tidbit: You would need to gulp down about 120 Olympic size pools of water to reach a therapeutic dose of the drugs detected by the AP investigation.

The easiest way to safeguard yourself against contaminants in your water is to use a filter. The National Resources Defense Council (NRDC) recommends choosing one that is certified by NSF International, the world leader in standards for public health and safety (look for the NSF seal of approval on the filter’s packaging).

If you do buy bottled water, be sure you know where it is sourced. If your bottle boasts that it is filled with “spring water,” you are most likely sipping simple tap water. Same applies for anything labeled "from a municipal source" or "from a community water system.”

In fact, 25% of bottled water on the shelves – including Coca-Cola’s Dasani and Pepsi’s Aquafina – are merely prettily-packaged city water. Check the label, the cap or call the bottler to make sure you are not wasting your money on something you can get for free at home.

If you choose to buy bottled water, go for brands with a known protected source and ones that have readily-available testing and treatment information that shows high water quality.

Regardless of where – or how – you get your water, do not deprive yourself. The Institute of Medicine advises that men consume roughly 3.0 liters (about 13 cups) and that women down 2.2 liters (about 9 cups) of water a day to stay hydrated and healthy. Filter and bottle your own water - this saves money and ensures the pureness, too.

There are a number of methods of water filtration, each with varying degrees of effectiveness, and varying costs. The general purpose of filtering water is to improve the water's hygiene and aesthetic qualities. Some of the available water filters are described below:

Activated Carbon (AC) Water Filters
Activated Carbon Filtration is an established technology that works through absorption of the problematic compounds, primarily to remove taste and odour but systems will also remove some harmful contaminents. AC is a highly porous material with a very large surface area. Chemical pollutants are attracted to and held by the AC's surface. These water filters are best suited for the removal of organic compounds.

Ultraviolet (UV) Water Filters
UV Filters are able to kill the majority of bacteria and viruses in the water which passes through them. However, they won't remove chemical pollutants from the water. Also you should note that the treatment is ineffective outside of the treatment area, so water should be used immediately after it is treated.

Water Distillation (Water Distillers)
Water Distillation involves heating the water to boiling point and condensing the steam. Pollutants with a boiling boint near that of water are hard to remove, but generally the distilled water is of a very high quality.

The major drawback to this method is that it requires a large amount of energy. Some people will also complain that the distilled water tastes flat (this is due to less dissolved oxygen).

Sand Filters
Sand based water filters have been used for over 100 years to treat waste water. They are generally used on a larger scale to treat a water supply for a whole community, and will be custom made. Most units require a constant flow of water to work correctly, and so wouldn't be suitable for well water treatment. However, recently a Canadian scientist, David Manz developed an intermitent unit. You can buy pre-built commercial units for home use which are typically used with swimming pool pumps.

Reverse Osmosis
In water filter terms, reverse osmosis (or hyper-filtration) is the process of filtering water under pressure through a semi-permeable membrane, allowing water to pass through but rejecting other particles such as bacteria, toxins, salts, and anything bigger than around 150 Daltons. 

 Other news