If you've switched to bottled water as your primary source of water in hopes of avoiding the perils of drinking unfiltered tap water, you may want to consider your options.

Scientists have concluded the longer a bottle of water sits on a shelf -- in a grocery store or your refrigerator -- you'll consume a greater dose of antimony, a silvery white metal of medium hardness that breaks easily.

The amount of antimony that leeches into the water you're drinking depends on the bottler and can vary greatly. Among 63 brands of bottled water produced in Europe and Canada, researchers detected concentrations of more than 100 times the typical level of antimony in clean groundwater (2 parts per trillion).

What's more, after letting bottled water samples sit for six months on a shelf at normal room temperatures, the concentration of antimony exploded by 90 percent among European brands and 19 percent in Canadian brands. The common denominator: Most products were packaged in polyethylene terephthalate (PET) containers. In fact, the lead researcher believes the amount of leeching will differ, based on exposure to sunlight, higher temperatures and varying pH levels.

Using a reverse osmosis filter, however, enables you to rely on your own well or municipal source for safe, clean water and give up bottles for good.