Answer:
Studies about water quality are difficult to find because it brings into question the need for better water filtration in local communities, and the need for federal drinking water standards that do not exist.
The Canadian Press on January 26,2003 reported a study from the University of Calgary that may cause you to change your bottled water drinking habits. Researchers collected water samples from 76 plastic bottles repeatedly used by elementary school students. Over 30% of the samples contained bacterial contaminants suspected to be caused from insufficient hygiene (ie. lack of thorough hand washing).
A University of Idaho study tested water samples taken from soft drink and water bottles made from plastic called polyethylene tetrephthalate (PET) which released toxins into the water with repeated hot water and soap exposure. One of the toxins in PET is a known carcinogen shown to cause liver damage and reproductive problems.
A study by Halina S. Brown, Ph.D. et al. In the American Journal of Public Health 1984 found that skin absorption of volatile organic compounds (VOCs) from chlorinated water was greater after a shower than when drinking the same water. Skin exposure allowed for greater absorption of toxic compounds than from the gastrointestinal tract. Studies like this should give those who swim in chlorinated pools or shower with chlorinated water cause for concern. The byproducts of chlorine, called trihalomethanes, are more toxic than the chlorine alone.
So whether lead is leaching into the water from old pipes, or plastic toxins are deposited into the bottled water, securing a safe water supple is essential to good health. Water testing is not easy to achieve or afford. One of the oldest, reliable laboratories for water testing is National Testing Laboratories, Ltd. In Ypsilanti. Michigan.