Tap Water Contamination: Health Risks and What Research Shows

Introduction

This paper examines the possible existence of tap water contamination — a topic of personal concern given the long-standing claim that tap water is unsafe and that avoiding contamination requires spending money on any number of schemes. These range from the comparatively modest expense of buying bottled water to the enormously costly project of retrofitting an entire home water system with purification equipment. It is particularly important to determine whether such warnings are simply a money-making strategy on the part of businesses or whether there is genuine cause for concern.

Even the cheapest alternative — purchasing bottled water — accumulates into a worrisome expense over time. On the other hand, purifying tap water may be a necessary safeguard for one's health, in which case the expenditure may be well worthwhile.

The initial assumption here is that tap water is not as contaminated as some claim. This assumption rests on the observation that greater public awareness campaigns would exist if the situation were truly dire. Smoking offers a useful comparison: the government goes to great lengths to warn the public against cigarettes, establishing programs at public expense to encourage smoking reduction. If tap water were dangerously contaminated, one might expect similar warnings and cost-reduced purification systems to be implemented at the government level.

Initial Assumptions About Tap Water Safety

Efforts are already underway to purify streams, and activists monitor water quality. While water may have been more contaminated at some point in the past, there is reason to believe the situation has improved.

To test this assumption, an internet search was conducted beginning with a basic Google search. This produced many unhelpful results — the majority of which were attempts to sell purification products (the number and diversity of such schemes is remarkable). Some sites, however, offered a clearer picture of the problem, its origins, and the current state of affairs.

Google Scholar provided a more nuanced description of the issue, though it required some effort to locate relevant review articles. Academic sources on this subject tend to approach the topic from a narrow angle, examining one specific chemical or exposure pathway at a time, which was not always immediately useful for forming a broad overview.

Research Process and Sources

The reality turned out to be more concerning than initially anticipated. The standard measurement used to estimate health risks associated with waterborne chemicals has been two liters of ingested water per day. However, exposure assessment models, pharmacokinetic models, and experimental data measuring breath concentrations of chloroform associated with inhalation and dermal exposure — such as during showering — have demonstrated that other pathways also contribute significantly to the body's chemical load (Weisel & Jo, 1996). As the research states directly: "the dose of volatile compounds associated with showering is similar to the dose resulting from ingesting 2 litres of water, the exposure upon which regulations are based" (Weisel & Jo, 1996, p. 48).

Epidemiological studies examining the effects of chlorinated water have found that people exposed to chlorinated by-products have elevated bladder cancer rates (Bove, Fulcomer, & Savrin, 1995). Other studies have suggested an association between chlorinated water and adverse reproductive outcomes (McGeehin et al., 1993).

Key Findings on Contamination and Health Risks

Water contacts the human body in numerous ways beyond drinking. People use it to clean contact lenses, brush their teeth, rinse dental appliances, and wash dishes, among many other daily activities.

Findings from the Environmental Working Group are particularly troubling: public water supplies in 42 U.S. states are contaminated with 141 unregulated chemicals for which the U.S. Environmental Protection Agency has never established safety standards. The states with the highest concentrations of these contaminants in their drinking water include California, New York, and Illinois (West, About.com).

It is for these reasons that many consumers are turning to bottled water as a precautionary measure. Presumed to originate from pure, contaminant-free natural lakes and rivers, bottled water is not, however, all that it claims to be. According to the United Nations Food and Agriculture Organization (FAO), bottled water does not offer superior nutritive value compared to tap water:

"There is almost a craze to drink 'natural' or 'spring' waters, either aerated or still. Many consumers believe that these waters, coming from springs, lakes, rivers or wells, have near-magical qualities and great nutritive value. This idea is false. Bottled water may contain small amounts of minerals such as calcium, magnesium and fluoride, but so does tap water from many municipal water supplies." (Latham, 1997)

The initial assumption was only partially correct. While hype does exist around water contamination, tap water may indeed be more contaminated than commonly assumed. The research deepened an awareness of how precious water is, how easily it can become contaminated, and how extensively it affects virtually every part of the human body through multiple exposure pathways.

Those who can afford it may invest in filtration and purification systems. Nevertheless, the picture is not entirely pessimistic. Even those with the fewest resources can take steps to prevent bodies of water from becoming recipients of toxic waste. Most importantly, all people can exercise greater care about the type of water they consume — an achievable step regardless of income level.

Conclusion

Weisel, C. P., & Jo, W. K. (1996). Ingestion, inhalation, and dermal exposures to chloroform and trichloroethene from tap water. Environmental Health Perspectives, 104, 48–51.

West, L. Tap water in 42 states contaminated by chemicals. About.com.