Article focuses on impact of clean water

The introduction of water filtration and chlorination in major U.S. cities between 1900 and 1940 accounts for one-half the steep decline in death rates during those years, according to an article published in the recent issue of the journal Demography.

The analysis found that clean water was responsible for cutting three-quarters of infant mortality and nearly two-thirds of child mortality during that time, according to Harvard economists and article co-authors David Cutler and Grant Miller.

"Inexpensive water disinfection technologies can have enormous health returns in poor countries, even in the absence of sanitation services," said Cutler.

In 2000, the World Health Organization and UNICEF found that more than one-fifth of the drinking water samples from existing water systems were contaminated with bacteria and pollutants. Worldwide, 1.1 billion people lack access to clean water.

Although not a substitute for appropriate investment in sanitation, low-cost water disinfection could prevent a significant share of the 1.7 million annual deaths from diarrhea-related diseases worldwide, according to Cutler and Miller.

"While the (South Asian) tsunami was an enormous, immediate catastrophe," Cutler noted, "the deaths from unclean water are likely every bit as large, but more spread out in time and space."

Cutler and Miller also write that, between 1900 and 1940, U.S. death rates fell 40 percent, more rapidly than in any other time in the nation's history. About one-half of that decline is the result of clean water, according to the study.

For their analysis, the authors used U.S. Census Bureau mortality statistics for specific urban areas; they also gathered information on the timing of the introduction of clean water technologies from reports published in municipal engineering and urban planning journals during the period. Water filtration and chlorination were introduced in the U.S. cities before sewage treatment and sewage chlorination, allowing the researchers to calculate the impact separately.

Cutler and Miller estimate that the social rate of return on clean water technologies in the United States was about $23 gain for every $1 spent. They calculate that the cost per person-year saved was about $500 in present day dollars. The authors add that, had they factored in the impact of less disease and greater productivity, their estimates of the social benefits of investment in clean water would have been much greater.

Demography is the peer-reviewed journal published by the Population Association of America. The full article, "The Role of Public Health Improvements in Health Advances: The Twentieth- Century United States," is available at http://www.prb.org/cpipr/demography/cutler.pdf .

This article originally appeared in the 04/01/2005 issue of Environmental Protection.

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