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Many U.S. citizens believe that thanks to our advanced technology and enlightened public policy we can consume without risk the food and water that are readily available to most of us, as citizens of a rich and privileged country. Some of those who subscribe to this buoyant and comforting attitude, however, may have lately experienced second thoughts. Because of various recent and widely reported incidents, many people are feeling concern about the quality and safety of our food and water.
This is not surprising; some of these incidents have resulted in serious, widespread sickness, even death. For example, several incidents were reported of people becoming sick from eating undercooked beef at fast food restaurants. In other incidents, more than 70 people became sick and one died in late 1996 from drinking Odwalla apple juice, a brand sold at health food stores, and last year lettuce from a small producer sickened at least 61 people in the U.S. Northeast. The latter two incidents were related to a strain of E. coli bacteria. Water too has raised public health concerns.
Microbial pathogens or contaminants in drinking water are being blamed for various gastrointestinal illnesses that have occurred in different parts of the country. U.S. citizens, in the unlikely event they had even given much thought to contaminated drinking water, would have considered it a condition out of the past or one associated with developing countries. Now waterborne sickness from microbial contaminants, some with strange and unlikely sounding names-e.g., Cryptosporidium, Giardia, Legionella and Norwalk virus-has become a seemingly modern concern even for people living in the United States.
Estimates project from seven to about 30 million Americans each year develop a gastrointestinal illness, possibly from drinking contaminated water. EPA also provides a wide range of figures when estimating the nation's annual medical and lost productivity costs due to waterborne illnesses, from $3 billion to $22 billion. Of much greater concern are the deaths related to microbial contaminants in drinking water.
The Centers for Disease Control and Prevention estimates 900 to 1,000 people die each year from microbial illnesses from U.S. drinking water. Other estimates run as high as 1,200 deaths. Although difficult to pin down, such figures indicate the existence of a serious problem.
Microbial Contaminants in History
Microorganisms are present everywhere in our environment, in soil, air, food and water. Also called microbes, microorganisms are living organisms, generally observable only through a microscope. Our exposure to them causes harmless microbial flora to establish in our bodies, although some microbes are pathogens and can cause diseases. These diseases are considered waterborne if the pathogens are transmitted by water, to infect humans or animals that ingest the contaminated water. Diseases transmitted by water are primarily those found in the intestinal discharges of humans or animals The presence of microbial contaminants in drinking water has plagued humans throughout history.
In fact, outbreaks of cholera, typhoid fever and dysentery are recurring themes in early U.S. history. For example, in 1850 and 1851, an especially aggressive outbreak of cholera occurred in Sonora, an area that included Tucson at that time. More than 1,000 people died in northwestern Sonora, while in Tucson the 122 deaths that occurred in 1851 far exceeded the number of recorded births that year that were 19. Due to microbial pathogens, a harsh reality confronted those seeking gold and glory in the hills of California. "Diarrhea," reported a doctor in Sacramento, "was so general during the fall and winter months and degenerated so frequently into a chronic and fatal malady that it has been popularly regarded as the disease of California...."
Waterborne microbial pathogens cause a whole range of diarrheal diseases. The hazards of fecal contamination and the principles of basic sanitation were recognized early. The occurrence of such outbreaks alerted people to the hazards of drinking contaminated water and prompted investigations into ways to prevent the occurrence of waterborne illnesses. Public health officials eventually achieved success in controlling the more common forms of waterborne diseases, at least in the United States and other developed countries.
Progress was due to the adoption of public health measures as well as the implementation of important water treatment techniques, such as filtration, disinfection and sewage treatment. Some believed the battle, if not won, was at least under control.
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