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ln the 1880s, the death rate from typhoid in the United States was
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imately 75—100 per 100,000 population. Today it is 0.1 per 100,000.
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ics of typhoid fever and other waterborne diseases are no longer the
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health problems associated with water pollution. ln their place are dieret
disease microorganisms and a complex of human health hazards that can' be -_
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related to the organic and inorganic substances dumped in the water in mam—
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quantities by our fast—changing technological civilization. Some of these“)
Substances, among them a variety of chemicals and metals, pose a diroCt
threat tohmna'nhealth of unCer'tain dimensions. Others, such as
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trients, threaten to degrade natural water quality, diminishing the
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of already precioüs drinküig Water and, in certain cases, promoting 'thç*
growth of toxic algae’andprotozoans.
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Before consideringsome
of" these new problems, a brief look at theold
ones is in order, for we can by no means let down our guard against diSe'a‘séi*
bacteria. ln “1969, when the Bureau of Water Hygiene, a division of the Pub
hc Health
Service (PHS), surveyed community water supplies serving
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than 18 million people [1], the“ water in 120 of the 969 systems studied was
found to exceed the limit fOr caliform density (the measure of
quality [2]. Most of the drinking
bacteria was foundfÿin‘
small communities. This same survey found that 85 percent of the water SYSj
tems investigated did not collectanadeqœte number of samples to mamtam
;
the regular surveillance
dangerous increasesn ,” 'f
coliform count. F orty-one percent of the isÿstems failed to meet the PH31952
drinking water standards in one
25 percent
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