关键词：水质 标准 水质标准 杀虫剂 杀虫
Why Is There Concern
About Pesticides in Drinking Water?
Pesticides pose a health threat not only because of their
toxicity, but also because of their widespread use in the U.S.
There are now about 21,000 registered pesticide products,
with almost 900 active ingredients. In a typical year, about
1.2 billion pounds of conventional pesticides and other
chemicals are used in the U.S. for pest control in agriculture,
residences, industrial, and commercial settings. 1 As a result
of their extensive use over the last half-century, pesticides
are ubiquitous in our environment, and human exposure is
virtually inevitable. National population-based surveys of
pesticide urinary metabolites in adults indicate widespread
exposure to pesticides. 2,3,4
Drinking water can be a significant source of chronic
pesticide exposure, especially in agricultural regions where
large quantities of pesticides are used. 5 Researchers at the
U.S. Geological Survey (USGS) found pesticides in more
than 95% of stream samples and almost 50% of ground water
samples collected throughout the U.S. 6 Ground water
contamination is critically important because 38% of the
water used for public water supplies is obtained from ground
water sources. 7 The USGS investigation also found that peak
seasonal surface water concentrations of pesticides frequently
exceeded federal drinking water standards in agricultural
areas. 6 Levels and occurrence of pesticides in surface water
and ground water vary considerably with the seasons and
local geology, with highest concentrations often occurring
in spring and early summer following rainfall. 8,9
What Are the Health Effects of Pesticides?
For many pesticides, our understanding of human health
effects is based largely on occupational or accidental
exposures, or laboratory animal studies, in which doses can
be relatively high. Effects such as weight loss, organ damage,
muscle degeneration, neurological damage, and cancer have
been documented based on such studies. In fact, more than
160 pesticide active ingredients have been classified as known
or suspected carcinogens by EPA and other organizations. 10
However, environmental exposures to pesticides, such as
through drinking water, usually involve relatively low
concentrations that may occur over long periods of time.
While the human health effects associated with chronic, lowlevel
pesticide exposures are not yet well understood, a
growing body of scientific evidence suggests that
environmental pesticide exposures are associated with
neurological and reproductive damage, effects on growth
and development, birth defects, endocrine disruption, cancer,
and other adverse effects.
Given the ubiquitous nature of pesticides in our
environment, this emerging evidence raises serious public
health concerns. Every effort must be made to use
precautionary strategies to minimize or prevent pesticide
exposures while further evidence is collected through
research. This fact sheet summarizes health effects
inform
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