Agriculture Reference
In-Depth Information
Parkinson's disease. To what extent has pesticide use over the
last few decades harmed human health? The more we learn,
the more difficult it is to say. In the early 1980s research con-
cluded that pesticides played a very minor role in human
health problems, leading some to conclude that virtually
nobody dies of cancer caused by pesticides. Since then we
have learned how difficult it is to determine the impact of pes-
ticides on health, given the variety of carcinogens we encoun-
ter (including charred meat, acrylamide in French fries and
coffee, and household cleaning supplies) and the long delay
between exposure and health impacts. Scientists are fairly cer-
tain that about one-third of cancer is caused by smoking and
another one-third is caused by poor diet, overweight, and too
little exercise, but the sources of the remaining third are dif-
ficult to assign.
Of this other third of cancers, pesticide use certainly seems
to play some role. Non-Hodgkin's lymphoma, prostate cancer,
melanoma, and a variety of other cancers are correlated with
pesticide use. People applying pesticides, living on farms, or
employed in pesticide manufacturing seem to have higher
cancer rates than people who rarely encounter pesticides.
The issue becomes even more complex when one considers
the many indirect ways pesticides affect humans. Honeybee
colonies have reduced dramatically in recent years in some-
thing called colony collapse disorder, and though the cause
isn't certain, pesticides could be partly to blame. Since we
rely on bees to pollinate much of our fruits and vegetables,
this indirect effect could negate any direct benefits of certain
pesticides.
There is little controversy over whether pesticides may
pose a potential harm. What is questionable is whether actual
harms are observable, and if they are, whether the benefits of
pesticides outweigh those health harms. For instance, a pesti-
cide may directly increase cancer rates slightly, but indirectly
cause a larger reduction in cancer rates by reducing substan-
tially the price of fruits and vegetables. When the Mayo Clinic
