18. Understand Pesticide Toxicity |
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Toxicity is the inherent ability of a pesticide to cause injury
or death, indicating how poisonous the chemical is.
Acute toxicity is the ability of a substance to cause harm as a
result of a single dose or exposure to a chemical. Chronic toxicity
is the ability of a substance to cause harm as the result of repeated
doses or exposures over time.
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The tests for acute and chronic toxicity are the only scientifically
based methods currently used to predict risks to users and consumers.
But they have limitations. These tests are usually done on rodents,
which may not always accurately predict effects on humans. Plus, they
do not take into consideration the possible interaction and effect
of several compounds together. |
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All
labels include the warning, “Keep out of reach of children.”
In addition, most labels include “signal words” which
give an idea of the pesticide’s toxicity or corrosiveness. These
signal words are relative terms. They indicate how pesticides compare
to one another. Even if a pesticide is considered to be relatively
low in toxicity, it can be a deadly poison at a fairly low dose. |
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“Danger-poison” indicates a highly toxic pesticide. It
may take a few drops to one teaspoon of the chemical in concentrated
form, taken through the mouth, to kill an adult. Severe injury may
occur at even lower doses. |
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“Danger” indicates a highly corrosive pesticide. Although
the pesticide may not be extremely toxic, it may severely injure the
eyes or respiratory and digestive tracts. It may also cause severe
skin burns. |
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“Warning”
indicates a moderately toxic or corrosive pesticide. On average, it
takes 1 teaspoon to 1 ounce of the chemical in concentrated form,
taken through the mouth, to kill an adult. Severe injury may occur
at lower doses. |
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“Caution” indicates relatively low toxicity or corrosiveness.
It takes more than 1 ounce in a single dose of the concentrated chemical
to kill the “average” adult. |
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