Silent Spring by Rachel Carson

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The area included in the fire ant program is predominantly fields and croplands. What about
the dairy cattle that graze on these lands? In treated fields the grasses will inevitably carry
res idues of heptachlor in one of its forms , and if the res idues are eaten by the cows the pois on
will appear in the milk. This direct transmission into milk had been demonstrated
experimentally for heptachlor in 1955, long before the control prog ram was undertake n, and
was later reporte d for dieldri n, als o us ed in the fire ant program.
The Department of Agriculture’s annual publications now lis t heptachlor and dieldrin among
the chemicals that make forage plants uns uitable for feeding to dairy animals or animals being
finis hed for s laughter, yet the control divis ions of the Department promote programs that
s pread heptachlor and dieldri n over s ubs tantial areas of grazing land in the South. Who is
s afeguarding the cons umer to s ee that no res idues of dieldrin or heptachlor are appearing in
milk? The United States Department of Agriculture would doubtless answer that it has advised
farmers to keep milk cows out of treate d pastures for 30 to 90 days. Given the small size of
ma ny of the farms and the larges cale nature of the program—muc h of the chemical applied by
planes—it is extremely doubtf ul that this recommendation was followed or could be. Nor is the
pres cribed pe riod adequate in view of the pers is tent nature of the res idues.
The Food and Drug Adminis tration, although frowning on the pres ence of any pes ticide
residues in milk, has little authority in this situation. In mos t of the s tates included in the fire
ant program the dairy industry is small and its products do not cros s s tate lines. Protection of
the milk s upply e ndangere d by a federal progra m is therefore left to the s tates themselves.
Inquiries addressed to the health officers or other appropriate officials of Alabama, Louisiana,
and Texas in 1959 revealed that no tests had been made and that it s imply was not known
whether the milk was contaminated with pes ticides or not.
Meanwhile, after rathe r than bef ore the control program was launched, s ome res earch into the
peculiar nature of heptachlor was done. Pe rhaps it would be more accurate to say that
s omeone looke d up the res earch already publis hed, s ince the bas ic fact that brought about
belated action by the federal government had been discovered several years before, and
s hould have influenced the initial handling of the progra m. This is the fact that heptachlor, after
a s hort period in the tissues of animals or plants or in the soil, assumes a considerably more
toxic form k nown as heptachlor epoxide. The epoxide is popularly des cribed as ‘an oxidation
product’ produced by weathering. The fact that this trans formation could occur had been
known s ince 1952, when the Food and Drug Adminis tration dis covered that female rats , fed 30
parts per million of heptachlor, had s tored 165 parts per million of the more pois onous epoxide
only 2 weeks later. Thes e facts were allowed to come out of the obs curity of biological
literature in 1959, when the Food and Drug Admi nis tration took action which had the effect of
banning any res idues of heptachlor or its epoxide on food. This ruling put at leas t a temporary
dampe r on the program; although the Agriculture Department continue d to pres s for its annual
appropriations for fire ant control, local agricultural agents became increasingly reluctant to
advise farmers to use chemicals which would probably res ult in their crops being legally
unmarketa ble.
In s hort, the Department of Agriculture embarked on its program without even elementary
investigation of what was already known about the che mical to be us ed—or if it investigated, it
ignored the findings. It mus t als o have failed to do prelimina ry res earch t o dis cover the
minimum amount of the che mical that would accomplis h its purpos e. Afte r three years of

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