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<br />pesticides
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<br />Use of chemicals to control pests has long
<br />bl'cn practiced in the Unil<.'d Stall's. Dec-
<br />ades ago, in"t'cts causing harm to agricul-
<br />tural crops were duskd with arsenical compounds
<br />or sulphurs. and inslocls Ihal carried human disease
<br />or wen;" rcg,mlcd as nuisances wac fought with
<br />sprays of light oils and pyrcthrin...
<br />Subsequently, "y"thc!ic, organic CtJmpounds
<br />Wt'n: developed lhat elTectively killed many insect
<br />pests long after the time of application. Other
<br />chemicals-I he herbicides-regulated the growth
<br />of broadlcaf plants, Mill others conlrolkd fungus
<br />of many Iypes.
<br />Over the years, several hundH'd basic chemicals
<br />have neen created and marketed in thousamls of
<br />formulations (0 control unwanted insects, plants,
<br />fungus growth, soil nematodes, small mammals,
<br />and olher pests, Not only were agricultural lands
<br />treated but homes. gardens, and turf were also
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<br />covered liherally, The Iotal tonnage of all liquids.
<br />granuk~, alld powders ro~e III thl' hundreds \If
<br />IhelUsands and thousands of IIses were devisl'd.
<br />The hcnefits. in terms nf increased food pro..
<br />duelion and the control of such killing disl';l.sCS
<br />as malaria and eneeph;llitis all over lhc world
<br />wac real and apparent, HOWever, knowledge of
<br />lhe pos.sihle sidl' dkcts of such chemicals elller..
<br />ing th~' l'lIvironrnent callie more slowly, ,
<br />By I Q44, reseiJreh had shown that the fir..t
<br />chlorinal....d hyJn>.:arh"1l compounds 'iueh as DOT
<br />mu..t he classed as killers elf !ish. By 1945, their
<br />ahilily III acculllulate in fally tisslles hecame ap-
<br />p,lrent.
<br />It is now known that some of the more per-
<br />sl'tnlt compound, ,He IHl'sl'nt ill IlK' ti"lIl" of
<br />hirds. fish, ;!nu othl'T wildlife and m:lIl as well,
<br />A concentrating dfc't taLes pbc, as tllll' sp~'cie'
<br />feeds on another and passes thc p':-.tieide from
<br />l'lll' Imk In anll:hcr in lhl' fllod chain, I knce, cer-
<br />tain predator hirds, fish. or animals m<l)' accumu-
<br />lak kvels se\leral Ihous,lIld limes the concen-
<br />tration in their enviTllnrnent.
<br />,,,"lan, Ilf Cl1urse, is at thl' top of this food chain.
<br />and the average American now carrics about I:!
<br />parts per million of DDT in his fany tissucs.
<br />'I here is nu dirl'ct e\lid....ncc thaI this eonccrHratll'n
<br />has a harmful elf....ct on humans. However, there
<br />is eviden,c lhal 'onecntrafeu pesticide residul'S
<br />have adversc effects on r....prnJuctinn, physiology,
<br />and rn:havior in some hirds and Illay threat,n the
<br />sur\lival of certain desirahlc species of wildlife.
<br />The oceans arc a final accumulation site for
<br />many of the Jx:rsistent chlorinated hydrocarhons.
<br />One quaTler of the world's cnlire production of
<br />nnr may havc heen transferred to thc sca by
<br />
<br />llelW, according to somc estimates, Some of its
<br />dTccls I'll the marine ~'nvir(lnrncnt have been
<br />dernonstr:Il~'d. Marine fish arc almost uni\lcrsally
<br />conlllminatl'd with residul'" of lhe persisll'nt pc!>ti-
<br />cid<.'s, and declining productioll of shrimp, crabs,
<br />and oy:-.tas in calalll areas is hdien.d to hl' di.
<br />reclly traeellhk, In pesticide eontaminaliml.
<br />:-':ew<.'r Iypes of chemical families include the
<br />Ilrganllphosphales ,lnd c;lrhamatc.... I.es:-. Pl'rsistent
<br />hut 1110rc toxic, these havc heen respllllsiblc for
<br />,,'eidl'ntal kills of hoth wildlife ;lElll humans. ,\lis..
<br />LIse of various pesliddes is implkated in up to
<br />:!OO human lkaths per ye<lf and thous:lIlds of
<br />cases of Sl'\'l're illness,
<br />ITllnically, hy relying too heavily for pest con-
<br />trol on th~' strale~y of chemical extl'rlllin;ltion.
<br />w<.' may well h;IVl' played into the hands of the
<br />insl'ct ('nl'my ilsdL y,ith ils trl.ll1l'lldotls ,apa,ity
<br />fnr adaptation and sur"i\lal. :\lnre and more in..
<br />sl'cl species, induding M\nll' of thost. th,lt carry
<br />human disl'asl" have dC\ldilped immunily to the
<br />(le:-.tieidl's whi,h had kept lhcm under conlrol.
<br />Thcy arc lhri\ling again, impcrvillus to such
<br />ch....mieal trealmelll, The :lllswcr to our prescnt
<br />ltilemma will Iwt 1'1.... found solely in the develop-
<br />ment "I' sakr more sekctive chemical formula-
<br />tiolh, although this is important. It r\:'quirl's, as
<br />"'l'II, Ih... dC\'c1opml'nl of allernali\,e slralegie:-. fllr
<br />dis<.'asc contw] and crup proleetion.
<br />j'l'rhaps no envirunmental prohlem illustrales
<br />mon' ekarly Ihan lhis pne tlK' ,nrnpkl( intra,..
<br />tiuns that takc place lhroughout the ,,'cosystcrn,
<br />and the caution that must he el(crcised to he sure
<br />that hcndidal changes made by man in one part
<br />of the system do not create scrious damage in
<br />anolher.
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