PESTICIDE-WILDLIFE RELATIONS 



In the controversial pesticide question, the 

 Bureau has wide responsibility for obtaining facts 

 on the immediate and long-range effects of pesti- 

 cides on wildlife resources. The objective of ex- 

 tensive investigations is to assist in the develop- 

 ment of methods and materials which will insure 

 effective pest control with the greatest possible 

 safety to man and wildlife. In the Bureau's con- 

 cept, safe use requires a multiple approach in re- 

 search: more selective chemicals; more accurate 

 dosage; substitution, where possible, of biological 

 or ecological methods for chemicals; use of less 

 persistent but still effective chemicals; rigid ad- 

 herence to prescribed directions; and, above all, 

 thorough testing prior to release for general 

 application. 



Improved methods and equipment. — In chem- 

 istry, the Bureau's research centers have given 

 special emphasis to the simplification of analytical 

 methods in order to reduce the time required for 

 determining pesticide residues in biological speci- 

 mens. 



The adaptation of the gas chromatograph, 

 employing an electronic-capture detector, to rou- 

 tine analyses for chlorinated hydrocarbon residues 



shows promise of reducing cost as well as increas- 

 ing sensitivity of pesticide detection without ex- 

 cessive "cleanup." 



New facilities have been added to the laboratory 

 at the Denver Center to aid in the. development of 

 methods and to allow the detection of lower levels 

 of certain materials. Such equipment includes 

 an Atomic Scanogram II Chromatogram Scanner 

 and a liquid scintillation counter to permit, detec- 

 tion and measurement of extremely minute quan- 

 tities of radioisotope-tagged pesticide materials 

 used in translocation and metabolism studies. 



Limited field observation on the effects of 

 experimental applications of Phosphamidon on 

 wildlife was possible through cooperation with the 

 U.S. Forest Service in tests to determine its suit- 

 ability for the control of spruce budworm and 

 hemlock looper. Additional joint investigations 

 are anticipated in order to attain a mutual goal 

 of replacement of chlorinated hydrocarbon insecti- 

 cides with less persistent pesticides for forest 

 insect, control. 



Persistent pesticides from remote areas. — Pesti- 

 cide residues have been isolated and identified 

 from aquatic plants and snails collected in north- 

 ern Canadian waterfowl nesting habitat, as well as 

 in the atmosphere in these areas. In an attempt 

 to understand better the presence of pesticides in 

 remote, and untreated areas, the Denver Center 

 developed an air-sampling device consisting of a 

 2-inch glass tube containing a loosely packed glass- 

 wool filter coated with mineral oil, fastened out- 

 side the airplane. 



Modern and highly specialized laboratory equipment permits measurement of minutely small quantities of pesticides 

 in animal tissues. A chemist I left ) using gas chromatograph for separation and analysis of pesticide residues, and 

 (right! a chemist preparing thin-layer chromatography plates for pesticide analysis. (Photos by Rex G. Schmidt) 



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