212 



1 EUGENE P. HAYDU 



2 was 2 to 6 times greater in the presence of SWL than in 



3 the controls. The concentration of SWL in the tests was 



4 3 to 5 times greater than those indicated to be harmful 



5 to oyster larvae in the FWPCA report. 



6 As already mentioned, I am at this particu- 



7 lar time less concerned with the oyster larval test as 



g such than with its possible applications. Actually, the 



9 concept and use of reference animals is by no means new. 



10 Such tests, with very sensitive species or life stages 



11 thereof, have proven to be especially useful in screening 



12 tests; for example, in establishing the relative toxicities 



13 of various substances. Reference animals are also commonly 



14 employed to determine preliminarily harmful and beneficial 



15 dosages of drugs for human use. The use of animals for 

 Ig these purposes is selective; that is, to those species 

 17 which most nearly react in the same manner as humans. 



Ig Indicative as these preliminary tests may be, final con- 



19 elusions are ultimately based on similar tests made with 



20 appropriate samples of the human population 



21 

 22 

 23 

 24 

 25 



It may be instructive at this point to refer 

 to the thoughts and suggestions of the National Technical 

 Advisory Committee on Fish, Other Aquatic Life and Wildlife 

 on this matter. After considerable deliberation, the 

 committee suggested certain basic guidelines in their 



