Third, we know too little about the fate of 
chemical compounds as they move from the 
target area to other segments of the environ- 
ment. We have inadequate knowledge of their 
movement in the atmosphere, into and through 
soils and into our streams, rivers, and oceans, 
There is a great void in our knowledge of 
the breakdown of pesticides in soils, plants, 
and water--and of the intermediates formed 
from this breakdown, Until this kind of infor- 
mation is available, we shall be living under 
a dark cloud of doubt as tothe complete harm- 
lessness of chemical pesticides, 
Fourth, we are handicapped by our lack of 
knowledge of the extent of buildup of toxic 
quantities of pesticides in the food chain--and 
of the mechanism of this buildup. Such knowl- 
edge would help identify potential nontarget 
hazards of pesticide usage and would assist in 
the diagnosis of alleged adverse effects of 
pesticides on fish and wildlife. 
Fifth, we need more information on the 
toxicity of pesticides to fish, wildlife and 
other animals. This would provide guidelines 
for restrictive use where potential hazards 
may exist. 
Last, but certainly not least, we need addi- 
tional scientific manpower trained in select 
disciplines of the physical and _ biological 
sciences to carry out the new lines of research, 
The background of these men will differ from 
that of their predecessors. There will be a 
higher proportion of organic chemists, bio- 
chemists, geneticists, physiologists, ecolo- 
gists, and climatologists--men with specific 
training to carry out specific assignments. 
Some new scientists are being supplied through 
expanded graduate training programs in our 
universities--the research component of which 
is supported at least in part by USDA grants 
or contracts, Others will come through the 
retraining or updated training of scientists 
within the department. Both the training and 
retraining programs will need to be stepped 
up drastically. 
The problems I have mentioned in develop- 
ing pest-control measures are essentially the 
same ones we face in using these measures, 
In using chemicals, our greatest difficul- 
ties stem from the fact that some of them 
tend to persist in the environment, that is 
they are biologically nondegradable. This fact 
is significant since the use of persistent 

63 
chemicals places in our environment com- 
pounds we cannot destroy. An even greater 
problem, however, is the fact that they may 
become widely disseminated as residues in 
soil and water and build up in the bodies of 
biological organisms used for food. Although 
we believe our food supply is safe at the 
present time, we are alert to the possibility 
of a pesticide buildup in the food chain and 
want to do all we can to prevent it. 
The only effective solution is to develop 
highly selective pesticides that can be applied 
precisely to kill only the pest we want 
destroyed--not anything else--and that per- 
sist just long enough to do the job. Pesticides 
that approach this ideal are on the market and 
their number is growing. 
In some cases, of course, persistence is 
desirable and assures effective destruction of 
some pests. When such compounds must be 
used because nothing else will do the job, 
obviously, we must use them but with the 
greatest possible caution. 
Another difficulty we face in using pesti- 
cides is related to the phenomenal expansion 
of their use in our modern society. Some 
pesticides are used today in quantities 100- 
fold or even 1,000-fold greater than those 
used in 1950 and in locations and for specific 
uses that were not even recorded in the sta- 
tistics of that year. It is only natural that 
difficulties arising from misuse or from 
movement to nontarget areas are more likely 
to occur today than 15 years ago. 
An omnipresent problem in the use of pesti- 
cides is the development of resistance by the 
pests to the chemicals, It is sometimes a race 
to finda new control method, chemical or other- 
wise, in time to take the place of the chemical 
to which the pest has developed resistance. 
Perhaps the most significant practical ob- 
stacle is the misuse and improper use of 
chemicals. In spite of valiant educational 
efforts by industry and public agencies, chem- 
icals are sometimes misused. One mishap, 
especially if not detected, can bring about 
serious damage to nontarget organisms--thus 
opening to criticism the many who carefully 
observe the safety precautions. 
In using biological control methods, we may 
have some difficulties similar to those asso- 
ciated with chemicals. We will have to be 
certain that the agents we select--parasites, 
