February 14, 1969

Dr. Thomas H. Jukes

Space Science Laboratory
University of California
Berkeley, California 94720

Dear Tom:

I certainly agree with you about the shrillness of the followers of Rachel
Carson. In fact, I have to say that for a rather long time I was so turned
off by that hysterical level of reaction that I refused to give very much
thought altogether to the possible substance of their concerns.

At this point I think we end up talking about rather different things. It
would be prepostrous to outlaw DDT. But I do not believe that we can blind
ourselves to the increasing abuse, particularly in large scale, wide area
application programs of an agent whose persistence in the environment is
quite remarkable and which does appear to be showing a build-up that would
be alarming even if one had absolutely no indication of possible harmful
effect.

If the analytical data on the distribution of DDT are themselves open to
question, then I would hope that you can bring your expertise to bear on this
and change our whole outlook on the question.

I do not think that I stated in my column that there was any iomediate anxiety
about reproduction in man, and that is not wy concern about the kinds of DDT
levels that would be in prospect for the next few years in the absence of any
prohibition. I agree with you about the import of the general toxicity data
on this score, although I think one would have to keep careful watch of pos-
sible genetic variation in DDT susceptibility,as has already been demonstrated
in barley. I am concerned about the phenomena that Conney has reviewed, which
open up the likelihood of some unexpected interactions between exposure to

DDT (and a variety of other substances! I am against smoking, too.) and the
variety of drugs thaf™&ommonly used these days.