DDT a problem of 30-50 years ago?

[Heath, Fred]

	Since the DDT is soluble in the fat of various creatures, the birds
on the top of the food chain such as the mentioned Peregrine as well as
three fish eaters, the Brown Pelican, the Bald Eagle and the Osprey, had a
tendency to get more concentrated DDT when they consumed their prey. Runoff
from agriculture put more DDT in rivers, lakes and estuaries, thus
increasing concentrations as you work up the food chain to fish eaten by
these large birds. Although it became apparent in these birds first that DDT
had this effect, there is no reason to believe that long term much of the
bird population could be effected.

	Consider this:  If DDT adversely effects bird populations, then
eventually the insect population will increase dramatically. Thus there will
then be a need to use even greater quantities of pesticides. Using the
convoluted logic I've seen on this on this list recently, might it be fair
to say that pesticide salesmen have a strong economic interest (like those
sneaky environmentalists, in saving endangered butterflies) pushing any
product which eventually rids the world of birds?  Pretty far stretch, I'd
say!

----Fred

> -----Original Message-----
> From:	Patrick Foley [SMTP:patfoley at csus.edu]
> Sent:	Friday, August 04, 2000 10:00 AM
> To:	dyanega at pop.ucr.edu
> Cc:	LEPS-L at lists.yale.edu
> Subject:	Re: DDT a problem of 30-50 years ago?
> 
> Doug, Paul and others,
> 
>     I am not a bird or toxicology expert, but I suggest a series of
> chapters in the
> book Peregrine Falcon Populations: their management and recovery. edited
> by Tom
> cade, James Enderson, carl Thelander and Clayton White 1988, The Peregrine
> Fund,
> Washington. D. C. Chapters 33-43 deal with the problems due to DDT, its
> metabolite
> DDE and other organochlorine contaminants.
>     The editors conclude that while some argument is possible about
> various aspects
> of the DDT story, "We take it as proven that a causal relationship exists
> between
> DDE residues in the maternal body and the abnormally thin-shelled eggs in
> Peregrines and many other birds." A large body of primary literature is
> cited,
> discussed and synthesized in this book which was peer-reviewed, unlike
> junkscience.com.
> 
> Patrick Foley
> patfoley at csus.edu
> 
> Doug Yanega wrote:
> 
> > Pat Foley wrote:
> >
> > >    But the main reason DDT is an environmental problem is its effects
> on bird
> > >reproduction. Does Paul Cherubini wish to argue that bird populations
> are
> > >unaffected by DDT exposure?
> >
> > Actually, he just posted evidence roughly to that effect, regarding the
> > original DeWitt study on quail. This leaves those among us who are
> anti-DDT
> > to come up with equal or superior citations (presumably with an opposite
> > conclusion) if we are to persist in defense of our position. I, for one,
> > will freely admit that I have never in my career actually seen any
> > peer-reviewed literature on DDT effects, so what opinions I have are
> > effectively based solely on decades-old hearsay and popular opinion. I'm
> > sure I'm not alone in this, and I'm willing to reconsider, based on what
> > evidence there actually may be (some of Paul's citations are compelling,
> > others are not). Of course, there is the additional complication, if
> some
> > of the citations he gives are to be believed, that there was a
> conspiracy
> > to keep pro-DDT studies from being published. In other words, an
> objective
> > conclusion about the danger of DDT may be impossible to obtain here,
> > because we may have one of those ugly situations - which we must
> honestly
> > admit *do* happen - where science and politics are too intertwined to
> > separate one from the other. That makes it unlikely that either side is
> > going to be able to present convincing enough evidence to "win" the
> debate
> > (so I'm not even sure it will do us any good to prolong this, but...).
> >         Accordingly, I'd politely request that further contributions to
> > this thread, if any, restrict themselves to presentation and discussion
> of
> > evidence from the primary literature, if at all possible. All else is
> > hand-waving, on BOTH sides. Hopefully we can get past the catcalling
> phase
> > quickly and move on.
> >
> > Peace,
> >
> > Doug Yanega        Dept. of Entomology         Entomology Research
> Museum
> > Univ. of California - Riverside, Riverside, CA 92521
> > phone: (909) 787-4315 (standard disclaimer: opinions are mine, not
> UCR's)
> >            http://insects.ucr.edu/staff/yanega.html
> >   "There are some enterprises in which a careful disorderliness
> >         is the true method" - Herman Melville, Moby Dick, Chap. 82