Joe writes:

> DDT damage
>
> The Mexican Government plans to phase out DDT in malaria control over the
> next ten years in favour of an integrated pest management (IPM) approach.

It
> is prioritizing a reduction in organochlorine pesticides such as DDT

because
> of the link between organochlorines and cancers. The Government also plans

to
> enhance the enforcement of restrictions against DDT use in agriculture,

which
> continues despite being made illegal in 1990. The Ministry of Health

reported
> organochlorine residues in 146 out of 439 samples examined between 1993 and
> 1995. Food contamination could account for the occurrence of unexpectedly
> high levels of DDE, a breakdown product of DDT, in the breast milk of women
> in Mexico City. According to an Environmental Health Perspectives report,
> Mexico is the leading DDT user in Latin America, and breast cancer is the
> second leading cause of death among Mexican women.
>
> Pesticide Monitor, vol 5, no 2.


Theodosius Dobzhansky, someone who I suspect that no one on this list knows
but who every biologist knows well, wrote 40 years ago, "pat answers to complex
problems are the hallmark of intellectual mediocrity."

The discovery of the insecticidal properties of DDT during WWII was
considered so great a discovery that it was awarded the Nobel Prize in 1948:

http://nobelprize.org/nobel_prizes/m...948/press.html

By 1962 however the first warnings of its pervasive effects of its long-lived
degraded products on birds and fish were being made, first by Rachel Carlson,
and later by a host of follow-on studies. Because of these studies, by the
middle 1980's, DDT had been banned essentially worldwide, except in case of
medical emergenies.

Just very recently, in September, almost 30 years after it phased out
widespread indoor spraying of DDT, the World Health Organization has announced that
DDT will be used as one of the three main tools against malaria. WHO is
recommending indoor residual spraying in epidemic areas, as well as in places with
constant and high malaria transmission. The USAID subsequently announced that it
would fund the use of DDT.

DDT was the first insecticide of a new class of molecules called
organochlorines, and although they proved to be enormously effective at the time, they
have now been almost universally banned. For a time, the organochlorines were
replaced by organophosphates. These chemicals have the advantage of having very
low environmental persistence, but the great disadvantage of high mammalian
toxicity. Indeed, most nerve gases, such as sarin, are some form of synthesized
organophosphate:

http://ipmworld.umn.edu/chapters/ware.htm

It's not possible to put poisons of any form into the environment in large
quantities and not expect some form of significant environmental degradations or
health ramifications. The problem of trying to balance human health and
agricultural concerns while maintaining a safe environment definitely meets the
criteria of a complex problem, and pat answers to this sort of problem are truly
a hallmark of intellectual mediocrity.

Wirt Atmar

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