All, We are going to be discussing this topic in the class I'm teaching - with most participants very concerned with both poverty AND conservation. So I'm pleased to be reading this discussion. Good to hear all sides.
To (a): how much needs to be in the environment to affect species? (Even though it may be less than before, is it still enough to cause any problems? To (b): but DDT must break down at some point. Does it really stay fully insoluable during the decomposition process? How long does this take, and at what point would it then travel outside the "house site" ? Thanks, Shelly >From: Paul Cherubini <[EMAIL PROTECTED]> >Reply-To: Paul Cherubini <[EMAIL PROTECTED]> >To: [email protected] >Subject: Re: DDT question >Date: Sat, 1 Sep 2007 08:29:08 -0700 > >Kelly Stettner wrote: > > > For some reason, I thought that Rachel Carson's allegation > > about sea bird eggshells had been disproven? > >Kelly, whether or not Rachel Carson's allegation was correct >is not relevant to the DDT indoor house wall treatment issue. > >Why? > >a) Because on a landscape scale, the amount of DDT used per >acre of land per year for malaria control (house wall >treatments) in developing countries is many >thousands of times LESS than the amount of DDT >that was used per acre per year in the USA on >agricultural crops in 1950's. Therefore indoor house wall >usage of DDT could not conceivably result in significant >outdoor biomagnification, bioaccumulation, demasculinization, >etc. environmental effects. > >b) DDT wettable powder is also relatively insoluble in water, >so even when a house collapses and decays, DDT will >not easily move from the house site. > >c) DDT mostly repels rather than kills mosquitoes from >treated homes, hence acquired resistance is not a big >problem either. Meanwhile, DDT buys time and could >save hundreds of thousands or millions of lives until (and >if) new, comparably cost-effective anti-malarial drugs or >pesticides for mosquito control are ever developed. > >Paul Cherubini >El Dorado, Calif. _________________________________________________________________ A place for moms to take a break! http://www.reallivemoms.com?ocid=TXT_TAGHM&loc=us
