Hmm...Perhaps "Paul Cherubini" missed the sentence in Relyea's paper where he
stated that they "applied each chemical at the manufacturer's recommended
maximum application rates (Sevin, 0.955 mL/ m2; malathion, 0.234 mL/m2; 2,4-D,
0.117 mL/m2; Roundup, 6.4 mL/m2".From real world observation, in the field
where actual applications occur, I note that intended application rate can vary
substantially from actual application rate...sometimes leading to higher doses
than intended. Furthermore, ag applicators often take the approach that "if 2
aspirin are good, then 4 must be better". I think what Relyea's study is
trying to tell us is that we should employ the precautionary principle here,
due to the fact that the history of pesticide toxicology hell has long been
paved with good intentions.
Chris Rosamond
> Date: Fri, 3 Oct 2008 16:29:50 -0700> From: [EMAIL PROTECTED]> Subject: Re:
> [ECOLOG-L] Insecticide Decimates Tadpole Populations Through the Food Chain>
> To: [email protected]> > Amartya Saha wrote:> > > what the study
> showed is that sublethal doses of malathion can> > negatively affect leopard
> frog tadpoles by affecting their food chain.> > Sublethal to leopard frogs,
> but lethal to zooplankton. Its a matter of> > insecticide/weedicide
> CONCENTRATIONS. Yes, it can be that in the field,> > such concentrations are
> often lower than in the U Pitt tank study.> > However there can be (and will
> be) instances where this concentration> > may be reached or even exceeded,
> depending on topography/drainage,> > rainfall and a host of other factors. >
> > Dr. Relyea's tank study was not representative of actual field >
> conditions, hence it was not capable of demonstrating whether> or not the
> formulation and dosage of Malathion routinely used> in ground or aerial
> applications for mosquito control (~ 0.5 - 4 > ounces per acre) leaves
> behind residues on natural tadpole > habitats (e.g. ponds and puddles) that
> are seriously lethal to > the zooplankton upon which the tadpoles feed.> >
> Paul Cherubini> El Dorado, Calif.
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