Ashwani raises a good and valid point, but one which also needs to be debated on a broader scale. There are many things we do which will have long-term consequences and we tend to ignore them. One clear and very long-term example is the disposal of radioactive wastes, but what about PCBs and dioxins? Lead? Mercury? Depletion of fossil fuels? Drug resistance fostered by heavy use of antibiotics? Society tends not to take a long view, and I am not sure that dealing with these issues on a chemical by chemical basis is the most effective approach. Itis hard to see any solution to the problem of getting society to balance short-term benefits against long-term consequences.
Bill Silvert ----- Original Message ----- From: "Ashwani Vasishth" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Wednesday, August 22, 2007 11:18 PM Subject: Re: Mosquito control, DDT etc. - boundaries and scales > This on-going debate over the use of DDT to check the spread of malaria is > really a debate over boundaries and scales. Different spatial, temporal > and organizational boundaries around what each side thinks is the proper > "problem space" are what make two quite opposing conclusions valid. > > We can bound the problem space to the hut in question, at the time-scale > of a mosquito's life span or to the life cycle of malarial infection, and > in the limited context of "malaria control" that reduces the number of > deaths from infection, and come to the conclusion that using DDT in > specific cases (the so-called "indoor use" strategy--which assumes that > DDT ceases to exist once it has been sprayed on walls and has done its job > of repelling mosquitos) makes sense. > > We can alternatively bound the problem space to the level of the > ecosphere, at the time scale of decades or centuries (which sees that DDT > continues to work long after it has "done its job" of repelling > mosquitos), and in the broader context of organisms other than mosquitos > (such as women who develop breast cancer, or seabirds that lay eggs > without shells, or sex reversal in fish, or the adverse impacts on polar > bears or penguins), and come to the clear conclusion that this is not at > all a good idea. > > Saying that using DDT is not a good idea is not at all the same thing as > saying lets not be bothered about the horrific number of infants and > adults who succumb to malaria each year. We must indeed act forcefully to > check this manageable disease, but we must act in a way that takes account > of ecological context and ecospheric consequence. > > Cheers, > - > Ashwani > Vasishth [EMAIL PROTECTED] (818) 677-6137 > http://www.csun.edu/~vasishth/ > http://www.myspace.com/ashwanivasishth > > > At 10:36 PM -0400 8/21/07, Jane Shevtsov wrote: >>Interesting. I just read about bednets with permethrin included in the >>fabric being very effective in malaria prevention. Unlike nets that are >>simply soaked in insecticide, or DDT sprayed in homes, these nets last >>several years without needing recharging or replacement. >> >>I realize that malaria is a much bigger health concern in Africa than >>persistent pesticides are, but have any measurements been made of DDT >>concentrations in the tissues of people who live in treated houses? I >>suspect this would be most important for women. >> >>Jane
