Nomoon -                Science and Life with a Dash of Humor

Look for It



“Silent Spring” & DDT Reexamined

written by Jason Lewis

“Silent Spring” & DDT Reexamined

We recently passed the fiftieth anniversary of the first publication of the book “Silent Spring,” Rachel Carson’s book which raised public awareness of pesticides and their risk to the environment. The bans on DDT are reportedly the eventual result of this book. As a child, I remember reading about DDT causing thinning egg shells in birds, which caused some of them to break open too early, which hurt the populations of endangered birds. More recently, I have seen some rebuttals to the claims made in this book. I’ve also seen the allegation made that the bans on DDT has been responsible for millions of preventable malaria deaths, especially in Africa.

This week, there have been several editorials, both in support and critical of the book. One article, in Slate, titled “Rachel Carson Didn’t Kill Millions of Africans, How the 50-year-old campaign against Silent Spring still distorts environmental debates” supports Carson. I expected to see more support of the claims in the book, maybe some justification of the ban on DDT, or an explanation of why the ban didn’t matter. Instead, the first half of the article seemed to be largely ad hominem attacks. The second half of the book promoted the idea that Carson was not responsible for ban, which seems to agree with the idea that the ban was a bad thing.

Quote:Carson did not seek to end the use of pesticides—only their heedless overuse at a time when it was all but impossible to escape exposure to them

But it’s a stretch to see how the mood surrounding Silent Spring was the prime cause of DDT’s exit from the fight against malaria.

Rachel Carson’s Deadly Fantasies, is critical article published at, that gives a quick overview. It mentions a fairly old 1992 article that was written by Entomologist, J. Gordon Edwards, which comments on specific pages of the book.

A few years ago, I stumbled across an article at, “100 Things You Should Know about DDT,” which gives a fairly comprehensive rebuttal of the claim made in “Silent Spring.” I just realized that this article was co-written by the same J. Gordon Edwards. Even if you aren’t a fan of the website and it’s founder, Steve Milloy, I don’t think that this compilation of information can easily be ignored for someone who seriously wants to look into the DDT issue. Some of the things that I recall are:

  • DDT exposure to birds did not cause egg shell thinning in the controlled experiements.
  • Egg shell thinning correlated to drought conditions.
  • Some birds has thicker egg shells during higher exposure to DDT.

In understanding is that DDT itself is a fairly inert chemical. This can be good and bad. It’s good in that this tends to make it less toxic to more animals. It can be bad in that it tends to break down slowly in the environment. It would seem that moderate use could be a good thing.

Leave a Comment - Here's your chance to speak.(eMail will not be published)