This is another in an occasional series of posts dissecting the claims made by JunkScience purveyor Steven Milloy’s “100 things you should know about DDT.” What I find in this list is a lot of deception, misleading claims, and general unjustified vitriol. In this post I’m looking at Milloy’s point #10.
10. Rachel Carson sounded the initial alarm against DDT, but represented the science of DDT erroneously in her 1962 book Silent Spring. Carson wrote “Dr. DeWitt’s now classic experiments [on quail and pheasants] have now established the fact that exposure to DDT, even when doing no observable harm to the birds, may seriously affect reproduction. Quail into whose diet DDT was introduced throughout the breeding season survived and even produced normal numbers of fertile eggs. But few of the eggs hatched.” DeWitt’s 1956 article (in Journal of Agriculture and Food Chemistry) actually yielded a very different conclusion. Quail were fed 200 parts per million of DDT in all of their food throughout the breeding season. DeWitt reports that 80% of their eggs hatched, compared with the “control”” birds which hatched 83.9% of their eggs. Carson also omitted mention of DeWitt’s report that “control” pheasants hatched only 57 percent of their eggs, while those that were fed high levels of DDT in all of their food for an entire year hatched more than 80% of their eggs.
Considering Carson’s careful citing of studies on all sides of the issue, and her use of sources dating back 30 years and more, it would be difficult for her to have “represented the science of DDT erroneously.” Carson got the science right. Milloy doesn’t even get the quote of Carson right, however, deleting her main point, and editing it to set up a straw man argument which misleads unwary readers.
Carson represented the science faithfully. Milloy simply dissembles in his accusation that she got it wrong.
In fact, Carson offered more than 50 pages of citations to studies, virtually everything available on DDT and the other chemicals she wrote about, up to the time of publication. Carson had started working on the issue in 1948, and worked almost solely on the work that became Silent Spring between 1959 and the book’s publication. None of the studies she cited has been retracted. Most of the studies were determined to be accurate in follow-up studies.
I discuss this at some length, below the fold. Read the rest of this entry »