Update the 1st: In the interest of being accurate, I’ve posted what the article actually says below. I didn’t have it with me when I originally wrote the post, although there is little different from what I said. Expect a more in-depth post this week when I’ve finished Carson’s book and make sure I understand just what DDT and DDE is doing to people. The author of the article, Michael Finkel, writes;
Soon after the [malaria eradication program collapsed, mosquito control lost access to its crucial tool, DDT. The problem was overuse-not by malaria fighters but by farmers, especially cotton growers, trying to protect their crops. The spray was so cheap that many times the necessary doses were sometimes applied. The insecticide accumulated in the soil and tainted watercourses. Though non-toxic to humans, DDT harmed peregrine falcons, sea lions, and salmon [emphasis mine]. In 1962 Rachel Carson published Silent Spring, documenting this abuse and painting so damning a picture that the chemical was eventually outlawed by most of the world for agricultural use. Exceptions were made for malaria control, but DDT became nearly impossible to procure. “The ban on DDT,” says [Robert] Gwadz of the National Institutes of Health, “may have killed 20 million children.”
Straw man, anyone?
As I mentioned this past weekend, the new issue of National Geographic features a cover-story on malaria. Reading over the story last night, the author makes some jabs at Rachel Carson’s Silent Spring (which I should finish tonight) and claims that not only did DDT only effect sea lions, salmon, and peregrine falcons, but that it has no harmful effects to humans, either. The author also included a quote from a researcher (I forget their name, I will include it when I do the final write-up) that says the ban on DDT may have killed 20 million children. I was quote outraged that National Geographic would print such drivel without any further clarification or facts to back up the assertions, so I decided to start looking through the technical literature to see what is known about DDT and organochloride toxicity. I’m going to do a longer write up tonight or tomorrow, but if you’re interested here are some resources you can check so you don’t have to wait for me.
Bug Girl has an entire serious of posts taking on recent attacks on Rachel Carson, Silent Spring, and environmentalists in general. They serve as wonderful primers and are well-worth the time to read;
DDT, Junk Science, and the attack on Rachel Carson
New York Times, DDT, and an asshole
Rachel Carson and Chemical News
DDT, Junk Science, Malaria, and the attack on Rachel Carson
Malarial Drug Resistance: exciting new development!
Wikipedia- Organochlorides: Toxicity
[Note: The Wiki DDT page is a bit of a muddle, and you can definitely see the influence of people who do not consider DDT to be harmful at all. I’d skip down to the Effects on Human Health section, although I’d check the sources for the information there as well.]
Also, beware the so-called “100 things you should know about DDT” page (by the contemptible J. Gordon Edwards and Steven Milloy), which is crass enough to show a photoshopped picture of Rachel Carson wearing a shirt that says “DDT: A weapon of mass survival.” What this page is doing on the Wikipedia entry under “Toxicity” I don’t know.
Here is the Scorecard entry for DDT as well, but it seems to be out of date and does not list its sources.
PubMed Abstract – Chronic nervous-system effects of long-term occupational exposure to DDT.
The paper suggests that there are long-term neurological effects among those who have applied the chemical.
PubMed PDF- Concentration of Organochlorines in Human Brain, Liver, and Adipose Tissue
Autopsy Samples from Greenland
Not about DDT specifically, but it does contain interesting information about organochlorines (DDT is one) and how they accumulate in marine mammals and people who eat those mammals.
1999 NJ DEP Fact Sheet – Historic Pesticide Contamination
This page is old, but it does suggest that up to 5% of my home state may still be affected by past use of pesticides like arsenic and DDT
Undated PDF – Peregrine Falcon’s in New Jersey
This page does not list its sources, but it states that DDT was banned in New Jersey in 1968, but use of the product caused a major crash in predatory-bird populations in the state (I also know of anecdotal evidence from an ecologist who helped re-establish ospreys in the Barnegat Bay area)
PubMed Abstract – In utero p,p’-DDE exposure and infant neurodevelopment: a perinatal cohort in Mexico.
Study suggests that DDE exposure during the first trimester of pregnancy may affect developing human children.
Abstract – The human health effects of DDT and PCBs (polychlorinated biphenyls) and an overview of organochlorines in public health
Very general abstract, but does note that some organochlorides do have effects on liver and neurological functions.
PDF Paper – Association of DDT and DDE with Birth Weight and Length of Gestation in the Child Health and Development Studies, 1959–1967
The study did not appear to come up with any strong correlation for male infants, advising that more study is needed.
PDF LEtter – Invited Commentary: Why DDT Matters Now
Summation of two paper appearing in a 2005 issue of the American Journal of Epidemiology. While the letter (and papers) are far from being iron-clad evidence, I did find this admission interesting; “…almost no data are available on the health effects of DDT exposure at the levels experienced by those living in sprayed homes.” In places where malaria is still a threat, the insides of homes are sprayed with DDT and people ingest DDE (either through metabolizing DDT themselves or the environment metabolizing it, which is then ingested). This brings up an interesting point; given the propensity of DDT to concentrate in tissues and be passed along in mother’s milk, over the course of various generations will DDT concentrations in humans go up, and if so, what effect will this have on health?
Paper PDF – Reduced Seminal Parameters Associated With Environmental DDT Exposure and p,p9-DDE Concentrations in Men in Chiapas, Mexico:A Cross-Sectional Study
This Journal of Andrology paper echoes what seems to be the case with DDT and reproductive effects, summed up by the authors as follows; “…nonoccupational exposure to DDT, as assessed by plasma p,p9-DDE concentrations, is associated with poorer semen parameters in men, indicating adverse effects on testicular function and/or the regulation of reproductive hormones.” The percentage of motile sperm went down, tail defects went up, and some suffered incomplete DNA condensation.
Fulltext Paper –THE HUMAN HEALTH EFFECTS OF DDT (DICHLORODIPHENYLTRICHLOROETHANE) AND PCBS (POLYCHLORINATED BIPHENYLS) AND AN OVERVIEW OF ORGANOCHLORINES IN PUBLIC HEALTH
While the abstract states that there is “no convincing evidence that organochlorines cause a large excess number of cancers,” the section on DDT has some interested correlations between DDT exposure and some kinds of cancers.
JSTOR Paper 1st page – DDT and Wildlife
A pre-Silent Spring (1946) paper that seems to dismiss claims of conservationists that DDT is dangerous to wildlife and humans.