Skeptical Inquirer 2015
For “Myth” 3 in her article ”Pesticides: Just How Bad Are They?” (May/June 2015) Hall states, “…99.99 percent of all the pesticides in our diet are natural components of the food….” (by volume? by weight? by molecular count? by list entry count?) “Any synthetic pesticide residue is a drop in the bucket compared to the much larger concentrations of natural plant pesticides.” And yet the agriculture industry finds this 0.01 percent essential for maximizing crop yields? How about we argue that since they’re only 0.01 percent, we just leave them out altogether?
Farther on, Hall cites a study claiming “…total mortality has been found to be consistently lower among pesticide manufacturers….” (This reminds me of the arguments in favor of attending church regularly.) What are we to conclude from this? Could the safety precautions imposed in the workplace to limit exposure to the pesticides be so frightening to the workers that they insist on organic foods at home? “Further study is indicated.”
Then, “…evolution has equipped the human body to thrive while eating foods with levels of natural pesticides several orders of magnitude greater than the levels of artificial pesticides in today’s foods.” Fine. I’ll cast my lot with the natural pesticides that evolution has conditioned my body to handle.
The May/June 2015 issue of Skeptical Inquirer read like an advertisement for the chemical industry. As an environmental chemist, I have seen numerous cases of real, quantifiable problems caused by the misuse of chemistry, damaging people and the environment. On the other hand, I’ve also had to confront people’s unfounded fear and misbelief. Skeptics and their opponents, true believers, exist in an equilibrium. There is a psychological equivalent to Chatlier’s principle, where a system in chemical equilibrium, when disturbed from that equilibrium, pushes back to re-establish the equilibrium. Skeptics, when confronted with misbelief, often over-react to that misbelief. The complete skeptic needs to be skeptical of the biases inherent in skepticism.
Orlicki asks about the 99.99% of pesticides in our diet that are natural. He could have answered his own question by consulting the reference provided in the article. The 99.99% figure is by weight. The synthetic pesticide residue of 0.01 percent in our food doesn’t mean we can “just leave them out altogether.” It says nothing about the usefulness of pesticides in agriculture, where they obviously increase crop yields by far more than 0.01 percent. The quotation from the study about the health of workers exposed to pesticides explains that it is likely due to the “healthy worker effect” and is seen worldwide. The point is that if pesticides were as bad as Leu thinks they are, we would expect to see a higher mortality among workers, and we don’t.
Evolution made us adaptable. It equipped our bodies to defend themselves not just against the natural pesticides our ancestors had already been exposed to, but against new ones not previously encountered. Defense mechanisms are not targeted to one specific toxin; and the distinction between natural and artificial is a meaningless one. I’ll cast my lot with my body’s ability to protect against toxins in general, especially considering that pesticide residues in food are 1000 times less than the lowest levels ever shown to have a harmful effect in humans.
I certainly agree with Weber that chemicals can cause harm and that over-concern and under-concern are both to be avoided. But I would argue that skeptics and true believers don’t “exist in equilibrium,” because positions based on evidence and positions based on belief can never be weighed on the same scale. I don’t think there are any “biases inherent in skepticism.” Good skeptics and good scientists are “biased” only in favor of scientific evidence, reality, and critical thinking. There is no bias involved in asking for adequate evidence before accepting a claim.
This was originally published in Skeptical Inquirer.
Letters to the editor in SI 39:5 criticizing my article on Chemophobia (SI 39:3) with my response.