Imagine you are an undergraduate attending an Ivy League university. You go to a routine department seminar. In the middle of his presentation the professor picks up a container from the lectern. He says it contains a pesticide. As he opens it, a faint cloud of brown powder rises from the tub. It is, says he, “very safe.” Then he digs his finger into the container and tastes some of the contents. He offers it to a man in the front row, who refuses it twice. Walking back to the center of the room, the professor looks towards you and pushes the container in your direction.
Apparently he wants you to join him in eating pesticide. What should you do?
This scene does not need to be imagined. Here is the clip:
It occurred at a Cornell University department seminar titled: “Biotechnology Is Helping Resource Poor Eggplant Farmers in Bangladesh–So why is GMWatch Against It?” that took place in March, 2019.
The pesticide in question is the insecticide Dipel.
Dipel is the proprietary name for a preparation derived from fermenting the bacterium Bacillus thuringiensis (var. Kurstaki). B. thuringiensis is a gut pathogen of many species, including humans.
Dipel is obtained by partially purifying the fermented mixture so that the final pesticide is composed of several different Cry toxins (which are considered to be the active ingredients), along with bacterial cell spores and cell debris. Dipel and similar products have long been used in spray programs against forest and agricultural pests. Dipel is also used in organic agriculture.
Feeding Dipel to one's students creates an impressive list of problematic issues. They include safety concerns, ethics concerns, questionable science, and, not least, by eating a pesticide and encouraging his students to do the same, the professor and his students broke the law.
Beginning with science, one can ask what scientific point is demonstrated by eating a pesticide? Whether one survives tasting Dipel says nothing about its safety. Eating is therefore simply a stunt. Moreover, if their professor truly thought this was a science experiment, then he needs reminding that experiments on human subjects require informed consent and ethics approval at the institutional level. However, no specific information about Dipel or its safety record was imparted to the audience. For instance, the professor could have, but did not, read out the official warnings on the label (of which more later).
The second issue concerns ethics. It is surely inappropriate for a professor ever to offer a pesticide to their students. Interactions between students and professors embody power imbalances that are considerable, some might say feudal. Students depend on their professors for grades and recommendations. Public seminars are a further pressure situation for students. The presence of senior departmental faculty at the seminar increases the pressure. Refusing the clear expectation of one faculty member in the presence of (loudly guffawing) others is not something that most students would do lightly. A professor's invitation to eat a pesticide is therefore not likely to be perceived by students as a free choice.
Is Dipel 'perfectly safe'?
It is hard to agree that Dipel and Dipel-type products are “very safe.”
In 1999, Bernstein et al. reported finding immune responses to Cry toxins in workers exposed to sprays of Dipel-type products. These researchers were investigating Dipel in the first place because in 1992 the use of Bt (a Dipel-type spray) in an Asian gypsy moth control program was linked to allergic respiratory and skin reactions among people exposed to the pesticide. Similar allergic reactions were documented during another Bt spraying in the spring of 1994. Rashes and oedema (swelling) were reported after a Dipel spray program in Oregon as well.
Another study of Dipel-type products and found that “low dose aerosol exposures to commercial Bt based biopesticides can induce sub-chronic lung inflammation in mice.”
More recently still, Torres-Martınez et al. noted that one of the active ingredients of Dipel, the protein toxin Cry1Ac, “despite being regarded as innocuous to mammals … does interact with mammalian cells,” and concluded that it “has the ability to induce mucosal and systemic immunogenicity.”
Other researchers have reported direct toxicity of Cry1Ac towards mammalian cells and warned that further studies were required “to clarify the mechanism involved in the hematotoxicity found in mice, and to establish the toxicological risks to non-target organisms, especially mammals, before concluding that these microbiological control agents are safe for mammals.”
It should also be noted that bacterial spore preparations of the very closely related Bacillus thuringiensis var israelensis) can be lethal to mice.
Finally, the mode of action of Dipel, and Cry toxins in general, is to make holes in membranes. The toxin punctures cells causing them to swell and burst. Affected cells die directly; or, especially in the gut, following the entry of pathogens to the damaged cells.
The significance of this mechanism of action is that, in the case of Dipel, there can be no safety argument based on the claim that humans lack the target structure (the cell membrane) that Cry toxins are designed to destroy. Therefore, Dipel-type pesticides should be regarded as inherently hazardous. Indeed some researchers have found that, contrary to all industry claims, Cry1Ac does bind to mammal intestines.
To claim Dipel is “very safe” ignores a great deal of scientific evidence.
Dipel, pesticides, and the law
The material safety data sheet (MSDS) that accompanies Dipel says: “It is a violation of Federal law to use this product in a manner inconsistent with its FIFRA [Federal Insecticide, Fungicide, and Rodenticide Act] pesticide labeling.”
The MSDS also contains this statement about prevention:
“Avoid breathing dust/mistspray
Wash thoroughly after handling
Contaminated work clothing should not be allowed out of the workplace
Wear protective clothing/eye protection/face protection”
The MSDS further says:
“Avoid contact with skin and eyes…In case of contact with skin or eyes, rinse immediately and seek medical advice. Wear suitable protective clothing and eye/face protection.”
In other words, the professor broke the law. First, he broke it by consuming Dipel himself. Second, he broke it by inappropriately exposing the three students who did eat it. And third, by failing to inform them of the necessary precautions once they were exposed.
The politics of pesticide eaters
The stunt of eating pesticides is not new. Entomologists as far back as the 1940s were filmed 'demonstrating' that DDT is “so-safe-you-can-eat-it”. Patrick Moore, the self-proclaimed Greenpeace founder turned glyphosate promoter has made a career claiming that drinking glyphosate was safe. At least until he was confronted with the opportunity to do so by a journalist at French TV station Canal+ .
— Kevin Folta (@kevinfolta) March 21, 2015
Whether they are scientists or not, and Kevin Folta is a horticulture professor, people who offer to taste pesticides are not doing science.
They are promoting corporate products. And, in fact, the Cornell professor was promoting a product too. The lecture “Biotechnology Is Helping Resource Poor Eggplant Farmers in Bangladesh — So why is GMWatch Against It?” describes a high-profile project he oversees for Cornell in Bangladesh.
Cornell and the Bangladesh government's Agricultural Research Institute (BARI) have used a Monsanto transgene to develop a GMO brinjal (eggplant) variety that kills insects. The eggplant contains the Cry toxin, Cry1Ac. It is one of the toxins in Dipel, which explains the Dipel tasting.
The purpose of the GMO brinjal, depending on who you ask, is to defend the crop against a shoot-boring insect pest, or to act as a trojan horse for GMO crops in Asia.
The project is controversial in other ways too. For one, because of an industry-funded 90-day rat feeding study that was examined by independent epidemiologist Lou Gallagher.
Gallagher wrote of the study: “current results from these rat feeding studies indicate that rats eating Bt brinjal experienced organ and system damage: ovaries at half their normal weight, enlarged spleens with white blood cell counts at 35 to 40 percent higher than normal.”
The effects on the rats are “consistent with hepatotoxicity” wrote Gallagher.
Secondly, some local observers believe the GMO Brinjal project is failing. A report from Bangladeshi NGO UBINIG states:
“A Deputy Agriculture Extension Officer (wishing to remain anonymous) said selected Deputy Agriculture Officers are given a target to give Bt brinjal seeds to one farmer only in three wards under a Union. Even that is difficult to find, because farmers do not want to take the seeds. A farmer given the seed once does not want to take it again, because the seeds do not grow well and do not give fruits. The plants are weak, and the fruits are not seen. On the other hand, farmers cultivating local varieties have good productivity and can earn good income. The officer was worried how to fulfill the target! It is very difficult to find farmers, but ‘we are helpless because we have to keep our job!’”
If the Bt Brinjal project is failing there is no mystery over the motivation for a sales pitch and perhaps no mystery either about why farmers, teachers, and government officials often feel so comfortable claiming that fracking fluids, plastic containers, toxic plumes, pesticides in food, lead in water, teflon pans, and the like are safe.
They likely learned it in college.