The Dangers of GMOs

Many GMO plants are engineered to contain their own insecticides. These GMOs, which include maize, cotton and soybeans, are called Bt plants. Bt plants get their name because they incorporate a transgene that makes a protein-based toxin (sometimes called the Cry toxin) from the bacterium Bacillus thuringiensis. Many Bt crops are “stacked,” meaning they contain a multiplicity of these Cry toxins. Their makers believe each of these Bt toxins is insect-specific and safe. However, there are multiple reasons to doubt both safety and specificity. One concern is that Bacillus thuringiensis is all but indistinguishable from the well known anthrax bacterium (Bacillus anthracis). Another reason is that Bt insecticides share structural similarities with ricin. Ricin is a famously dangerous plant toxin, a tiny amount of which was used to assassinate the Bulgarian writer and defector Georgi Markov in 1978. A third reason for concern is that the mode of action of Bt proteins is not understood (Vachon et al 2012); yet, it is axiomatic in science, that effective risk assessment requires a clear understanding of the mechanism of action of any GMO transgene so that appropriate experiments can be devised to affirm or refute safety. All this is doubly troubling because some Cry proteins are toxic towards isolated human cells (Mizuki et al., 1999).