Chemicals; there’s that word again. Most of us know these “chemicals” are found in our food, water, clothing; never really knowing what a chemical is, only knowing we should avoid them. Nowadays, our society as a whole is quite concerned with the toxicity of pesticides that we are releasing into our environment, with reason. Many researchers are proposing more “natural” methods, shying away from the traditional synthetic pesticides. However, all these notions of what is “natural” and what is “chemical” or “synthetic” are quite arbitrary.
A chemical is, by definition, any element or combination of elements from the periodic table (1). This entails that water, as a substance, is a chemical. The single most important substance needed for our survival, is indeed a chemical. In reality, a chemical is any substance that can react in a chemical reaction. Many of the reactions necessary for our metabolism in fact use water. Negative connotations are often given to this word “chemical”, referring to some kind of dangerous substance that was created in a lab and should not be ingested by humans. This is the kind of arbitrary distinction that is made in the regulation of pesticide use, for organic crops (2). How can one substance be more “natural” than another if they are all composed of elements found in nature? (3)
This leads us to the notion of the word “natural” and how it relates to the word “synthetic”. Synthetic pesticides are commonly known as pesticides that have been substantially modified by man, for the use of killing pests. This is again, another completely arbitrary definition. Many products are modified by man, for example baking a cake, entails a chemical reaction to obtain a certain product. However this “synthetic” product, is not considered to be harmful per say, even though it did undergo a substantial modification.
These new biological weapons against pests are praised for being natural solutions that will be less harmful for our environment. It is true that these biopesticides are less toxic, as they do persist in the environment for lesser amounts of time, and are more specific to the targeted pest (4). However, these biopesticides are also being synthesized and improved through laboratory manipulations. Many of these biopesticides are actually derived from natural peptides, found in spider venom, for example. Spider venom, is in fact a chemical that is naturally occurring and an insecticide. Being that it is specific to insects, it poses little to no threat to us humans or other mammals. Nonetheless, it’s mass production is far from being a “natural” process.
These biopesticides are also known to provoque less resistance by insects. This is true in a natural setting; the chemicals used by spiders or plants that are natural insecticides are quite effective and insects take a long time to become resistant (5). However, let’s not forget that in nature, these chemicals are used on a small scale, and in a very diverse environment. These biopesticides are being proposed for large scale agricultural applications. Frequent biopesticide application, combined with large scale farming of one variety of crop at a time, will generate pressure for pesticide resistance by insects (6). These natural chemicals will encounter the same kind of pest resistance that we are currently seeing with “synthetic” pesticides.
As a consumer, it is quite easy be overwhelmed by scientific terms and branding that is intended to be confusing, such as organic status. Biopesticides are an interesting new development in the pest control field, that could really improve environmental conditions with their lesser toxicity. It is however very important to understand that toxic does not necessarily mean bad; in this case we are looking to eliminate pests, which entails that a certain amount of toxicity is important (7). Likewise, synthetic does not mean bad, and natural does not mean good. A chemical is only as good or bad as what we use it for and the value we associate to it.
(1) What Does Chemical Mean in Science? (n.d.). Retrieved December 9, 2018, from https://study.com/academy/lesson/what-does-chemical-mean-in-science.html
(2) Trewavas, A. (2001). Urban myths of organic farming. Nature, 410(6827), 409.
(3) “What’s Natural.” Understanding Science. University of California Museum of Paleontology. 9 December 2018. <https://undsci.berkeley.edu/article/natural>
(4) Gupta, S., & Dikshit, A. K. (2010). Biopesticides: An ecofriendly approach for pest control. Journal of Biopesticides, 3(Special Issue), 186.
(5) Ikonomopoulou, M., & King, G. (2013). Natural born insect killers: spider-venom peptides and their potential for managing arthropod pests. Outlooks on Pest Management, 24(1), 16-19.
(6) Whalon, M. E., Mota-Sanchez, D., & Hollingworth, R. M. (Eds.). (2008). Global pesticide resistance in arthropods. Cabi.
(7) Biondi, A., Desneux, N., Siscaro, G., & Zappalà, L. (2012). Using organic-certified rather than synthetic pesticides may not be safer for biological control agents: selectivity and side effects of 14 pesticides on the predator Orius laevigatus. Chemosphere, 87(7), 803-812.