As I’ve been walking around my neighborhood, I’ve noticed that some homeowners (thankfully, a minority) have had their lawns sprayed with Sevin (chemical name, carbaryl). The lawn spraying companies use it primarily to control the chinch bug, though it is secondarily targeted at the June beetle grubs. On a cost-benefit analysis, danger to human health and the environment versus the much ballyhooed “perfect lawn,” this seems to me to be a no brainer.
Carbaryl is an acetylcholinesterase inhibitor. Acetylcholinesterase is an enzyme present in the nervous systems of all animals, from a jelly fish to an Albert Einstein, that is essential for proper nervous system functioning. This means that all animals to varying degrees are affected by a compound such as carbaryl. It is non specific and therefore detrimental to the ecosystem, let alone human health. The acute symptoms of exposure to carbaryl, as declared on the Material Safety Data Sheet (MSDS) supplied by the company that produces it, reads like a witches’ brew: burns skin and eyes, causes nausea, cramps, diarrhea, salivation, vomiting, sweating, blurred vision, lack of coordination, convulsions. Yet, it’s the longer term effects of carbaryl exposure that are even more concerning.
In a landmark 2001 study done by a group of French and American scientists, it was determined that carbaryl caused damage to the DNA of human liver cells. In that same year, a study of 4,000 farmers in four midwestern U.S. states revealed that those who had used carbaryl were 30-50 per cent more likely to contract Non Hodgkin’s Lymphoma, a form of cancer, than those who hadn’t used it.
Then, a group of U.S. scientists in 2010 concluded from studying 56,285 pesticide applicators, that people who applied carbaryl on a routine basis were 1.7 times more likely to contract skin melanoma than those who didn’t. I wonder why P.E.I. has the highest rate of skin cancer in the country?
Two excellent, highly analytical (2010, 2012) reviews of the literature by Canadian and U.S. scientists, respectively, concluded that maternal exposure to insecticides (e.g. carbaryl) during pregnancy, whether in an occupational or residential setting, significantly increased the chances of the offspring developing childhood leukemia, as was also the case if the children were exposed post partum. In the second of these reviews, the authors concluded that “there is a growing body of literature that suggests that pesticides may induce chronic health complications in children, including neurodevelopmental problems, birth defects, asthma, and cancer.”
The Environmental Protection Agency in the U.S. considers carbaryl to be “likely to be carcinogenic in humans.” Even the company’s own MSDS states “this product contains ingredients that are considered to be probable or suspected human carcinogens.” The EPA also deems carbaryl to be toxic to a wide array of animals. Of greatest concern to P.E.I. would be fish, oysters, and honey bees. No wonder that several countries have banned carbaryl: United Kingdom, Denmark, Australia, Germany, Sweden, Iran and Angola.
The costs of using carbaryl cannot be seen to be greater than the benefits of ridding a lawn of chinch bugs. Most lawns, kept in good condition by natural methods, recover from chinch bug damage. I use a mild detergent solution to treat the chinch bug brown areas on my lawn. Then, I overseed. For natural ways to combat this insect, go to the Nova Scotia website (http://www.novascotia.ca/nse/pests/docs/chinchbug.pdf).
But, don’t spray with carbaryl.
By Roger Gordon (guest opinion)
Roger Gordon, Stratford, is a retired biologist and former Dean of Science at UPEI who has published extensively on biological methods for controlling insect pests.