記事を書いたユーザー： Rivka Seeman

While commodity crops like corn and soybeans are now typically grown using genetically engineered (also called bio-engineered) seeds, the wheat industry in the US has so far been cautious about introducing genetically modified wheat to the market. That is since Monsanto abandoned plans to do exactly that, back in 2004 due to concerns raised by American farmers about the ability of the US to export GM wheat abroad. Despite USDA claims that bio-engineered wheat is safe, consumers have reservations (“Monsanto's Genetically Engineered Wheat Scandal Is No Surprise, by Paul Klein, Forbes magazine”). While genetically modified corn and soybeans are primarily grown as animal feed or for use in processed foods, wheat is a crop grown to be consumed directly. That makes it a harder sell (“Explainer: Biotech corn and soy widely used, consumers still wary of GM wheat,” Reuters, 3月 3, 2023, Julie Ingwersen).

That’s not stopping Argentina and Brazil, responsible for 90% of the wheat grown in South America, from moving forward with plans to cultivate genetically modified wheat. Argentina, which grows wheat for consumption and export has been plagued by variable rainfall which affects its wheat yields. In response, an Argentinian Biotechnology company, Bioceres, engineered a drought-resistant wheat, called HB4, using a gene from a sunflower. It was approved for use in Argentina in 2020. Trials are ongoing but appear to be yielding a larger harvest than wheat grown without the gene. Bioceres announced on 3月 3, 2023 that CTNBio, the National Biosafety Commission of Brazil's Ministry of Science, Technology, and Innovation, has given full approval for the commercialization and cultivation of HB4 wheat in Brazil.

Proponents of biotechnology, also known as genetic engineering or genetically modified organisms, note that reduced yields due to drought require the cultivation of more and more land in order to produce more food, leading to deforestation. HB4 wheat addresses this problem by maintaining the yields during a drought without resorting to cultivating larger swaths of land for agriculture. (“Brazil says farmers can grow and market GMO wheat,” The Fern Ag Insider, 3月 5, 2023).

What has gotten less attention is that in addition to being engineered to grow under drought conditions, HB4 wheat was also modified to tolerate the weedkiller glufosinate. Much of the health concerns over genetically modified foods are due to the fact that these crops have been genetically modified to withstand グリホサート, a common herbicide that has been implicated in non-Hodgkin's lymphoma and many other diseases. This allows farmers to douse the crop with the herbicide without hurting the crop. Opponents of genetically modified crops point out that consumers wind up ingesting these possibly dangerous herbicides when they eat the food. In fact the Environmental Working Group (EWG) reported in 2022 on a CDC study that found that 87% of children tested, had detectable levels of glyphosate in their urine.

The question arises as to whether HB4, drought-resistant wheat will face the same concerns over glufosinate as other GM crops do over glyphosate. It seems likely that it will, as Matt Blois, writing for C&EN Chemical and Engineering News, reports that the World Health Organization’s (WHO) chemical safety program “recommends classifying glufosinate as a little bit riskier than glyphosate, which is categorized as slightly hazardous. Similarly,” he continues, “the EPA’s recommended safety limit for glufosinate residue in drinking water is lower than the limit for glyphosate.” (“Replacing glyphosate in the garden won’t be easy,” Matt Blois, 12月 17, 2021). Symptoms of glufosinate poisoning can include shock, respiratory arrest, unconsciousness, convulsions, amnesia, and death. "Glufosinate Herbicide Intoxication Causing Unconsciousness, Convulsion, and 6th Cranial Nerve Palsy,” Journal of Korean Medical Science, Vol. 11, 11月 28, 2013.

Scientific research has demonstrated that exposure to toxicants, nutrition imbalances, and under or over-nutrition at key periods of development can have a far-reaching impact even when none is apparent at birth. This impact can include a predisposition to later cancers, obesity, diabetes, auto-immune disorders, and cognitive deficits. (“Developmental origins of non-communicable disease: Implications for research and public health” Barouki et. al., Environmental Health, 2012, 6月 27). Even in very small doses, glufosinate can have a large impact, particularly when exposure occurs prenatally and in early infancy. Laugeray et. al. exposed mice to low doses of inhaled glufosinate during pregnancy and observed what they call, “significant effects of GLA maternal exposure on early reflex development, pup communication, affiliative behaviors, and preference for social olfactory cues…showing a striking resemblance to changes seen in animal models of Autistic Spectrum Disorders” (“Pre- and Postnatal Exposure to Low Dose Glufosinate Ammonium Induces Autism-Like Phenotypes in Mice,” Frontiers in Behavioral Neuroscience, 2014; 8: 390). Further research on low levels of glufosinate ingestion during sensitive periods may show similar concerns. The precautionary principle would urge that unless and until research shows otherwise, there is reason to assume that glufosinate residue on food is best avoided especially during early development.

Currently, glyphosate is sprayed on conventionally grown wheat as a drying agent before harvest. If HB4 wheat eventually comes to the United States, it will likely come with a residue of glufosinate. Consumers who wish to avoid chemical herbicides should know that genetically modified crops are not allowed to make an organic claim and neither are crops sprayed with glyphosate. The best way to reduce your family’s exposure to these dangerous herbicides is to buy organic wheat and other grains.