US says Mexico ‘abandoned science’ in GM corn limitations

By Johnathan Hettinger

The United States has doubled down on allegations that Mexico is violating international trade rules by working to ban imports of genetically modified (GM) corn for human consumption, arguing in a filing made public this week that Mexico has “abandoned science” in expressing concerns about how GM corn impacts human and environmental health.

Mexico is violating its obligations under the United States-Mexico-Canada Agreement (USMCA), making “factual and legal errors” in attempting to justify its decision to ban GM corn for use in tortillas and and dough and to gradually move away from the use of GM corn in animal feed, the US said in its formal rebuttal to Mexico’s case.  

The 120-page US response, filed with a tribunal charged with arbitrating the trade dispute, said that Mexico has not shown that GM corn is likely to harm humans or native Mexican varieties of corn that are not genetically modified as Mexico has feared. 

The US filing comes in response to a 189-page report issued by Mexico explaining the risks it sees posed by GM corn.

For years, Mexico has allowed the import of GM corn in the country, but the administration of Mexican President Andres Manuel Lopez Obrador has taken aggressive moves against the import of GM corn and against the use of glyphosate weed killer in the country, citing concerns threats to the health of the Mexican population as well as to the health of the environment. Glyphosate is commonly used by US farmers in growing a wide range of crops, and is sprayed directly over the tops of growing corn and other crops that have been genetically engineered to withstand the weed killer. In addition to being genetically altered to withstand herbicides, GM corn has also been engineered to manufacture its own toxin to repel insects. 

“Mexico has legitimate concerns about the safety and innocuousness of genetically modified corn… and its indissoluble relationship with its technological package that includes glyphosate,” the Mexican government’s report states. There is “clear scientific evidence of the harmful effects of direct consumption of GM corn grain in corn flour, dough, tortilla and related products,” Mexico stated. More evidence is needed, Mexico says, to determine “whether and to what extent, such risks are transmitted to food products further downstream…”

Mexico argues that the burden of proof is on the US to show that GM corn is safe. Mexico has accused the US regulatory system of being corrupted by its close ties to industry. In its response, the Mexican government cited studies that they said showed links between GM corn and glyphosate and human health concerns.

The US counters that Mexico should have issued a risk assessment to back up its decision, and the response filed with the tribunal does not replace that requirement. 

Timothy Wise, a senior advisor at the Institute for Agriculture and Trade Policy, said that the US response ignores the science that Mexico used to defend itself. 

“The US government still fails to take seriously the evidence Mexico has provided showing ample cause for its precautionary restrictions on GM corn in its tortillas,” Wise said. “Mexico justifiably wants scientific evidence that GM corn with glyphosate residues is safe to eat for Mexicans, who consume ten times the corn we do in the US and do so not in processed foods but in minimally processed foods. The US has provided no such evidence.” 

For example, US risk assessments are based on US corn consumption, but in Mexico, people are estimated to get 1,000 calories a day from corn. 

Mexico is also working to ban glyphosate. A Mexican ban on glyphosate was set to go into effect April 1, but was delayed indefinitely in late March.

In addition to health concerns, Mexico has expressed concerns about its the purity of its native corn varieties and how GM corn could potentially impact them, but the US argues those concerns should be better addressed through other “less trade-restrictive measures.”

There are “20 years of literature which shows that GM corn contamination has occurred in Mexico,” Monserratt Téllez Serrano, political advocacy coordinator at Seeds of Life in Mexico, said in a webinar hosted by IATP on Thursday. “The whole US framework is focused on profit for corporations, whereas here in Mexico we focus on the defense of ancestral cultures and the biodiversity and the free exchange of native seeds and the defense from GM corn contamination.”

Mexico imports very little GM corn for human consumption, and argued that because of this, it is not a large trade disruption, but the US said that US farmers make decisions based on approvals in import markets. 

“US farmers and biotechnology companies view Mexican approval of new products as a precondition for US farmers to plant the products,” the US said.