Billions of genetically modified mosquitoes are expected to be released within the next two years as part of an expanded version of an Environmental Protection Agency (EPA) study — but the project is receiving criticism from advocacy groups that believe it could be dangerous.
The EPA is looking to broaden its work to Monroe County in Florida and four counties in California: Stanislaus, Fresno, Tulare and San Bernardino.
Under the project’s revised Experimental Use Permit (EUP), the EPA is permitted to release nearly 2.5 billion Aedes aegypti mosquitoes containing a protein called Tetracycline Trans-Activator Variant (tTAV-OX5034) into the wild.
The goal of the project is to reduce the transmission of harmful diseases commonly carried by mosquitoes such as dengue, Zika, yellow fever and chikungunya, according to USA Today.
Developed by the biotechnology company Oxitec, these new male mosquitoes mate with the existing females in hopes that their offspring will not survive long enough to mature, USA Today reported.
Rajeev Vaidyanathan, director of U.S. programs for Oxford-based Oxitec, told The San Bernardino Sun that “only the male larvae survive to adulthood.”
“All the female progeny die as larvae,” Vaidyanathan told the outlet. “So this is a way of controlling an invasive mosquito species.”
In 2021, millions of genetically altered mosquitoes were released in the Florida Keys after the EPA received approval for the pilot project that May, according to Reuters.
To start the experiment, six boxes of the genetically modified mosquito were placed in various locations across 120 miles in the Keys, per the report.
Meredith Fensom, Oxitec’s head of global public affairs, told Reuters last May that the mosquitoes being studied in the experiment emit a fluorescent light to help easily identify them when they are captured.
“That’s how we monitor for the project before, during and after to understand the mosquito population,” Fensom said, per the outlet.
The EPA’s study has faced backlash, with some environmental advocacy groups criticizing both the purpose and methodology.
Though Perls expects peer-reviewed data to come out soon, she is worried about the risks posed to the public during such an experiment, per USA Today‘s report. She has also expressed concern about the lack of confirmed transmission of diseases from Aedes aegypti in California.
“There’s no immediate problem, and there are a lot of unknowns,” she told the outlet, noting that she is concerned about the risks that come from moving forward despite a lack of widespread, peer-reviewed scientific data from the past year, per the outlet.
Jaydee Hanson, a policy director for the International Center for Technology Assessment and Center for Food Safety, told the Sun that he believes Oxitec’s experiment should be conducted in a controlled environment to avoid setbacks like places spraying to kill the pesky insects.
Hanson believes that Oxitec should have done its study in a manner similar to how Oxitec and the U.S. Department of Agriculture released diamondback moths in New York State in previous years.
“What the [department] did, in part at our urging, were tented trials,” Hanson said. “You have an enclosed environment where you try to replicate the environment you’re releasing the insect into, as much as you can, to see what happens.”
But the four California counties are in locations where agriculture is occurring, according to Hanson. One of the main chemicals used in pesticide sprays, he said, could prove problematic.
“These mosquitoes are genetically engineered to stay alive if they can get access to tetracycline,” Hanson told the Sun. “If the female mosquito can get access to tetracycline, it can keep living and keep breeding.”
Hanson also expressed concern about some of the secrecy behind the project, as Oxitec is permitted to keep portions of their research results private while conducting their experiments.
Hanson has argued that “the parameters that the EPA has put on this experiment are inadequate,” according to the Sun.
“Big portions of the environmental effects have been blacked out (on reports) and, more concerning to me, most of all the discussions of the allergic reactions to these mosquitoes has been blacked out,” Hanson told the Sun. “If this is the best thing since sliced bread, show us how you slice it.”
Hanson told the Sun that he hopes Oxitec’s solution is “less toxic” than other options, like spraying pesticide, but remains concerned about possible health impacts.
“I would like them to feel better by disclosing all of their human health effects,” he explained. “I’m someone who has acute allergic reactions to things. I’d like to know when they’re releasing these things. That’s just the basic human right to know.”