Billions of genetically modified mosquitoes are slated to be released over the next two years as part of an extended version of an Environmental Protection Agency (EPA) research — but the initiative has come under fire from advocacy organizations concerned that it might be deadly.
The EPA said Monday that it will prolong its current investigation into lowering the population of Aedes aegypti, a popular mosquito in the United States, until April 2024.
The EPA is expanding its operations to Monroe County, Florida, and four counties in California: Stanislaus, Fresno, Tulare, and San Bernardino.
The EPA is approved to release roughly 2.5 billion Aedes aegypti mosquitoes expressing a protein called Tetracycline Trans-Activator Variant (that-OX5034) into the wild under the updated Experimental Use Permit (EUP).
According to USA Today, the project’s objective is to limit the transmission of mosquito-borne illnesses such as dengue, Zika, yellow fever, and chikungunya.
According to USA Today, these new male mosquitoes mate with existing females to expect their progeny not to live long enough to develop.
According to Rajeev Vaidyanathan, head of US projects at Oxford-based Oxitec, “only male larvae survive to adulthood.”
“All female offspring perish as larvae,” Vaidyanathan said to the outlet. “In other words, this is a method of eradicating an invading mosquito species.”
The EPA and Oxitec did not reply quickly to PEOPLE’s request for comment on the program.
According to Reuters, millions of genetically modified mosquitoes were released in the Florida Keys in 2021 after the EPA clearance for the pilot study in May.
According to the article, six boxes of the genetically engineered mosquito were placed in various areas over 120 miles of the Keys to begin the experiment.
According to Meredith Fensom, Oxitec’s head of worldwide public affairs, the mosquitoes used in the experiment produce bright light to aid their identification when collected.
“That is how we monitor the mosquito population before, during, and after the experiment,” Fensom told the newspaper.
The EPA’s study drew criticism from several environmental advocacy groups, who questioned both the study’s goal and methodology.
Dana Perls, Friends of the Earth’s food and technology program manager, told USA Today that the Oxitex research is “a destructive act that is unsafe for public health.”
Though Perls anticipates peer-reviewed data to be released shortly, she is concerned about the hazards to the public presented by such an experiment, according to USA Today. She has also voiced worry about the absence of verified Aedes aegypti illness transmission in California.
“There is no imminent problem, and there are many unknowns,” she told the site, adding that she is concerned about the dangers associated with proceeding despite a lack of extensive, peer-reviewed scientific evidence from the previous year.
According to Jaydee Hanson, policy director at the International Center for Technology Assessment and the Center for Food Safety, Oxitec’s trial should be undertaken in a controlled context to avoid setbacks such as areas spraying to kill the troublesome insects.
Hanson feels Oxitec should have conducted the study similarly to how Oxitec and the United States Department of Agriculture released diamondback moths in New York State in past years.
“At our insistence, the [department] conducted tented testing,” Hanson explained. “You have a confined setting in which you attempt to duplicate as closely as possible the habitat into which the insect will be released to see what occurs.”
However, Hanson notes that the four California counties are agricultural areas. According to him, one of the primary compounds utilized in pesticide sprays might be troublesome.
“These mosquitoes have been genetically altered to survive in the presence of tetracycline,” Hanson said to the Sun. “If the female mosquito can obtain tetracycline, she can continue to live and reproduce.”
Hanson also voiced worry about the project’s secrecy, as Oxitec is entitled to keep sections of its study results confidential while conducting its studies.
According to the Sun, Hanson has stated that “the criteria set by the EPA for this trial are insufficient.”
“Much of the environmental impact has been blacked out (on reports), and, more troubling to me, the majority of the talk about allergic reactions to these insects has been blacked out,” Hanson told the Sun. “If this is the greatest invention since sliced bread, please demonstrate how you slice it.”
Hanson told the Sun that while he hopes Oxitec’s method is “less harmful” than alternatives such as pesticide spraying, he is concerned about potential health consequences.
“I’d want to make people feel better by sharing all of their adverse human health impacts,” he stated. “I have severe allergic responses to some items. I’d want to know when they’re going to release them. That is just a fundamental human right to know.”