Researchers from George Mason University have reviewed evidence suggesting that neonicotinoid insecticides, the world's most widely used pesticides, may harm male reproductive health. Based on 21 animal studies, the review found consistent links to reduced sperm quality, hormonal disruption, and testicular damage. The findings highlight the need for further human studies amid widespread exposure through food.
A comprehensive review conducted by George Mason University researchers, spanning studies from 2005 to 2025, indicates that neonicotinoid pesticides—commonly known as neonics—pose potential risks to male reproductive health. Led by alumna Sumaiya Safia Irfan and student Veronica Sanchez, the analysis examined 21 experimental animal studies, primarily on rodents, revealing consistent evidence of harm from exposure.
"We concluded it is possible that exposure to these chemicals can lower sperm quality, disrupt hormones, and damage testicular tissue," said Irfan, the study's first author and a master of public health in epidemiology graduate from George Mason.
Neonics, the most extensively used class of insecticides worldwide, are applied to crops and absorbed into soil, water, and plant tissues, leading to residues in consumed foods. All reviewed studies reported negative impacts on sperm quality in male rats and mice. "Many individuals may not realize that insecticide residue found on food could be a contributing factor to infertility," noted Sanchez, a master of science in chemistry student and research assistant at the George Mason Center for Applied Proteomics and Molecular Medicine.
While animal data provides insights, the effects on humans remain uncertain, prompting calls for more research. "These findings warrant pause for reflection, as the extent of the effect of neonics on human health is not yet fully understood," said Sanchez, who will graduate in fall 2025. "There needs to be further research into the effects of neonics on humans so we can begin to discuss mitigation strategies."
Melissa Perry, Dean of the College of Public Health and a contributing author, added, "Neonicotinoid insecticide use in U.S. agriculture has grown significantly over the last decade, so we know that exposures happen routinely for a large number of people. We need to conclusively determine how this affects members of the American public."
To reduce exposure, experts recommend thoroughly washing produce, though systemic pesticides like neonics are difficult to remove completely. "The best way is to be aware of what you are buying and shop responsibly," Irfan advised.
The study, titled "Reproductive Risk of Neonicotinoids: A Review of Male Rodent Studies," was published in the December 2025 issue of Environmental Research (DOI: 10.1016/j.envres.2025.122903). Contributing authors include Michael Bloom, Helen Chin, Jenna Krall, Anna Pollack from the College of Public Health, and Virginia Espina and Lance Liotta from the College of Science.