Researchers have uncovered evidence hinting that the most common bug spray ingredient, DEET, might cause reproductive problems by affecting the formation of egg cells during pregnancy.
- By STEPHANIE DUTCHEN
The findings come from a study in C. elegans - worms that don't look like they have much in common with humans yet serve as surprisingly useful bellwethers of how toxins in the environment affect human reproduction.
The research, published Jan. 4 in iScience, raises difficult questions. Chief among them is how to balance the possible reproductive harms of DEET-containing products in people - including infertility, miscarriage, or birth defects - with the need to ensure that people remain protected from diseases transmitted through insect bites, such as malaria, Lyme disease, West Nile virus, and Zika virus disease.
Whether and how much DEET use causes reproductive problems in humans will need to be confirmed in future studies. Such studies have been scarce to date in humans because of the ethical concerns involved.
Harvard Medicine News spoke with study senior author Monica Colaiácovo, professor of genetics in the Blavatnik Institute at Harvard Medical School, about what her team found and what it means.
Harvard Medicine News: Why did you conduct this study?
Monica Colaiácovo: The biggest motivator was how high DEET scored in our initial screens of how various chemicals in our environment affect meiosis, using the model organism C. elegans. Meiosis is the type of cell division that creates eggs and sperm. DEET was one of our top hits in terms of chromosomes not separating properly, so eggs end up with abnormal numbers of chromosomes. In humans, this can cause miscarriage, stillbirth, infertility, and genetic conditions such as Down syndrome. We knew we had to look at this carefully.
