Teenage males who consume certain pesticides might have defective sperm, according to researchers at the Milken Institute School of Public Health.

Melissa Perry, a professor and chair of the department of environmental and occupational health at the public health school, led a research project based on sperm and blood samples from 90 men who lived in the Faroe Islands, an island in the North Atlantic, to find a link between fertility and consuming environmental pollutants. The study, which was published Wednesday in the journal Environmental Health Perspectives, revealed findings that indicate that people should be aware of the pesticides they take in.

Perry said in a press release that there’s not yet enough evidence to relate how “pollutants may be affecting the maturation of the testicles and their function,” but this is the first step in finding a relationship.

Perry and her team collected blood samples from 33 men at age 14 to track the amount of pollutants found in their sperm and blood samples later in life. She also used a sperm imaging system to look for “sperm disomy, a condition in which sperm cells have an abnormal number of chromosomes,” according to the release.

Perry chose to research men in the Faroe Islands because the population there tends to eat pilot whale meat and whale blubber, which contain high concentrations of organochlorine pesticides, the toxin that Perry screened in sperm and blood samples. These pesticides are banned in the U.S.

“This study, and others like it, suggest that any decisions about putting biologically active chemicals into the environment must be made very carefully as there can be unanticipated consequences down the road,” Perry said in the release.