Can pesticide exposure before pregnancy affect babies’ health

A newly published study co-authored by UCLA researchers links women's exposure to agricultural pesticides, even before becoming pregnant, to poorer health in infants.

The peer-reviewed study, published in the March edition of the Journal of Exposure Science & Environmental Epidemiology, found that exposure during preconception to certain commonly applied pesticides - particularly those belonging to the classes of organophosphates, pyrethroids and carbamates - was associated with lower Apgar scores. The score, a commonly used measure given to newborns within five minutes of birth, is strongly correlated with the babies' long-term health outcomes, researchers said.

"Pesticide exposures disrupt biological functions in humans, raising concerns about potential effects on newborn health and development," said Dr. Beate Ritz, a co-author of the study and professor in the departments of environmental health sciences and epidemiology at the UCLA Fielding School of Public Health. "These findings suggest that interventions aimed at mitigating maternal agricultural pesticide exposures may improve newborn health."

Along with Ritz and Kimberly Paul, assistant professor at the David Geffen School of Medicine at UCLA who received her master's and doctoral degrees from UCLA Fielding, the multi-institutional study included researchers from Harvard's T.H. Chan School of Public Health and was led by scholars from the University of Arizona.

"Pesticides are designed to be toxic - very often, the biological mechanisms that they act on are present not just in insects and weeds, but also in humans. They have demonstrable biological effects on human health," said Melissa Furlong, an assistant professor at the University of Arizona's Mel and Enid Zuckerman College of Public Health and the senior author of the study, which was supported by the National Institutes of Health.

The research group analyzed pesticide use registries that contain comprehensive records of all pesticide applications across the state. Arizona is one of the two states in the U.S. that maintain pesticide use registries, which include information such as crop type, pests, brand name and active ingredient of the pesticides used.

The team collected all birth certificate records in Arizona and linked them to the state's pesticide registry. They found that exposure to certain classes of pesticides during preconception and pregnancy were associated with low Apgar scores, which are predictive of certain neurological outcomes of newborns and correlated with a baby's health through childhood.

Though the study found a strong correlation, it does not definitively state that pesticide exposure during preconception and pregnancy harms the newborns' health. However, in the future, the team will examine Medicaid records in Arizona to see if this association holds true for actual neurodevelopmental disorders through childhood.

The team shared a few recommendations to reduce pesticide load in households that are close to agricultural areas. Simple measures like vacuuming and dusting homes, using doormats and avoiding walking with shoes inside the house can lower the pesticide load. For those who use well water, it may be beneficial to use water filters. For those in agricultural areas, it is important to change air filters at least once a month during pesticide spray seasons.

"Most importantly, try not to use indoor insecticides during pregnancy," Furlong said.