An update of the impact of pesticide exposure on memory and learning

The dependence on the use of pesticides in agribusiness leads to an increase in human exposure to these chemical compounds through occupational activity, contamination of the environment, food and water. The nervous system is the target of most insecticidal pesticides and when these are poorly selective, they can harm non-target species, including humans. This work aimed to investigate the effects of pesticide exposure on memory and learning. Articles published in PubMed database between 2015 and 2024 were reviewed. One hundred and sixty-one articles were included in this review, of which one hundred and thirty two were preclinical studies and twenty-nine were human studies. Among preclinical studies, exposure to organophosphates, pyrethroids, neonicotinoids, carbamates, in addition to herbicides, fungicides and mixed exposures was associated with learning and memory deficits in animals such as bees, mosquitoes, fishes, mice, rats, and bats. Olfactory, associative and aversive learning, as well as memory capacity were affected by the exposure to pesticides. Most human studies evaluated the environmental and occupational exposure to organophosphate pesticides, pyrethroids and carbamates associated with the outcomes of interest. Living close to pesticide application areas and having parents working in agriculture were associated with worse learning and memory scores in childhood and adolescence. Prenatal exposure to insecticides has already been associated with poorer attention skills and attention-deficit/hyperactivity disorder (ADHD) symptoms, intellectual disability, autism spectrum disorder, motor delays, and attention problems. In adults, exposure during occupational activity was also associated with poorer memory and learning performance. The evidence found in this review suggests that pesticides with different mechanisms of action were able to cause some cognitive impairment. Developmental exposure, as well as chronic environmental and occupational exposure, can contribute to poorer cognitive performance, especially in learning and memory.