Childhood Pesticide Exposure Linked to Shifts in Puberty Timing, Study Finds

Exposure to certain pesticide-related chemicals during childhood may subtly shift the timing of puberty in girls, with two different compounds pushing it in opposite directions, according to a study published in Environmental Research by researchers from the University of Granada and the ibs.granada Biomedical Research Institute in Spain.

The study followed 506 girls participating in the INMA (Childhood and Environment) birth cohort from Asturias, Guipúzcoa, Sabadell and Valencia. Researchers collected urine samples between 2013 and 2016, when participants were 7 to 10 years old, and tracked them until ages 14 to 16 to record when each girl had her first menstrual period.

Girls with higher levels of ethylenethiourea (ETU), a residue from dithiocarbamate-type fungicides, tended to reach menarche at a younger age; ETU can interfere with thyroid function, which helps coordinate growth and development. A different pattern emerged for TCPy, a compound formed when the body breaks down the insecticide chlorpyrifos: girls in whom it was detected generally began menstruating later, an association that was particularly noticeable among participants who were overweight or obese.

Earlier menarche has been associated with emotional and psychological difficulties during adolescence and a higher risk of hormone-dependent cancers, including breast cancer, later in life, while delayed puberty can also signal disruptions in development. Chlorpyrifos and dithiocarbamate fungicides such as mancozeb and maneb are no longer approved in the European Union over concerns about neurological development, fertility and environmental damage, though exposure can continue through residues, imported products or other pesticides that remain in use elsewhere in the world.