4FRONT
ENVIRONMENT
Inquiry : José Ricardo Suárez and Briana Chronister investigate floriculture crops in Ecudor .
Hidden Dangers : Researchers from the Herbert Wertheim School of Public Health and Human Longevity Science at UC San Diego are studying how exposure to common herbicides impacts the adolescent brain .
WHAT LIES BENEATH
Adolescent brain function impacted by commonly used herbicides .
BY TYLER DELONG
F resh-cut flowers , houseplants and other greenery bring joy and beauty to homes and offices . They ’ re also big business . In Pedro Moncayo , an agricultural area located in the Ecuadorian Andes , 21 % of adults work in the floriculture industry . While economic projections are trending upward across the globe , a concerning reality lurks beneath the surface : herbicides used to grow these vibrant crops may be reducing brain function in adolescents .
Photo : ESPINA study research team
“ Many chronic diseases and mental health disorders in adolescents and young adults have increased over the last two decades worldwide , and exposure to neurotoxic contaminants in the environment could explain a part of this increase ,” says José Ricardo Suárez , associate professor in the Herbert Wertheim School of Public Health and Human Longevity Science at UC San Diego .
For more than a decade , researchers have been aware of a connection between insecticide exposure and changes in neurocognitive performance in young children . But a recent study in Pedro Moncayo led by Suárez and Briana Chronister , doctoral candidate in the UC San Diego- San Diego State University Joint Doctoral Program in Public Health , shows that exposure to common herbicides may be associated with reduced brain function in adolescents as well .
In Pedro Moncayo , flower crops are subjected to a range of pesticides , including over 50 fungicides ( for controlling mold and mildew ), more than 20 insecticides ( for controlling insects ) and two known herbicides ( for controlling weeds ), although many more may be present .
In urine samples collected from 519 adolescents ( ages 11 to 17 ) residing in Pedro Moncayo , researchers measured metabolite concentrations of glyphosate and 2,4-dichlorophenoxyacetic acid ( 2,4-D ), two of the most widely used herbicides in the world . They also evaluated the neurobehavioral performance of study participants . Both herbicides were detected in a high percentage of participants and exhibited strong associations with decreased cognitive functioning , including attention and inhibitory control , language and social perception .
Glyphosate and 2,4-D are two among the more than 800 pesticides registered for use in the U . S ., many of which have been associated with a range of health problems .
“ There is considerable use of herbicides and insecticides in agricultural industries in both developed and developing nations around the world , raising exposure potential for children and adults , especially if they live in agricultural areas ,” says Chronister .
Yet exposure isn ’ t just limited to production regions . In 2022 , the United States imported $ 3.3 billion in cut flowers from 81 countries across the globe — with no limit on the amount of pesticide residue they may carry .
“ Sadly , very little is known about the safety and long-term effects on humans for most of these chemicals ,” says Suárez . “ Additional research is needed to truly understand the impact .”
14 SPRING 2024