Although the effects may be short-lived, they can still last for around three months—and because pesticides are never suspected, the children may end up with an ADHD diagnosis that results in a drug prescription.
It's often hard to prove a direct cause-and-effect in most environments because pesticide levels can be constant and never high enough where a connection becomes more obvious, but scientists have an opportunity once a year in Ecuador to test the effects.
Ecuador is the world's third largest producer of cut flowers, which are prepared primarily for Mother's Day in the US. There's a peak pesticide spraying season—and researchers from the University of California at San Diego were able to monitor for any neurological changes before and after the spraying in a group of 308 children, aged four to nine.
The children "displayed lower performance" in attention, self-control, visual abilities in connecting with the world, and hand-eye co-ordination. The children were assessed for a hundred days after the spraying had stopped.
The effects happen at a critical time for the children; their lower mental and learning abilities occur between May and July when they're often sitting for critical exams that determine where next they go in their schooling.
The reactions also have all the hallmarks of ADHD (attention-deficit, hyperactive disorder) which can trigger long-term drug therapy.