Pesticide danger to growing brain

PRENATAL exposure to a common pesticide can cause brain abnormalities, a US-based study has shown.

Chlorpyrifos (CPF), a widely used organophosphate insecticide, has been associated with significant structural changes to the brain.

Researchers compared 20 children who had high exposure to CPF with 20 children who had low exposure. 

They found that exposure associated with “routine”, non-occupational use – without any signs of acute exposure –was associated with significant abnormalities on the cerebral surface.

The cognitive and behavioural processes impacted by the affected regions include attention and receptive language, social cognition and reward, emotion and inhibitory control, the authors wrote. 

Moreover, they said the “high exposure” group actually had “relatively modest” exposure to CPF; “doses that were measurable only because of the remarkable sensitivity of the CPF assay”.

CPF exposure is common in agricultural communities as the pesticide has been used to control insects affecting cotton, sugarcane, fruit and vegetables crops.

A review by the Australian Pesticides and Veterinary Medicines Authority in 2006 led to restrictions on indoor and household use of the chemical.

A further preliminary report was published in 2009 and a final report is pending.

Previous research has shown that organophosphate insecticides are detectable in amniotic fluid and cross the placenta.

Prenatal exposure has been associated with smaller head size, low birth weight, deviant neonatal reflexes, attention problems and neurodevelopmental anomalies. 

PNAS 2012, online 30 April