Children in Ecuador whose mothers were exposed to pesticides while pregnant had increased blood pressure and diminished ability to copy geometric figures as compared to a control group, according to an epidemiological study in the March issue of Pediatrics.
The results appear to be independent of current exposure to the chemicals. The mothers themselves were reported to be healthy.
A team of researchers led by Philippe Grandjean, adjunct professor in the Department of Environmental Health at HSPH, analyzed data on 72 children aged seven or eight years old in the rural Tabacundo-Cayambe area in Northern Ecuador. The children were examined by a physician and were given a battery of standardized tests for neurobehavioral functions. Thirty-seven of the children had mothers whose self-described occupational histories indicated that the women had been exposed to pesticides during pregnancy, typically by working in greenhouses. Dose-response relationships and the exact timing of the exposures' impact were not established due to the nature of the study design.
In the exposed children, the average systolic blood pressure was higher than in those who were unexposed (104.0 mm Hg versus 99.4 mm Hg). An increase in diastolic pressure was not statistically significant. Hypertension among children and adolescents is defined based on a range of blood pressures in healthy children, and children above the 95th percentile are considered hypertensive. In the Pediatrics study, nine children exceeded the approximate 95th percentile of 113 mm Hg. Seven of those children had prenatal pesticide exposure.
Prenatal pesticide exposure was also associated with a decreased ability to copy figures presented to the children as part of a standardized Stanford-Binet test. Adjusted regression analysis indicated that the exposed children experienced a developmental delay on this aptitude of four years. The authors noted that the confidence interval, or range of value, for this coefficient was relatively wide but was a statistically significant finding in a study of limited size, suggesting that the effect could be substantial.