At that time the law required that applications of certain pesticides be reported to the state. This group of women was compared with 611 women who gave birth to infants with no birth defects, and both groups of women were matched to data on pesticide applications in their area. The findings are published in the March issue of the journal Epidemiology. The timing of the exposure played an important role, Bell noted. However, the researchers were unable to directly measure the women's exposure to the pesticides.
More study is needed to confirm the association, the authors conclude.
A statewide database of all applications of restricted pesticides was linked to maternal address to determine daily exposure status. We examined five pesticide chemical classes. The odds ratios for all pesticide classes increased when exposure occurred within the same square mile of maternal residence.