Pesticides: An Old But Still Serious Problem of Poisoning

The studies suggest that organophosphates, a widely used class of pesticides that act on the central nervous system, hamper the development of some parts of the brain in children, leading to lower IQs and attention problems. Preliminary evidence also suggests that pesticide exposure may affect sexual differences in certain brain regions during early childhood development.

A main culprit in the Columbia study, chlorpyrifos, was phased out in 2001 for most residential use, and urban exposure in the United States has dropped dramatically—but it's still widely used in agriculture. And a whole generation may already be suffering subtle but prolonged effects, says epidemiologist Virginia Rauh, deputy director of the Columbia Center for Children's Environmental Health." 

http://www.sciencemag.org/content/341/6147/740.full

How many problems are these things causing? I would bet they affect the incidence of autism, ADHD and also damage the immune system.