Sure have been.  Up until 17 years ago, Chlorpyrifos was a common ingredient in lawn insecticides and ant/roach sprays.  Do not remember any unusual problems caused by such usage. In fact, prior to 2000, I used to treat lawns and ornamentals with Chlorpyrifos.  The treatments worked the first time.  Now, the so called safer alternatives require repeated applications.  I have an alternative theory on behavioral and neurological problems in children.  What is now called a problem was considered a lack of parenting and discipline.  ADHD? No such thing when I was younger.  Back then, I was expected to pay attention, focus, remember, and be quiet.  Now, a child that does not do that has its parents blaming pesticides and then has the doctor prescribe amphetamines.  Which is what Ritalin and Adderal are.