I have handled pesticides all my adult life and wondered if this affects my health and that of genuine handlers like pest control operators. This link clearly answers that question.
“The pesticide applicators were consistently and significantly healthier than the general population of Florida.” That makes sense. These men work hard out in the fresh air and sunshine. The surprise is that this is a U.S. Library of Medicine report!
They studied over 33,000 pesticide applicators in Florida over an 18 year period (1975-1993). This was when we could use some hairy-scary carcinogens. That explains why there was an increase in prostate cancer in this study. http://www.ncbi.nlm.nih.gov/pubmed/10341741
Besides, the average nozzle-jockey gets safety training, wears protective gear, and reduces his exposure in every way possible. Guaranteed, none of us has worms.