I couldn't have said it better myself:

Green Grass isn’t Greener (Pesticide Dangers)

A few years ago, I met a man, an organic landscaper, who told the story of his next door neighbor. He was on his way out to his car one morning when he heard a hello. As he turned and waved to his neighbors, he noticed their 1 year old standing on the grass barefoot, his feet yellow from the fertilizer strewn all about the yard. Within that year the baby died of leukemia. The man never discussed the possible causes with the parents, but he had his suspicions based on what he had learned about fertilizer as an organic landscaper. He knew all about pesticide dangers; he knew they could kill.

For those who think that the leukemia couldn’t possibly have been from the fertilizer (much of which contain pesticides), think again. According to BeyondPesticides.org, a study published in the Journal of the National Cancer Institute finds that household and garden pesticide use can increase the risk of childhood leukemia as much as seven-fold. AND studies show that children living in households where pesticides are used suffer elevated rates of leukemia, brain cancer and soft tissue sarcoma.