I'm a farmer and part of my livelihood is the use of chemicals. Herbicides, instecticides, and other pesticides are things I use almost every day during the growing season.
I quote from the PBS article:
"Of the more than 75,000 chemicals registered with the Environmental Protection Agency, only a fraction have gone through complete testing to find out whether they might cause problems for human health."
This is a lie. In order to obtain EPA registration, a chemical in it's raw from is fully tested for its effects on human health. And, by law, this information has to be included on the products labels. The registration process takes a long time. Many new agricultural pesticides being released to licenced restricted use pesitice applicators today were developed by the chemical companies in the early 1980's. They've spent the last 20 years on the EPA's desk.
No one really knows the effect that chemicals have down the line in food or whatever. I don't think that this can really be proven because of the lenght of time (mulitple generations) involved. But chemical effects in their original form are fully tested.
Don't believe everything you read.