Slightly off topic to start - returns to the topic in the end...
Autism 20 years ago affected 1 in 180 Children in the US. Soon after that changed to 150. Today it's one in about 65 (or so). They claim it is not due to better reporting...
Given that, what is going on? Is it the Air, Water, Food Supply, or Electromagnetic radiation (ie. Cell Phones and so on) I'd love to know what happened. Is it antibiotics for cattle, the wrong fertilizer for crops, or is it Cell Phones?
I do not know, and I'd like to.
I'd say the GPS would probably be safe. Cell Phones are probably safe too. However, cell phone usage has increased dramatically in the last 20 years, and so has Autism.