Why is it 1 in 42 boys that get autism?

Numbers vs real life: Some people have a theory that toxins in the environment may be one of the causes of autism. The word toxins refers to substances that are increased in our world due to our modern, industrialized society. That means all the things that we use, or that are used to produce the goods we have, can be the toxins in our environment. There are too many chemicals or substances to count.

Hard to say: Your odd numbers aside, we don't really know for all cases. An emerging finding after research on the human genome is the frequent small gene abnormalities found in many of these kids. That implies the trigger to the defects involved are present in the egg or sperm before conception. I worry that environmental agents we adults have experienced trigger this before the kid is conceived.