Is it unhealthy to send my son to preschool under 200 metres away from a freeway? im worried about developing health conditions especially cancer. my beautifuldad recently passed from mesothelioma so im extremely health anxious of what we breath in?

You are a good mother to worry about such things but here's one I would not consider worth the effort. Control the things you can, investigate when you need to. There are hundreds of other risks that have importance in raising kids. I would consider this near the bottom of the top ten thousand.

There are studies which associate respiratory problems with close proximity to busy freeways. The lung continues to develop from infancy to the age of 8 years approximately. if there is an alternative in a less polluted area, this would be potentially beneficial. Is your child a former premature infant? otherwise healthy? family history of asthma? Avoid smoke and pollution exposure when possible.