It would be interesting to look at the impact of this on, e.g. cancer rates among people living at sea level versus cities with high elevation, e.g. Quito in Ec

It would be interesting to look at the impact of this on, e.g. cancer rates among people living at sea level versus cities with high elevation, e.g. Quito in Ecuador. It is interesting, and there are some studies exploring this and related issues. The results are not always immediately intuitive! https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4113517/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4113517/ is one good place to start.