[FiatLuxDave]

It would be interesting to see what adding radon would do to the section on air pollution (arguably, radon is a form of air pollution, albeit not particulate).

Since the current estimate in the USA is about 10,000 deaths per year (https://www.ncbi.nlm.nih.gov/pubmed/2118410), with of course, some dissent (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5590909/), this is large enough to show up on the graph, especially for the developed countries.

Unfortunately, getting good data on radon-related death rates is difficult, as it must be parsed out of lung cancer rates with a number of assumptions applied. I figure that getting good data is in your wheelhouse. If not, I could probably put you in touch with someone at AARST or NRSB who may have better data.

Congrats on the Launch:HN!