I am borrowing an air quality monitor from a friend right now and stumbled on
this blog post that went into quite a bit of depth on the impact of PM2.5 levels. (They also
took the Wirecutter to task on some half-baked claims around an Ikea air purifier in a related post.)
Hard left-turn - they also did a
deep-dive on abortion laws in 27 countries using publicly available data. tl;dr - laws in the US range from most permissive in the world (Vermont) to most restrictive in the world (Texas).