Ask HN: Healthiest places a software dev/data scientist would relocate to?

For the last 10 years I've been working as a Software developer/Researcher (plus a bit of data science) in Eastern Europe (Sofia/Bulgaria). Lately, I keep thinking about relocating to a better place. The main problem I've now in Sofia is the air pollution. It is getting worse year over year. I can't really give you objective figures on PM2.5, PM10 etc, because the authorities are not very transparent on this, but you can really see it in the air. Another less important thing that I could improve upon while relocating is the climate. It is a bit colder here than I would enjoy. WRT income, I wouldn't say that Sofia is something spectacular, but it isn't too bad either. If you are a decent, experienced professional, you can make a net income of around $ 45k/y, while living expenses (rent, car, food, some vacation, etc) are around $15k/y. So, with these considerations in mind, I was asking myself whether I (+ wife and kid) could relocate to a place where the main health factors (air/water/food/stress) are better and I could enjoy work/life and have fun :). I googled for a while, but didn't really come up with something inspiring. It would be great if you, lovely people, can share your experience or give some advice. Thanks!