Air pollution is definitely a concern, especially with the growing population. I came across this air pollution map on aqicn.org that shows real-time air quality around the world. The screenshot below is of the United States, and shows that earlier today, we had a good to moderate air pollution level. If you check out the site, you can see a map of the world and compare how each country or continent is ranking in their current air level rate. The map is color-coded with green being good, yellow being moderate, orange is unhealthy for sensitive groups, red is unhealthy, purple is very unhealthy and dark red is hazardous.