After over 16 years, the World Health Organization (WHO) updated its air quality guidelines, including its recommended limits for one of the world’s biggest killers, PM2.5 air pollution. The WHO lowered their annual PM2.5 limit by half, from 10 micrograms to 5 micrograms per meter cubed. This comes to welcome … Read more
What is the difference between PM2.5 and AQI measurements? There are some good answers here Richard Muller and Sandeep Chowdary. I’ll add a bit more explanation about PM 2.5 AQIs and a funny quirk about how they are calculated using stepwise linear functions. How Is PM 2.5 AQI Calculated? (Note: … Read more
Air pollution is a serious problem in Hong Kong, and Hong Kongers often complain that the worst of it comes from Mainland China. Is that fact or a convenient scapegoat? After all, Hong Kong is a densely populated developed city with one of the busiest ports in the World – … Read more
A user on Quora asked recently how bad the air pollution in Nepal is. Nepal has glorious mountains and shining temples. But how is the air? I checked the World Health Organization’s global PM2.5 database. According to that database, Kathmandu’s PM2.5 particulate pollution averaged 49 micrograms/m3 in 2013: … Read more
