Here’s a question I often get asked: “I don’t want to hear the fan while I sleep, so can I run my air purifier for an hour and then turn it off before sleeping?” The logic is that, since the doors and windows are closed, once we clean all the air in the room, it […]
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Hong Kong’s air quality might not be as good as you think
Hong Kong doesn’t come to mind when you say the words ‘air pollution’. However, I just analyzed data on Hong Kong’s PM2.5 pollution and found that PM2.5 air quality levels averaged 30 micrograms in 2018. What does that mean for Hong Kong’s air quality? Based on this data from Berkeley Earth, Hong Kong averages three […]
How’s the Air in London? See the Data
I just analyzed data on London’s PM2.5 pollution and found that it averaged 12 micrograms in 2018. What Does That Mean? Based on this data from the King’s College London, London’s air quality is slightly above the WHO annual limit. That limit is important because research shows that even levels around 10 micrograms affect our […]
Does the Climate in Bangkok Aggravate the Air Pollution in the City?
I just analyzed Bangkok’s PM2.5 data (what is PM2.5?), and I found it varies systematically by season and time of day. Bangkok Average PM2.5 First, some basics. In 2018, Bangkok averaged 27 micrograms of PM2.5. That puts Bangkok just under three times the WHO annual limit. Bangkok’s Air Pollution: The Bad News But […]
Do Air Purifiers Remove PM2.5?
I wondered this same question—do air purifiers really get the small particles of PM2.5? I wondered because I saw lots of air purifier tests on pollen, but pollen is generally 10 microns or larger, whereas I was really concerned about the stuff below 2.5 microns. So I went out and bought a laser […]
How’s the air quality in Bangkok? See the data
Bangkok saw some terrible air quality and high PM2.5 levels during the start of 2019, with news reports of schools closing and government limiting car usage. But just how bad is Bangkok’s air quality? I analyzed 2018’s PM2.5 data, provided by the Thailand Government monitor near the Chulalongkorn Hospital in Bangkok, and here’s what I found: […]
India Test: Is Indoor Air Just as Polluted as Outdoor Air?
Whether indoor air is just as polluted as outdoor air is an important question for all of the millions of people living in heavily polluted cities. Yet I’ve heard a lot of disagreement about this question. I’ve heard people tell me it’s the same — “indoor air comes from outdoors anyway, so it’s the same.” […]
This One Region in China Saw a Pollution Miracle in 2018
New analysis from Smart Air shows that China is making progress on its “war on air pollution.” PM2.5 air pollution was down in 14 out of China’s 15 largest cities. Yet one region saw far more progress than the rest. South Sees Modest Air Quality Gains In southern China, from Shanghai to Shenzhen, […]
China’s 15 Biggest Cities Saw Better Air in 2018 — Except This One
A new analysis of air quality from 15 of China’s largest cities shows that PM2.5 fell in all cities—except one. From Shenzhen to Xi’an, air pollution was down in 2018. Yet Zhengzhou, capital of Henan province, actually saw pollution rise 7%. With this increase, Zhengzhou now averages over 6 times the World Health […]
Did Beijing’s Air Get Better in 2018?
Analyzing new air quality data, Smart Air found that Beijing’s PM2.5 dropped 14% in 2018 compared to the year before. Despite the improvement, Beijing still averages nearly five times the World Health Organization’s annual limit. Improvement Came Mostly from Winter Enforcement By breaking down the data month by month, analysis shows that the air quality […]