What is Asbestos? Asbestos is a mineral that makes a great fiber. People use that fiber in lots of building materials, like insulation, paints, electric wiring, wall boards, and floor tiles. Asbestos might be all around us. Should I Be Concerned? When any of these materials break apart, the asbestos can […]
Author: Thomas Talhelm
Is Asbestos a Problem in China?
This commonly used material may be more dangerous than formaldehyde So why do so few people talk about it in China? One day a few years ago, a Chinese friend of mine asked me about jiaquan (甲醛). “Huh?” I had to look it up. Turns out it means “formaldehyde.” At that point, I started to […]
When Wind Blows From This Direction, Shanghai’s Pollution is 5 Times More Likely to Be Toxic
Calvin Quek from Greenpeace analyzed how PM2.5 changes with depending on which way the wind is blowing in Shanghai: The data is simple. When the wind is coming from the industrialized areas to the west of Shanghai, toxic air pollution is more likely. When the wind blows in from the ocean, bad air days are much less likely. In Beijing, the […]
Chengdu’s PM2.5 Now as Bad as Beijing
It’s nerd Christmas! The US Embassy’s 2016 PM2.5 data just came out. And there’s a surprise in the data from Beijing and the US Consulate in Chengdu: Chengdu just barely edged out Beijing for highest PM2.5. I had to go out to two decimal places to find that difference. How Bad is That? OK, so […]
Did China’s Air Improve in 2016?
The US Embassy’s complete data for 2016 is now out! Smart Air analyzed the data to see if China’s air got any better in 2016. There are a few reasons to think 2016 was a good year. China has moved to tighten standards on gasoline and diesel and increase renewable power. 2016 also saw the […]
Do we need car air purifiers?
Soon after I started making DIYs, people emailed me asking if we could make a DIY for their car. My initial reaction was, “Great idea!” On the highways, we’re surrounded by all of that awful pollution. Best to get a car air purifier. But as a methodical nerd, I wanted to do some tests first. […]
What time of day is air pollution lowest?
My intuition has always been that there is least air pollution at night because there are fewer cars on the road and fewer factories humming. Apparently I’m not alone: 139 voted for their guess about what time of day has the least air pollution (lowest PM 2.5), and night time came in first: I also know […]
Xiaomi Auto Mode Leaves Air Unsafe for 86% of hours
For the last three years, I’ve been saying clean air doesn’t need to cost an arm and a leg. So when the Xiaomi 2 air purifier came out for under 1,000 RMB (10,000INR), I assumed it works just fine. But I had never gotten around to testing it—until now. And what I found shocked me. The […]
Xiaomi Auto Mode Leaves Air Unsafe for 86% of Hours – Supplemental Data
Data and Test Details Settings The app asks what size the room is. How Xiaomi uses that data is a little opaque, but it would be logical that settings for larger rooms will run the purifier harder, so we used the highest allowable setting, 34-37m2. It should be noted that the Xiaomi also has a […]
How Accurate is the 1 Micron Dylos? Official PM2.5 Comparison Test
Everyone who buys an air quality monitor wants to know how it compares to the official numbers to confirm its accuracy. When I bought a Dylos DC1100 Pro laser particle counter, I did a comparison test with the US Embassy. I put my Dylos Pro outside the window of my apartment (at Nanluoguxiang) 70 times […]