3 ms·
> but PM2.5 under 300 isn't that bad. That's 300μg/m3. A 5 μg/m3 increase in estimated annual mean PM2.5 was associated with a 13% increased risk of coronary
by literallycancer 9y ago
> but PM2.5 under 300 isn't that bad.
That's 300μg/m3.
A 5 μg/m3 increase in estimated annual mean PM2.5 was associated with a 13% increased risk of coronary events...
http://www.bmj.com/content/348/bmj.f7412 http://www.bmj.com/content/348/bmj.f7412
The city where I live has PM10 over a 100 on bad days during the winter, and I try to avoid opening the windows if at all possible (I have an air filter, but it's annoyingly loud). Note that smaller particles are more dangerous - PM10 are relatively big. PM2.5 isn't even measured by most weather stations here.
You can easily smell PM10 concentrations over 60 or so.
- dmoy 9y agoThey mean bad relative to a normal day in Beijing, not in absolute terms.
- kurthr 9y agoYes, no one wants to live in smog... even 100 PM2.5 is bad. It's just normal in northern China, especially in the winter. Bay area air quality has been bad recently too, but complaining about it would show less empathy than our neighbors deserve.
- seanmcdirmid 9y agoDifferent scales. When the Bay Area hits 100 PM2.5, that is considered really really bad, heck, just being above 30 is considered bad. 100 in Beijing during winter is a good day, you don't have to go outside with your mask on.
- mikeash 9y agoWhen you routinely see numbers in the 400s and sometimes over 500, a mere 300 is a welcome reprieve.