The air we breathe

The idea of Mask Week (11/17/2007-11/24/2007) got us thinking about the air we breathe in Shanghai. We know it's bad for us, we can see the haze nearly every day, but just how bad is it. So we got on the web and found the historical records for Shanghai air quality provided by the Shanghai Environment Education Centre, you can also go here to find records for 84 Chinese cities.

Since the beginning of the year Beijing has had an average Air Pollution Index (API) of 96, while Shanghai ranks in at an average API of 67 (we might be the most polluted city in China but at least we don't have the worst air pollution). Guangzhou somehow beats them all at 61. Shanghai did have the highest API of the three cities for the year at 500 (holy crap!) on April 2nd and the second highest API at 413 on January 19th. Recently Shanghai's air has had an API in the 50's.

The rating system used by China can be viewed here. Anything under 100 is supposed to be "good", so Shanghai had 276 "good" days while Beijing had just 207 and Guangzhou had 283. It is recommended by the National Environmental Monitoring Centre that during slightly polluted to lightly polluted days (API of 101-200), "The cardiac and respiratory system patients should reduce strength draining and outdoor activities." Shanghai had 27 of these days, Beijing 83 and Guangzhou 17. The real fun starts at anything over 300 though which the US EPA considers hazardous. Shanghai had 2 of these days while Beijing had just one. During these days, "The aged and patients should stay indoors and avoid strength draining; the ordinary should avoid outdoor activities."

When the API gets above 100 healthy people can experience eye irritation, wheezing, coughing, phlegm and sore throats and other respiratory ailments. Sick people generally get sicker.

So what's in all that tail pipe exhaust we call air? Well air pollution is generally composed of four major components, Nitrogen dioxide which is toxic if inhaled in the right amounts, sulphur dioxide which was used by Napoleon to execute people, Ozone which is associated with premature death, and last but not least particulate matter (crap in the air).

Photo from 摩根