The proverbial Question "Is it safe to breath today?"

And the answer of course is it depends on who you believe.

Officially, Shanghai's air quality was "good" yesterday (see picture at left). But at the American Consulate it was a different story. Readings there indicated that the city air was "unhealthy for sensitive groups" throughout most of the day.
The issue of course is just what is an acceptable level of particulates in the air. Monitoring equipment at the consulate is basically the same as equipment at the Shanghai Environmental Monitoring Center. The difference is China and America have different standards for air quality.

Data from the consulate, based on its monitoring machine in its offices on Huaihai Road showed that PM2.5 density began rising from 10am yesterday to a peak of 70 micrograms per cubic meter when the air qulaity was defined as "unhealthy". It remained at around 60 throughout the afternoon.

Here's the rub - China's acceptable daily limit for PM2.5 is 75 micrograms per cubic meter compared with about 25 micrograms in the United States.

The city's readings showed that PM2.5 reached a high of 68 at 11am in Putuo District and 82 in Zhangjiang in the Pudong New Area, the only two spots whose readings are made public. Granted the data from the consulate is only able to measure the air quality of the limited space around the consulate but you have to believe this number holds true for much of Shanghai.

So why worry when China says the air is OK? To begin with PM2.5 sized particles are about 1/30th the width of a human hair and we are at risk because these particles are small enough to lodge deep in our lungs and even enter our bloodstream - sounds wonderful doesn't it?.

Here's the best question of the day from a man named Shu Jiong who is an environmental professor at East China Normal University (do you think there is an East China Abnormal University). Shu questioned whether it was proper for the consulate to use US standards to evaluate Shanghai's air quality. He said, "the two countries have different demographic situations and are at different stages of development, so it will be more suitable to use the Chinese standard to evaluate the air quality in Shanghai". There you have it  - the real thinking behind the difference in standards. China is developing so its OK for it's industries to pollute the air and its citizens to breath more PM2.5 particulate.

Why didn't I think of that.