Dangerous Levels of Smog in China

An aerial image of the area affected, courtesy of NASA Earth Observatory

Last Friday authorities in Shanghai and other areas of China closed down schools and ceased construction projects due to a major air pollution issue. The dirty air, or smog, is being attributed to a collection of human-based activities like burning coal, car exhaust, and factory pollution, as well as the current natural weather patterns. Shanghai is a coastal city that usually has some breeze so pollution levels can stay fairly mild, but the recent weather has left little wind and the pollutants have built up in dangerous amounts. The World Health Organization has set a safety guideline of 25 micrograms of PM (particulate matter) 2.5 particles per cubic meter, and last Friday afternoon, the air in the city reached an amazing 602.5 micrograms per cubic meter. Greenpeace, an environmental group, is attributing this to slow-moving and low-hanging air masses that carried factory pollution into Shanghai from other provinces to the northeast. The northeastern areas of China such as Beijing, frequently have large smog events, but it is less common for this to spread so for to the south. Combined with the large amounts of pollution a city like Shanghai already produces, you can see how this quickly became a bad situation.

This is a situation where you have a human-based hazard (pollution) interacting with weather to create a worse-than-usual situation for the residents of Shanghai. Shanghai is a big city that creates a lot of pollution on its own, but when you add a weather pattern that is pulling even more from other large cities far away, you get a uniquely bad situation. Pollution is always a potential hazard, especially to ones health, when choosing to live in a large metropolitan area. These extremely large cities in China experience some sort of smog on a fairly frequent basis, but an event like this is rather rare. Beijing and Shanghai are about 750 miles apart, and yet they are closely connected to this event. The weather really made this a worst-case scenario, and there probably isn't a lot you could do to prevent this from happening again without gaining support for widespread reduction in pollution production. China is still very much a developing country with a lot of factories and vehicles. It is unlikely that they would reduce their pollution output much as it would hurt the economy, so for now it seems as though those who chose to live there (and those who have no choice) are stuck living with the daily health hazard known as smog.

http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=82535

http://www.washingtonpost.com/world/asia_pacific/smog-at-extremely-hazardous-levels-in-shanghai/2013/12/06/07a4a4bc-5e4b-11e3-8d24-31c016b976b2_story.html