Originally Posted by cooperwx
Sorry for dropping in from the SE US, but I noticed this thread and find it very sad that masks are necessary to breathe in Taipei.
What is the cause of this extreme pollution?
-Jason
The main kinds of masks you would need to wear would be active carbon filter masks. The ones you see on the street remove particulate matter (such as dust), but a carbon mask is necessary to block gaseous matter (such as exhaust). A carbon mask usually runs in excess of $100 U.S. and, as far as I know, none are available here. So, in essence, the ones they use are useless.
I have a carbon mask, and even that has a difficult time straining much of the pollution.
A large part of the cause is 2-stroke scooters and general traffic. However, there are emission regulations, but they are pretty lax, and its nearly impossible to reduce any 2-stroke engine, as the oil is added directly to the engine (think lawnmower). Another massive addition would be oil refineries (which are plentiful due to relaxed industrial emissions laws) and coal-fired power plants. All of these in a small area.
Finally, if you look at the geography of Taiwan you see why the air remains that way. Much like Mexico City and Los Angeles, a low-lying area surrounding by mountains (or with mountains on the side farthest from the direction of the prevailing wind) tends to trap pollution. What happens is that as the pollution rises from the city, the colder air coming off the top of the mountain traps the air in the lower part of the valley. Then, because the mountains act as a wall, the air cannot be pushed away from the city, so its doubly trapped and builds up.
This can easily be seen by cresting the mountains, or riding along the east coast. The densely populated west coast has filthy air, but on the east, protected by mountains and underpopulated, the air is clean and fresh.
When a typhoon or other storm comes through, it brings winds from an easterly direction, pushing the pollution northeast, and clearing the sky. On those days, you can easily see the difference, with blue skies and breathable air. In large part, the length of time since a storm (or change in prevailing wind direction) is directly visible by the quality of the air.
Hope that explains it for you.