The pollution situation in Bangkok has improved dramatically since the year 2000. The
main source of air pollution used to be buses which belched out diesel smoke. That changed
around 2005 when buses were converted into Natural Gas Vehicles (NGV) and Liquified
Petroleum Gas (LPG) vehicles.
There was also a campaign to do better maintenance of the vehicle engines. The
government has also invested in a lot of infrastructure and tax incentives to encourage
production and use of natural gas to fuel commercial vehicles. Natural gas is more economical
than diesel. Also, Thailand has abundant reserves of natural gas but not much oil, so use of
natural gas instead of imported oil helps the trade balance and local economy, in addition to
creating a whole new economic sector and jobs.
Back in the year 2000, stand in one place, and there would periodically be vehicles like
this, mainly green buses, other buses, private commercial vehicles, private cars and even
motorcycles. When the traffic light turned green, a big smoke of pollution rose and takes a few
minutes to dissipate. That has been reduced greatly, with just a little smoke due to some
motorcycles. In the old days, if I needed to walk on a main road, I would be sure to walk upwind.
Now, I no longer notice. From tall buildings, the air would be clear at sunrise but by noon
it was difficult to see more than a few kilometers. Now, it stays pretty clear all day.
If you have respiratory problems, such as asthma, you may still want to go live by the
seaside or in the suburbs, but many people with respiratory problems are OK in Bangkok.