[eitally]

I believe you, but it's also true that in many parts of the world, those "trucks" are actually air conditioned buses.

<source: I work for a global manufacturing company with 14,000 people in China, 2,000 in India, 12,000 in Mexico, 10,000 in EU, and 15,000 around the rest of the world.>

[sleepyhead]

You have to go in a tourist bus to get an a/c bus in Cambodia. The trucks for these workers have full natural a/c and traffic pollution nicely blended in.

Also note that these workers are mostly from rural areas. Where educational level is very low.