As far as I know the air pollution in Thailand is largely attributed to forest fires rather than vehicle emissions [0]. Funny enough, this also seems to be the

As far as I know the air pollution in Thailand is largely attributed to forest fires rather than vehicle emissions [0]. Funny enough, this also seems to be the case for Portland, Oregon [1]. [0] https://www.washingtonpost.com/world/2019/05/07/northern-thailand-was-once-paradise-now-forest-fires-have-made-air-worse-than-beijings/ https://www.washingtonpost.com/world/2019/05/07/northern-tha... [1] https://www.kgw.com/mobile/article/weather/air-quality/portlands-air-quality-second-worst-among-major-cities-worldwide/283-586223379 https://www.kgw.com/mobile/article/weather/air-quality/portl...