Chiang Mai has been ranked as the most polluted city in the world since April 7. The city has a level of fine particles PM 2.5, so small that they can seep into the bloodstream, of 290 micrograms per cubic meter.
This is nearly 70 times the maximum threshold set by the World Health Organization (WHO) The theme of air pollution is making its way among the campaign themes of some candidates in the general elections that will take place in a month. The Clean Air Act has been rejected times by the Prime Minister's Office.