Chiang Mai tops world’s most polluted cities

Thai tourist hotspot Chiang Mai was blanketed by hazy smog Friday, as residents and visitors to the usually picturesque northern city were left wheezing in the toxic air. According to the IQAir website, the AQI reading in Chiang Mai is 200. Thailand’s Pollution Control Department reported that PM2.5 dust in eight Northern provinces has reached the Red level.
Levels of PM2.5 pollutants, cancer-causing micro particles small enough to enter the bloodstream through the lungs were classified as "very unhealthy" and hit more than 35 times the World Health Organization's annual guideline. High levels of pollution frequently hit Thaksin's hometown of Chiang Mai during the early months of the year when farmers often burn crops to clear land, and forest fires and exhaust fumes also add to the problem.