Covered in smog: On April 6, people in Chiang Mai (清迈), Thailand, wore masks on the streets. Over the past few weeks, thick smog has covered Bangkok, Thailand's capital, and 58 of the country’s 76 provinces, with especially high levels in the north and northeast. Chiang Mai has been hit the hardest, ranking as one of the most polluted cities in the world several times in March. The main reason is that farmers have been burning fields from November to March, according to the BBC. Also, the weather is usually dry during this time every year, leading to wildfires across the country. The government is now cracking down (严厉打击) on illegal burning.