After hours spent in the thick pollution-choking parts of northern Thailand, Pon Doikam gets home and blows her burning nose to find blood clots spattered across the tissue.

¡°It¡¯s suffocating,¡± the 36-year-old coconut seller said in Chiang Mai, a tourist destination among the areas affected by dangerous pollution levels this week.

¡°It feels like you¡¯re trapped in the smoke constantly.¡±