Why is there smog in summer? I'm going to travel to Dabie Mountain in Anhui, but I don't think I need to go.

In cities with dense fog, there are many particles in the air, including bacteria and viruses, which are irritating to patients with a history of respiratory diseases and even to the respiratory tract of healthy people. Listen to the electrostatic activated carbon mask to remind you to reduce unnecessary outdoor activities, or wear a mask before going out to prevent poisonous fog from invading your lungs through your nose and mouth.