Shanghai chokes on smog as air heavily polluted

Shanghai's Air Quality Index reached 214 at 2pm Thursday, meaning the air was "heavily polluted."

The pollution level was the second highest on a six-tier scale, the city's environment monitoring center said.

The density of fine PM2.5 particles climbed to 164.4 micrograms per cubic meter at 2pm, more than double the national limit of 75. PM2.5 particles are considered particularly dangerous because they can go deep into the lungs.

The center recommended that residents reduce outdoor activities, especially seniors, children and those with respiratory diseases.

Heavy rain hit the city in the morning and thundershowers are expected at times, the Shanghai Meteorological Bureau said. Skies will be mostly overcast.

The forecast calls for more clouds and a chance of rain tomorrow and Saturday.