People walk along a snow-covered section of the Great Wall in Beijing Wednesday. [China Daily]

Hospitals have reported a rise in recent weeks in the number of people seeking treatment for respiratory ailments.

Zhang Shunan, a doctor at the China-Japan Friendship Hospital, said: "I have been treating up to 60 people a day.

Half of them were elderly suffering from coughs because of the polluted air."

Deng Yu, who is seven months pregnant, said she suffered from throat pains when she got up on Tuesday morning.

"I kept tearing when I went out shopping. I was told such conditions are caused by excessive sulfur dioxide in the air," she said.