You are listening to NEWS Plus Special English. I'm Mark Griffiths in Beijing.
Psychiatrists in China are calling for closer studies on the negative impact of smoggy days on mental health.
Senior clinical psychiatrist Tian Cheng-hua, a professor of psychiatric research at Peking University, says few people realize that severe air pollution could trigger "smog depression".
Scientists have proved that some types of depression are closely associated with conditions such as seasonal change and lack of sunlight.
Beijing saw nearly 60 days of serious pollution in the past year, with residents enduring, on average, a smoggy day every six to seven days.
Professor Tian says cases of increased anxiety and feelings of hopelessness caused by bad weather conditions such as smog, cloudy skies, rain and lack of sunlight are no longer rare in the hospitals.
He suggests that on heavy smoggy days, mental patients, particularly those with depression, stay indoors and turn on the lights, even in the daytime.
Scientists have found that smog can alter the brain's composition, and can lead to depression and loss of memory.
A 95-year-old man in southwest China's Sichuan province has become the oldest person in the world to have a pacemaker installed in the left ventricle.
The man, Chen Zong-yu, had a heart attack last August. His heart disease cannot be eased by medication so he received a surgery to install the pacemaker.
Chen was discharged from hospital, the West China Hospital of Sichuan University, on Jan 1st this year.
Previously, the oldest patient to have a pacemaker installed in that hospital was 81 years old. Worldwide, the oldest person to have such a surgery was 85 years old.
This is NEWS Plus Special English.