Exposure to smog is severe hazard

BEIJING - Experts are worried that particulate matter in the air, which is in higher concentrations in North China because of the heavy fog since the weekend, may lead to various respiratory diseases including lung infections and cancer.

Shi Yuankai, vice-president of the Chinese Academy of Medical Sciences Cancer Hospital, said longtime exposure to particulate matter especially the particulate matter smaller than 2.5 micrometers (PM2.5) which can go directly to the alveoli of the lungs, is a major health hazard.

"Even if we can manage to keep the country's smoking rate flat, the lung cancer rate is expected to keep rising for 20 or 30 years and worsening air pollution could be the major culprit," he said.

Air quality in the capital has deteriorated because of the heavy fog. Beijing's air was slightly polluted on Monday, according to the China National Environmental Monitoring Center.

However, the United States embassy, which conducts its own measurements based on the concentration of PM2.5 in the air, rated Monday's air in Beijing as "hazardous".

Zhong Nanshan, a respiratory expert and academician of the Chinese Academy of Engineering, echoed Shi's concern.

He said that without intervention, PM2.5, a major cause of choking smog, would replace smoking tobacco as the top risk factor for lung cancer.

In Beijing, the lung cancer rate has increased by 60 percent during the past decade, even though the smoking rate during the period has not seen an apparent increase, said Mao Yu, deputy director of the Beijing Health Bureau.