A major study of more than 20,000 people in the Chinese city of Guangzhou has shown that exposure to passive smoke is putting many non-smokers at risk of developing chronic lung disease (including chronic bronchitis and emphysema).

The results, published in the Lancet this week, suggest that exposure to passive smoke could cause up to 1.9 million deaths from chronic obstructive pulmonary disease (COPD) amongst non-smokers across China.

Researchers from the University of Birmingham used data from the Guangzhou Biobank Cohort to examine the link between passive smoking and COPD in 20,430 men and women aged over 50 years. A total of 15379 people who had never smoked were included in the study.

The Guangzhou Biobank Cohort Study ultimately aims to recruit 40,000 people from the city to examine genetic and environmental influences on health and chronic disease.

The researchers gathered detailed information about participants’ exposure to passive smoking at home and at work. Researchers also assessed each participant’s lung function using spirometry testing.

The lead researcher Dr. Peymané Adab explains: “We have known for some time that COPD is a major cause of death in China, but there has been very little work done to see what the risks may be for passive smokers.

The results from our large study in Guangzhou clearly showed that prolonged exposure to passive smoke significantly increased the risks of developing COPD and other respiratory symptoms.

We were also able to show that exposure to passive smoking is widespread in Guangzhou. This is something that has significant public health implications not just in Guangzhou but for China as a whole.”

The researchers found that people exposed to high levels of passive smoking (equivalent to 40 hours a week for more than five years) were on average 48% more likely to develop COPD. Over a quarter of participants who had never smoked experienced this high level of cumulative lifelong exposure. More than half the population experienced exposure to some passive smoke at home or in the workplace.

Professor KK Cheng from the research team adds: “At the moment China has very few restrictions on smoking despite the enormous health effects for the population.

The results of the this study provide further support for urgent measures in China to tackle passive smoking and to increase the availability of smoking cessation services across the country.”

The main investigators of the Guangzhou Biobank Cohort Study also have a longstanding interest in smoking control in China. Their current work includes smoking cessation programmes in Guangzhou and other cities in China. These latter initiatives are supported in part by Cancer Research UK. 

For further information or to request a copy of the paper contact Ben Hill, Press Officer, University of Birmingham, Tel 0121 4145134, Mob 07789 921 163, email b.r.hill@bham.ac.uk



The paper: Passive smoking exposure and risk of COPD among adults in China: the Guangzhou Biobank Cohort Study is published in the Lancet.

The Guangzhou Biobank Cohort Study

The Guangzhou Cohort Study is a collaborative research project between The Universities of Birmingham and Hong Kong, and The Guangzhou Occupational Diseases Prevention and Treatment Centre in China. The study commenced in October 2003 and is recruiting men and women over the age of 50, from a city in southern China (Guangzhou) - a population that has undergone rapid economic transition. So far about 25,000 participants have been recruited, with plans for a final sample size of 40,000. Participants undergo detailed baseline characterization and phenotypic assessment, with storage of their genetic materials.

The main long term aim of the study is to examine the effects of genetic and environmental influences on health and chronic disease development (particularly circulatory disease, chronic respiratory disease, cancer and dementia).

University of Birmingham Medical School

The School has a long history of serving a national need, and has been providing excellence in medical education for nearly two centuries.  Most recently, the School has shown its commitment to the local area by the successful expansion of the School of Medicine, doubling its medical student intake in the last five years.  Over 85% of students stay in the area in which they trained, once they have qualified.

The School of Medicine has a strong record and extensive experience in providing and managing clinical learning involving sixty-five general practices and sixteen teaching hospitals. All sixteen teaching hospitals, and an increasing number of teaching General Practices are linked to the University by a broadband IT virtual campus supported by a web – enabled e-learning and an electronic curriculum, resources; that will strengthen the learning experience for students.