What's Contributing to Lung Cancer Among Nonsmokers?

Lung cancer in Chinese women linked to indoor air pollution

(RxWiki News) According to a new study, indoor air pollution is a major contributing factor for high lung cancer rates among nonsmoking Chinese women. This pollution is caused by fine particles produced by heating fuels, cooking oils and secondhand smoke.

"If you have a persistent cough, see your doctor."

Lina Mu, MD, PhD was the lead author of the University at Buffalo study.

"Our results show that besides smoking, indoor air pollution contributes significantly to women's lung cancer risk in China," said Dr. Mu, assistant professor of social and preventive medicine in the UB School of Public Health and Health Professions.

About 60 percent of Chinese men smoke, while smoking among women in China is uncommon. Still, women in that country have among the highest rates of lung cancer in the world – 21 cases per 100,000. And only about 20 percent of those cases occur in women who smoke, according to Dr. Mu.

For the study, Dr. Mu and her colleagues worked with 429 Chinese women from Taiyuan City. A total of 197 women had lung cancer and 232 of the participants served as healthy controls.

Home to heavy industry, the Asian Development Bank's 2012 annual report ranks Taiyuan City in the top 10 most polluted cities in the world. Steel and electronics manufacturing, along with coal mining and processing are among the industries in this northern Chinese city.

The study revealed an association between various sources of indoor air pollution and lung cancer among nonsmokers. These sources included secondhand smoke at work and solid fuel – particularly coal – used for cooking and heating.

Cooking oils used for stir-frying and deep-frying also produce cancer-causing compounds. These, too, increased women’s lung cancer risks.

"We found that the smallest type of particulate matter is the type associated with the higher risk of lung cancer among nonsmoking Chinese women," Dr. Mu said in a statement.

The fine particles that coal combustion and passive smoking produce were noted as the biggest contributors.

Dr. Mu said that smoking is a key social activity in China. "Men tend to gather and smoke together, often in small, enclosed spaces, especially in offices."

The study authors concluded, "Indoor air pollution plays an important role in the development of lung cancer among non-smoking Chinese women."

One of the America's leading lung cancer experts, D. Ross Camidge, MD, PhD, told dailyRx News, “The causes of lung cancer have started to become of increasing interest as the progress in identifying the underlying molecular drivers of the established cancers has been made. Clearly larger studies and a consistent message will be required to drive environmental change, but it is only by finding the underlying causes and modifying them that we can have the greatest impact on this disease - by preventing it from occurring in the first place,” said Dr. Camidge, who is the director of the lung cancer clinical program at the University of Colorado Hospital in Aurora.

This study was published in the January issue of Cancer Causes & Control. This research was supported by the National Nature Science Foundation of China, the National Institutes of Health and the Alper Research Center for Environmental Genomics of the UCLA Jonsson Comprehensive Cancer Center. No conflicts of interest were disclosed.

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Review Date: 
February 3, 2013