Clinical Citations: Can exposure to wood smoke cause lung cancer?

Although tobacco smoke is considered to be the most prevalent cause of lung cancer, other types of smoke also appear to be significant risk factors. For example, a recent study conducted in Mexico found that close to 39% of persons with lung cancer were nonsmokers who had been exposed to wood smoke for more than 10 years. Moreover, serologic analysis indicated that wood smoke exposure produced changes that were similar to those that have been associated with lung cancer.

Delgado and associates obtained blood samples from 62 patients with lung cancer, 9 patients with chronic obstructive pulmonary disease, and 9 controls. Of those with lung cancer, 23 were tobacco smokers and 24 were exposed to wood smoke. Western blot assays and densitometric analysis were used to identify and evaluate p53, phospho-p53, and murine double minute 2 (MDM2) isoforms, which have been associated with lung cancer.

Wood smoke produced changes in p53, phospho-p53, and MDM2 protein expression similar to those caused by tobacco smoke. The authors noted that many of the lung cancer patients who had been exposed to wood smoke were women who lived in rural areas, and that these women typically were exposed to wood smoke for several hours a day.