Wood Smoke Tied to Lung Cancer in Nonsmokers
Mexican Researchers Say Long-Term Exposure May Cause Lung Cancer
July 11, 2005 -- Mexican researchers say wood smoke may cause lung cancer in
Javier Delgado, MSc, and colleagues report the finding in Chest.
They work at Mexico's Instituto Nacional de Enfermedades Respiratorias.
Most of the nonsmoking lung cancer patients they saw were rural Mexican
women living in poverty. They had burned wood for many hours a day for more
than a decade.
That's very different from gathering around the hearth occasionally.
"Tobacco smoke is still considered the main cause of lung cancer,"
write the researchers.
About Lung Cancer
Lung cancer is the No. 1 cause of cancer deaths for men and women alike,
according to the American Cancer Society (ACS).
The ACS predicts that there will be more than 172,000 new cases of lung
cancer in the U.S. this year.
Smoking is "by far" the leading risk factor for lung cancer, states
the web site of the ACS.
Wood Smoke Study
Delgado's team doesn't question the threat posed by tobacco smoke. But other
factors could also play a role in lung cancer, they write.
They studied 62 lung cancer patients. Six women and 17 men had smoked
tobacco for more than 10 years.
An additional 22 women and two men were nonsmokers who had been exposed to
wood smoke for an average of 44 years. They used traditional wood-burning
stoves in their kitchens -- with no chimney to let the smoke out of the
"We found that 38.7% of the lung cancer patients examined were
nonsmokers with a history of continuous wood exposure for more than 10
years," write the researchers.
The patients' blood samples were checked.
For comparison, blood samples from nine healthy nonsmokers without wood
exposure were also screened. So were samples from nine people with chronic
obstructive pulmonary disease (COPD).
The nonsmoking, wood-burning lung cancer patients had higher levels in their
blood of certain proteins linked to cancer development.
Wood smoke, like tobacco smoke, may affect the genes that govern those
proteins, write the researchers.
"It is important to consider wood smoke exposure as a possible risk
factor for the development of lung cancer in [nonsmokers]," they write.