Smog May Boost Risk for Several Cancers
By Steven Reinberg
FRIDAY, April 29, 2016 (HealthDay News) — Long-term exposure to fine particles of air pollution — from cars, trucks, power plants and manufacturing facilities — is tied to an increased risk of dying from several kinds of cancer, a new study suggests.
“Air pollution remains a clear, modifiable public health concern,” said researcher G. Neil Thomas, a reader in epidemiology at the University of Birmingham in England.
“Put simply, the more of these particulates there are in the air, the greater the risk of getting these cancers,” Thomas said, although the study did not prove the particles actually cause cancer.
The study, involving more than 66,000 older residents of Hong Kong, found an increased risk of dying from cancer for even small increases in exposure to these tiny particles of air pollution, which are measured in micrograms per cubic meter (mcg/m3). For example, the overall risk of dying from cancer increased 22 percent with every additional 10 mcg/m3 of exposure, the researchers said.
The raised risk seemed higher for some cancers than others: The additional air pollution was linked to a 42 percent rise in the risk of dying from cancer in the upper digestive tract, and a 35 percent increased risk of dying from liver, bile duct, gall bladder and pancreatic cancer, the researchers said.
Among women, the increased exposure was tied to an 80 percent heightened risk of dying from breast cancer. Among men, the higher pollution levels carried a 36 percent increased risk of dying of lung cancer, the study authors said.
“This study, combined with existing research, suggests that other urban populations may carry the same risks,” Thomas said. “The implications for other similar cities around the world are that pollution must be reduced as much and as fast as possible.”
Although the role of air pollution in cancer is not fully understood, it could include defects in DNA repair, alterations in the immune response or inflammation that triggers the growth of new blood vessels that allow cancer to spread, Thomas said. In cancer of the digestive organs, heavy metal pollution could also affect gut bacteria and promote development of cancer, he suggested.