Newly Discovered Air Pollutants May Cause Lung Problems (HealthDay)

MONDAY, Aug. 18 (HealthDay News) -- Recently discovered so-called freeradicals that are attached to small particles of air pollution could causelung damage and perhaps even lung cancer, researchers report.

If confirmed through further research, the finding could help toexplain why nonsmokers develop tobacco-related diseases like lung cancer,said lead researcher H. Barry Dellinger, the Patrick F. Taylor Chair ofenvironmental chemistry at Louisiana State University.

It has been known for years that free radicals exist in the atmosphere,and these atoms, molecules and fragments of molecules can damage cells. Ithad been thought that these particles, which can be produced bycombustion, exist for less than a second and then disappear.

"What I found out is that combustion-generated particles containenvironmentally persistent free radicals," said Dellinger. "When theradicals are associated with particles, they can apparently existindefinitely."

These free radicals are remarkably similar to the free radicals foundin cigarette tar, Dellinger said. "The implication is you can have thesame environmentally related diseases by exposure to airborne fineparticles that you can get from cigarettes," he said.

Dellinger noted, however, that one would have to smoke about 300cigarettes a day to be exposed to the same level of environmental freeradicals found in moderately polluted air.

The findings were to be presented Monday at the American ChemicalSociety annual meeting, in Philadelphia.

The persistent free radicals (PFRs) discovered by Dellinger's teamattach themselves to small particles of air pollution as they leavesmokestacks, car exhaust pipes and household chimneys, and continue toexist as free radicals. Particles of air pollution containing metals, suchas copper and iron, are more likely to remain in the atmosphere and cancarry these PFRs great distances, Dellinger said.

As PFRs are inhaled, they're absorbed by the lungs and other tissuesand cause cell damage that can lead to problems such as asthma, emphysemaand lung cancer. However, there's still no direct evidence linking PFRs toany of these diseases, he said.

Dr. Neil Schachter, a professor of pulmonary medicine at Mount SinaiMedical Center in New York City, thinks it's premature to blame persistentfree radicals for the adverse effects of air pollution.

"These airborne free radicals are of interest, but I am not sure we areat a point where our scalpel is sharp enough to dissect the individualcomponents of air pollution that cause problems for people," he said.

It's possible that persistent free radicals are responsible for therespiratory damage caused by pollution, Schachter acknowledged. "There arestudies that show that modifying free radicals can alter the course ofdisease," he said. "But the implications of this -- what it means toclinics, what it means to doctors, what it means to regulators -- I thinkwe are a long way from pulling that together."

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