A new study carried out by a team of researchers led by H. Barry Dellinger from Louisiana State University, concluded that air pollutants, also known by the name of free radicals, may be one of the main causes of lung affections, even cancer.

The free radicals, a recent discovery, are atoms or molecules attached to small particles of air pollution and have been known to exist in Earth’s atmosphere for some time now.

Researchers did know for some time that free radicals can cause damage to human cells, but, so far, it was believed that these radicals couldn’t resist long enough to really cause considerable damage. They were thought to exist for only a fraction of a second.     

The latest findings, which were presented at the American Chemical Society annual meeting held in Philadelphia, Pennsylvania, reportedly showed that free radicals can have unlimited life if combined with air pollution particles. Researchers said the free radicals are very similar to tar found in cigarettes, which explains why people who do not smoke develop smoking-related diseases such as lung cancer anyway.

Dellinger, the leader of the research, said the particle generated by combustion have “environmentally persistent free radicals." He estimated that the smoking of 300 cigarettes per day would be the equivalent of the level of exposure to free radicals one faces in an environment with moderately polluted air.

The process of persistent free radicals generation starts with combustion. From car exhaust pipes or smokestacks, the free radicals leave as they attach themselves to small particles of air pollution. The particles, which contain copper and iron, remain in the atmosphere and carry the free radicals with them. When inhaled and absorbed in the lungs, the particles containing free radicals cause severe damage to tissues and can cause a number of diseases, even lung cancer.