It is widely known that smoking increases your risk of lung cancer. That is not the only risk factor, however. Air pollution plays a role as well.

A study by Oregon State University suggests reducing air-polluting PAHs may lower levels of lung cancer deaths.

High emissions of polycyclic aromatic hydrocarbons (PAHs) can be linked to lung cancer deaths in the United States and countries with a similarly high socioeconomic rank, including Canada, Australia, France, and Germany, according to a study by Oregon State University.

Researchers reviewed a range of information from 136 countries, including average body mass index, gross domestic product per capita, the price of cigarettes, smoking rates, and the amount of PAHs emitted into the air. PAHs are a group of more than 100 chemicals, some of which are carcinogenic when inhaled or ingested. They most commonly come from vehicle exhaust and burning coal and wood.