A new study indicates that tiny floating particles can grow semi-solid around pollutants, allowing them to last longer and travel much farther than what previous global climate models predicted. 
Pollutants from fossil fuel burning, forest fires and biofuel consumption include air-polluting chemicals known as polycyclic aromatic hydrocarbons, or PAHs. In the United States, the Environmental Protection Agency (EPA) has identified several PAHs as cancer-causing agents. 
Done by researchers at Oregon State University (OSU), the U.S. Department of Energy's Pacific Northwest National Laboratory, or PNNL, and Peking University of China, the study stems from a new way of looking at how the pollutants ride through the atmosphere and estimated cancer risks around the world as a result. 
"We developed and implemented new modeling approaches based on laboratory measurements to include shielding of toxics by organic aerosols, in a global climate model that resulted in large improvements of model predictions," said PNNL climate scientist Manish Shrivastava and lead author of the study published online this week in the Proceedings of the National Academy of Sciences.

Source: QNA