What do downtown Los Angeles and a 9,000 foot summit in the Oregon Cascades have in common? Air pollution. While observers can point to the vast population and its accompanying pollution in southern California, one must look a bit further away to explain the causes of pollution on remote and pristine mountaintops.
According to Dan Jaffe, an atmospheric chemist at the University of Washington-Bothell who runs the Mount Bachelor observatory in the Cascades, we need to look across the Pacific Ocean to China.
Anyone who has looked at flight plans while flying across the US may notice that flights from west to east are generally faster than flights from east to west. This is because prevailing winds in the northern hemisphere generally travel from west to east. Unlike California to New York air travel though, not all tailwinds bring benefits.
Jaffe notes that ozone measurements on top of Mount Bachelor have reached 50 parts per million (ppm), most attributable to pollution blown across the ocean from China. EPA standards for safe levels will be between 60 and 70 ppm in the next few years, leaving almost no allowance for any pollution - natural or manmade - to emanate from the US.
Mountaintops are not the only places that pollution from China has been found. A 2010 study found that _ of the ground-level ozone found in Sacramento Valley in California came from Asia. But pollution from Asia can reach much farther than the west coast. In 2001, dust carried from a storm in China that dropped on the US led to health advisories as far east as Atlanta, Georgia.
But what are the real consequences for Americans? The Environmental Protection Agency (EPA) estimates that pollution carried from Asia is responsible for hundreds of deaths annually in the US. While this pales in comparison to the significantly reduced life expectancy in China of up to 5 years, measures to protect the United States are still warranted.
For one, plans to expand US and Canadian coal exports to China are being questioned in light of the fact that, while only China reaps the energy, the malignant environmental effects are mutually shared. There have been some signs of China being open to working with the rest of the world on environmental issues, as indicated in a statement issued during a US-China summit in June of this year.
Jaffe does note that China is making significant progress confronting its air quality problem; and certainly he believes the US still has its own part to play in reducing air pollution. However, it is increasingly evident that the futures of China and the US are inexorably bound. When it comes to pollution, it is indeed a small world, after all.