The article is wrong. From the abstract: 'We tested whether Pb isotope ratios in airborne particles can be used to directly evaluate the Asian contribution to

The article is wrong. From the abstract: 'We tested whether Pb isotope ratios in airborne particles can be used to directly evaluate the Asian contribution to airborne particles of anthropogenic origin in western North America, using a time series of samples from a pair of sites upwind and downwind of the San Francisco Bay Area. Our results for airborne Pb at these sites indicate a median value of 29% Asian origin, based on mixing relations between distinct regional sample groups.' If it was unfounded, the reviewers would have shot it down.