Long-term exposure to air pollution was linked to faster progression of atherosclerosis in a new major epidemiological study. In an article appearing on The Lancet on May 24 2016, researchers led by Joel Kaufmann at the University of Washington report the result of the Multi-Ethnic Study of Atherosclerosis and Air Pollution, involving more than 6,000 people from six US cities, between 2004 and 20014. In this population, for each additional exposure of 5 mg/m3 of PM2.5 , coronary artery calcium progressed by 4.1 Agatston units per year and for each additional exposure of 40 ppb of NOx, coronary artery calcium progressed by 4.8 Agatston units per year. These results represent about a 20% acceleration in the rate of calcification. Participants experienced average exposures comparable to the current US ambient air quality standards for PM2.5 (between 75% and 180% of the standard). The article was accompanied by an editorial by Bert Brunekreef at Utrecht University and Barbara Hoffman at the University of Düsseldorf. The MESA Air study was funded by EPA in 2004 with a STAR grant