David Pettit, an attorney with NRDC, emphasizes that California has the nation’s best collection of data on air pollutants and their sources through the California Environmental Air Quality Act. No other state collects data on pollution like California. Meanwhile, Barry Wallerstein, executive officer of California’s Air Quality Management Division, earlier emphasized how California’s southern air basins have the highest exposures of air pollution in the U.S. — they account for almost a quarter of the nation’s negative ozone exposure, and over half of the nation’s negative particulate matter exposure. 

So when does the stellar data collection start adding up to stellar air quality?