As transportation emissions of volatile organic compounds (VOCs) have decreased due to stricter controls on air pollution, the relative importance of chemical products such as pesticides, coatings, printing inks, adhesives, cleaning agents, and personal care products has increased correspondingly. In a recent study we published in Science Magazine, we show that these volatile chemical products now contribute fully one half of emitted VOCs from petrochemical sources in Los Angeles. We hope these results will spur additional research and inform decisions about mitigating sources of ground-level ozone, fine particulate pollution, and air toxics. If you want to know more about how paints, pesticides, and perfumes contribute to pollution - ask us anything! Dr. Brian McDonald is an atmospheric scientist at the University of Colorado Boulder who works at the National Oceanic and Atmospheric Administration, and whose expertise is on air quality models and emission inventories Dr. Chris Cappa is a professor at the University of California, Davis in the Dept. of Civil and Environmental Engineering, whose work centers on the sources, fate and impacts of small particles in the atmosphere Dr. Jessica Gilman is a Research Chemist at NOAA and specializes in the measurement and chemistry of volatile organic compounds (VOCs) in the atmosphere. Dr. Joost de Gouw is a senior research scientist at the Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder. His expertise is in the sources and transformations of organic compounds in the atmosphere.