Imagine you're sitting in rush hour traffic somewhere in Southern California, and you hear this story about a new study warning you that sitting in rush hour traffic can be worse for your health than previously thought. You learn that the researchers, including Rodney Weber, professor in the School of Earth and Atmospheric Sciences, studied Atlanta traffic. Somehow that doesn't make you feel any better; Weber's team found toxic particulate pollution is worse on a freeway than off, and pollution levels are higher during the morning commute than the afternoon drive home.