The key is to confine the movement of the electron.
Many unanswered questions remain about how air pollution affects health.
For instance, many pollutants exist in both particle and gas phases, which are deposited differently in the lungs and have different physiological effects. Difficulty in getting good measurements of these gas and solid phases has complicated the EPA's effort to establish air quality standards. Lara Gundel and colleagues have devised an air sampler that is being used around the country to resolve these issues. Scientists at the Lab's Center for Environmental Biotechnology have shown that underground microbes can transform toxic chromium pollutants into less toxic compounds. What's more, the process may be accelerated by the presence of volatile organic wastes, compounds often found at contaminated sites.