The Air Quality Conference reviewed the state of science and policy on the pollutants mercury, trace elements. and particulate matter (PM) in the environment. Critical issues dealing with impacts on health and ecosystems, emission prevention and control, measurement methods, and atmospheric reactions and modeling were addressed. US Secretary of Energy Bill Richardson, in a keynote address discussed challenges to a deregulated power industry posed by the air quality issues of fine particulates, ozone transport, acid gases, hazardous air pollutants, and carbon emissions. The role and importance of sound science to establish environmental policy was clearly emphasized throughout the conference in technical papers; in policy presentations by Senator Kent Conrad (D-ND), Senator Byron Dorgan (D-ND), and Mr. Dirk Forrister, Chairman of the White House Climate Change Task Force; and in the panel discussions. (C) 2000