Sulfur oxides are among the most common and most injurious of the pollutants that contaminate the Nation's air and threaten public health and welfare. The Department of Health, Education, and Welfare has underway a large-scale research and development program focused on technology for dealing with the sulfur oxides problem. This document was prepared for use in the planning and programming of our sulfur oxides research and development effort and as an aid to coordination of the work of the various organizations involved in this effort. This five-year plan will be updated annually to reflect the progress of research and development conducted and supported not only by the Federal Government, but also by non-governmental organizations, to the extent that such organizations make information on their work available to us.