Pollution of the environment is a world wide concern and is the subject of broadly based R&D into means of prevention and remediation. The innovation proposed here is the design of and electron beam source for clensing air.Bombardment by electrons has proven to be effective in destroying a wide spectrum of chemical and biological pollutants. Maintaining air purity becomes particularly critical in densely populated closed spaces. Such as occupied buildings, passenger transport vehicles, orbiting space vehicles and lunar or planetary exploration stations. The work proposed here is to appraise the feasibility of down sizing this effective technology to meet the much more restrictive cost, weight and reliability requirements attendant to commercial passenger transportation and manned space exploration. Key to meeting those requirements are carbon nanotube (CNT) field emitters to replace the thermal electron sources as was done, by MPT, in developing the cold cathode x-ray tubes subsequently produced by Oxford X-ray Technology. MPT, working with Valence Corporation and others, have developed systems for eliminating odors and chemical components from air streams exhausted from sewerage treatment, large scale painting and food processing plants and environmental remediation installations.