ABSTRACT
The scientific effort within the Environmental Monitoring Systems Laboratory (EMSL), U.S. Environmental Protection Agency (EPA), for development and evaluation of new and improved methods for monitoring air quality has been driven by interest in three main topics: toxics, acidic deposition, and indoor air quality. Reliable instrumentation for EPA's monitoring networks and for special studies are needed to obtain data bases from which to distill information relevant to regulatory and scientific questions being addressed by the agency.
