This review discusses sources and types of air pollution; collection, fractionation and chemical analysis of air samples; and in vitro bioassay systems capable of quantitating mutagenicity of these air samples and their components. Case studies utlizing bioassays to detect mutagenicity, such as the Tradescantia plant assay (on-site) and the Ames/Salmonella bacterial assay (off-site) are reviewed. Problems such as sample size, complexity of the air sample (both vapor-phase and particulate), and artifact generation are discussed. The state-of-the-art techniques for air-pollution analysis (an integrated biological and chemical approach) are reviewed, and directions for future research are commended. Methods for collection of air particulate and vapors are reviewed, as are solvent extractiona nd further fractionation of particulate organic matter into various chemical groups (e.g. acid, base, PNA, PN, NPN). Methods for chemical identification of individual components by GC/MS/computer systems and collection and assay methods for vapor-phase components are included. Experimental results comparing Tradescantia with Ames/Salmonella mutagenicyt studies are presented (certain vapor-phase organic substances were highly mutagenic for Tradescantia plant stamen hairs). Bacterial mutagenesis test results of air particulates and their extracts indicated the major portion of the activity resided in the acid, base and PNA fractions. Different types of mutagens identified in fractionated air-particulate extracts are discussed, and recommendations for the use of integrated chemical-analytical and biological screening systems in further studies of toxic air pollutants are proposed.