The proposed work will investigate the patterns of chemical metabolites in the urine of people who have been exposed to chemical mixtures. The short term objective of this work is to develop methods for measuring exposure to complex mixtures. The work will involve the measurement of metabolites in urine with the aid of pattern recognition techniques. The results of pattern recognition will then be used in the quantitation of exposure. The long term objective of this work is the reduction of occupational and environmental disease by the improved identification and management of chemical exposure.