This text provides a critical summary of research approaches applied in epidemiologic studies on workplace hazards. It describes the historical development of occupational epidemiology, methods for characterizing exposures, and techniques for designing and implementing studies. The relative strengths and limitations of various study designs for investigating specific health outcomes are emphasized. Also included are presentations of basic and relatively advanced statistical analysis methods, exposure and dose modeling, and subsequent applications of data derived from epidemiologic research, such as in meta-analysis and risk assessment. Throughout, the book illustrates methodological concepts with examples drawn from the peer-reviewed epidemiologic literature. This second edition is an update to the first edition in several notable respects. This text contains descriptions of more recent methodological developments, including the design features of case-cohort and case-crossover studies, and methods for repeated measures analyses. There is also a new chapter on occupational health surveillance. The book concentrates on exposure assessment, describes applications of quantitative exposure data in dose-response modeling, and examines the recognition that improvements in workplace risk identification and quantification requires careful integration of these approaches.