The Worker Health Chartbook, 2004 is a descriptive epidemiologic reference on occupational morbidity and mortality in the United States. The Chartbook includes more than 400 figures and tables describing the magnitude, distribution, and trends of the Nation's occupational injuries, illnesses, and fatalities. This 2004 edition of the Worker Health Chartbook builds on the foundation established in the first edition, published in 2000. The Chartbook is intended as a resource for technical and nontechnical audiences, including agencies, organizations, employers, researchers, workers, and others who need to know about occupational injury and illness. This concise, chart-based document consolidates information from the network of monitoring systems that forms the cornerstone of injury and illness surveillance in the United States. The document is intended to fulfill the NIOSH strategic goals for preventing occupational injury and illness and to guide research and prevention efforts. The Worker Health Chartbook, 2004 contains five chapters and three appendices. Chapter 1 describes the U.S. labor force and the health status of workers. Chapter 2 focuses on the demographic characteristics of workers (age, sex, occupation, industry, and case severity) and 33 types of occupational injuries and illnesses that affect them: amputations; anxiety, stress, and neurotic disorders; asbestosis; asthma; back, including spine and spinal cord; bloodborne infections and percutaneous exposures; bruises and contusions; byssinosis; carpal tunnel syndrome (CTS); coal workers' pneumoconiosis (CWP); cuts and lacerations; dermatitis; disorders due to physical agents; disorders associated with repeated trauma; dust diseases of the lungs; fatal injuries; fractures; hearing loss; heat burns and scalds; hypersensitivity pneumonitis; lead toxicity; mesothelioma; musculoskeletal disorders; nonfatal injury; pneumoconioses; poisoning; respiratory diseases; respiratory conditions due to toxic agents; silicosis; skin diseases and disorders; sprains, strains, and tears; tendonitis; and tuberculosis. Chapter 2 also examines the magnitude, trends, and geographic distribution of these conditions. Chapter 3 focuses exclusively on agriculture, presenting data on fatal and nonfatal injuries among adults and children in agriculture and examining selected health conditions of farm workers. Chapter 4 concentrates on high-risk industries and occupations and reflects NIOSH research priorities in mining and construction. Chapter 5 addresses special populations, exploring available occupational injury and illness data on young workers, older workers, and Hispanic workers. The three appendices complement the chapters with details about source data and programs. Appendix A describes the 21 survey and surveillance programs used by the contributors; it includes program contacts and reference citations for follow-up by users. Appendix B examines various aspects of data collection, analysis methods, and dissemination practices that limit the uses and inferences of data. Appendix C provides a bibliography of reference materials from the public domain, including data tables, report forms and documentation, government news releases, and research articles.