The Hanford Site occupational health program is designed to provide professional services in support of the health and safety of more than 10,000 workers on the Site. The program is based on fundamental occupational health tenets of medical surveillance, prevention, identification and limited treatment and rehabilitation of work related diseases and injuries, and education. The service mix is composed of a broad array of primary, secondary and tertiary activities designed to prevent or intervene as early as possible in work-related illness and injury. Services include risk-based medical surveillance examinations and monitoring evaluations, diagnosis and treatment of injury or disease, occupational medicine and nursing, psychological counseling and evaluations, employee assistance counseling, substance abuse testing, ergonomic assessment, exercise physiology and work conditioning, monitored care and case management, fitness for duty evaluations, health education and wellness promotion, infection control, emergency and disaster preparedness and support, and work site field and facility visits.