Occupational health has two main objectives: the protection of workers from health hazards associated with the working environment, and the promotion of workers' health. Fundamental aspects of health protection are health risk management, information and training, first aid and medical treatment. Risk management comprises risk characterization, and exposure assessment. Integrating information on the identified hazards and exposure levels, and assessing the likelihood and severity of health effects performs risk characterization. Health surveillance includes medical surveillance and biological monitoring. The physician in charge of the occupational health programme, taking into account the results of the risk assessment process should determine frequency and contents of periodical medical examinations. Pre-employment medical examinations should be carried out in order to determine the physical ability to do the job the candidate is recruited for. Periodical medical examinations are aimed at detecting, in an early and reversible phase, any adverse effect attributable to exposure. A worker should undergo a broad medical examination when returning to work after a significant illness. Records of occupational health programmes should be filed and kept for at least 30 years.