[Shiftwork. Impact on health and safety in the working environment].

Biological rhythms are highly disrupted by night shiftwork (NSW), and any perturbation of social and family life negatively affects performance efficiency, health and social relations. These undesirable aspects have acute and chronic components. The effects manifest themselves not only as increased accidents' frequency, but also as sleep disturbances, excessive daytime sleepiness, psychosomatic disorders that may variously interact to configure a "shift-lag" syndrome, with acute and chronic manifestation. Chronic effects increase the risk of psychoneurotic, cardiovascular and gastrointestinal diseases. The effects of NSW on women are much more pronounced because of their reproductive function and family obligations. Recent Italian legislation (1999, 2003) on night-work has essentially recognised it as a new risk factor and has established that workers' health should be safeguarded through preventive check-ups and regular controls by occupational health physicians. This involves that now occupational health physicians are required to inform workers on coping strategies, and carefully assess health disorders with absolute or relative contraindications. Data from international literature and from our group production are revised and discussed.