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Cadernos de Saúde Pública

On-line version ISSN 1678-4464Print version ISSN 0102-311X

Cad. Saúde Pública vol.20 n.6 Rio de Janeiro Nov./Dec. 2004 



Forum: work hours and health



Lúcia Rotenberg

Laboratório de Educação em Ambiente e Saúde, Departamento de Biologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brasil



Work is both a characteristic human activity and a way of obtaining money, yet it can also be a source of illness. The temporal aspects of work – when work takes place and for how long – belong to the area of work organization and can be viewed as part of the work environment. Like other characteristics of labor settings, some aspects of work schedules can be detrimental to workers' health. The current forum focuses on several spheres of health and wellbeing, ranging from compatibility between work and family life to the aggravation of various symptoms and the increased risk of chronic non-communicable diseases.

Frida M. Fischer analyzes the current demand for work schedules that include night and shift work, emphasizing that the classic work pattern of the "5-day, 40-hour workweek, with weekends off and only daytime work" is increasingly rare among the workforce in modern societies. Fischer has worked extensively in companies and institutions, and her paper presents a comprehensive view of shift work systems from the perspective of workers' health and wellbeing. Among a variety of work arrangements, she has selected three examples of Brazilian schedules, analyzing their effects on workers' sleep and alertness. She also emphasizes the importance of shift work schedules' characteristics and work organization, as well as the use of ergonomic principles in the implementation of workplace safety practices.

Claudia R. C. Moreno and Fernando M. Louzada present an updated analysis of human chronobiology, ranging from the molecular to the behavior level. The article discusses the notion that human life is regulated by three types of clocks – solar, social, and biological – considering work schedules as part of our social clock. The concept of the body's temporal organization is presented to explain key consequences of night work and/or alternating and irregular shift work. Readers can benefit from the authors' expertise on both chronobiology and its applications, so that certain measures aimed at favoring adaptation to night and shift work are easily understood.

Long working hours represent another facet of work features deserving attention from the Public Health field. The third paper, by Paul Landsbergis, thus discusses health effects related to long work hours, including fatigue, which is an evident consequence of overtime, as well as accidents and injuries, musculoskeletal disorders, psychological symptoms, unhealthy life styles, and increased risk of hypertension and cardiovascular diseases. The underlying mechanisms for cardiovascular diseases and hypertension, the main topics of this article, include excessive work, which can act directly as a stressor or as a factor that increases exposure to other work-related risks or favors the occurence of so-called unhealthy behaviors.

The articles' contents are interconnected, for example, chronobiological concepts can aid the understanding of sleep disorders among shift workers. Meanwhile, the potential health consequences of long working hours and statistics on the worldwide spread of overtime and shift work reflect a major concern as to relations between work schedules and Public Health. These issues certainly justify the reevaluation of work schedules according to policies that ascribe priority to workers' biological and social characteristics.