21st International symposium on shiftwork and working time: the 24/7 society--from chronobiology to practical life.

Some significant changes have taken place in the global economy in recent decades impacting dramatically on the organization of work. The so-called ‘‘productive restructuring’’ has come with a growth of precarious work, work intensification, reduction in employment rates, flexibility of working times and off-hours not necessarily favorable to the wellbeing of workers. The global economic adjustments have also resulted in the weakening of labor unions, increase of informal jobs and structural unemployment in many countries (Kawachi, 2008; Quinlan et al., 2001; Santana, 2012). In addition, we face increasing age of the working population and the permanent presence of inequality at work and in health (Costa & Di Milia, 2008). Even in the select group of the so-called ‘‘developed industrial countries’’ we can often observe many cases of bad working conditions that contribute to the early development of work-related illnesses, both physical and mental, affecting not only the workers but also their families and social lives. In 2007, The International Labor Organization published the document ‘‘Working time around the world: Trends in working hours, laws and policies in a global comparative perspective’’ (Lee et al., 2007). The authors noted the large variation in the length of the weekly working hours and resting times within work sectors and countries. According to these authors. . . ‘‘Adjustments of the duration of decent work must meet five criteria, all interconnected which is why the work arrangements should: preserve health and safety, be family-friendly, promote gender equality, enhance productivity, facilitate workers’ choice of their working hours’’. For example, the rapid economic growth and productivity gains have contributed to rising wages in some Asian developing countries, but the benefits of growth have not translated into shorter work hours’’ (ILO, 2005). A recent report from ILO (2014) pointed out that ‘‘employment and social challenges remain acute in most emerging and developing countries. More than half of the developing world’s workers (i.e., nearly 1.5 billion people) are in vulnerable employment’’. Night and shiftwork, long and irregular working hours are usually associated with other environmental and organizational health risk factors (Caruso, 2014; Caruso et al, 2006; Harma & Kecklund, 2010). In recent years, a significant number of publications have reported negative outcomes related with shiftwork/night work and/or length of working time associated with metabolic diseases, as well as cardiovascular diseases. However, many issues, including the increased risk of developing malignant tumors during night work are still controversial (Ijaz et al., 2013; Haus & Smolensky, 2013). Currently a number of cohort studies utilizing more comprehensive measures aim to look more closely at this outcome. This new evidence is needed to develop better protection of workers in addition to the usually recommended actions. Shiftworkers and night workers can be at a severe disadvantage compared with day workers. In many cases, the former have to cope with multiple stressors associated with adverse work organization; they may also be exposed to other stressorssuch as chemical contaminants, strenuous work activities combined with poor living conditions. As researchers we must look at the combined effects of several stressors in order to better understand and put into practice safer threshold exposure limits and prevent aggravation of work-related