Working more than 55 hours a week increases the risk of death from heart disease and stroke, according to a United Nations study out Monday. The report by the UN’s World Health Organization and International Labor Organization agencies comes as the Covid-19 pandemic accelerates workplace changes that could reinforce the tendency to work longer hours. The WHO-ILO study, published in the journal Environment International, is the first global analysis of the risks to life and health associated with working long hours. It does not focus on the pandemic but on the preceding years. The authors synthesised data from dozens of studies involving hundreds of thousands of participants. “Working 55 hours or more per week is a serious health hazard,” said Maria Neira, director of the WHO’s environment, climate change and health department. “It’s time that we all — governments, employers, and employees — wake up to the fact that long working hours can lead to premature death.” The study concluded that working 55 hours or more per week was associated with an estimated 35-percent increase in the risk of suffering a stroke, and a 17-percent rise in the risk of dying from ischemic heart disease, compared to working 35 to 40 hours.