Health and Safety Executive HSE workplace fatigue webpage http://www.hse.gov.uk/humanfactors/topics/fatigue.htm United Kingdom HSE workplace fatigue webpage 3.5 million people in the UK Human factors: why fatigue is important Health and Safety Executive http://www.hse.gov.uk/humanfactors/topics/fatigue.htm http://www.hse.gov.uk/humanfactors/topics/fatigue.htm 3.5 million people in the UK HSE work irregular h… αιτιώδη παράγοντα τραγικών δυστυχημάτων HSE website. work irregular hours