A worker who knows all the ins-and-outs of their position and has spent years on the site will be more efficient than someone who has just started. But, learning on the fly in situations like this could be riskier than you may think. Research from Toronto’s Institute for Work & Health shows that workers who had been at a job for a month or less had three times the risk of suffering a lost-time injury compared to those who had been at a job for over a year.