No job is totally safe. Everything we do comes with risk, no matter how small. But some jobs carry much more risk than others. The Independent crunched the numbers to find the most unhealthy jobs in the US. The rankings are based on data from a US Department of Labour database that measured six health risks, ranging from exposure to contaminants to time spent sitting. Here are the 20 jobs that most put your health at risk. They’re ranked on a scale of 1 to 100.