Police work is far less dangerous than common perception. Similar danger as an average construction worker.
Could be a case where better awareness of the statistics would actually improve the problem.
Also though, danger resulting from your own stupidity, from other peoples stupidity, and from other peoples malicious activities, hit different psychologically IME. I'm willing to bet consturction workers get a lot less of the third and a lot more of the first.
Maybe something that better training could help with a bit, but probably not fix. Also selecting people who are well suited for that sort of environment.