Fiddle with the value of life and the discount rate and you can have any answer you want in health and safety. Perhaps the most important, is that it is often unnecessary to impute income for the most important benefits. The benefits themselves can often be quantified and discounted in their own way. Those that cannot be readily quantified are especially poor candidates for imputed income. I currently favor the Harvard Center for Risk approach to discounting human life.
Death is a fact of life.
Though there are undoubtedly exceptions, it is difficult to argue that the last two years of the eighth decade on life support are of equivalent quality to the second decade just out of college. Or that when a choice must be made, donated organs go to those who can likely get more out of them. So we human discount life. We just do it differently. BTW, I share at least some the disdain others may have for imputing monetary value on human life, then discounting it.