In the German newspaper “Süddeutsche Zeitung” on 16th of February 2016 there was an interesting article about daily risks titled “You should not forget to enjoy”. It was referring to a unit measuring individual risk called micromort. The definition of lethalities among one million people goes back to a publication of Ronald A. Howard (1989): Microrisks for Medical Decision Analysis. International Journal of Technology Assessment in Health Care, 5, pp 357-370.
Based on the risk estimates of medical treatments it provides a comparative scale for risks in general. But like any other one out of xyz it does not cure the difficulties in understanding probabilistic concepts in general and it does not address the quite different perception of nominal identical risks. In this sense, beware of elephants – as they kill more people per year than sharks – and stop smoking in hydrogen cars. The latter not because of explosive hazards, but simply each smoked cigarette results in 0.7 micromorts and hydrogen cars do not yet provide statistics. So, no risk … no life.