No surprises at all. I do, like you, expect there are substantial differences in risk for those who smoke outdoors. I am either smoking outside or in a cavernous and drafty shop open from floor to 12’ peak. Both of those environments mean less smoke is getting into my lungs compared to someone smoking in a house or office. That said, I know I am taking a risk.Is there a surprise here? BTW, whats the death rate for pipe smokers who only smoke outdoors? Did they include that? If not, sloppy work!
And yet, people in my family seem to get cancers of various sorts at the same rates regardless of whether they live clean or chain smoke. I am walking a middle road, for what good that may (or may not) do.