I tend to endorse your smoking solution to 60 stick a day, but like all things in life science will come to bear and it is widely acknowledged that most vape 'fuels' contain contaminants, some proven and some yet to be proven, which are harmful. Unexpectedly in a recent survey of many 'fuels' this included nicotine, six out of a hundred plus. My point here is that there is no safe way to check levels at POS.