Today, maybe. Btw, a side line to the point as do qualify your defintion, other peoples'' definition of casual and very casual vary a lot, I know people that if a pack lasts more than one day they consider that casual.
"Pack year" is often used as a risk assessment: https://en.wikipedia.org/wiki/Pack-year 1 pack year in a lifetime is not safe, but it is a vastly lower risk profile than a pack+ per day smoker.