Ayatollah Mahdi Hadavi Tehrani's opinion regarding the foregoing question is as under: "Smoking tobacco (cigarettes and hookah) is absolutely haram because it is injurious to health."
It should be noted that the jurisprudential argument of the verdict of Ayatollah Mahdi Hadavi Tehrani concerning the prohibition of smoking tobacco is based on its being harmful and injurious to health. Perhaps, in the same way, the jurisprudential reference for the verdict of Ayatollah Makarem Shirazi can be the injurious nature of tobacco. However, it is better for you to ask his own office about the jurisprudential argument behind his verdict. For further details vide:
1. Index: The Islamic law concerning smoking tobacco, question No.1521 (site: 1555).