29 November 2001

One Billion Deaths From Tobacco

by Kate Melville

In the October issue of the journal Nature Cancer Reviews, Penn State science historian Robert Proctor predicts that, left unchecked, tobacco products will cause up to one billion deaths by the end of the 21st century. Proctor's prediction is the result of his historical analysis of how many cigarettes it takes to produce a given level of mortality, plus an analysis of global smoking rates and trends. He shows that lung cancer was an extraordinarily rare disease before the 20th century, so rare that physicians were astonished whenever they saw a case. It was not even medically described until the 18th century and, for many years thereafter, was notoriously difficult to diagnose. A Penn State distinguished professor of history and co-director, Science, Medicine and Technology in Culture Initiative, he points out the direct correlation in the rise in incidences of lung cancer and the rise in the number of smokers.

Lung cancer was first linked to cigarettes in 1912 by physician and pathologist Isaac Adler, and several other medical professionals reasserted the link in subsequent years. However, the first formal quantitative analysis of the link did not occur until 1929, in Dresden, Germany. That same year, global cigarette consumption was already at around 600 billion cigarettes per year. It would rise to 10 times that amount by its peak in 1990. In his article, Proctor traces the medical research advances by which lung cancer was linked to cigarettes, the global spread of tobacco usage, the political obstacles to tobacco control, and the growth in cancer rates worldwide.

As a result, Proctor is able to present statistics showing there is about one lung cancer death for every 3 million cigarettes consumed. An important component to that statistic, he says, is that "cigarette smoke is unlike radon, asbestos, aniline dye or most other carcinogens in that the dosages delivered to the body are remarkably uniform. Cigarettes are pretty much the same size and composition throughout the world, as are the routes by which the body is exposed. And as consumption rates are carefully recorded by governments (primarily for taxation purposes), it is fairly easy to predict the long-term cancer consequences of a given level of consumption."