Chemicals, Cancer, and Prevention:

Death and disease were configured quite differently at the end of the nineteenth century than they were at the end of the twentieth. In the United States of a century ago, contagious diseases such as pneumonia, typhoid, tuberculosis, and diarrhea represented the greatest threat to human health and survival. Cancer, on the other hand, was of only marginal importance, in both absolute and relative terms (Department of the Interior Census Office 1896). By the 1930s, however, cancer and contagious diseases had switched places in the official statistics. Cancer was now the second leading cause of death (behind heart disease) and contagious diseases had moved several rungs down the ladder. This trend continued during the second half of the twentieth century, as age-adjusted cancer incidence and mortality rates continued creeping upwards and the specter of life-threatening contagious diseases continued to recede. ¹