Will checking out a library book give you scarlet fever? That was a serious question a hundred and forty years ago.
In the second half of the Nineteenth Century, public health rose as a major social concern in many Western nations. Preventing the spread of infectious diseases through proper sanitation was a high priority for public policymakers.
At the same time, public libraries began to proliferate across the United States and the United Kingdom. This led to worries and, eventually, a public panic about library books as a locus of contagion. Joseph Hayes writes at Smithsonian:
Books were viewed as possible vehicles of disease transmission for several reasons. At a time when public libraries were relatively new, it was easy to worry about who had last handled a book and whether they might have been ill. Books that appeared to be benign might conceal diseases that could be unleashed “in the act of opening them,” Mann says. People were concerned about health conditions caused by “inhaling book dust,” Greenberg writes, and the possibility of “contracting cancer by coming in contact with malignant tissue expectorated upon the pages.”
The great book scare reached fever pitch in the summer of 1879, Mann says. That year, a librarian in Chicago named W.F. Poole reported that he had been asked whether books could transmit disease. Upon further investigation, Poole located several doctors who claimed to have knowledge of disease-spreading books. People in England started asking the same question, and concerns about diseased books developed “roughly contemporaneously” in the United States and Britain, Mann says. [...]
In response to the panic, libraries were expected to disinfect books suspected of carrying diseases. Numerous methods were used for disinfecting books, including holding the books in vapor from “carbolic acid crystals heated in an oven” in Sheffield, England, and sterilization via “formaldehyde solution” in Pennsylvania, according to Greenberg. In New York, books were disinfected with steam. A study in Dresden, Germany, “revealed that soiled book pages rubbed with wet fingers yielded many microbes.