The School of Tropical Medicine and the Cornelius Rhoads Scandal (1926-1949)

The School of Tropical Medicine was established in 1926 by an act of the Puerto Rican Legislature to continue research initiated by the Anemia Commissions and the Institute of Tropical Medicine. Affiliated with Columbia University in New York, the school trained health professionals and conducted research on tropical diseases of high prevalence in Puerto Rico, including hookworm, malaria, and tropical sprue. The institution made genuine contributions to medical knowledge, but it also embodied the colonial relationship between mainland medical establishments and Puerto Rican bodies available for study.

In 1931, Dr. Cornelius P. Rhoads, a pathologist working with the Rockefeller Anemia Commission at Presbyterian Hospital in San Juan, wrote a letter that would become one of the most disturbing documents in Puerto Rican colonial history. In the letter, Rhoads described Puerto Ricans as 'the dirtiest, laziest, most degenerate and thievish race of men ever inhabiting this sphere,' and claimed he had killed eight patients by injecting them with cancer cells. He wrote that he was 'gruelling [sic] on this gruesome job' and expressed the desire 'to exterminate the population.'

The letter was discovered by a laboratory assistant and turned over to Pedro Albizu Campos, president of the Nationalist Party, who publicized it internationally. Rhoads claimed the letter was a joke written after a party where his car had been vandalized. An investigation found no patients in his care had died under suspicious circumstances, and Rhoads went on to a prestigious career heading the Sloan-Kettering Institute and receiving Time magazine recognition. However, the American Association for Cancer Research later renamed a prize that had honored him after a review confirmed the letter's offensive content.

The incident crystallized Puerto Rican fears about being used as experimental subjects by colonial medicine—fears that were not unfounded. The school's researchers had experimentally controlled patients' diets and referred to them as 'experimental animals' in correspondence. This history formed part of a larger pattern that included the mass sterilization campaign of the 1930s-1970s and the birth control pill trials of the 1950s, establishing Puerto Rico as a colonial laboratory where ethical standards were routinely relaxed.