After reading about the epidemiologically-derived contributions of Snow, Jenner, and Semmelweis, I was motivated to find a real-world application of epidemiology that held some historical significance. I believe the scientific article: “Radiation-induced Leukemia: Lessons from History” (Finch, 2007) does exactly that. This article holds unique perspective because, in a section titled: ‘Discovery and Mistakes’, it chronicles a time when ionizing radiation was not intuitively linked to incidences of leukemia (Finch, 2007). People made casual observations regarding patterns in certain professions, but no empirical data was presented until around 1945. The second section of the article, titled: ‘1945 to the Present’ begins to explain the role of epidemiology as it expanded the scope of repercussions attributed to frequent irradiation. Some specific epidemiological findings include: 1.) Epidemiological evidence presented in “Leukemia in Radiologists” (March, 1944) suggests significantly increased incidence of leukemia in physicians and radiologists when compared with their non-medical counterparts. 2.) The incidence of leukemia in children correlates significantly with diagnostic in utero radiation scans (Stewart et al., 1956). 3.) In 1957, researchers were able to identify a significant association between leukemia incidence and a history of treatment with x-ray radiation. (Court-Brown) I would also like to comment on a section of the required reading. On Page 11, while discussing the public health contributions of Semmelweis, the text describes garnering political support as a fundamental step in designing a public health intervention. I suppose this is common sensical. If we are to affect large-scale change as public health professionals, we will require the advocacy of those serving as representatives of the collective will of the people. Before reading this passage however, it never occurred to me how easily an intervention can fail, even with the support of irrefutable epidemiological data.