TY - CHAP M1 - Book, Section TI - Environmental Injury A1 - Butts, John D. A2 - Reisner, Howard M. PY - 2020 T2 - Pathology: A Modern Case Study, 2e AB - External factors, forces, and agents play a significant role in the causation of human disease. The environment in which we live is hardly benign and we are constantly exposed to its potential hazards. These include physical, chemical, thermal, and electrical forces as well as ionizing radiation. Noncommensal microbiological organisms are also external agents. While within the spectrum of human disease there are conditions where external factors have little or no role, such as some inherited disorders of metabolism or the muscular dystrophies, in most human afflictions external factors interact with host factors to produce disease. Certain lung cancers are linked to cigarette smoking and liver disease is a well-documented consequence of heavy alcohol consumption, yet in spite of the clear evidence that links these two agents to these diseases, it is also the case that only a minority of smokers and drinkers respectively develop them. At the other end of the spectrum lie the instances where external forces or agents are essentially the only factors as in trauma from a natural catastrophe like an earthquake or a human-made event such as a motor vehicle crash. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/04/19 UR - accessmedicine.mhmedical.com/content.aspx?aid=1173768076 ER -