Svetlana Vladimirovna Fomicheva – Ph.D. honey. Sciences, senior researcher Institute of Cellular and Intracellular Symbiosis, Ural Branch of the Russian Academy of Sciences. Ilya Vladimirovich Fomichev is a gastroenterologist, head of the Osnova Medical Center. In the book, the authors talk about their approach to treating workers employed in the oil and gas sector, not as ordinary citizens, but as those who have their own specific work, requiring its own specific treatment, taking into account their professional characteristics. In the process of production, transportation, and processing, workers in the oil and gas industry are faced with harmful production factors. Harmful substances that are part of the produced gas or accompany it with the produced oil, such as hydrogen sulfide, mercaptans, carbon disulfide, sulfuric anhydride, sulfur dioxide, sulfur dust, are present in the air of the working area simultaneously in greater or lesser concentrations. Their accumulation in the body leads to systemic chronic intoxication, causing adaptation of the body at the intracellular level to external unfavorable factors. These changes in the cell relate to the organs and systems into which they enter from the external environment. The body can compensate for the effects of natural gas for a long time. But not unlimited. In due course, changes at the intracellular level turn to functional changes in the organ. The book draws attention to cholesterol metabolism, the development of atherosclerosis and the danger of oxygen starvation among workers in the oil and gas sector; a clear chain is built from the initial exposure to natural gas components, with chronic exposure to the body, to its influences at the cellular and intracellular level. New approaches to the prevention of morbidity among workers in the oil and gas sector have been proposed.