The need to protect the environment In the cities people live in conditions of strong promiscuousness, but in this case do not act restricting the number of natural processes, such as reduced access to the resources of nutrients causing the fertility decline in emigration and to protect populations against natural promiscuousness On the contrary, there is a constant influx of population to urban areas and thus increase the concentration to which residents respond like other mammals - the increase in the level of stress. It is the cause of many neuroses, personality disorders and other mental disorders. The anonymity of the person in large human subrogation also favors disclosure of the social pathology and deviation. Stress and too fast pace of life causes the development of many somatic diseases - diseases of the stomach and duodenum wristwatch and hypertension - leading to heart attacks and Wylie At the same time, incorrect nutrition, sedentary lifestyle and lack of activity for many people is the cause of obesity and coronary heart disease. Characteristic is the increasing prevalence of allergies. Significant events are associated with the development of civilization, road, aviation, railway.