ABSTRACT
For hundreds of thousands of years, throughout his phylogenetic evolution, man had been a biological entity, perfectly adapted to his natural environment. About ten thousand years ago he left this natural environment for an agglomerative, artificial one: first primitive villages and then, about five thousand years ago, metropolises such as those of Mesopotamia, Egypt and the Roman Empire. Except for these few large cities of the past, however, it is only in the twentieth century that urbanization has become a characteristic trait of human settlements, and it is in part because of the relatively short period of time involved that man has not been successful in adapting to this artificial environment. Another reason, however, is that man is still dependent on his natural environment for sources of energy; yet there are ever-increasing denaturalizing factors harmful to health that have been interposed in the new, artificial environment; factors such as air pollution, water pollution, and physiological stress. Thus, the discord between man and his new artificial environment is increasing, and man's health suffers.
