1. Environmental factors The environment refers to the sum of various natural and social factors that surround human space and directly or indirectly affect human life. Therefore, humanistic environment includes natural environment and social environment.
(1) The natural environment, also known as the material environment, refers to the objective material world around human beings, such as water, air, soil and other organisms. The natural environment is a necessary condition for human survival. In the natural environment, the main factors affecting human health are biological factors, physical factors and chemical factors.
Biological factors in the natural environment include animals, plants and microorganisms. Some animals, plants and microorganisms provide the necessary guarantee for human survival, but others affect or even endanger human health in a direct or indirect way.
Physical factors in the natural environment include airflow, air temperature, air pressure, noise, ionizing radiation and electromagnetic radiation. Under natural conditions, physical factors are generally harmless to human body, but when the intensity, dose and time of some physical factors exceed a certain limit, it will cause harm to human health.