Environment refers to the external world with human beings as the main body, which is the unity of various natural and social factors that matter and phenomena interact with human beings on the earth, the material basis for human survival and development, and an important condition closely related to human health. People's life is always in a certain natural environment, social environment and man-made environment, and is often influenced by both material and spiritual factors. In order to survive and develop, improve the quality of life and maintain and promote health, human beings need to make full use of various resources in the environment. However, due to natural factors and human social behavior, the environment will be destroyed and human health will be affected. When this kind of injury and influence is within a certain limit, the adjustment function of environment and human body has the ability to restore the unbalanced state to its original state. If it exceeds the limit that the environment and the body can bear, it may cause ecological imbalance and damage to the physiological function of the body, and even lead to short-term and long-term harm to human health. Therefore, human beings should improve environmental awareness, recognize the relationship between environment and health, standardize social behavior (prevent environmental pollution, maintain ecological balance, and promote the development of environmental ecology to a virtuous circle), establish laws and standards for environmental protection, and avoid environmental degradation and imbalance. This is an important criterion for correctly handling the relationship between human beings and the environment.
The first chapter is the relationship between human beings and the environment.
Abstract the concept of environment; * * * The same elements in different environments; Hygienic characteristics of the environment; Characteristics of the relationship between environmental factors and health; The relationship between physical hazards and health; Relationship between chemical hazard factors and health. Environmental pollution; Public hazards and diseases. Principles of prevention and control measures for environmental pollution.
Section 1 Environmental Elements
Environment, involving living environment, production environment and social environment, can be summarized as biological, chemical, physical and social psychological factors.
First, the biological factor.
The living matter in the biosphere is interdependent and mutually restricted, constantly exchanging material energy and information, and jointly forming a complex of biology and environment, namely an ecosystem. Humans rely on organisms to form a stable food chain, thus obtaining nutrients necessary for survival; Using biological drugs to prevent and treat diseases; Greening beautifies the environment, cultivates sentiment, etc. While creatures themselves benefit mankind in the process of continuous reproduction, some creatures will also bring certain threats to human health and life. For example, pathogenic organisms can become vectors including serious infectious diseases; There are biological factors such as carcinogenic and teratogenic toxic substances in the food chain; There are sensitized pollen and biological dust (animal feathers, hair, etc.). ) In the air.
Due to the accumulation of production and life experience, human beings have long understood the laws of biological factors that endanger human health in the environment and have rich prevention and control experience, so the seriousness of biological factors that endanger human health and life has declined.
Second, chemical factor (chemical factor)
There are natural inorganic chemicals, synthetic chemicals and chemical components in animals, plants and microorganisms in human living environment. Naturally occurring inorganic chemicals are the main substances that constitute the human body. Some elements are rare in organisms, but they are indispensable. They are called trace elements. Many chemical elements are harmless to the body under normal contact and use, and long-term exposure to excessive or low doses will have harmful effects (called poisons). Common chemical factors in the environment include inorganic compounds, such as metals and metalloids; Sulfur oxides, nitrogen oxides, carbon oxides, hydrocarbons, organic solvents, etc. Produced by coal, oil and other energy sources in the combustion process; Raw material intermediates or wastes (waste water, waste gas and waste residue) in the production process; Pesticides; Food additives and inorganic and organic substances in the form of dust. While creating a high degree of human civilization, chemical substances also bring inestimable harm to human health.
Third, the physical factor.
People will come into contact with many physical factors in their daily life and production environment, such as air temperature, humidity, air pressure, sound waves, vibration, radiation (ionizing radiation and non-ionizing radiation) and so on. In the natural state, physical factors are generally harmless to the human body, and some are necessary external conditions for human physiological activities. Only after a certain intensity and/or a long time of contact will it cause harm to different organs and/or system functions of the body. With the progress of science and technology and the development of industry, people are exposed to more and more harmful physical factors from living environment and production environment, and the health hazards brought about by them should be paid enough attention.
Four. social psychological factors
Human health and diseases are social phenomena, and the improvement of health level and the occurrence, development and outcome of diseases are bound to be restricted by social factors. Social factors generally include social system, social culture and socio-economic level, which affect people's income and expenditure, nutritional status, living conditions, opportunities to receive scientific knowledge and education, etc. Social factors also include people's age, gender, customs, religious beliefs, occupation and marital status.
Psychological factors refer to the factors that cause people's social behavior and even the functional state of body and organs to change under specific social environment conditions. Psychological factors focus on individual and internal emotions (excitement, inhibition, anxiety, depression, fear, anger, sadness and other psychological tensions) and attitudes and concepts towards the surrounding environment and things.
Because the change of social environment often affects the physical and mental health of individuals, psychological factors are often closely related to social environment, so they are often called social psychological factors.
Psychological stress is a normal response of people to adapt to the environment, but if the intensity is too large and the time is too long, it will make people's psychological activities out of balance, lead to dysfunction of nerve activities, and even lead to emotional diseases, psychosomatic diseases, and even serious mental diseases. Therefore, it should be emphasized that the individual's psychological state should adapt to the changes of social environment as soon as possible, so that the individual and the changing social environment can be adjusted into a coordinated whole, so that any changes in social environment will not make people in a state of psychological imbalance and/or neurological dysfunction for a long time, thus preventing the occurrence of physical diseases.