Environment is the sum total of various factors on which human beings and creatures depend for survival and development. Environment includes natural environment and social environment. Environment and people are opposed to each other, restricted, interdependent and transformed. Environment provides all necessary conditions for human survival and development, and human beings adapt to the ever-changing external environment through self-adjustment; At the same time, it also constantly transforms the environment and creates environmental conditions conducive to its own survival and development. The stronger the ability of human beings to transform the environment, the stronger the role of the environment on human beings. While human beings are transforming the environment, they also bring a lot of wastes to the environment, causing environmental pollution, adversely affecting human health and even endangering life.
(1) natural environment
The natural environment of human beings, also known as the material environment, can be divided into two categories. One kind refers to the natural primary environment, such as air, water and soil. The other is the secondary environment, which is caused by the additional influence of industrial and agricultural production and human settlement on nature and changes the living conditions of human beings. It is the main environmental factor endangering human health.
(2) Social environment
Social environment, also known as immaterial environment, refers to the external world in contact with social subjects. Its subject includes individuals and groups. Social environment is composed of political system, economic culture, education level, population status, human behavior and other factors, and it is an environmental system formed by material production system created by human beings through long-term conscious social labor and accumulated material culture.
Environment and health
(1) Health hazards of air pollution
① Air pollutants enter the human body in a large amount in a short time, which will lead to acute harm. The reasons are as follows: first, the meteorological conditions in polluted areas have changed, and a large number of pollutants have accumulated at low altitude and cannot spread; The other is that accidental discharge makes a large number of harmful substances enter the atmosphere in a short time, causing serious pollution.
② Chronic hazards
Living in a low-concentration polluted air environment for a long time will cause chronic potential harm to the body and increase the incidence of chronic respiratory diseases. For example, smoking causes lung cancer, asbestos causes asbestosis, and silica causes silicosis.
③ Carcinogenesis
Carcinogenesis of air pollutants is another manifestation of chronic harm, and it is one of the important reasons for the rising incidence and mortality of modern lung cancer. Experiments have proved that more than 30 kinds of air pollutants have carcinogenic effects, the most prominent of which is polycyclic aromatic hydrocarbons, represented by 3,4-benzopyrene. It is a highly active carcinogen formed by incomplete combustion of coal, oil, natural gas and wood. 3,4-benzopyrene can be separated from soot, coal tar, automobile exhaust, aircraft exhaust and asphalt dust. The carcinogenicity of some elements such as arsenic, lead, cadmium, chromium and beryllium has been confirmed in animal experiments.
(2) Health hazards of water pollution
Water is a basic component of human body, and it is also an indispensable substance for life activities and industrial and agricultural production. Water is a valuable natural resource. Water body is a natural water body with land as a relatively stable boundary. If many foreign substances are mixed into natural water sources, the water quality will be reduced, and the impurities will be reduced by physical methods such as dilution, mixing, volatilization and precipitation, chemical methods such as oxidation, reduction, acid-base neutralization, combination and decomposition, as well as the degradation of organic substances by aquatic organisms. This is the self-purification ability of water bodies. When the quality of discharged substances exceeds the self-purification ability of water, the physical and chemical properties of water change, the water quality deteriorates and the use value of water decreases, which is called water pollution.
(3) Harm of soil pollution to health
After the soil is polluted to a certain extent, due to the mechanical action and physical, chemical and biochemical actions of the soil, pathogens are killed, and organic matter is decomposed to produce humus and inorganic salts that are sanitary and harmless and can be used by plants, which is called soil self-purification. When soil is polluted by organic wastes or poisons, its content exceeds the self-purification ability of soil itself, soil pollution is formed. After the soil is polluted, the impact on human body is mostly indirect. Mainly through the soil-plant-human body or soil-water-human body these two basic links have an impact on the human body. The impact on health is as follows:
① cause poisoning
The wastewater discharged from industrial "three wastes" contains heavy metal poisons such as lead and cadmium, which can cause chronic cadmium poisoning (pain) and lead poisoning through rice after irrigation; Chronic arsenic poisoning and mercury poisoning caused by pesticide pollution in soil containing arsenic and mercury; After "three wastes" and pesticides pollute the soil, surface water and groundwater are polluted by rainwater, and people can cause poisoning through drinking water, food and livestock feed.
② Inducing cancer
Recent studies have further confirmed that cadmium, phenoxy herbicides and chlorophenol pesticides have carcinogenic effects on people. The soil is contaminated by radioactivity. External irradiation and internal irradiation (through respiratory tract and digestive tract) can not only induce cancer, but also lead to dizziness, fatigue, alopecia and leukopenia or increase.
③ spreading diseases.
Soil polluted by feces, garbage and sewage containing pathogens can become the transmission medium of related diseases, such as typhoid fever, paratyphoid fever, dysentery and tuberculosis. There are also tetanus, gas gangrene, botulinum and so on. It can survive in soil for a long time and become an important source of infection for people infected with these diseases.
(4) the impact of noise on health
Any incongruous sound that interferes with people's normal rest and sleep and affects people's normal work, study, thinking and conversation is noise. China stipulates that the post noise intensity of working 8 hours a day: newly-built enterprises should not exceed 85 decibels, and existing enterprises should be appropriately relaxed to 90 decibels. The main noise sources in daily life and production are:
① Industrial noise: the impact noise and motor roar from various machinery and high-speed equipment in the factory, such as the noise generated by looms, pneumatic tools, smelting equipment, ball mills, forging, chainsaws, mixers and pile drivers on the construction site.
② Traffic noise: It mainly comes from noise generated by various vehicles, trains, planes and ships. During startup and operation.
(3) Living noise: The main sources are noise from bazaars, high-pitched noise from entertainment places, sports venues and propaganda tools, and noise from home tape recorders, televisions, washing machines and sewing machines.
The harm of noise to human health can be reflected in the nervous system, cardiovascular system and digestive system, but the effect on the nervous system is the most direct. Long-term exposure to noise has adverse effects on people's nervous system, mainly manifested in hearing loss; Noise can also cause neurasthenia syndrome such as headache, dizziness, tinnitus, palpitation and sleep disorder; The damage to cardiovascular system is mainly manifested in the acceleration or deceleration of heart rate and unstable blood pressure; Can cause gastrointestinal dysfunction, loss of appetite, emaciation, decreased gastric juice secretion, and slow down gastrointestinal peristalsis of the digestive system.
(5) The influence of social environment on human health.
Social environment has great influence and restriction on people's health. As a group of high school students who are experiencing the process of growth, development and socialization, they are also deeply influenced and restricted by the social environment without exception. There are more than 800,000 primary and secondary schools and 1 1,000 institutions of higher learning in China, with more than 200 million students, accounting for more than 1/5 of the population of China. They not only account for a large proportion of the social population, but more importantly, they represent the future of mankind and the hope of national rejuvenation and national prosperity. Therefore, it is of great and far-reaching significance to study various social factors that affect their healthy growth, especially family environment, school environment, peer groups and socio-political, economic and cultural environment, so as to lay a good foundation for their physical and mental health before entering society.