Encyclopedia of Family Medicine

Chapter 7 Environmental Hygiene and Self-Care (1)
human beings live in the environment

Environment refers to the sum of objective things surrounding people.The external conditions that human beings depend on for survival are called the human environment, that is, everything outside the human body belongs to the environment.The environment affects humans, and human activities are constantly changing the environment.The human living environment is formed by the interaction between the natural environment and the social environment.

Human beings cannot survive without the environment.For example, food, water, oxygen, etc. in the environment are all necessary for survival.But in the natural environment, there are also a large number of factors that endanger health.For example, pathogenic microorganisms, poisonous animals and plants, geological damage, such as earthquakes, volcanic eruptions, etc.

Various factors in the environment are as follows:
Necessities for life: food, water, oxygen, certain wavelengths of ultraviolet light.

Physical factors: temperature, air pressure, vibration, electromagnetic radiation, noise, etc.

Biological factors: microorganisms, toxins, allergens, biological waste, biological antagonists (animal, vegetable).

Chemical factors: inorganic substances, metals, rare earth metals, metalloids (elements and their compounds).

Organic matter: aliphatic hydrocarbons, aromatic hydrocarbons, etc.

Production waste: combustion products, macromolecular products, industrial waste.agricultural waste.

Social and psychological factors: customs, crowding, needs, life, rhythm, cultural education, etc.

Natural Environment and Ecological Balance

The area in which humans and creatures live on the surface of the earth is called the biosphere.Various plants, animals and microorganisms are distributed in the biosphere, and they together form a biological community, interact with the surrounding environment, and constantly exchange material, energy and information, and together form a complex of organisms and the environment, this is the ecosystem.An ecosystem is a complex, time-varying dynamic system in which energy, matter, and information are exchanged and transferred continuously, forming a continuous flow.When this operation is in balance, it is called ecological balance.However, this balance is relative.When some internal factors or external conditions of the ecosystem change, the balance of the ecosystem will be affected, and in severe cases, it will be destroyed.Therefore, the ecological system is always in the process of unbalanced-balanced-unbalanced development, and exchanges material and energy, promoting its own evolution and development.

The destruction of ecological balance has both natural and human factors.Natural causes mainly refer to the damage to the ecosystem caused by the changes in nature, or the harmful factors existing in nature, such as volcanic eruptions, earthquakes, tsunamis, floods, epidemics, endemic diseases and other natural disasters.Man-made factors are man-made damage caused by human production and living activities, such as the pollution of the environment by the three wastes, and the environmental degradation caused by the blind development of natural resources.It not only destroys the ecological balance, leads to the degradation of the ecosystem, but even disintegrates the entire ecosystem, causing immeasurable harm to human beings, and this damage is often difficult to reverse.Therefore, the protection of ecological balance is to maintain the basic conditions for the survival of human beings, and should be widely concerned by people.

environmental impact on health
The environment has a great impact on health. It can be said that all human health problems are more or less related to the environment, except for a few diseases that are purely genetic factors such as tay-eyed idiots and sickle cell anemia.

With the development of modern science and technology, profound changes have taken place in people's lifestyle and living environment, and a series of diseases have emerged as the times require.Modern urban life makes more and more people live in high-rise buildings. People living on high-rise buildings cannot enjoy the full protection of the geomagnetic field, and suffer from intractable headaches and insomnia, sometimes accompanied by dizziness, diarrhea, dermatitis and joint pain. .For this kind of disease, the treatment effect is usually satisfactory after taking artificial magnetic fields such as magnetic pillows and magnetic chairs as supplementary adjustments.

Dazzling light sources, such as dazzling multicolored lights, neon lights, stage, and dance halls in the market, not only endanger people's vision, but also interfere with the function of the central nervous system of the brain.Long-term exposure to this dazzling light source will cause severe headaches, upset and insomnia, and some people will also experience syndromes such as difficulty concentrating, rapid memory loss, and loss of appetite.

Microwave is widely used in modern science, which belongs to a kind of high-frequency electromagnetic radiation.Radio transmitters, TV relay stations, and radars are scattered all over the place, and high-voltage wire networks and electrified railways criss-cross.Long-term exposure to microwave radiation can cause harm to the functions of the human central nervous system and cardiovascular system.People who have been engaged in various microwave operations for a long time have a high proportion of headaches and insomnia.People living nearby, due to the influence of microwave radiation, some people will have symptoms such as headache, fatigue, insomnia or lethargy.

The quality of the living environment is important
The living environment is directly related to the prosperity and development of human beings.Scientists have shown that places with many long-lived people in the world, such as the Caucasus in the Soviet Union, the Andes in South America and southern Bulgaria, all have a beautiful natural environment.

There are 10 centenarians per 30 people in Bama County, Guangxi, China, which ranks first in the country.Dr. Keiichi Morishita, president of the International Association of Natural Medicine, visited Bama and announced in Japan on November 1991, 11 that the Association of Natural Medicine listed Guangxi, China, as the fifth longevity town in the world.Through investigation and research, it is analyzed that these long-lived elderly people first have a good natural environment.Bama is located in the subtropical monsoon climate zone, with rich vegetation, fresh air, plenty of sunshine, and no industrial pollution. All centenarians live in mountainous areas at an altitude of 1-250 meters.A good natural ecological environment is conducive to reducing diseases and delaying aging.

People who live in the downtown all hope to have a comfortable and beautiful living environment, and some trees and flowers can be planted in the courtyards of residents.Trees and flowers can not only weave green shade for the courtyard and purify the air, but also produce a "phytoncide" secretion during its growth activities, which can kill some protozoa, bacteria, and fungi.Such as pepper, tansy, peony, pine and cypress, etc. can repel mosquitoes, flies, bedbugs, and fleas; the secretions of Chinese toon, Ailanthus sinensis, safflower, poppies, etc. can volatilize strong irritating gases, killing bacteria and insects in the air. some insects.At the same time, flowers, plants and trees have the function of preventing wind and retaining dust, which can promote the exchange of hot and cold air, form a breeze in the community, and keep the ambient air fresh.In short, courtyard greening can create a beautiful, clean and comfortable living environment, and make people's living room buildings blend in a state full of vitality.

A beautiful environment is conducive to human health, prolongs life, and can promote the development of human civilization.

The dangers of environmental pollution

Broadly speaking, when the natural environment is affected by external factors and changes its original state, it is polluted.For pollution caused by natural factors, the ecosystem has a certain regulatory function. Within a certain range, natural pollutants can be recovered through self-purification without causing obvious harm.

The current environmental pollution mainly refers to changes in the composition or state of the environment due to various human factors, causing direct or indirect or potential harm to people's health.

There are many reasons for environmental pollution, mainly including three aspects: chemical, physical and biological.The common sources of environmental pollution are as follows:
Productive pollution: The three wastes (waste water, waste gas, and waste residue) formed by industrial production cause pollution of air, water, soil, food, etc.; the use of pesticides (insecticides, herbicides, etc.) in agricultural production causes pesticides in crops and livestock products residual.

Living pollution: improper disposal of domestic wastes such as garbage, sewage, excrement and urine can pollute the air, soil, water, food, and hospital sewage can contain pathogenic microorganisms.

Other pollution: noise, vibration and various waste gases generated during transportation, microwaves and other electromagnetic waves generated by electromagnetic wave communication equipment, radioactive waste and fly ash emitted by atomic energy and isotope agencies.

With the development of production, the increase of population, and the continuous expansion of the ability and scope of human development and utilization of natural resources, there have been many public hazards caused by environmental pollution in human history.For example, Minamata disease caused by chronic organic mercury poisoning in Minamata Bay, Japan, and chemical plant poisoning incidents.

chemicals in the environment
In addition to the many naturally occurring chemicals in the environment, there are an estimated 200 million synthetic chemicals.Human activities release 10 to 100 times more chemicals into the environment than volcanoes and rock weathering.A large number of chemical substances have entered the production and living environment of human beings. While being used by human beings, they also have various impacts on human beings.

Chemicals in the environment include:
(1) Naturally occurring chemical substances refer to the main elements in nature and the main substances that constitute living organisms.Some elements are found in very small amounts in living organisms and are called trace elements.

(2) Man-made chemical substances, such as chemical raw materials, intermediates, auxiliary agents, and by-products in the production process, waste water, waste gas, and waste residues generated in the production process, pesticides, and fertilizers used in agriculture.

Cigarettes, hair dyes, cosmetics, toothpaste, and synthetic detergents used in daily life are all products of man-made chemicals.For example, there are friction agents, foaming agents, flavoring spices, wetting agents, thickeners, and some fluorine and preservatives in the toothpaste formula. Long-term intake of toothpaste can cause localized enteritis.Therefore, rinse your mouth several times after brushing your teeth and do not swallow toothpaste, especially for children.

(3) Chemical substances of animal, plant and microbial origin.Some animals and plants contain toxic chemical components, such as puffer fish containing tetrodotoxin; stale fish contains histamine; apricot, peach, plum, loquat kernels and cassava contain cyanogenic glycosides; crude raw cottonseed oil contains toxic cotton phenol.Food poisoning can occur after eating.

Molds are ubiquitous in the environment and use the enzyme system of Aspergillus to ferment sauce and soy sauce, but aflatoxins can cause cancer.

Toxic Effects of Chemical Substances

With the improvement of living standards, people are very particular about home interior decoration.Since most of the decoration materials are chemical products, such as plastic wallpaper, plastic floor or chemical fiber carpet, these products contain formaldehyde, a chemical synthetic material.When formaldehyde is emitted indoors, it will cause the occupants to cough for a long time, runny nose, and even have difficulty breathing.Therefore, rooms with wallpaper or chemical fiber carpets generally have to be opened for half a year before people can live in them.

Improper use of gas water heaters can lead to carbon monoxide poisoning.The oxygen consumption of a water heater is equivalent to 4 gas stoves burning at the same time.Because the water heater consumes a lot of oxygen and will produce multiple harmful gases such as carbon monoxide at the same time, when the carbon monoxide in the indoor air reaches 1000ppm, people can die within 2 hours; when it reaches 3000ppm, people can die in half an hour.If the indoor ventilation is not smooth, it will also cause death due to hypoxic respiratory failure.Therefore, gas water heaters cannot be installed privately.Once installed, you must pay attention to safety when using it, making it a messenger of happiness, not a demon of disaster.

Wooden chopsticks coated with paint, the paint falls off during use and is swallowed by mistake.Paint contains many harmful substances such as lead and chromium, especially after the nitro component is absorbed by people, it will synthesize the carcinogenic ammonium nitrite with nitrogen-containing substances.Therefore, once the paint on the lacquer chopsticks falls off, do not continue to use it.

Plastic bags made of polyethylene or polypropylene are non-toxic to humans.This kind of plastic bag is transparent and slightly milky white, feels smooth when touched, makes a crisp sound when shaken by hand, floats automatically in water, emits a yellow flame and emits a waxy smell when ignited.And another plastic bag made of polyvinyl chloride is harmful to people.Slightly yellow in transparent, sticky to the touch, muffled sound when shaken, sinks to the bottom quickly when put into water, emits green flame when burning, extinguishes immediately when leaving the flame.

Chemicals and Health Effects

Chemical substances enter the human body through the respiratory tract, skin, and digestive tract, causing functional or organic changes.Symptoms and signs of disease appear.According to the speed of the lesion and the characteristics of the action, it can be divided into:
Acute and chronic toxicity: Acute mercury poisoning damages the kidneys; carbon monoxide poisoning causes persistent coma.

Chronic specific toxic effects: including mutagenic effects, carcinogenic effects, and teratogenic effects.If tetracycline is used before 12 weeks of pregnancy or during long-term pregnancy, there is a risk of finger deformities or congenital cataracts.Aflatoxin can cause liver cancer; soot and asphalt can cause lung cancer and skin cancer.

The factors that affect the damage of chemical substances to human body are:
(1) Characteristics of chemical substances: Different chemical substances have different toxic effects.Its physical and chemical properties are determined by its way of entering the body, absorption and distribution.

(2) Dose and duration of action: High doses of exposure produce effects in a short period of time.Low doses require prolonged exposure.

(3) Combined effect of multiple factors: smoking and exposure to asbestos increase lung cancer mortality; acid and alkali antagonize each other; high temperature can promote poison absorption and metabolism; vibration can increase the incidence of mercury poisoning or lead poisoning; D2 and D3 are formed, thereby enhancing the body's anti-rickets effect.

(4) Individual susceptibility: The degree of development, health status, physiological and nutritional status, living habits, and genetic factors of the body can all affect the state of the body's response to chemical substances.For example, fetuses and newborns are more sensitive to certain chemical substances than adults because the detoxification enzyme system has not yet formed, and the elderly have low stress function and are susceptible to adverse effects of chemical substances; women are more sensitive to lead and benzene than men.

physical factors in the environment
In the environment, humans are exposed to a variety of physical factors.The main components of the physical environment are as follows:
Temperature: high temperature, low temperature.

Air pressure: high air pressure, low air pressure.

Sound waves: audible sound, ultrasound.

Vibration: whole body vibration, local vibration.

High-energy particles: neutrons.

Electromagnetic radiation: (1) ionizing radiation: alpha particles, beta particles; (2) ionizing radiation: x-rays, gamma rays; (3) non-ionizing radiation: ultraviolet rays, visible light, infrared rays, rays, microwaves, long-wave radio frequency.

Under natural conditions, physical factors are generally harmless to the body, and some are necessary external conditions for human physiological activities.Only when the intensity and dose exceed a certain level or the contact time is too long can it cause damage to the human body and affect the functions of different organs (such as eyes, ears, skin, fingers or bones, etc.), and some can affect the whole body.Most of the harmful physical factors are related to a large amount of energy consumption, such as radiation and high temperature generated by nuclear power plants, X-rays radiated from poorly shielded TV sets, and so on.

How to prevent heat stroke at high temperature
When the ambient temperature reaches above 34°C, it is called a high temperature environment.The human body can maintain a body temperature of around 37.9°C because the metabolism of various organs and tissues in the body, as well as the heat generated by labor and exercise, can dissipate heat through the skin surface, breathing and sweating, and achieve balance under the regulation of the temperature regulation center.If the body's regulatory function is exceeded and heat balance cannot be maintained, resulting in heat accumulation in the body, heat stroke occurs.

Symptoms of heat stroke include mild headache, dizziness, tinnitus, vertigo, nausea, weakness, thirst and profuse sweating.After leaving the high temperature environment and taking a short rest, the symptoms can subside.

Mild heatstroke, in addition to various symptoms of heatstroke symptoms, the body temperature rises to above 38 ℃, which may be accompanied by facial flushing, chest tightness, dry and hot skin, and some develop into early exhaustion, with pale complexion, profuse sweating, and clammy skin. , rapid pulse, etc.People with these symptoms can basically recover within 5 hours after taking rest and leaving the high temperature environment in time.

Severe heatstroke manifests itself as muscle cramps or passing out.

People with heatstroke should leave the high temperature environment immediately and rest in a cool and quiet place. The patient should lie on his back with his head not elevated, loosen his clothes, drink salty drinks, and take some heat-relieving medicines such as Shidishui and Jieshu Tablets.Folk scraping therapy is also effective in treating heatstroke.Severe heat stroke must be sent to the medical department for emergency treatment.

High temperature heat stroke often occurs in workers who work in high temperature, workers who work in the open air in summer, tourists in summer, the elderly in the family, people who are bedridden for a long time, puerpera and infants.Workers who work in high temperature should improve their working conditions and strengthen their personal protection. In summer, tourists should wear shade hats and loose clothing to ensure drinks and nutrition. At home, pay attention to indoor ventilation.

Sources of Air Pollution

Air pollution mainly refers to the pollutants produced in the process of human production and life, which is the result of the combined effects of factors such as its quantity, concentration, nature, and duration in the atmosphere, which may affect the life of organisms and human health in some areas .Atmospheric pollution is sometimes called air pollution.

There are three types of sources of air pollution:
People use coal, oil, natural gas, firewood, etc., and release a large amount of pollutants into the atmosphere during the combustion process.

When industrial and agricultural solid waste, such as municipal solid waste, is incinerated, many pollutants are discharged into the atmosphere.

Harmful gases emitted during industrial production.

Pollution sources can be divided into two types: stationary sources and mobile sources:
Stationary sources: When air pollutants come from certain fixed units or locations, these units and locations are fixed sources of air pollution.Thermal power plants are the largest stationary source of air pollution. During the production process, a large amount of dust and sulfur dioxide are generated due to coal combustion.There are more than 2000 million tons of pollutants emitted by thermal power plants in the United States every year, of which sulfur dioxide accounts for 50% of the emissions and dust accounts for 25%.In addition, industries such as metallurgy, iron and steel, and chemical industry also have a great impact on air pollution.

Flow source: mainly means of transportation, such as automobiles, trains, planes, ships, etc.Compared with factory pollution sources, the scale is small and scattered, but the quantity is huge and frequent, and the total amount of pollutants they emit is also very considerable.More than 90% of lead pollution in urban air in developed countries comes from automobile exhaust.

(End of this chapter)