Environmental pollution affects health liability insurance. As a market-oriented institutional arrangement to solve the problem of compensation for environmental infringements, protect the legitimate rights and interests of victims, and strengthen environmental management and control, it has attracted increasing attention. Below are the papers related to environmental pollution and human health that I have carefully compiled for you. I hope it will be helpful to you!
Papers related to environmental pollution and human health Part 1
Abstract: As we all know , Environmental pollution not only causes irreparable damage to nature, but also causes various harms to human health. This article reviews the impact of the current status of my country's atmospheric environment on human health in recent years, including the acute and chronic effects of air pollutants on human health, the effects of changes in meteorological factors inducing cardiovascular and cerebrovascular diseases, respiratory diseases and immune function.
Keywords: air environment; air pollutants; total suspended particulate matter; meteorological factors; human health
1. Air pollutants
Air pollutants are atmospheric Pollutants are foreign substances that enter the environment near the ground or in the lower atmosphere, usually in gaseous form. Such as nitrogen oxides, sulfur oxides and carbon oxides, as well as flying dust, suspended particles, etc., and sometimes formaldehyde, radon and various organic solvents, which have adverse effects on the human body or the ecosystem. The main air pollutants include: carbon monoxide (CO), nitrogen oxides (NOx), hydrocarbons (H air pollutants C), sulfur oxides and particulate matter (PM), etc.
2. What are the effects of pollutants in the air on the human body?
2.1 The main hazards of sulfur dioxide SO2: forming industrial smog, making it difficult to breathe at high concentrations, and is the famous London smog The culprit of the incident; after entering the atmosphere, it is oxidized into sulfuric acid (SO4) to form acid rain in the clouds, which is very harmful to buildings, forests, lakes, and soil; it forms suspended particulate matter, also known as aerosol, which enters the lungs as people breathe and is harmful to There is direct damage to the lungs.
2.2 The main hazards of suspended particulate matter TSP (such as dust, smoke, PM10): it enters the lungs with breathing and can be deposited in the lungs, causing respiratory diseases. Particulate matter easily adheres to a variety of harmful substances, some of which are carcinogenic, and some can induce pollen allergies; they are deposited on the leaves of green plants, interfering with the process of plants absorbing sunlight and carbon dioxide and releasing oxygen and water, thereby affecting the health and growth of plants; Heavy particulate matter concentration will affect the respiratory system of animals; kill microorganisms, cause changes in the food chain, and then affect the entire ecosystem; block sunlight and may change the climate, which will also affect the ecosystem.
2.3 The main hazards of nitrogen oxides Nox (such as NO, NO2, NO3): irritate people's eyes, nose, throat and lungs, increase the incidence of viral infections, such as causing bronchitis and pneumonia Influenza induces cancer in lung cells; forms urban smog, affecting visibility; destroys leaf tissue and inhibits plant growth; forms nitric acid droplets in the air, producing acid rain.
2.4 The main hazards of carbon monoxide CO: It is easily combined with hemoglobin that carries oxygen in the blood, and the binding speed is 250 times faster than oxygen. Therefore, at extremely low concentrations, it can cause hypoxia to humans or animals. harm. In mild cases, it may cause dizziness and headache; in severe cases, brain cells may be permanently damaged or even suffocate to death; it is very harmful to patients with heart disease, anemia and respiratory diseases; it may cause fetal growth impairment and mental retardation.
2.5 The main hazards of volatile organic compounds VOCs (such as benzene, hydrocarbons): easily produce photochemical smog under the action of sunlight; have direct toxicity to plants and animals at a certain concentration; are harmful to the human body There is a risk of causing cancer and leukemia.
2.6 Photochemical oxides (such as ozone O3) Main hazards: Low-altitude ozone is the strongest oxidant and can react with almost all biological substances. It can damage rubber and paint at very low concentrations. , fabrics and other materials; ozone has a great impact on plants. When the concentration is very low, it can slow down plant growth. When the concentration is high, it kills leaf tissue, causing the entire leaf to wither, and ultimately causes plant death. For example, the death of trees along the highway has been analyzed to be related to ozone; ozone has many effects on animals and humans. Harmful effects, especially damage to the eyes and respiratory system, aggravation of asthma-like allergies.
2.7 The main hazards of toxic trace organic pollutants (such as polycyclic aromatic hydrocarbons, polychlorinated biphenyls, dioxins, formaldehyde): they are carcinogenic; they have the effect of environmental hormones (also called environmental hormones).
2.8 The main hazards of heavy metals (such as lead and cadmium): Heavy metal particles enter the human body with breathing. Lead can damage the human nervous system and reduce children’s learning ability. Cadmium can affect bone development and is extremely harmful to children. ; Heavy metal particles can be directly absorbed by plant leaves, or they can be absorbed by plants after falling into the soil and enter the human body through the food chain; heavy metal particles falling into rivers move with the water flow, or are deposited in ponds, lakes, or flow into the ocean. It is absorbed by aquatic organisms, accumulates in the body, and eventually enters the human body along with aquatic products.
2.9 The main hazards of toxic chemicals (such as chlorine, ammonia, fluoride): direct harm to animals, plants, microorganisms and human bodies.
2.10 The main hazards of unpleasant odors: directly causing discomfort or injury to the human body; being toxic to plants and animals; destroying the living environment of microorganisms, thereby changing the entire ecological situation.
2.11 Radioactive substances Main hazards: Carcinogenic and can induce leukemia.
2.12 The main hazards of greenhouse gases (such as carbon dioxide, methane, chlorofluorocarbons): block the heat from the ground from radiating to outer space, causing the earth's surface temperature to rise, causing climate warming and large-scale disasters floods, storms or droughts; increasing summer heat, increasing the incidence and mortality of cardiovascular diseases in summer; climate warming will cause the glaciers in the North and South Poles to melt, causing sea levels to rise, with the result that low-lying island countries and Coastal cities are flooded; climate warming will continue to expand the desertification area on the earth, straining global water and food supplies.
3. There are three main ways for harmful substances in the air to invade the human body and cause harm:
After the atmosphere is polluted, due to the different sources, properties and duration of the pollutants, the Differences in meteorological conditions, geographical environment and other factors in polluted areas, as well as differences in people's age and health status, will cause different harm to the human body. Harmful substances in the atmosphere invade the human body and cause harm mainly through the following three ways: (1) Entering the human body through direct breathing; (2) Adhering to food Or dissolve in water, allowing it to invade the human body with food and drink;
(3) Enter the human body through contact or irritation of the skin. Among them, invading the human body through breathing is the main way and the most harmful. The harm of air pollution to humans can be roughly divided into three types: acute poisoning, chronic poisoning, and carcinogenesis.
4. Other hazards to human health
After air pollution, due to the differences in the source, nature, concentration and duration of pollutants, the meteorological conditions and geographical environment of the polluted area, etc. Differences in factors, even people's age and health status, will cause different harms to each person.
The impact of air pollution on the human body is first to feel uncomfortable, and then there will be a reversible physiological reaction, and further, acute harmful symptoms will appear. The harm of air pollution to humans can be roughly divided into three types: acute poisoning, chronic poisoning, and carcinogenesis.
(1) Acute poisoning
When the concentration of pollutants in the air is low, it usually does not cause acute poisoning of the human body. However, under certain special conditions, such as in factories, Special accidents during the production process, large amounts of harmful gases leaking out, sudden changes in external weather conditions, etc. can cause acute poisoning of people. For example, the leakage of methyl isocyanate from Pabol Pesticide Factory in India directly harmed the human body, killing 2,500 people and injuring more than 100,000 people.
(2) Chronic Poisoning
The chronic toxic effects of air pollution on human health are mainly manifested in the illness that occurs after pollutants act continuously on the human body at low concentrations for a long time. rate increases, etc. In recent years, the incidence of lung cancer among urban residents in China has been very high, with the highest incidence rate in Shanghai. Respiratory diseases among urban residents are significantly higher than those in suburban areas.
(3) Carcinogenesis
This is the result of long-term effects. It is due to pollutants acting on the body for a long time, damaging the genetic material in the body and causing mutations. If the germ cells mutate If it causes various abnormalities in the offspring, it is called teratogenesis; if it causes sudden changes in the genetic material and genetic information of the organism's cells, it is also called mutagenesis; if it induces tumors, it is called carcinogenesis. The "cancer" referred to here includes benign tumors and malignant tumors. Carcinogens in the environment can be divided into chemical carcinogens, physical carcinogens, biological carcinogens, etc. The carcinogenesis process is quite complex and generally has an initiation stage and a growth promotion stage. Factors that can induce tumors are collectively called carcinogens. Tumors caused by long-term exposure to carcinogens in the environment are called environmental tumors.
5. Countermeasures and measures to solve or alleviate air pollution
5.1 People’s aspect
Use less plastic bags, cloth bags for shopping, and vegetable baskets for groceries , use trash cans to carry garbage. Instead of disposable batteries, use rechargeable batteries, and hand used batteries to a battery recycling station. Use less chemical detergents, makeup, and care products, such as hair dyes, to reduce water pollution and harm to your own health. Do not capture, sell, or kill wild animals, and do not eat wild animals. If you encounter such things, report them. Care for wild animals, do not disturb them, and do not invade, occupy or destroy their territory. Protect your home and don't litter in public places. Garbage classification, food scraps and peels are put together, fermented at high temperatures to make fertilizers, glass and plastics are put together for recycling and regeneration, increasing the garbage recycling rate and reducing pollution. Save water, save electricity. Save paper. Don’t cut down trees indiscriminately. 10. When traveling, try to walk instead of driving, riding a bicycle, taking a bus or train. Try not to drive a car alone.
5.2 Government and enterprises
Formulate strict atmospheric environment quality standards, limit emissions from stationary pollution sources and automobile pollution sources, and strengthen the management of emission control areas.
Adjust the energy structure, increase the proportion of non-polluting or less polluting energy, and develop solar energy, nuclear energy, hydro energy, wind energy, geothermal energy and other energy sources that do not produce acid rain pollution.
Actively develop new technologies for the utilization of coal, promote coal purification technology and conversion technology, improve coal burning technology, improve pollutant control technology, and adopt major measures such as flue gas desulfurization and denitrification technology.
Strengthen the monitoring and scientific research of air pollution, timely grasp the emission and migration status of sulfur oxides and nitrogen oxides in the atmosphere, and understand the spatial and temporal changes and development trends of acid rain in order to take timely countermeasures.
Adjust industrial layout, transform serious polluting enterprises, improve production technology, increase energy utilization, and reduce pollution emissions.
Paper 2 on Environmental Pollution and Human Health
The most direct and easily felt consequence of environmental pollution is the degradation of the quality of the human environment and its impact on human life. Quality, physical health and productive activities. For example, urban air pollution causes air pollution and increases people's morbidity rates; water pollution worsens the quality of the water environment and generally reduces the quality of drinking water sources, threatening people's health and causing premature birth or malformation of fetuses. Serious pollution incidents not only bring health problems, but also cause social problems. With the intensification of pollution and the improvement of people's environmental awareness, disputes and conflicts among people caused by pollution are increasing year by year.
Because people did not fully anticipate the negative impacts of highly developed industries and failed to prevent them, they have led to three major global crises: resource shortages, environmental pollution, and ecological destruction. Human beings continue to discharge pollutants into the environment. However, due to the diffusion, dilution, redox, biodegradation, etc. of the atmosphere, water, soil, etc. The concentration and toxicity of pollutants will naturally decrease. This phenomenon is called environmental self-purification. If the discharged substances exceed the self-purification capacity of the environment, adverse changes in environmental quality will occur, endangering human health and survival, and environmental pollution occurs.
At present, environmental pollution problems have occurred to varying degrees around the world. Aspects with global impact include atmospheric environmental pollution, ocean pollution, urban environmental problems, etc. With the globalization of economy and trade, environmental pollution has increasingly shown an international trend. The problem of transboundary transfer of hazardous wastes that has emerged in recent years is a prominent manifestation in this regard.
1. The harm of air pollution to the human body
The air mainly contains nitrogen and oxygen. Oxygen is what humans and animals need most, accounting for about 21% of the air; if When the oxygen content in the air drops to 16%, the burning candle will be extinguished; if it drops to 7%, people and animals will soon be suffocated to death. The air also contains gases and substances such as water vapor, carbon dioxide, sulfur oxides, nitrogen oxides, and dust. If the content of harmful gases and dust such as sulfur oxides, nitrogen oxides, and dust in the air is too high, the air is polluted. The more harmful gases and dirt are mixed in the air, the more likely the air will be polluted. The more severe it is, the greater the harm to humans, animals and plants. Air pollution first harms people's health, secondly affects the growth of animals and plants, and can also cause global climate change.
Air pollution causes respiratory diseases in the human body and increases mortality in the population. The lung cancer mortality rate in severely polluted areas in Chongqing has increased year by year, exceeding 50 people per 100,000 people, which is 4.7 times higher than in relatively clean areas. The lung cancer mortality rate in individual neighborhoods in Changsha City is as high as 94.36 people/100,000.
2. The harm to the human body caused by the enhanced greenhouse effect and climate warming
In recent decades, due to the impact of human activities, especially the sharp increase in energy consumption, and the destruction of forests Destruction, resulting in increasing carbon dioxide content in the air, increasing the greenhouse effect and warming the world's climate. This will increase the incidence of respiratory diseases, cancer, headaches, etc., and encourage the occurrence and spread of tropical epidemic diseases such as malaria.
3. The impact of acid rain on human production and life. Acid rain is called the god of death in the air. It can acidify soil and lakes, causing forests to decline and wither, and many aquatic organisms to be unable to survive. And then affect human production and life. Moreover, acid rain also has an erosive effect on cultural relics and buildings.
4. The impact of water pollution.
The consequences of water environment pollution are serious. Not only has industrial and agricultural production suffered losses, but the catch of freshwater fish has also dropped significantly. Many rare fish species such as Yangtze River shad and Heilongjiang haha Fish production dropped sharply, and some even disappeared. Deaths of fish and poisoning of humans and animals caused by pollution occur frequently across the country. The incidence of digestive system cancers such as liver cancer, stomach cancer, and esophageal cancer increases year by year across the country. my country's water environment pollution has reached a point where it must be controlled.
5. Noise pollution has a great impact on residents’ lives and health
According to statistics from 29 environmental protection departments, more than 30% of letters and visits from the public reported noise problems. . The incidence rates of deafness, high blood pressure, heart disease, and neurasthenia among some factory workers are as high as 30% to 60%. According to statistics from the Otolaryngology Department of Shanghai First Hospital, about 1/3 of patients with ear diseases are caused by noise. In some areas, noise has threatened the intellectual development of young people. Relevant departments predict that if no measures are taken, 85% of my country's urban residents will be unable to work and live normally by the end of this century.
The root cause of the problem of water pollution lies in environmental pollution. This year, the promotion of environmental protection has reached the point of speaking out. However, protection only exists in people's hearts, and the external environment has not changed much.
Technology is a double-edged sword that brings us convenience but at the same time harms the water sources we depend on for survival. Only by producing higher-tech water filtration equipment can we reduce the impact of water pollution on human health.
As we all know, water, like sunlight and air, is an indispensable material condition for the survival of all life on earth and indispensable for human production activities. Maybe you can't imagine that water, regarded as the source of life, is quietly threatening our lives after being seriously polluted. Pollution has made water a heavy topic in life. 80% of human diseases are related to water. Drinking water safety mainly includes water quantity and quality. At present, drinking water quality problems in some rural areas of our country are very prominent. One of the causes of water quality problems is man-made, that is, water pollution, and the other is natural, that is, high fluorine water, high arsenic water, brackish water formed by the geology itself, etc. In the south, there is also the problem of schistosomiasis epidemic water. Long-term drinking of high-fluoride water can cause dental fluorosis in mild cases, and osteoporosis, bone deformation, or even paralysis and loss of working ability in severe cases. In fluoride-affected areas, dental fluorosis, "bucket legs" and hunchback disease frequently occur, which directly affects the schooling, military service, employment and marriage of school-age people.
In some places, villagers are only 0.8 to 1.4 meters tall. "Short Village" has appeared, and the villagers are suffering from tremendous physical and psychological pain. In recent years, diseases caused by drinking high arsenic water have been newly discovered in Inner Mongolia, Shanxi, Xinjiang, Ningxia and Jilin. Long-term drinking of water with excessive arsenic can cause arsenic poisoning, which can lead to skin cancer and cancer of various internal organs. Brackish water mainly tastes bitter and is difficult to drink directly. Long-term drinking can lead to gastrointestinal dysfunction and low immunity. In Shangba Village in Wengyuan County, Guangdong Province, poisonous water pollution that seriously exceeds the standard has caused serious damage to the health of the villagers. Skin diseases, liver diseases, cancer, etc. are high-risk diseases in the village. According to incomplete statistics, 250 people died in Shangba Village from 1986 to 2001, including 160 people under the age of 50, accounting for 64% of the deaths; 210 people died of cancer, accounting for 84% of the deaths. , the youngest person who died from cancer was only 7 years old. According to a World Health Organization survey, 80% of human diseases are related to water. According to statistics, more than 25 million children in the world die every year from drinking contaminated water. Relevant data shows that 24% of people in our country drink water of poor quality, about 10 million people drink high-fluoride water, about 30 million people drink high-hard water, and 50 million people drink high-fluoridated sewage. These data show up every year. Uptrend. According to statistics, 5 million people in China die from diseases caused by water pollution every year. This cold data is enough to prove that water, the source of life on which human beings depend for survival, is suffering from increasingly serious pollution and has become the number one killer of human life. According to relevant sources, there are more than 2,000 kinds of organic pollutants detected in water at home and abroad, 114 of which are or suspected to be carcinogenic, teratogenic, and mutagenic? Can detect more than 100 kinds of organic pollutants. According to surveys, some farmers in Shaoguan, Heyuan and other cities in Guangdong have suffered from cases of underdevelopment, mental retardation, dementia, deformities and other cases in their newborns due to long-term drinking of water contaminated with radioactive and harmful minerals. In some rural areas in Maoming, Shantou and other cities, after drinking contaminated shallow groundwater, not a single young man passed the annual military conscription physical examination since 1989, and the physical examination concluded that liver function was abnormal.
Paper 3 on Environmental Pollution and Human Health
The basis of human health is the human living environment. Only an ecosystem with rich biodiversity, stability and sustainable development can ensure There are many factors that affect the stability and sustainable development of human health. The more important ones include lifestyle factors, environmental factors, biological factors and health care service factors. Among them, environmental pollution is the enemy of human health. The closest relationship to the environment is that life uses elements in the environment to build itself.
1. The relationship between human health and chemical elements
The human body contains a large number of chemical elements. Among these elements, except for carbon, hydrogen, oxygen, and nitrogen, which can form various organic substances in the body, other elements have certain chemical forms and structures to form various biological complexes, functional proteins, enzymes, etc., which are present in human tissues. in, or as a material from which the human body is composed. Either as a carrier of blood oxygen transport, or as an activator of enzymes, or as a regulator of electrolyte balance in body fluids, or as a correspondent for information transmission between human cells, these elements work together to complete the metabolic functions of the human body. .
However, due to the long-term evolution process of human beings, they have not formed an ecological adaptation mechanism to the elements that have changed greatly in terms of quantity and quality in the modern social environment. Some elements in the environment are harmful to the human body. Some are necessary, some are non-essential, not optional. Any chemical element in the human body that exceeds a certain standard will become a harmful element to the human body. For example, iron is an essential element for the human body. It plays the role of forming blood, forming hemoglobin, transmitting oxygen, and maintaining organ function. However, excessive intake of iron by the human body will damage the pancreas and gonads, and even cause heart failure, diabetes, and cirrhosis of the liver. Fluorine is also an essential element for the human body. Fluoride plays a positive role in preventing dental caries and promoting tooth growth. Fluorine also participates in various redox reactions and calcium and phosphorus metabolism in the human body. However, excessive fluoride can cause dental fluorosis, skeletal fluorosis and bone hyperplasia.
The contents of most elements in modern humans are higher than those in ancient times, and many of them are harmful to human health. They have hidden toxicity in the human body. When they exceed a certain threshold, the human body will be poisoned and even die.
For example, excessive intake of copper once caused the Toyama Itai-itai disease in Japan, which caused a sensation in the world. Patients who ate rice with high copper content for a long time suffered as many as 72 natural fractures in the whole body, causing screams and pain. Lead is also a potential hazard, and currently its main source is the anti-knock agent in gasoline? Tetraethyl lead. Before the age of gasoline, the ancient Romans had begun using lead in large quantities. The ancient Romans used lead to make containers for storing syrup and cider. Some historians believe that stillbirths, spontaneous abortions and infertility caused by lead poisoning were the reasons for the low birth rate among the upper classes of the Roman Empire, which led to the ultimate decline of ancient Rome. As lead is mined and used in gasoline, more and more lead is found in the environment. Lead poisoning can shorten human lifespan, cause depression, fatigue, anemia, and even affect children's intelligence.
2. The human body’s accumulation of pollutants
The more substances humans use their intelligence to obtain, the more obvious the “Pandora’s Box” effect will be. According to statistics, 96,000 chemicals have entered the human environment. While these chemicals bring huge benefits to human life, they also cause a large number of environmental problems. 100 years ago, the inventor of DDT (Swiss Dürer) won the Nobel Prize for his invention of DDT. Now many countries have listed DDT as a banned substance due to the harm it causes to the environment and human body. .
Modern science has proven that the human body’s accumulation and amplification of toxic substances is astonishing. Studies have shown that wastewater, waste gas, and waste residues from industrial factories and mines are discharged into the environment, causing environmental cadmium pollution. As a result, the rice and other crops grown by local residents contain excessive cadmium. Residents have long-term consumption of cadmium-contaminated grains, vegetables, etc., resulting in a cadmium load in the body. Gradually increasing, the biological half-life of cadmium in the body is as long as 10-30 years, making it the most toxic substance known to accumulate in the body. The continuous accumulation of cadmium can cause various pathological changes in those who are exposed to it. Acute or long-term inhalation of cadmium-containing smoke can cause lung inflammation, bronchitis, emphysema, pulmonary fibrosis and even lung cancer. Renal lesions mainly caused by long-term, low-dose exposure to cadmium pollution are manifested by reduced renal tubular absorption function and increased low-molecular-weight protein content in urine. When cadmium is poisoned, the absorption rate of calcium and phosphorus in the kidneys decreases, and the metabolism of vitamin D is abnormal. If things go on like this, it can lead to osteoporosis or osteomalacia in those exposed to cadmium. Cadmium can also cause tumors in the lungs, prostate and testicles. All are due to the food chain and bioaccumulation amplification. The famous physicist Newton died in 1692 due to severe insomnia, indigestion, forgetfulness, worry and delusions. More than 100 years later, people analyzed the hair samples of the great physicist and found that Newton died of lead, arsenic, and cadmium poisoning. These elements were leaked when Newton used metals for alchemy experiments. Newton would never have imagined that his body would absorb his alchemy elements and he would die as a result.
3. The pathways and hazards of environmental pollutants entering the human body
Environmental pollutants that have an impact on human health mainly come from wastewater, waste gas, and waste residues formed during industrial production processes, including urban Garbage etc. The characteristics of environmental pollutants affecting human health include: first, a large scope of influence, because all pollutants flow with the biogeochemical cycle and have an impact on all contacts; second, they have a long action time, because many toxic substances are present in Degradation in the environment and in the human body is slow.
The main ways in which environmental pollutants enter the human body are through the respiratory tract and digestive tract. They can also enter through the skin and other ways. Gaseous pollutants generally enter the human body through the respiratory tract. Due to the different structures of various parts of the respiratory tract, the absorption rates of pollutants are also different. The alveolar area of ??the human body reaches 90 square meters, and poisons are absorbed by the lungs very quickly, second only to intravenous injection. The diameter of pollutants entering the alveoli generally does not exceed 3 μm, while most particulate matter with a diameter greater than 10 μm adheres to the mucosa of the respiratory tract, trachea and bronchus. Gaseous substances that are more water-soluble, such as chlorine and sulfur dioxide, are often dissolved by the upper respiratory tract mucosa and irritate the upper respiratory tract, and rarely enter the alveoli; while most of the gaseous poisons that are less water-soluble (such as nitrogen dioxide, etc.) can reach the alveoli. . After pollutants enter the human body, they are transported to various tissues of the human body by the blood. Different toxic substances are distributed differently in various tissues of the human body. Generally speaking, heavy metals are often distributed in the bones of the human body, while organic pesticides are often distributed in fat tissue. Toxins are hidden in tissues for a long time and can accumulate in tissues, causing potential danger to the body. The liver, kidney, gastrointestinal and other organs of the human body have certain biological transformation effects on pollutants.
Among them, the liver is the most important. The metabolic process of pollutants in the body can be divided into two steps. The first step is redox and hydrolysis. This metabolic process is mainly related to the mixed function oxidase system; the second step is the conjugation reaction, which usually goes through one or two steps of reaction. The originally active toxic substances may be converted into inert substances and play a detoxifying role. After being biotransformed in the body, various pollutants are excreted through the kidneys, digestive tract and respiratory tract. A small amount is excreted through sweat, milk, saliva and other secretions. Some of them reach the hair through the metabolism of the skin and leave the body. Different pollutants have different critical concentrations and critical times that harm the body. Harm will only occur when environmental pollutants accumulate in the body and reach the poisoning threshold.
The continuous new diseases in recent years have made us worry about whether the environment we live in can still allow us to survive. According to incomplete statistics, from the Ebola hemorrhagic fever that appeared in Zaire in 1977 to the SARS that appeared in China in 2003, more than ten disease pandemics have broken out around the world. In addition to the bird flu that has recently ravaged Europe and Asia, People can't help but ask: Why are infectious disease outbreaks so frequent now? There may be several reasons. First, human activities have caused changes in the ecological environment. South America and Asia, which have large areas of tropical rainforest, are now hard to see what they used to be. And due to the destruction of human activities, the rainforest, known as the "kidney of the earth," has also suffered a lot of damage. Asia has the largest population in the world, and due to the imbalance between economic development and population growth, it needs to claim a large amount of natural resources from land; and a large number of slums in South America are gradually integrated into cities, which inevitably leads to the occurrence of various diseases and plagues . Research on the 1998 outbreak of disease caused by the Nipah virus in Malaysia showed that the outbreak was closely linked to deforestation. Due to the large reduction in forest area and lack of food, flying foxes are forced to migrate from the forests where they have lived for generations to farmhouse orchards to feed. Many pig farms in Malaysia are adjacent to orchards. The pigs eat fruits contaminated by flying foxes, which can cause fatal diseases. viruses brought into human society. Secondly, population movement accelerates the spread of diseases. Disease is likely to spread as people move around. The world influenza pandemic is considered the largest plague in the history of the world. It first appeared in the United States. It became popular in France when the American Expeditionary Force brought it to France during World War I, and spread throughout the world from January to May of the following year. There was also SARS, which first appeared in Guangdong, my country, in 2002. In a short period of time, it Mass spread and human activities cannot but be said to be a very important reason.