Scientific life: ecological environment and human health

The destruction of the ecological environment by natural factors may cause huge damage to human life and property, and even outbreaks of disease. However, the destruction of the ecological environment by natural factors often has obvious regional characteristics, and the frequency of occurrence is relatively low. Human factors such as environmental pollution damage the human ecosystem more severely. It can cause various scales of acute and chronic toxic events, increase the incidence of cancer in the population, and even have a serious impact on the development and health of future generations. Environmental pollution has no national boundaries to destroy the ecology. It not only affects its own country, but may also have an impact on the global ecological environment.

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1. Hot issues on environmental pollution

(1) Air pollution

1. Global warming and human health

Climate warming has increased the incidence of certain diseases spread by biological vectors and endemic in the tropics, such as malaria, dengue fever, yellow hot rain, vermicelli, Japanese encephalitis, measles, etc. The epidemic period has been extended, and the epidemic area has moved to cold regions. Extension.

2. Ozone layer destruction and human health

The role of the ozone layer: oxygen molecules are irradiated by strong sunlight, especially short-wave ultraviolet radiation to generate ozone. Conversely, ozone can absorb ultraviolet rays with a wavelength of less than 340 nanometers, and decompose ozone into oxygen atoms and oxygen molecules, so that the ozone in the ozone layer always maintains a dynamic balance. The ozone layer can absorb most of the short-wave ultraviolet rays that are harmful from solar radiation and affect human life and survival. According to research, for every 1% reduction in O3 in the ozone layer, the incidence of squamous cell carcinoma in the population may increase by 2% to 3%, and human skin cancer patients will also increase by 2%. The morbidity index of respiratory diseases and eye inflammation will increase in people in polluted areas. Since the material base DNA of the genetic genes of all organisms is susceptible to ultraviolet rays, the destruction of the ozone layer will seriously affect the reproduction and reproduction of animals and plants.

3. Nitrogen oxide pollution and human health

Nitric oxide, nitrogen dioxide and other nitrogen oxides are common air pollutants, which can stimulate the respiratory organs, cause acute and chronic poisoning, and affect and endanger human health.

4. Sulfur dioxide pollution and human health

The harm of sulfur dioxide to the human body is:

(1) Irritating to the respiratory tract. Sulfur dioxide is easily soluble in water. When it passes through the nasal cavity, trachea, and bronchi, it is mostly absorbed and retained by the inner membrane of the lumen, turning into sulfurous acid, sulfuric acid and sulfate, which enhances the stimulating effect.

(2) The combined toxicity of sulfur dioxide and suspended particulate matter. Sulfur dioxide and suspended particulate matter enter the human body together. Aerosol particles can carry sulfur dioxide to the deep lungs, increasing the toxicity by 3-4 times. In addition, when suspended particles contain metal components such as iron trioxide, it can catalyze the oxidation of sulfur dioxide into acid mist, which is adsorbed on the surface of the particles and is substituted into the deep part of the respiratory tract. The stimulating effect of sulfuric acid mist is about 10 times stronger than that of sulfur dioxide.

(3) The cancer-promoting effect of sulfur dioxide. Animal experiments have shown that 10 mg/m3 of sulfur dioxide can enhance the carcinogenic effects of carcinogen benzo[a]pyrene (Benzo(a)pyrene; 3,4-Benzypyrene). Under the combined effect of sulfur dioxide and benzo[a]pyrene, the incidence of animal lung cancer is higher than that of a single carcinogen. In addition, when sulfur dioxide enters the human body, the vitamins in the blood will be combined with it, causing the balance of vitamin C in the body to be imbalanced, thereby affecting metabolism. Sulfur dioxide can also inhibit and destroy or activate the activity of certain enzymes, causing disorder in the metabolism of sugar and protein, thereby affecting the growth and development of the body.

5. Carbon monoxide pollution and human health

The carbon monoxide that enters the human body with the air can be combined with hemoglobin (Hb) in the blood after entering the blood circulation through the alveoli. The affinity of carbon monoxide and hemoglobin is 200-300 times greater than that of oxygen and hemoglobin. Therefore, when carbon monoxide invades the body, it will quickly synthesize carboxyhemoglobin (COHb) with hemoglobin, preventing the combination of oxygen and hemoglobin to form oxyhemoglobin (HbO2). ), causing hypoxia to form carbon monoxide poisoning. When inhaling carbon monoxide with a concentration of 0.5%, as long as 20-30 minutes, the poisoned person will have weak pulse, slow breathing, and finally exhaustion to death. This kind of acute carbon monoxide poisoning often occurs in workshop accidents and inadvertent heating of the home.

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2. Room pollution and human health

1. Pollution of harmful substances contained in building decoration materials: various new wooden building materials such as plywood, paint, coatings, adhesives, etc. will continuously release formaldehyde. Formaldehyde is a cytoplasmic toxicant, which can be absorbed through the respiratory tract, digestive tract and skin. It has a strong stimulating effect on the skin, can cause the coagulation and necrosis of tissue proteins, has an inhibitory effect on the central nervous system, and is also a lung carcinogen. Various solvents and adhesives used in decoration can cause pollution of volatile organic compounds such as benzene, toluene, xylene, and trichloroethylene.

2. Kitchen pollution: When cooking and burning, various fuels are incompletely burned under the condition of insufficient oxygen supply, and a large amount of polycyclic aromatic hydrocarbons are generated. The aromatic hydrocarbons gradually polymerize or cyclize at 400℃~800, and the generated benzo[α] Pyrene is a strong carcinogen. During the cooking process, cooking oil decomposes at a high temperature of 270, and its smoke contains polycyclic aromatic hydrocarbons such as benzo[α]pyrene and benzanthracene. Cooking oil, together with foods such as fish and meat, can generate hydrocarbons at high temperatures. , Aldehydes, carboxylic acids, heterocyclic amines and more than 200 kinds of substances, their genetic toxicity is far greater than benzo[α]pyrene.

3. Hydrogen sulfide and methyl mercaptan emitted from toilets and sewers can also cause chronic poisoning reactions.

4. Pollution of cosmetics, daily chemicals and chemical products.

5. “Electronic fog” pollution: Air conditioners, color TVs, computers, refrigerators, copiers, mobile phones, walkie-talkies and other electronic products produce electromagnetic waves-”electronic fog” to varying degrees during use. “Electronic fog” can cause headaches, fatigue, nervousness, restless sleep, and affect children’s development.

 


Post time: Oct-15-2021