First, the harm of environmental pollution to health
1, health hazards of air pollution
Air pollution directly or indirectly affects human health, causing uncomfortable reactions of sensory and physiological functions, subclinical and pathological changes, clinical signs or potential genetic effects, acute and chronic poisoning or death.
The impact of air pollution on health depends on the type, nature, concentration and duration of harmful substances in the atmosphere, and also depends on the sensitivity of human body. For example, the harmful effect of floating dust on human body depends on the particle size, hardness, solubility and chemical composition of floating dust, as well as various harmful gases and microorganisms adsorbed on the surface of dust particles. Different chemical properties, toxicity and water solubility of harmful gases will also cause different degrees of harm.
The concentration of chemical pollutants in the atmosphere is generally low, which mainly produces chronic toxic effects on human body. Inhalation of harmful chemicals that directly stimulate the respiratory tract will cause bronchial reflex contraction, spasm, cough, sneezing and increased airway resistance. Under the chronic action of poisons, the resistance of respiratory tract will gradually weaken, thus inducing chronic respiratory diseases, and even serious pulmonary edema and pulmonary heart disease may occur. Epidemiological survey data show that urban air pollution is the direct cause or inducement of chronic bronchitis, emphysema and bronchial asthma. In areas with serious air pollution, the total mortality and incidence of respiratory diseases are higher than those in areas with light pollution. The symptoms of chronic bronchitis get worse with the aggravation of air pollution.
Second, the health hazards of water pollution
The increasingly serious water pollution poses a great threat to the survival and safety of human beings and becomes the main obstacle to the sustainable development of human health, economy and society. According to the investigation of international authoritative organizations, 8% of all kinds of diseases in developing countries are spread by drinking unsanitary water, which causes at least 20 million deaths worldwide every year. Therefore, water pollution is called "the world's number one killer".
Water pollution affects industrial production, increases equipment corrosion, affects product quality, and even makes production impossible. Water pollution affects people's lives, destroys ecology, directly harms people's health and causes great damage.
(1) After water pollution harms human health, pollutants enter the human body through drinking water or food chain, causing acute or chronic poisoning. Arsenic, chromium, ammonium, pyrene, etc. It can also induce cancer. Water polluted by parasites, viruses or other pathogenic bacteria will cause many infectious diseases and parasitic diseases. Water polluted by heavy metals is harmful to human health. Water and food polluted by cadmium will cause kidney and bone diseases after people eat it. Ingestion of 20 mg of cadmium sulfate will lead to death. Lead poisoning can lead to anemia and insanity. Hexavalent chromium is very toxic, which can cause skin ulcers and cause cancer. Drinking arsenic-containing water can cause acute or chronic poisoning. Arsenic inhibits or deactivates many enzymes, leading to metabolic disorders, skin keratinization and skin cancer. Organophosphorus pesticides can cause neurotoxicity, while organochlorine pesticides can accumulate in fat, which is harmful to endocrine, immune and reproductive functions of human beings and animals. Most polycyclic aromatic hydrocarbons are carcinogenic. Cyanide is also a highly toxic substance. After entering the blood, it combines with the pigment oxidase of cells, which interrupts breathing and causes respiratory failure, suffocation and death. We know that 80% of the diseases in the world are related to water. Typhoid fever, cholera, gastroenteritis, dysentery and infectious liver disease are the five major diseases of human beings, all of which are caused by unclean water.