Air pollution caused by fireworks and firecrackers

Setting off fireworks will produce gases such as sulfur dioxide, nitric oxide and nitrogen dioxide, and it is an invisible "killer". When the smoke is filled, these gases will do some damage to the respiratory system and nervous system, stimulate the eyes, and some will contribute to the occurrence or development of some chronic diseases. When the concentration of harmful substances such as sulfur dioxide in the air exceeds the allowable value, it will stimulate respiratory mucosa, damage lung tissue, and cause or induce bronchitis, tracheitis, pneumonia, emphysema and other diseases. In addition, some poisons combine with hemoglobin in the human body, which is easy to cause hypoxia and poisoning symptoms.

The nitrogen oxides produced by the combustion of fireworks and firecrackers will undergo photochemical reaction after being irradiated by sunlight and ultraviolet rays, resulting in photochemical smog, which is a toxic secondary pollutant that will irritate people's eyes and nasal mucosa, thus causing pathological changes and headaches.

First, suspended particle pollution.

Particles that can naturally settle in the air are called dustfall, while particles suspended in the air with a particle size less than 100 micron are called total suspended particles (TSP), and those with a particle size less than 10 micron are called inhalable particles (PM 10). Inhalable particulate matter can float in the atmosphere for a long time because of its light volume, ranging from several kilometers to dozens of kilometers, which can cause continuous accumulation in the atmosphere and gradually aggravate the pollution degree. Inhalable particulate matter has complex components and strong adsorption capacity. For example, it can adsorb various metal dust and strong carcinogen benzo (a) pyrene, and adsorb pathogenic microorganisms.

Inhalable particles enter the lungs with human breathing air and stay in different parts of the respiratory tract by collision, diffusion and deposition. Most of them with particle size less than 5 microns stay in the upper respiratory tract. Particles trapped in the nasopharynx and trachea, together with harmful gases such as sulfur dioxide (SO2) entering the human body, stimulate and corrode mucous membranes, damage mucous membranes and cilia, cause inflammation and increase airway resistance. Persistent effects can lead to chronic nasopharyngitis and chronic tracheitis. Particles trapped in bronchioles and alveoli can also combine with nitrogen dioxide, damaging alveoli and mucous membranes and causing inflammation of bronchi and lungs. Long-term persistent effects will also induce chronic obstructive pulmonary disease and secondary infection, which will eventually lead to an increase in the mortality rate of cor pulmonale.

Second, sulfur dioxide pollution and human health

Sulfur dioxide is a common and important air pollutant, and it is a colorless irritating gas. Sulfur dioxide mainly comes from the combustion of sulfur-containing fuels (such as coal and oil); Smelting sulfur-containing ores (especially nonferrous metal ores with more sulfur); Production processes in chemical industry, oil refining and sulfuric acid plants.

The harm of sulfur dioxide to human body is:

1, stimulate respiratory tract. Sulfur dioxide is easily soluble in water. When it passes through the nasal cavity, trachea and bronchus, it is blocked by the water in the lumen and becomes sulfurous acid, sulfuric acid and sulfate, which enhances the stimulation.

2. Joint toxic effects of sulfur dioxide and suspended particles. Sulfur dioxide enters the human body together with suspended particles, and aerosol particles can bring sulfur dioxide deep into the lungs, increasing toxicity by 3-4 times. In addition, when suspended particles contain metal components such as iron oxide, it can catalyze the oxidation of sulfur dioxide into acid mist, which is adsorbed on the surface of particles and replaced in the deep respiratory tract. The stimulating effect of sulfuric acid mist is stronger than that of sulfur dioxide 10 times.

3. The role of sulfur dioxide in promoting cancer. Animal experiments show that 10 mg/m3 sulfur dioxide can enhance the carcinogenicity of benzo (a) pyrene. Under the combined action of sulfur dioxide and benzo (a) pyrene, the incidence of lung cancer in animals is higher than that of a single carcinogen. In addition, after sulfur dioxide enters the human body, vitamins in the blood will combine with it, which will unbalance the balance of vitamin C in the body, thus affecting metabolism. Sulfur dioxide can also inhibit, destroy or activate the activities of some enzymes, so that the metabolism of sugar and protein is disordered, thus affecting the growth and development of the body.

Third, nitrogen oxide pollution and human health.

Nitrogen oxides such as nitric oxide and nitrogen dioxide are common air pollutants, which can stimulate respiratory organs, cause acute and chronic poisoning, and affect and endanger human health. Among nitrogen oxides, nitrogen dioxide is the most toxic, 4-5 times more toxic than nitric oxide. Nitrogen oxides in the atmosphere mainly come from automobile exhaust and waste gas produced by coal and oil combustion. Nitrogen oxides mainly stimulate respiratory organs. Because nitrogen oxides are insoluble in water, they can invade bronchioles and alveoli in the deep respiratory tract, and slowly dissolve in water on the surface of alveoli, forming nitrite and nitric acid, which have a strong stimulating and corrosive effect on lung tissue and cause pulmonary edema. After nitrite enters the blood, it combines with hemoglobin to produce methemoglobin, which causes tissue hypoxia. Generally speaking, when nitrogen dioxide is the main pollutant, the damage to the lungs is obvious, and nitrogen dioxide is also related to the pathogenesis of bronchial asthma. When nitric oxide is the main pollutant, methemoglobinemia and central nervous system damage are more obvious. More than 95% of nitrogen oxides (NOx) emitted by automobiles are nitric oxide, which is gradually oxidized into nitrogen dioxide after entering the atmosphere. Nitrogen dioxide is a highly toxic brown gas, which is irritating. When the amount of nitrogen dioxide reaches a certain level, it will participate in the formation of photochemical smog when it encounters conditions such as still wind, inversion temperature and strong sunshine. The concentration of nitrogen dioxide in the air is closely related to human health, and there have been cases of illness and death caused by short-term exposure to high-concentration nitrogen dioxide. For example, on May 1929, 124 people died in a fire at Creaer Hospital in Cleveland. The direct cause of death was that the photographic film containing nitrocellulose caught fire and produced a large amount of nitrogen dioxide.

Fourthly, photochemical smog pollution.

Photochemical smog is a kind of irritating light blue smog produced by nitrogen oxides and hydrocarbons discharged into the atmosphere under the action of solar ultraviolet rays. It contains ozone (O3), aldehydes, nitrates (PAN) and other complex compounds. These compounds are secondary pollutants produced by photochemical reactions, mainly photochemical oxidants. Under unfavorable temperature or unfavorable meteorological conditions, smoke will accumulate, causing air pollution events, irritating people's eyes and respiratory tract or inducing various respiratory tract inflammation, which will endanger human health. This pollution incident first appeared in Los Angeles, so it is also called photochemical smog in Los Angeles. In recent years, photochemical smog has appeared not only in the United States, but also in Tokyo, Osaka, Kawasaki, Sydney, Australia, Genoa, Italy, Mumbai, India and many other cities with many cars. After being irradiated by sunlight and ultraviolet rays, nitrogen oxides produced by fireworks and firecrackers will undergo photochemical reaction, producing a photochemical smog, which is a toxic secondary pollutant. The most prominent harm of photochemical smog to human body is to stimulate the mucous membrane of eyes and upper respiratory tract, causing eye redness and laryngitis, which may be related to the stimulation of secondary pollutants such as aldehydes. Other hazards of photochemical smog to human body are related to ozone concentration. When the ozone concentration in the atmosphere reaches 200- 1000 μ g/m3, it will cause asthma attack, aggravate upper respiratory diseases, irritate eyes and reduce visual sensitivity and vision. When the concentration is 400- 1600 μ g/m3, as long as it is exposed for two hours, symptoms of tracheal irritation will appear, which will cause pain under the sternum, decrease the lung permeability and make the body anoxic. No matter how high the concentration is, there will be headaches, narrowing of lung airways and emphysema. If the contact time is too long, it will also damage the central nervous system, leading to thinking disorder or pulmonary edema. Ozone can also cause potential systemic effects, such as inducing chromosome aberration of lymphocytes, destroying enzyme activity and hemolytic reaction, affecting thyroid function, and calcifying bones at an early stage. Long-term inhalation of oxidants will affect the metabolism of cells in the body and accelerate aging.

The reporter learned that during the Spring Festival, the most artillery shells were produced on New Year's Eve and the early morning of New Year's Day. In less than 12 hour, 60 tons of fireworks were cleared and transported away in Tieling City, Liaoning Province. It is understood that although Tieling City issued a regulation prohibiting the discharge of fireworks at high altitude last year, there are still some large fireworks sold in Tieling this year, which are as big as paint barrels or fruit boxes. The largest fireworks weigh 50 kilograms, so the volume of paper scraps produced is also very large, and some large fireworks are more than half as high, which makes it impossible to clean vehicles. Only manual hand-held and centralized transportation can be used for cleaning.

/view/494 CB 3 ddad 5 1f 0 1dc 28 1f 12a . html