Fireworks and firecrackers are one of the legacies left to us by our ancestors. For a long time, during traditional festivals, especially the Spring Festival, whether in rural or urban areas, we are used to putting a little fireworks and firecrackers to foil the festive atmosphere.
In addition, the main component of fireworks and firecrackers is gunpowder. According to the record of Compendium of Materia Medica, gunpowder has the effect of “clearing wet and removing plague”, which is also an important reason for setting off fireworks and firecrackers during the Spring Festival. This custom has been passed down to the present.
So, if large-scale fireworks, whether it can effectively kill the virus in the air?
The main ingredient of gunpowder
In ancient times, in pursuit of immortality, some people usually did something called alchemy.
At that time, the main substances used in alchemy included sulfur, saltpeter, and some carbon containing substances, such as aristolochia, saponin, etc., were mixed in a certain proportion to make alchemy.
And in the process of refining elixir “, this heating or burning explosion can occur, inspired by this phenomenon, people gradually, Dan medicine “recipe” and refining method, used in other fields, such as some variety show, fireworks production, but also applied to some military weapons manufacturing, become one of the “four great inventions” in ancient China.
In the production of modern gunpowder, the main raw materials used are nitrite, sulfur and charcoal particles, and the proportion of the three is 15:2:3.
Among them, the active ingredient of nitrite is potassium sulfate, the active ingredient of sulfur is sulfur, and the active ingredient of charcoal is carbon.
The product of burning gunpowder
The combination of nitrite, sulfur and charcoal particles in a certain proportion, under high temperature conditions, will produce violent combustion or explosion reaction, the theoretical final product is potassium sulfide, nitrogen and carbon dioxide.
In respect of specific fireworks, firecrackers are set off in pursuit of higher gorgeous effect, and on the basis of the above three kinds of material mixing, appropriate to add some metals chemical nature very lively, and some salt substances, these substances can occur under high temperature burning bright, different colors of light, these new materials mainly include magnesium, aluminium, zirconium, strontium nitrate, malachite, barium nitrate, sodium fluoride, and so on.
In the combustion process of mixed gunpowder, under the action of high temperature, in addition to the theoretical generation of potassium sulfide, nitrogen, carbon dioxide, there will also be derived a series of other substances, such as: nitrogen will react with oxygen to generate nitrogen oxide;
Insufficient combustion of charcoal, carbon monoxide;
The sulfur reacts with oxygen to form sulfur dioxide.
In addition, some solid components of fireworks and internal gunpowder will be released into the surrounding air in the form of powder at the time of explosion. All the products above will finally be presented in the form of smoke with different colors, such as gray, black and white.
These gases and fine particles of flue gas, excitant odour is very strong, look from the composition, production process with industrial enterprises discharge of waste gas and fuel emissions exhaust of motor vehicles, straw burning the generated flue gas and so on, all have certain of the same material, if a long time to breathe the gas, the respiratory system, nervous system of human body and sense organs such as eyes, in a strong stimulus, causing the blood oxygen ability insufficiency, the cell metabolism disorder such as a column problem, harmful to health is bound to.
Can the smoke from fireworks kill the virus?
Virus is a kind of special between living and inanimate bodies, its pathogenic mechanism is simply put, through a certain way of transmission into the cell of the host, rely on the material and energy in the cell of the host, to achieve self-replication, so as to achieve the purpose of survival and guarantee reproduction.
Virus pathogenic mechanism and harmful bacteria, most of the bacteria is beneficial or harmless to human body, the rest of the pathogenic mechanism of harmful bacteria, mainly to invade object release harmful to the body of the proteins, enzymes and other toxins, or change the original structure and function of normal flora, through the way of cell division in the body’s internal environment reproduce, eventually make the body cells of normal physiological activities is restrained, biological activity is reduced, causing the disease.
Although viruses and bacteria have different pathogenic mechanisms, they both need a specific route of transmission, that is to say, they need a certain vector to realize their transfer, so as to achieve the purpose of finding a new host.
Among them, the transmission route of bacteria is more complex, such as relying on droplets, body fluids, blood, feces, skin damage, mother and baby, insect bites, etc., can achieve transmission.
Viruses, on the other hand, have far fewer routes of transmission than bacteria and rely on droplets, body fluids or blood to spread.
From the point of view of the mixture of gas and solid particles produced by fireworks and firecrackers, it is easy to combine with the water vapor in the air to form aerosol groups. The inside of the aerosol group will absorb part of flue gas substances, such as sulfur dioxide, carbon dioxide, nitrogen oxides and so on, making the pH value of the aerosol group is weak acid.
Whether bacteria or viruses, after leaving the host environment, they have certain environmental tolerance in the pure natural environment. When they exceed their tolerance range, they will also become inactive, either inactivated or die.
Most bacteria and viruses, the tolerance of acid in the nature is not strong, so, in a sense, whether fireworks setting off the smoke, and smoke from the burning of straw, or car tail gas, etc., these pollutants, can produce a certain inhibitory effect of viruses and bacteria, this is undeniable, however, the distance to kill them not go far enough.
Why do you say that?
On the one hand, is not to say that the viruses and bacteria in acidic substances, will die, must is long enough, the condition of acid is strong enough, and large-scale fireworks, if bad weather conditions, such as static unstable weather, so has the potential to flue gas in the region of space time is relatively long, not easy to spread, and also from aerosol mass which is formed by the flue gas acid is stronger, may achieve the purpose of make viruses, bacteria inactivation, but we can’t do it every space flue gas concentration, acid is very strong, that is to say not every area of the flue gas is beyond the tolerance ability of the virus.
On the other hand, the spread of viruses and bacteria needs transmission media, if the air is very clean, then the virus and bacteria will lose the transmission carrier and opportunity.
So, precisely because of fireworks and firecrackers, increased a lot of aerosols in the air, thus provides a movable platform virus, bacteria, although somewhat to the activity of bacteria inhibition, but with when they are in the process of the flap suspension aerosol, once encountered the right environment, will become active again, makes transmission range and a higher risk of infections.
Although the smoke produced by large-scale fireworks and firecrackers can inhibit the activity of viruses and bacteria to a certain extent, it is still far from the purpose of effective killing, and it will also create a certain carrier space for the spread of viruses.
At the same time, in this process, the strong smoke will also make the human body, other organisms have a serious impact, it can be said that the gain outweighs the loss.
Moreover, large-scale discharge, in addition to causing regional air, water, soil and noise pollution, but also easy to cause fire, human injury, building damage and other accidents.
Therefore, for the folk handed down the tradition of setting off fireworks, we should use a dialectical vision to look at.
We can neither beat it to death with a single blow, nor accept it entirely with the current scientific and technological level. We need to make further rational planning and formulate and implement more scientific and practical control measures.