Flowers In The House Are Useful And Necessary (part 3)

2024 Author: Sebastian Paterson | [email protected]. Last modified: 2023-12-16 13:47

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Environmental pollution

The presence of microorganisms in our environment is not the most terrible, but quite natural phenomenon, since all living things are connected with each other at least by food chains, which we know from school. In natural ecosystems, all organisms and substances are closely interconnected: organic remains are rather quickly processed, destroyed by worms, insects, molds and bacteria, turning into elementary particles, from which complex macromolecules are then synthesized again.

It turns out "waste-free reproduction", where there is no concept of "garbage", since there is no accumulation of matter unused by other organisms. It is completely different in the life of mankind, where production technologies strive for independence from the environment, intensively littering it with their waste. Unfortunately, most of the production waste is not recycled, because this requires new technologies and large investments in their implementation. Man-made debris is now littering even outer space, not to mention mountains of debris on earth. But this is not the worst thing in the current situation at the beginning of the 21st century.

Many industries are associated with the release of substances poisonous to the human body into the environment. We have a poor idea of this, but scientists around the world have been studying these problems for a long time and cite horrifying data from their research. Over the past century, mankind has slowly poisoned itself with the end products of "technogenic metabolism." Experts have come to the conclusion that about half or even more of all health problems are associated with environmental pollution by products of man-made industries. According to German researchers, the air contains over 1000 harmful compounds, including about 250 highly toxic and 15 carcinogenic … In closed rooms, where we spend most of our lives 22-23 hours a day, measurements show that the concentration of hazardous substances everywhere is 2-5 (often 100!) Times higher than the maximum permissible norms (MPC).

According to the figurative expression of Hippocrates, the ancient Greek physician, air is the "pasture of life." One of the indicators of its pollution is the concentration of suspended particles (PM) in it. These are microparticles of smoke, soot, liquid droplets resulting from the combustion of various substances, especially waste, car exhaust, emissions from industrial enterprises, agricultural production, dust from the use of household chemicals, road and construction dust. This also includes plant pollen, fungal spores 2–8 µm in size, bacteria (0.5–5 µm), viruses (0.5 µm). Human dwellings almost always contain shells, eggs and excrement of microscopic mites, the size of which does not exceed 0.2 mm.

The World Health Organization believes that the mass of HF should not exceed 90 micrograms per cubic meter of air. Real numbers in many large cities of the world are much higher than this figure. It is estimated that up to 1500 tons of dust (1.5 kg per 1 m2) are deposited annually in large industrial cities per 1 km2. Statistical data indicate that at the end of the 20th century, the annual increased concentration of HF in the air of industrialized countries caused more than 500 thousand deaths, and several million people fell ill with bronchitis and similar respiratory diseases. And at the beginning of this century, the statistics do not change.

Another important indicator of air purity is the concentration of poisonous gases (nitrogen dioxide, carbon monoxide, sulfur dioxide and ozone), as well as volatile organic compounds (formaldehyde, toluene, benzene, ammonia, trichlorethylene and many other similar substances)

The source of harmful compounds, oddly enough, is the person himself. It is estimated that, together with the exhaled air, more than one and a half hundred different chemical substances - the products of his vital activity - every minute get into the room where the person is. Here and carbon dioxide, acetone, ketone compounds. Many substances released from sweat are volatile. In a closed environment where people spend most of the day side by side, this becomes a big problem. Airing does not help: outside the window - city highways, saturated with toxic substances and dust. Indoor air is often more polluted than the atmosphere.

In the last quarter of the 20th century, the International Center for Habitat Quality and Energy Saving proved that poor indoor air quality in premises is the cause of the so-called SNZ - Unhealthy Building Syndrome. People in such rooms began to feel bad, while doctors were unable to identify a single known disease in which such a condition occurs. Symptoms of DFS are reminiscent of a sluggish flu, with a constant headache, irritated eyes, nose and throat, a dry cough, the skin becomes dry, and itching occurs. All this is often accompanied by dizziness and nausea, fatigue and loss of concentration, increased sensitivity to odors. Surprisingly, these symptoms disappeared as soon as people left such an "unhealthy" building. Employeesforced to work in such premises for a long time, more serious health disorders gradually developed: joint pains began, insomnia developed, and such conditions could continue for years.

At the end of the 20th century, the problem of SNZ was recognized not only by ecologists and doctors, but also by government organizations in most developed countries of the world. Now experts are thinking how to solve this problem.

The solution, it would seem, suggests itself: do not use harmful materials, strengthen control over the quality of office equipment, vehicle operation, isolate from the external environment and create a high-quality system for cleaning and disinfecting indoor air. I recall something like submarines, autonomously existing for many months. Individual equipping of workplaces with air ducts is still in the realm of fantasy. Or each house should be built as an orbiting space station, which is also not realistic yet. That is, they are looking for a solution to the problem in the creation of new technologies - as before, with their own waste and a new problem of their disposal. The circle closes again.

A completely different approach to solving the problem of getting out of the "trap of civilization" was found, oddly enough, in space. The main task of the specialists of the National Aeronautics and Space Agency (NASA) was to clean the air in the pressurized compartments of spaceships and orbital stations. Traditionally, this was done chemically by circulating air. But in 1980, an unexpected discovery was made at the John Stennis Space Center. It turned out that some indoor plants are able to actively remove volatile organic compounds from the atmosphere of confined spaces.… Living filters in the form of plants can save lives! It turned out that some plants absorb formaldehyde, benzene, trichlorethylene and effectively remove them from the air. The experiments used the most common plants: aglaonema, gerbera, dracaena, ivy, sansevier, spathiphyllum, ficus, chamedorea and others. Experiments have shown that it is possible to successfully use plants for air purification not only in space, but also on earth.

How does this happen? Plants are known to absorb carbon dioxide and other gases through stomata - holes located on the surface of leaf blades. Plant cells can be thought of as tiny water containers. Many gases dissolve well in water. Therefore, the absorption of gases by the plant occurs very quickly. For example, during one summer day, one hectare of forest absorbs 220-280 kg of carbon dioxide from the air. Together with this gas, many other gases and volatile organic compounds enter the plant. Plant physiologists have noticed that many poisonous substances make plants breathe more intensively, that is, plants react actively to poisons. It is logical to assume that in the process of long evolution, plants have developed protective mechanisms that allow them to neutralize harmful substances and gases,entering tissues along with carbon dioxide. NASA experiments have confirmed this assumption.

It turned out that different types of indoor plants react differently to volatile organic compounds. Some are better at removing formaldehyde from the atmosphere, while others are better at removing xylene or toluene. The rates of neutralization of these poisons by different types of flowering plants are also different. To generalize the results of experiments with plants, NASA specialists have derived a generalized coefficient of the efficiency of air purification by a plant. It was calculated taking into account the degree of danger of the absorbed gases, the width of their spectrum, as well as the rate of their absorption. The coefficient is expressed in conventional units from 0 to 10. In the next issue we will give a list of plants that effectively purify indoor air.