In scientific terms, clean air refers to a specific combination of components such as nitrogen (N2), oxygen (O2), argon (Ar), carbon dioxide (CO2) and water vapour. Their quantity can differ depending on the location and specific environmental conditions. However, air contains gases with variable concentrations also known as air pollutants. There are six major air pollutants that are set as criteria by the Federation of European Heating, Ventilation and Air Conditioning Association (REHVA). They should be found in specific quantities based on the criteria established by WHO (World Health Organisation) for air to be considered clean.
Where does the problem lie?
There are plenty of medical conditions that come as a result of inhalation of air that contains high levels of air pollutants. Therefore, it is important that outdoor and indoor spaces are equipped with sensors that can detect the levels of air pollutants and guarantee air quality. Although it is difficult to maintain air quality that is entirely void of air pollutants, low levels of air pollution guarantee human safety.
Nowadays, life has become so fast-paced that people need to juggle their career, personal and social life. This is exactly when they are the most prone to forgetting about the environmental factors that play a key role in everyday life. For instance, a long day spent at the office with high levels of CO2 can result in unpleasant medical conditions such as headaches, fatigue and muscle twitches. In order for human beings to live their lives healthily, air quality should be of high priority.
Main Air Pollutants
To understand better air quality, it is important for one to be informed of the types of air pollutants, their sources, the chemical reactions they take part in and their impact on human health.
1. Particulate matter (PM) refers to a mixture of solids or liquid droplets that are found in air. They vary in terms of size, chemical composition and shape. The particles that are 10 micrometres (PM10) or less and 2.5 micrometres (PM2.5) or less in diameter are considered dangerous since they can be inhaled and they can enter your lungs, negatively affecting your respiratory system. Additionally, some of them can even go into your bloodstream.
Particles can also form acid rain that harms the environment and damages buildings and monuments. Another example of the presence of PM2.5 and PM10 in air is the formation of haze in cities. Haze leads to reduced visibility, which can result in traffic accidents since drivers are unable to see obstacles, pedestrians and other moving vehicles.
Some of the main sources of PM2.5 and PM10 are power plants and automobiles which emit chemicals such as sulphur dioxide and nitrogen oxides that are a result of complex chemical reactions. Additionally, particles are directly emitted by construction sites, fields, unpaved roads and fires. Some of the sources can be found indoors and can include activities such as smoking, cooking on a woodstove, burning food when cooking, lighting candles and fireplaces. Dust and pollen, which can enter indoor areas through open windows, are also regarded as a source of PM2.5 and PM10.
2. Ozone (O3) is another air pollutant that is formed due to complex chemical reactions in the atmosphere. The major components responsible for the formation of ozone (O3) in polluted atmosphere are nitrogen (N2) and volatile organic compounds (VOCs).
The main sources of nitrogen oxides (Nox) and volatile organic compounds (VOCs) are the emissions form cars, power plans, chemical plants, electric utilities, gasoline vapours and refineries which react in the presence of sunlight creating ozone (O3). Ozone (O3) is most commonly found in urban areas, however, it can be spread through long distances by wind resulting in higher levels of pollution in rural areas as well. It is one of the main components of smog, which leads to reduced visibility and air quality.
When breathed in, O3 can cause irritation and inflammation of the respiratory system, resulting in coughing, chest discomfort and increase in asthmatic attacks for the ones suffering from the medical condition. When exposed to high levels of O3 for long periods of time, children, the elderly and individuals with respiratory illnesses are particularly prone to developing reduced lung function. Additionally, O3 can affect adversely nature and vegetation. It reduces plant growth, photosynthesis and biodiversity.
3. Nitrogen dioxide (NO2) belongs to a group of highly reactive gasses called nitrogen oxides (NOx). Nitrogen dioxide (NO2) is formed in combustion processes involving nitrogen and oxygen.
The main factor for the presence of NO2 in air is the burning of fuel. In this sense, emissions from power plants, vehicles, industrial activities and residential heating play a key role in NO2 levels. In addition, enclosed parking garages require proper ventilation since vehicles produce emissions that are hazardous to health. In this case, the detection of CO2 can be used as criteria for the overall safety of the enclosed parking garages since huge amounts of CO2 are emitted in the combustion of fuel. The CO2 sensors of Sentera are specifically designed to detect CO2 levels, ensuring that they are within a safe range. As a result, Sentera outdoor CO2 sensors are a key element of any ventilation system in enclosed parking garages.
Nitrogen dioxide (NO2) has damaging effects on human health. Exposure to high levels of NO2 over short periods can result in irritation and inflammation of the airways in the human respiratory system. As a result, symptoms such as coughing, difficulty breathing and wheezing may occur.
There also exists an environmental effect of NO2. Nitrogen dioxide (NO2) in combination with water, oxygen and other chemicals forms acid rain. Moreover, NO2 reacts with other air pollutants creating smog and damaging air quality.
4. Carbon monoxide (CO) is a colourless, odourless and tasteless toxic gas. It can be freely combined with air and it is a source of fuel. It also burns with a distinguishable
violet flame. Levels of carbon monoxide can be both found indoors and outdoors.
violet flame. Levels of carbon monoxide can be both found indoors and outdoors.The main sources of CO indoors are unvented gas or kerosene heaters, leaking chimneys, furnaces and boilers. Additionally, there are activities that can increase the levels of CO indoors such as smoking and cooking on a gas stove. The outdoor sources of CO are vehicles or machinery that are powered by the combustion of fossil fuels. As a result, high levels of CO can be found in attached garages, parking areas and roads.
The effects of CO are hazardous to human health. Low levels of CO can cause fatigue in healthy people and chest pain in people with heart diseases, especially if they are exercising or under stress. The short-term exposure results in reduced oxygen delivery to the heart. Exposure to high levels of CO can lead to dizziness, headaches, confusion, nausea and reduced vision, coordination and brain function. The highest levels of CO are more likely to happen indoors and can be fatal to humans.
In terms of environmental impact, CO can participate in chemical reactions resulting in the creation of ozone (O3), which has a harmful effect on nature and vegetation.
Nowadays, most vehicles are designed to emit more carbon dioxide (CO2) and less carbon monoxide (CO) in the combustion of fuel. In addition, the fact that CO can react with oxygen (O2), resulting in the formation of CO2, demonstrates a direct link between CO and CO2 levels, especially in enclosed parking garages where air quality depends significantly on a proper ventilation system. The outdoor CO2 sensors of Sentera are specifically developed for accurate CO2 measurements, which can guarantee human safety in enclosed parking garages.
5. The other widely used gas by vehicles is LPG. Due to the environmental impact and state policies, the use of diesel powered engines is shrinking and is being replaced by LPG powered engines that are not that harmful to nature. LPG is used to describe two natural gas liquids: propane and butane, or a mix of the two. LPG vapour can cause fainting and choking in poorly ventilated environments.
To provide safe and healthy control of indoor air quality, a continuous gas monitoring system is necessary.
Sentera’s CO2 sensors are suitable for the measurement of air quality in enclosed parking garages. What is more, these multifunctional sensors also measure temperature, relative humidity and ambient light levels. Based on the temperature and humidity measurement, the dew point is calculated. All these values are available via Modbus RTU.
6. Volatile organic compounds (VOCs) refer to a variety of chemicals such as benzene, toluene, ethylbenzene and xylenes that are found both indoors and outdoors as a result of combustion, evaporation and house renovations. Additionally, they participate in the formation of ozone (O3), haze and acid rain, causing damage to the environment. Some of the main sources of VOCs are cleaning supplies, paints and lacquers, pesticides, permanent markers, building materials and furnishings and office equipment such as copiers and printers.
Volatile organic compounds (VOCs) adversely affect human health and can lead to a variety of symptoms such as nose and throat irritation, allergic skin reaction, headaches, loss of coordination, fatigue and dizziness. Some VOCs are proven to be carcinogens. Studies show that VOC levels are higher indoors rather than outdoors. Having this in mind, Sentera’s room TVOC sensors are designed to measure the level of VOCs indoors and detect any crucial changes. Subsequently, more fresh air is supplied in the room, resulting in lower levels of VOCs.
Conclusion
In conclusion, clean air depends on numerous factors, therefore, air quality needs to be constantly monitored, so human safety is ensured, especially in indoor environments. Additionally, public buildings need to follow certain ventilation regulations that guarantee air quality. The regulations present safety levels, which should not be exceeded in order for the air to be considered safe.