What is Air Pollution - Causes, Effect & cautions
What air pollution is and what are air pollution causes?
Environmental pollution occurs when the pollutants contaminate our natural surroundings. It is a crucial concern for humanity and can affect your health adversely. Air pollution is one of the main factor contributing to general environmental problems and disturbs our ecosystem balance and gives rise to illness and global warming.
Air pollution refers to particulates, harmful material and gases, pollutants and biological molecules into the air. It can be caused by both humans as well as natural factors. The leading causes of air pollution are the burning of fossil fuels, excessive mining, agriculture-related activities. And also exhaust from factories and vehicular pollution.
There are some major outdoor pollutants such as carbon monoxide, sulphur dioxide, nitrogen dioxide, Lead and ground-level ozone depletion. While cigarette smoke, gases from organic compounds, burning conventional fuels causes indoor air pollution. These pollutants are detrimental to both human health as well on the planet earth. It causes global warming, acid rains, respiratory and heart problems.
Air Pollution – A global health hazard
Poor air quality kills people. According to the study, Air pollution kills more than than 7 million people every year. Air pollution can cause higher strokes, cancer, heart diseases, and respiratory diseases such as asthma and chronic bronchitis. Studies also show that people from urban areas suffer more from lower lung function levels, emphysema and breathing diseases. Sometimes the air pollution may also affect the central nervous system.
According to study an early exposure of children to air pollution is hazardous. Even it is worse for pregnant women and harm the coming child’s health. It hurts their central nervous system and can lead to autism spectrum disorder and schizophrenia.
The fetus is susceptible to environmental conditions. Air pollution may also lead to pregnancy complications and long term health problem for future children.
Apart from human health air pollution also impacts global weather and agricultural conditions. Plants start suffering from yellowing leaf and which leads to reduced growth. It ultimately causes to global warming and its adverse effects.
What is Air Quality Index?
The Air Quality Index (AQI) gives us information about the surrounding air. It tells us how much polluted or clean our air is?
Government and its agencies use this AQI to inform about how polluted the air is currently.
Also, it gives a forecast about how polluted the air will become in future. Major cities across the world track the AQI daily. Indian Capital Delhi is observing 300 plus AQI level. Even for sometimes it touches 900 AQI. Please read about Delhi Air Pollution Here.
How to calculate and scale Air Quality Index?
The Air Quality Index is the calculation of some components available in the air. It is the measurement of particulate matters (PM 2.5 and PM 10) availability in air. The emission of Sulfur Dioxide (SO2), Nitrogen Dioxide (NO2) and Carbon Monoxide gas in the atmosphere. It also checks the strength of ground-level ozone (O3).
The Air Quality Index calculation performed hourly and published by the government. For example, AQI at 7 AM gives the measurement of AQI between 6 AM to 7 AM. According to WHO most of the health problems are directly or indirectly connected with breathing in polluted air. AQI scale is based on a range between 0 to 500. The more significant number of AQI, the high level of pollutants in the air. This number gives awareness among people so that they can know about the air quality of their area. You can search for AQI on google for the big cities around the world. The AQI for Delhi is currently very unhealthy and high, so it is not suitable for people health.
You can check the real-time Air Quality index of most of the places across the globe online.
Please follow the below table which will give you a clear understanding of AQI.
Air Quality Index Scale -
|Green||Good (0 -50)||Perfectly healthy- No need to take any precaution.
Green colour indicates saftey.
|Yellow||Moderate (51 - 100)||Air quality is acceptable, however, sensitive people
should decrease their extended or heavy exertion to outdoor.
|Orange||Unhealthy for Sensitive |
Groups (101 -150)
|Peoples from sensitive groups may experience health
effects. Active children and adults and also people with respiratory disease (like asthma) should avoid prolonged outdoor exertion. There are likely to be no effect on general public health.
|Red||Unhealthy (151 -200)||Everyone may start experiencing some of the health
problems. Mostly the members of sensitive groups may experience more serious health problems. People should limit their prolonged outdoor exertion.
|Purple||Very Unhealthy |
|This is an alarming condition for various health problems. The entire population is likely to be affected by various breathing problems.
Active children and adults and also people with respiratory disease such as asthma should avoid all outdoor exertion. Others should redue it to a greater extent.
|Maroon||Hazardous - 300+||Health alert to everyone, they may experience more
serious health issues. Everyone should avoid all outdoor exertion.
What are the Factors affecting AQI and causes Air pollution?
Air pollution affects human health adversely and has long term exposure like global warming, cancers, and various heart diseases. While the eye irritation, sneezing, coughing, dizziness, headaches are some short term effects. The heatwaves, extreme weather conditions and also food crops disturbances are immediate effects of global warming.
Particulate matter, Sulphur Dioxide (SO2), Nitrogen Dioxide (NO2), Carbon Monoxide (CO), Lead are primary air pollutants.
1. Particulate matter
These are mixtures of tiny particles and also liquid droplets into the air. The matters smaller than 10 micrometres are PM10. PM10 and PM2.5 particles are tiny and even invisible to the naked eye.
Human Hairs (50-70 microns). > PM10 particles (Dust, pollen, mould etc.). > PM2.5 (combustion particles, organic compounds, metals etc.).
PM10 – These are particles less than 10 micrometres in diameter. It produces by both combustion and non-combustion processes. The motor vehicle engines, windblown dust, sea salt, industries and fires have PM10.
PM2.5 – These are particles less than 2.5 micrometres in diameter. These are mainly by-products of combustion processes. The smoke from the motor vehicle, industries, reliable fuel heaters and fires contains PM2.5. It may enter the bloodstream and cause cardiovascular problems. It can cause asthma, allergies and even heart attacks.
TSP (total suspended particles) – The particles up to about 100 micrometres in diameter are TSP.
75% of air particulate matters have resulted from human activity while 25% by nature. The primary sources are unburnt residues from vehicles and industries.
In nature, particulate matters releases from volcanic ashes, bush fires, dust storms, sea spray etc.
The human activities are the leading cause of the particulate matter. Industrial pollution, exhaust from power plant & vehicles, tobacco smoke, volatile organic compounds, household exhausts etc. releases particulate matter. PM 10 and PM 2.5 are the most dangerous among all particulate matter.
Particulate matters produced from:
Combustion processes – From engines, power stations, bushfires, wood heaters etc.
Non-combustion activities – From earthworks, windblown dust, unpaved roads etc.
The particles which are larger than 10 micrometres in diameter, usually not affecting human health. Yet, it may cause some nuisance problems. These particulate matters are the most dangerous among all pollutants. It has a very high risk for human health. It can pass into our breath and go deep inside the lungs.
Particles greater than PM10 doesn’t reach till respiratory tract. The cilia and mucus trap them. But smaller than PM10 can get till respiratory tract. These particles cause various health issues. It can result in asthma, lung cancer, premature delivery, low birth weight, cardiovascular and respiratory diseases.
2. Sulphur Dioxide (SO2)
Sulphur dioxide (SO2) is a colourless gas. It has a very sharp and irritating odour. Generally, the burning of fossil fuels and mineral ores that contain sulphur emits SO2. Industries also produce it.
Naturally, it emitted during a volcanic eruption. People exposed to sulphur dioxide has a greater chance of getting a cough, colds, shortness in breath, asthma and fatigue. It affects the respiratory system, lung function and also irritates the eyes.
When it combines with water and air, it forms sulfuric acid. The sulfuric acid is the main component causing acid rain. Ultimately the acid rain is very disastrous. It causes deforestation, effects buildings and also affects aquatic life.
3. Nitrogen Dioxide (NO2)
Nitrogen dioxide is a toxic gas; it affects human health and enters inside while breathing. Nitric oxide is a colourless gas and also oxidized in the atmosphere to form nitrogen dioxide. Although Nitrogen dioxide has an odour and is acidic. It is a highly corrosive gas and also causes acid rain in the environment.
Exposure to nitrogen dioxide may result in chronic respiratory diseases like bronchopneumonia, emphysema, chronic fibrosis, and bronchitis. Long-term exposure to high levels of nitrogen dioxide can cause chronic lung disease. High levels of nitrogen dioxide are also harmful to vegetation. They can cause foliage, decreasing growth or reducing crop yields. It may affect persons ability to smell an odour and senses. It can also fade and discolour furnishings and fabrics. Sometimes it reduces visibility, and also react with surfaces.
This gas produces from motor vehicles, burning of fuel. Nitrogen oxides are one of the critical components of photochemical smog. They make the yellowish-brown colour of the pollution while burning. Suppose any house has a low ventilation system. The indoor appliances like gas stoves, wood or gas heaters may produce a significant amount of nitrogen oxides.
4. Carbon monoxide (CO)
Carbon monoxide is a colourless and odourless gas. It produced when substances containing carbon (like coal, petrol, gas and even wood) are burnt in insufficient air supply. In urban areas, motor vehicles and industries are the primary sources of this pollution. Carbon monoxide emitted by the incomplete burning of fuel inside the engine.
Carbon monoxide is obnoxious gas and has severe health impacts on humans as well as on animals. It results in stroke, atherosclerosis, and hypertension. Generally, when we inhale oxygen, it binds with haemoglobin and flows through the blood. But when we inhale carbon monoxide. The carbon monoxide binds to the haemoglobin in the blood instead of oxygen. It forms the carboxyhaemoglobin and reduces the oxygen-carrying capacity of the red blood cells. It decreases the oxygen supply to tissues and organs, especially the heart and brain. Oxygen is the primary source of energy supply to the body. For people with cardiovascular disease, this can be a severe problem. These effects are reversible as soon as the exposure to carbon monoxide stops you will again feel healthy.
Pregnant women should be very cautious with exposure to carbon monoxide. Inhaling of carbon monoxide can cause serious health concerns like premature delivery. It may also result in a reduction in birth weight of the child.
5. Ground-level ozone (O3)
Ozone is a colourless, highly reactive gas with a distinctive odour. It formed during electrical discharges like in lightning. It generally found in the upper atmosphere at altitudes of 15–35km. At ground-level ozone produced by chemical reactions between sunlight and air pollutants.
Chemical substances like nitrogen oxides and volatile organic compounds react to form photochemical oxidants. Ozone is one of the main components of photochemical smog. These reactions generally occur during intense sunlight. Bushfires generate large quantities of the pollutants that form ozone.
The upper atmosphere ozone layer protects the earth from harmful ultraviolet radiation from the sun. At the same time, ground-level ozone causes health problems like Headaches, cough, chest discomfort. It also leaves irritation in the eyes, nose, and throat. At elevated levels, ozone can also reduce vegetation growth. Also reduces visibility and can damage materials such as rubber, fabric and paint. People living in coastal areas experience high levels of ozone in the air they breathe.
6. Air toxics compounds
These are gases, particles or aerosols present in the low-level air. It can be harmful to human, plant as well as to animal life. Air toxics includes volatile organic compounds, polycyclic aromatic hydrocarbons, heavy metals and also aldehydes.
Sources of air toxics –
The primary source is Combustion processes from engines, power stations, bushfires etc.
Also, there are Non-combustion activities Like the solvents used in cleaning and paint manufacture industries.
Volatile Organic Compounds. – These are groups of carbon-based chemicals that evaporate at room temperature. You can experience them in every house. Common household materials like paint, cleaning products produce VOCs. Air conditioners, refrigerators and other equipment use coolant gases, that also produces VOCs. Also, the perfumes, insect killers, mosquito coils, etc. can cause the air’s VOCs emission. Different VOCs have different health effects. It affects indoor air quality and also makes it difficult for breathing.
The VOC react with the oxides of nitrogen in the presence of sunlight and create smog. It restricts visibility and can irritate the eyes and lungs.
Some common air toxins are benzene, formaldehyde, polycyclic aromatic hydrocarbons, xylenes, toluene.
Benzene is an organic compound with a molecular formula C6H6. During its normal state, it is a colourless liquid. It is available in fossil fuels. Benzene emitted into the environment by both natural as well as human activities.
Vehicular emissions are the primary source of benzene in the environment. While industries like petroleum refining, service stations etc. also emit benzene. Tobacco smoke also contains benzene. Benzene is a toxic chemical and capable of causing genetic change and chromosomal aberration. High exposure of benzene can cause cancer in the kidney, stomach, pancreas, brain, bladder, respiratory tract and uterus. Long-term exposure to benzene may result in blood and immune system disorders, including anaemia and leukaemia. However, benzene does not have immediate short-term or acute health effects.
Women are more susceptible to benzene poisoning as compared to men. It causes menstrual disorders and affects the development of the fetus in pregnant women.
Toluene – It is also a colourless organic liquid and a molecular formula C6H5.CH3. It is produced by burning organic matter, such as wood, coal and petroleum products. Toluene occurs naturally in crude oil.
Motor vehicle emissions are the primary source of toluene. It produced from tobacco smoke. In comparison, the highest concentrations of toluene produced from household products, such as paints, thinners, adhesives and cigarette smoke. The main effect of toluene exposure is damage to the central nervous system.
It a colourless gas with a molecular formula of CH2O, While known as formalin. Mostly used as an aqueous solution to disinfect and preserve tissue and specimens. It releases from motor vehicle exhaust, domestic solid fuel and gas combustion and also tobacco smoke. Its exposure can result in eye, nose and upper respiratory tract irritation.
Lead is a cumulative toxicant which affects every system of the human body. Depending on the level of exposure, Lead can also affect the nervous system, kidney function, immune system, reproductive system. It is very harmful to young children. Once lead exposed to the body, it distributes throughout the body in the blood. Later it accumulated in the bones. We can know about Lead in the body by measuring the lead count in the blood. Lead is distributed over the liver, brain, bones and kidney.
Along with children, women are at high health risk from Lead. During pregnancy and lactation lead released into the blood. It affects the development of the fetus. In some instances, lead also found in breast milk and fetus.
Exposure to lead happened by water, dust, contaminated air, food, and consumer products. There is a specific occupation like ore and metals processing in which lead exposure is high. Lead exposure also affects the oxygen-carrying capacity of the blood. A small exposure to LED in Infants and young children are hazardous. It can cause behavioural problems, learning deficits and also lowers the IQ.
What is Acid Rain and how it affects the environment
Acid rain is a severe issue in the environment, and it affects most of the things. The pH level of normal water lies between 6.5 to 8.5. Simultaneously, the clean rain is also acidic and has a pH between 5.0 and 5.5. When the rain combines with sulphur dioxide (SO2) or nitrogen oxides (NO), it becomes more acidic. The pH value for acid rain is around 4. Sulphur dioxide and nitrogen dioxide first oxidized. Later it reacts with water and forms sulphuric acid and nitric acid, respectively. The polluted air contains particulate matter which acts as a catalyst for this reaction.
The acid rain is severe and damages to respiratory disorders in humans and also injuries to plants. It washes away all plant nutrients and causes excellent damages to plant. Acid rain also affects the buildings, structures made from metal and stones. It involves the polish, shine, paint and also reacts with the surface in the long term. After falling on the earth, the acid rain flows into rives and finally reaches to oceans. They damage vegetations and aquatic life.
Acid rain has also affected the Taj Mahal. Taj Mahal is in Agra and is build of Marble. Marble contains traces of iron in it. While a small amount of acid rain can oxidise the iron present into marble. It finally changes the colour of marble from white to yellow. There are many industries and power plants around the Agra. They emit a high level of pollutants and these pollutants cause acid rain.
What is Indoor Air Pollution and how to reduce It?
We always think of outdoor air pollution caused by industries and vehicles. However, indoor air pollution is also harmful and causes various health issues. The cooking fuel, cleaning liquids, mosquito sprays, and tobacco smoke are the leading cause of indoor pollution. Use of charcoal, wood, crop waste and animal dung releases indoor air pollution. We should switch to clean cooking fuel and install a proper ventilation system inside the home. Our home and kitchen appliances like washing machine, refrigerator, air cooler, air conditioner, dishwasher, geysers, laptops etc. also releases harmful heat and gases.
In India, the government took the initiative to distribute LPG ( liquefied petroleum gas) under Ujjwala Yojana. Also distributing LED bulbs are the welcome n Initiatives in the same direction.
Ways to decrease indoor air pollution –
Usually, the concentration of pollutants inside the house is more than outside. It is always better to reduce indoor pollution for a healthy life. There are some natural as well as artificial ways to reduce it.
Natural ways to reduce indoor air pollution
- Plant more trees – Trees clears the surrounding air by taking carbon dioxide and releasing oxygen to the atmosphere.
- Remove your shoes and also change your clothes immediately after entering the house. Your clothes observe a lot of pollen, dirt, smokes from the surrounding. It would be best if you always took a shower and also wash your hands regularly.
- Get rid of mould – The damp areas in your house and surrounding generate decay. These moulds emit spores into the atmosphere, which are harmful to human health. Always use mould remover as well as keeps the place moisture-free.
- Regularly wash your curtains, mats and bedding to reduce the dust from the house.
- Regularly remove clutter from your homes. Replace old newspapers, clothes, clean the fans, windows etc.
- Please keep your pet clean, bath them regularly, wipe their paws etc.
- Use clean and clear cooking fuel to reduce indoor smoke.
- Avoid smoking inside the house – Smoking is injurious to health, and you should avoid it. But smoking inside your home will affect the non-smokers as well.
- Avoid any hard chemicals, strong fresheners, too much camphor etc. inside the house.
- You should also minimize the use of home appliances like washing machines, laptops, batteries, refrigerators etc.
Apart from these many natural ways, you can install good Air purifier inside your home. Please read this article Air purifier Buying Guide before buying an Air purifier.
How to control air pollution?
To control air pollution, we must take such steps which will reduce the pollutants in the air. We already know low air quality has very harmful and disastrous effects on human health. It mainly affects the respiratory and cardiovascular systems and causes several diseases. These pollutants also damage plants and buildings and reduce visibility.
There are many ways we should follow to minimize the air pollution effect.
- We should use a shared car service, use carpool and public transport. The better way is to use a bike and even cycle to reduce vehicular pollution. Always try to walk more whenever it is possible. Switch to electric cars and bikes to minimizes the consumption of fossil fuels.
- Maintain your vehicle in good condition and regularly check its pollution level. It will help you to reduce fuel consumption and minimizes the running cost.
- It would be best if you buy appliances with higher energy ratings to reduce its energy consumption. Also always try to purchase products which are easily recycled.
- Plant more trees to clean the air and its surroundings.
- Farmers must not burn the agricultural remains, and the government should find out alternatives to recycle those agriculture remains. We can use agriculture waste to Make Ethanol.
- Instead of traditional cooking fuel, we should use LPG and electrical induction system.
- Try to use environment-friendly paints and cleaning products.
- Industries must use pollution control devices to remove pollutants. They must filter and recycle before disposing of the industrial waste. There must be fines for violating the rules. While appreciation for following the best practices.
Some More Best Practices –
- Always try to conserve energy wherever it is possible. Like, switch off light, fans, appliances etc. when not in use. Switch off the car and bike engines while waiting in traffic.
- Switch to renewable energy and get rid of fossil fuels and Maximizes the use of solar energy and wind energy etc.
- Build more green buildings and cities.
- In homes, we should install solar energy, increase ventilation. It would be best if you use an Air purifier to clean indoor air.
- The most important is to spread awareness among people about these best practices and the harmful effects of Air pollution.
- Install Kitchen Chimney inside the kitchen to eliminate harmful smoke and gases from the kitchen. Also better to choose Air conditioners and air coolers with air purifying filters. Also limit the use of home appliances like refrigerators, washing machine, geysers and many more.
- For eliminating indoor air pollution, you can install an Air purifier. Also inside the kitchen, you should install a kitchen chimney which will eliminate any harmful gases.
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Air pollution is harmful to public health as well as for plants and animals. It is more harmful especially to children, pregnant lady and elderly and sick people. Sometimes a long term exposure to less concentrated pollutants is more dangerous than a short exposure to a higher concentration. We should clean the environment on an individual as well as community level. Each of us should work towards the betterment of our environment.
It is never too late to start. The sooner we start, the sooner we can clean our environment.