What causes polluted air?

Nowadays we are exposed to so many pollutants both visible and invisible. Whether outdoor or indoor, the quality of air is getting worse. The exposure to such high levels of pollution have led to several health threats and environmental impacts.

So, in this article we will discuss air pollution, what are its sources, what are the health impacts related to them, and what measures we can take to protect ourselves from the impact of harmful pollutants. 

What causes polluted air?

There are several air pollutants in the air that causes polluted air namely; 

  • Sulfur dioxide
  • Nitrogen dioxide
  • Ozone
  • Carbon monoxide
  • Particulate matter (PM10 and PM2.5)
  • Volatile Organic Compounds (VOCs)
  • Chlorofluorocarbons (CFCs)

What are the sources of these air pollutants?

The following are the sources of the major air pollutants:

Sulfur Dioxide

Sulfur Dioxide is an irritant gas. If you happen to inhale this gas it can irritate your nose, throat and lungs. 

Sources of Sulfur Dioxide 

 The most common sources includes; 

  • Coal fired power stations
  • Oil refineries
  • Shipping
  • Coal burning
  • Diesel vehicles

Nitrogen Dioxide

Nitrogen dioxide is a gas. When inhaled it can cause irritation in your throat and lungs. 


Sources of Nitrogen Dioxide

The main sources of NO2 are: 

  • Vehicular traffic
  • Coal powered stations
  • Industrial emissions 


Ozone is a pungent gas which is present in the stratosphere. It protects us from the effects of harmful UV rays. But when formed at ground level it causes several harmful effects. Ozone is the main component of photochemical smog. 

Sources of Ozone

When the oxides of nitrogen and certain volatile organic compounds react with each other in the presence of sunlight, it gives rise to ground level ozone. 

Carbon monoxide

CO is a colourless odourless and toxic gas. 


Major sources of indoor carbon monoxide:

  • leaking chimneys and furnaces, 
  • wood stoves, gas stoves, 
  • generators 
  • gasoline-powered equipment
  • tobacco smoke


PM10 and PM2.5 

The PM10 particles are defined as particles having the size range of either 10 or less than 10 microns. These particles are small enough to enter your throat as well as lungs. whereas , PM2.5 are the particles having the size of 2.5 microns or smaller. PM2.5 is very small in size. It is mainly found in smoke.


Sources of PM10 and PM2.5

Common sources include:

  • Dust
  • Fire smoke
  • Vehicular exhausts
  • Industrial emissions
  • Common sources includes:
  • Smoke from fires
  • Vehicular exhaust 
  • Industrial emissions 


Volatile Organic Compounds (VOCs) 

Volatile Organic Compounds are defined as compounds having high vapor pressure and low solubility in water. Mostly VOCs are man- made chemicals. Some VOCs are suspected to cause cancer such as Benzene. It is a known human carcinogen.

Sources of VOCs

Common sources of Volatile Organic Compounds (VOCs) at home include:

  • Paints and solvents
  • wood preservatives
  • aerosol sprays
  • household cleaners and disinfectants
  • air fresheners
  • stored fuels
  • dry cleaned clothes.


Chlorofluorocarbons (CFCs)

CFCs are basically man made compounds that destroy the ozone layer in the stratosphere. The ozone in the stratosphere acts as an earth’s protective shield and protects us from harmful UV radiations. CFCs also have a global warming effect. 


Sources of CFCs

Some major sources of CFCs includes:


Air conditioners


Aircraft Halon

Fire extinguishers 


How do these pollutants affect our health?

These air pollutants have the following health effects:

Health impacts of SO2Health effects of NO2Health effects of OzoneHealth effects of carbon monoxide Health effects of PM10 and PM2.5Health effects of VOCsHealth effects of CFCs
WheezingCoughingHealth effects caused by NO2 includes:CoughingExposure to this toxic gas can irritate your throat and lung linings. impaired vision and coordination, dizziness, confusion, nausea CoughingRunny noseStinging eyeseye, nose and throat irritation,shortness of breath, CFCs can cause asphyxiation
Shortness of breathWheezingShortness of breathCauses difficulty in breathing angina, impaired vision and reduced brain function.  WheezingCoughingdizziness, skin problems.cardiac sensitization
People having existing lung conditions are more prone to its effects. It can worsen the condition of people with lung conditions.The people at higher risk includes; children, elderly, and people with lung conditions.fatigue in healthy people and chest pain in people with heart    diseaseChest tightness,Difficulty in breathing headaches, fatigue, nausea,but the potential for chronic effects is less. 


What can we do to protect ourselves from these harmful pollutants?

There are some measures you can adopt to reduce your exposure to these harmful pollutants :

Keep a check on air pollution levels

You can keep a check on the air quality index of your area to get insight about the pollution levels. There are certain websites designed for this purpose such as the Environmental Protection Agency. These sites can be accessed anytime of the day.

You can also get information from local radio, television, and newspapers. This way you can plan your outdoor schedule accordingly. 

Avoid outdoor trips during the peak hours

Avoid going outdoors during the peak hours of pollution. Air pollution levels are highest in the afternoon, so try not to go outside at that time. Doing so can increase the chance of getting exposed to high levels of pollution. Avoid outdoor exercising when the Air Quality Index is greater than 300. 

Avoid going to high-pollution areas

Pollution levels are the highest near the roadways especially within 1/4 mile of a road. Highly congested urban areas and smoking areas should also be avoided. 

By Installing an air purifier

The outdoor pollutants can also infiltrate through your house. Which affects the indoor air quality of your house. Other than that the indoor pollutants may also originate indoors. 

Given below are the links of few air purifiers that will keep your house clean and safe:

Air purifier : Germ Guardian Air Purifier

  • Features: Germ guardian 5 in 1 air purifier is an electrostatic HEPA air filter and offers a removal efficiency of about 99.97% against particles as small as 0.3 microns. 
  • Efficiently removes harmful germs like viruses, odor causing bacteria, mold spores, mildew, and other allergens like;  dust, pet hair, and other large particles; like PM10
  • The efficient UV-C light kills airborne viruses such as influenza, staph and rhinovirus. 
  • The filter also removes the VOC concentration with the help of titanium dioxide. 
  • The activated charcoal filter is effective against cooking odor, tobacco smoke, fumes, pet odor etc. 
  • Offers quiet operation; with the Ultra-quiet sleep mode it operates on low sound levels to get you a good night’s sleep.  
  • GermGuardian Air Purifiers are ideal for medium to large rooms having an area of about 743 sq ft.

Air purifier: Instant Air Purifier

  • Features: Instant air purifiers are proven to kill 99.9% of Covid-19 virus, bacteria, mold, and other harmful viruses. 
  • With its Advanced 3-in-1filtration; HEPA-13, Activated Carbon, Antimicrobial coating and plasma ion technology it removes 99.97% of pollutants like particulate matter tobacco smoke, pet dander, certain odors and other impurities. 
  • Its advanced sensors offer a 24×7 air quality monitoring with auto fan speed adjust feature.
  • It filters the air in an area of 126 sq ft 5x per hour 
  • With its whisper quiet night mode it offers lower noise for a sound sleep.
  • The filters last upto 8 month, after that it needs to be replaced.

By installing an HVAC systems 

The HVAC system works efficiently towards filtering airborne contaminants and also helps in continuous circulation of air.

Given below are the links of few HVAC systems that will keep your house clean and safe:

HVAC System:  Honeywell F300E1019 Electronic Air Cleaner

  • Features: This can be operated with gas, oil and AC systems. 
  • Efficiency for capturing particles is upto 98%.
  • Has a very low pressure drop

HVAC System: DAIKIN Inverter Air Conditioner Heat Pump System

  • Features: Daikin’s ductless technology offers  greater  energy efficiency; cools and warms up the room fast.
  • Smart inverter technology with integrated inverted variable speed compressor
  • Provides continuous heating and cooling with minimum temperature fluctuations.
  • Quiet operation; with indoor sound levels as low as 37 decibels. 

Using fans for the improvement of air flow

If opening windows are not feasible consider using bathroom and stove exhaust fans. Try placing the fans close to an open window or a door. This ensures better air circulation and draws the air borne particles like viruses, bacteria and particulates out of your house.

Below are the best exhaust ventilation and for improving the air flow in your room:

Fan: AC Infinity AIRLIFT Exhaust Fan

  • Features: Offers high airflow; draws out heat, moisture, odor, and dust etc.
  • EC-motor with PWM-control increases and reduces energy consumption and noise levels (67dB)
  • Blades are made of aluminum that are resistant to liquid and dust

Fan: VENTISOL Variable Shutter Exhaust Fan

  • Features: Provides superior airflow; ideal for  garages, gardens, attics, barns, greenhouses, basements etc.
  • Easy installation consists of hard wire connection for wiring.
  • Body made of galvanized steel frame, 3 aluminum shutter blades, fully enclosed ball bearing motor, self closing shutter system provides protection to fans when not in use.
  • It’s suitable for ventilating a building to the outside.
  • Powerful & Efficient: 120 volts at 70W, 0.57 amps, with 1680rpm


Use of evaporative coolers 

Evaporative coolers are also known as swamp coolers. They help in increasing the ventilation in the room and also cools down the indoor air. Evaporative coolers are ideal for dry climates. They require water to provide cooling and also enhances the relative humidity of the room.

Below are some links to the best evaporative coolers that offers better airflow for your room:

Evaporative cooler: Pro Breeze Evaporative Air Cooler 

  • Offers powerful cooling with its  waterfall cooling technology that propels air through an ice cold honeycomb filter.
  • A portable swamp cooler air conditioner ideal for room, home office or bedroom.
  • This is a 3-in-1 appliance which can operate as an air cooler, a cooling fan and a humidifier.
  • It runs at just 0.0065 kw/h, which is much more energy efficient than an air conditioner hence it is energy efficient & cost-effective

Evaporative cooler: Air Cooler Sunday Living

  • This swamp cooler has a double layer water circulation system which purifies air can also be used as a humidifier or a fan
  • Water tank has a large capacity with visible water level window 
  • This cooler does not have compressor and chemical refrigerants and hence it is environmental friendly 
  • Comes with a bladeless cooling solution 
  • Cost effective Compared with your costly AC,
  • Safer to use in the household that has children or pets.

Other FAQs about Air Quality that you may be interested in.

What causes PM10 in the house?

What causes bad air quality?

What are the symptoms of poor air quality?


So, in this article we discussed air pollution, what are its sources, what are the health impacts related to them, and what measures we can take to protect ourselves from the impact of harmful pollutants. We hope you found this article helpful. 



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