The quality of air in your home is heavily impacted by a variety of indoor-generating pollutants and outdoor air pollutants that seep into your house through windows, and drafty doors.

Among the most notable indoor air pollutants are the following:

  • Combustion sources like oil, gas, kerosene, coal, wood, tobacco smoke, etc.
  • Harmful household products – such as cleaning chemicals, paints
  • Biological contaminants, such as dander, pollen, mold, mold spores, mildew, radon
  • Stoves, heaters, fireplaces and chimneys, and central heating and cooling systems
  • Carbon monoxide, carbon dioxide, ozone
  • Formaldehyde – found in old paint cans and household products
  • Pesticides
  • Asbestos
  • Lead
  • Carpets
  • Outdoor air pollution

(Sources: USEPA and the HowStuffWorks website)

Improving Air Quality in Your Home
To improve the air quality in your home, the advice from the U.S. Environmental Protection Agency (EPA) is to control the pollutants, work to eliminate them and ensure your home is properly ventilated.  Without proper ventilation, indoor air pollutants can build up in a home.  If the level of outdoor air contaminants is high, as it is in Delhi, ventilation with fresh outdoor air is not an option, so the focus becomes cleaning and filtering the air that is inside your house.

Below is some information on the types of indoor air cleaners and what they do, according to the EPA as well as some information on the use of plants to help clean the air in your home.

Residential Air Cleaners
Two types of air-cleaning devices can remove particles from the air: mechanical air filters and electronic air cleaners.

Mechanical air filters remove particles by capturing them on filter materials. Some mechanical air filter machines contain HEPA or high-efficiency particulate air filters. According to the EPA, mechanical air filters with true HEPA filters are defined as having a minimum efficiency between 99.97 percent and 99.999 percent in removing particles of  0.3 µm size from the air. Which means, when used properly (in the right sized room, with no outside air flow and clean filters) these machines are designed to catch most of the particles in the air down to those even smaller than the PM 2.5 particles that are most concerning to health.

Electronic air cleaners, such as electrostatic precipitators, use a process called electrostatic attraction to trap particles. Ion generators, or ionizers, disperse charged ions into the air. These ions attach to airborne particles, giving them a charge so they can attach to nearby surfaces such as walls or furniture, or to one another, and settle faster. However, some electronic air cleaners can produce ozone, a lung irritant.

For more information, on residential air cleaners, their efficiency and effectiveness; guidance to their comparison and evidence of their usefulness, see the below information from the U.S. EPA

For more information about indoor air pollution and indoor air filtration systems, please check out this page on the EPA website

Purchasing Air Filtration Systems
f you are in the market for a home air purifier, the best place to start your search is to review the ratings on Consumer Reports. Here you can compare popular brands like Sharp, IQAir, Blueair, and Philips. Or check out the free service, ConsumerSearch.

If you are shopping in Delhi, your next question may be how to get one. Currently there aren’t many local vendors of air purifier machines but below we have listed three  (send a note to if you know of others and we will list them). Note: the filters on most air purification machines need to be changed when they are “full”. These machines were made to filter a lighter pollution load and therefore may recommend you change the filters less often than may be necessary. Some machines, like the IQAir have a light that will go on when the filter needs changing.

DelhiAir does not endorse or recommend any product or service for air filtration.

1) Breathe Easy Consultants Pvt Ltd
CEO, Barun Aggarwal at
Paharpur Business Centre
21 Nehru Place Greens, New Delhi 110019, INDIA
Direct: +91 (0) 11 26207493
Mobile: +91 (0) 98737 44440
Web: &
Products: Sharp and IQAir. (Exclusive distributor of IQ Air machines in India.)

2) Blueair India Pvt. Ltd.
Vijay Kannan, Head of India Office

Also, check out Do It Yourself (DIY) websites if you are interested in building an air filtration system yourself, which can be more economical and satisfying too. Here are a few websites for DIY ideas:

Finally, for a  look at one doctor’s experience comparing the effectiveness of air purifiers in his home in Beijing, see the following articles written by Dr. Richard Saint Cyr, MD. He has tested different air purifiers and has a ranking of what works best in Beijing’s environment. His webpage is full of information about air pollution and its attendant health issues.

Indoor Air Quality Testing
If you would like to have the air quality in your home or office tested, below are some local companies that offer this service (Delhiair does not endorse any company or product. Please send an email if you know of other local companies offering this service:

1) Breathe EasyTM
Paharpur Business Centre, Delhi
Phone: +91-11-2620 7451
Mobile: +91 96544 17019

2) SGS House
4B, Adi Shankaracharya Marg Vikhroli (West)
Mumbai, 400083
Phone: +91 98670 19105
Fax: +91 22 6640 8829

One recent independent air quality test (April 2015) of four brands, Sharp, BlueAir, Euromate, and Camfil, showed the following results against the levels of PM 2.5 in a Delhi home:

Screen shot 2015-04-11 at 10.55.04 AM

Indoor Plants: Natural Air Purifiers
In addition to air filtration systems, certain household plants can help reduce the indoor air pollution in your house.  A 1989 National Aeronautics and Space Administration (NASA) study came out with a list of common indoor plants that could help absorb, neutralize, and remove many toxic pollutants. (NASA Study)

In a 2009 TED Talk, Delhi native and researcher Kamal Meattal discussed how three particular plants, the Areca palm, Mother-in-Law’s Tongue and the Money plant (all available in Delhi and India) interact with indoor pollutants, thus providing a compelling reason to grow fresh air.

Also, check out this article from Dr. Richard Saint Cyr.

For further information about how to reduce your exposure to indoor pollution, you can see what the US Embassy in Beijing recommends here. Also, read about more tips in this recent article in the New Indian Express, Indoor, not outdoor, pollution is the silent killer stalking you.