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Indoor Air Quality Sources, Facts & Concerns

November 2, 2017 9:12 AM by Tennant Company

What is Indoor Air Pollution, and What are The Causes?

Air pollution indoors can be just as bad (if not worse) than outdoors. What makes indoor air so important is the fact that we are exposed to it more consistently and for longer periods of time; we also breathe it at a higher concentration.

Furthermore, the less-diluted and mostly-trapped air in enclosed “ecosystems” (your home/workplace), can host a whole array of pollutants equal in harmfulness to anything experienced in, say, polluted outdoor city air. 

This is especially true if there is poor ventilation, if many different chemicals (e.g., cleaning & personal-care products) have been imported, if these places are well insulated, if pets are found, and if the heat and humidity factor is high. 

Indoor Air Quality Facts

Other information directly attributable to poor indoor air quality (IAQ):

  • Indoor air can be two to ten times more harmful than outdoor air
  • It’s responsible for an 18% reduction in work productivity
  • 20% of employees suffer from major illnesses tied to air pollution
  • 6,000 new potentially-harmful chemicals are developed yearly; add these to the thousands already in use
  • Harmful non-living indoor contaminants include: formaldehyde, tobacco smoke, grease, pollen, asbestos, dirt, lead, ammonia, pet dander, etc.
  • Microorganisms in indoor air include: mildew, mold, viruses, bacteria, dust mites, etc.

Symptoms and Health Problems

The key thing to take away is that many of the pollutants inside our homes and workplaces are health-compromising, as illustrated by these facts:

  • 50% of all illnesses are associated with or exacerbated by indoor air pollution (American College of Allergies)
  • Well-insulated homes/workplaces can keep out naturally-air-cleansing negative ions and ozone
  • A well-insulated building’s allergen count is 200% higher than poorly-insulated ones
  • According to World Health Organization (WHO), 40% of all buildings pose serious health threats — including cancer, TB, Influenza, COPD, asthma, eye irritation, allergies, sick-building syndrome, etc.
  • Most persons spend 80% to 90% of their time indoors — hence, most of the air they breathe is the “indoor” type

The fact that we spend most of our time indoors is reason enough to be concerned, if we also acknowledge that:

  • Indoor air quality in most instances and places is unacceptably bad
  • Air pollution is responsible for many medical problems
  • There are practical, affordable ways to reduce, if not remove, this significant danger to our health

How to Improve Indoor Air Quality?

The bad news is that, globally, outside air quality is increasingly getting worse. This is especially true in heavily developed industrial locations. While there isn’t much that individuals can do about that problem, there is much that can be done to improve the air inside your home and place of work. 

What you can do falls into two separate categories:  Things you can do about poor indoor air quality, and things you should stop doing which contributes to or worsens the problem.

Things you can do, include:

  • Regularly and faithfully change the air filters (in your HVAC system, your vents, etc.) that help keep dust, pollen and other pollutants out of facilities; consider getting HEPA and electronic air filters, if possible
  • Vacuum (with a HEPA-filtered machine only) and clean the premises regularly
  • Avoid toxic-chemical cleaners
  • Install an Energy Recovery Ventilator or ERV, which removes bad air to place it with filtered air; it makes your HVAC system more efficient by returning cooled/heated air to HVAC unit
  • Strictly control humidity and heat — both of which can increase pollutant concentrations indoors — levels by adjusting thermostats, using dehumidifiers, etc.
  • In addition to smoke detectors, consider installing carbon monoxide detectors
  • Consider installing radon gas detectors, especially in basements and areas where radon gas has been known to show up
  • Neutralize some pollutants by using such things as air cleaners that utilize hydroxyl radicals, ozone, negative ions, and UV light — these can kill many types of microorganisms known to induce disease — including viruses, bacteria, fungi, mold spores, etc.
  • Practice proactive cleaning and pollution prevention practices

Things you should stop doing:

  • Using air fresheners — most contain harsh, potentially toxic chemicals that can irritate the sinuses and do other types of harm
  • Strive to not let the humidity inside get too high — high humidity can be the source of or a contributor to poor IAQ
  • Manage or mitigate incomplete combustion sources involving oil, gas, kerosene, coal or wood
  • Don’t keep dangerous or fume emitting substances or liquids in the home or place of work
  • Don’t smoke indoors
  • Avoid tracking pollutants into the home — pet dander, fleas, pollen, dust/dirt, etc. — wipe or change shoes when entering home


Properly managing indoor air quality isn’t just about being comfortable but also about staying healthy. By following some very basic rules and guidelines, you can greatly reduce the air pollution that is most probably present in both your home as well as the places where you work or spend significant time in.

The choice is yours: ignore the problem or, by doing the smart thing, prevent easily-avoidable dilemmas and complications.

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