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Indoor Air Quality: 7 Basic Questions About Mold

By Kurina Baksh
Published: October 27, 2016 | Last updated: January 10, 2017 01:55:17
Key Takeaways

Mold problems often develop out of sight, so it's important to know the risks and how to mitigate them.

Caption: Mold growing on a wall near a window Source: ja-aljona / Envato Elements

Most people spend the majority of their workday indoors, where the only opportunity for a breath of fresh air comes from opening a window. In many cases, this can be considered a health hazard since the concentration of biological contaminants tends to be much higher in indoor spaces than outdoors.

To make matters worse, indoor atmospheres are the perfect breeding ground for hundreds of specifies of bacteria and fungi, especially when there is enough humidity and moisture for them to thrive.

Mold is one of those biological contaminants, and one that every workplace should worry about. It often grows in places that are out of sight, the spores it releases into the air are invisible, and people often experience adverse health effects from them without knowing that mold is the culprit.


In this article, we'll go over some of the basic facts about mold, what makes it a workplace hazard, and what steps you can take to prevent mold from becoming a problem.

What Are Biological Contaminants?

Biological contaminants are living organisms (or the products of living organisms) that are harmful to human health or can cause discomfort.

Categories of biological contaminant include:

  • Viruses
  • Fungal spores
  • Mold
  • Dust
  • Pollen

Since all of these can be airborne, can be breathed in, and can pollute indoor environments, all of these can affect indoor air quality (IAQ). In sufficient concentrations, they can make the indoor air hazardous.

What Causes Mold to Grow?

Molds are a type of fungus that reproduces by releasing microscopic spores into the air.

High levels of moisture or humidity create optimal conditions for molds to grow. This is why they will often grow in under bathroom sinks or inside walls where a pipe has leaked.

Window frames are also hot spots for molds. The difference in temperature between the outside and inside air causes condensation on the glass. This condensation then accumulates at the base of the window frame. If it is not wiped clean regularly, mold is almost certain to develop.

(Learn more about Indoor Air Quality: The Invisible Hazard in Every Workplace)

Which Type of Mold Should You Worry About?

There are different species of mold, each with its own properties.


Some will grow in different environments, with some tending to accumulate on organic matter (like spoiled food) while others will typically be found on flat surfaces like walls and floorboards.

The easiest way to distinguish molds is by their color. When inspecting your workplace, you might find green mold, white mold, or black mold.

While their health effects vary, it doesn't really matter from a health and safety standpoint. All mold should be treated as an indoor air quality hazard, regardless of its specific properties. No matter the type of mold, the response is the same: removing the mold, wearing respiratory PPE when dealing with it, and taking steps to prevent future mold issues.

(Learn how to Work Safely with the Proper Respirator)

What Are the Health Issues Associated with Mold Exposure?

The inhalation of mold spores can exacerbate existing health problems, as well as create new ones. Molds produce mycotoxins, which are known to beg toxic to humans. Exposure to these mycotoxins gradually wears down the immune system, which can result in respiratory problems or allergies.

The most common symptoms of mold exposure are:

  • Headaches
  • Difficulty concentrating
  • Fatigue
  • Cough or congestion
  • Irritation of the eyes, nose, and throat
  • Aggravation of asthma

Mold can also make the following allergy symptoms worse:

  • Tightness in the chest
  • Wheezing
  • Shortness of breath
  • Eye irritation
  • Nasal congestion

How Can You Detect Mold in the Workplace?

The most reliable method to identify the presence of mold is to conduct a thorough visual inspection of the indoor environment. Here are some tips to follow when doing so:

  • Look for signs of water damage (e.g. discoloration, stains)
  • Closely inspect any dark spots or patches that might be mold
  • Check for puddles of water around sinks, tubs, air conditioners, refrigerators, and humidifers
  • Check the following areas for signs of water damage or mold:
    • Ceiling tiles
    • Walls (including wallpaper and drywall)
    • Floors
    • Window sills and door frames
    • Carpets
    • Furniture
    • Insulation

You can also bring in a trained professional to perform a surface sampling procedure, which involves scraping potentially affected surfaces and having a lab analyze the samples for traces of mold.

How Can Mold be Removed or Cleaned?

Mold that only affects a small area (less than one square meter) can be cleaned using detergent and water. Anyone tasked with cleaning mold should do so while wearing gloves and a respirator.

For larger areas, enlist the help of commercial cleaners. They will be able to remedy the issue and contain the spread.

Contaminated building materials, such as mold-infected ceiling tiles, should be disposed of and replaced. All water-damaged carpet should be cleaned within 24 hours. If this is not possible, consider throwing them away.

(Learn more in A Spotlight on Mold Remediation)

What Can Be Done to Prevent Mold?

Since mold can grow in any area with sufficient moisture, the best method of prevention is to reduce moisture and humidity. This can be done by:

  • Eliminating sources of moisture
  • Keeping the relative humidity of the indoor environment at 30 to 50 percent using air conditioners or humidifiers
  • Installing exhaust fans to vent out areas where moisture is unavoidable (such as washrooms)
  • Insulating cold surfaces to prevent condensation
  • Performing regular maintenance on the building's HVAC system to ensure it remains in good working order
  • Cleaning up immediately after any flooding or serious spill
  • Repairing all water leaks immediately
  • Keeping stagnant water sources clean and disinfected

(Find out Why HVAC Winterization Is Important for Health and Safety)

Keep the Air Clean

Poor indoor air quality can affect the wellbeing of workers and put their health at risk. Everyone should be able to breathe clean air at work. By ensuring a mold-free environment, you are taking an important step to ensure that they can.


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Written by Kurina Baksh

Kurina Baksh is a Health, Safety and Environment Professional from Trinidad and Tobago. As a recent graduate in the field, she is trained to analyze and advise on a wide range of issues related to her area of expertise. Currently, she is an independent consultant who develops public outreach and education programmes for an international clientele. She strongly believes that increasing public outreach and education can promote hazard awareness and ultimately save lives.

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