Dr Jackson Kung'u- Mold Specialist

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Dr. Jackson Kung’u (PhD)- Mold Specialist.
Phone: 905-290-9101
Mobile: 437-556-0254

Home | Indoor Air Quality

Indoor Air Quality

Sick Building Syndrome

What is Sick Building syndrome?

Sick Building Syndrome (SBS) is a term used to describe situations in which building occupants experience acute health symptoms that appear to be linked to the time spent in a building with no specific cause that can be identified. The complaints may be localized in a particular room or zone, or may be widespread throughout the building. SBS related complaints have increased in recent years and result when a building is operated or maintained in a manner that is inconsistent with its original design or prescribed operating procedures. Sometimes indoor air problems are a result of poor building design or occupant activities.

Indicators

Occupants of sick building syndrome buildings complain of symptoms associated with acute discomfort, e.g., headache, eye, nose, or throat irritation, dry cough, dry or itchy skin, dizziness and nausea, difficulty in concentrating, fatigue and sensitivity to odors. The cause of the symptoms is not known. Most of the complainants report relief soon after leaving the building.

Possible Causes

Many factors contribute to the sick building syndrome and sometimes it is difficult to pinpoint the cause.

  • Inadequate ventilation: This implies insufficient outside air, insufficient airflow and inadequate circulation. An improper system design or operation, and occupant tampering with HVAC system may be the cause.
  • Chemical contaminants from indoor sources: Copying and printing machines, computers, carpets, furnishings, cleaning materials, smoke, paints, adhesives, caulking, perfumes, hairsprays, solvents emit  VOCs or volatile organic compounds that affect indoor air quality.
  • Chemical contaminants from outdoor sources: Pollutants from motor vehicle exhausts; plumbing vents, and building exhausts (e.g., bathrooms and kitchens) can enter the building through poorly located air intake vents, windows, and other openings or a nearby garage.
  • Biological contaminants: Bacteria, molds, pollen and viruses are types of biological contaminants. These contaminants may breed in humid and damp conditions, stagnant water that has accumulated in ducts, humidifiers and drain pans, or where water has collected on ceiling tiles, carpeting, or insulation. Sometimes insects or bird droppings can be a source of biological contaminants. Physical symptoms related to biological contamination include cough, chest tightness, fever, chills, muscle aches, and allergic responses such as mucous membrane irritation and upper respiratory congestion.

Possible Solutions to Sick Building Syndrome

In order to overcome sick building syndrome, a detailed indoor air quality investigation is a prime requirement. This involves identifying underlying causes and determining corrective actions. It begins with gathering information on the following:

  • the occupants’ activities
  • the HVAC system
  • possible pollutant pathways
  • possible contaminant sources.

Once the information is available, air sampling may be conducted to assess the level and types of chemical and biological contaminants. Moulds are serious biological contaminants that severely affect the indoor air quality. They can cause many health related symptoms like allergies, cough, cold, irritation, nausea, fatigue and fevers. Mould can be sampled using a simple air pump or a tape. You may refer the following link for a demonstration on Air Sampling for mould:
http://www.moldbacteria.com/presentations/index.html

Primary assessment confirms presence and further tests reveal the identity of moulds. This could help draw conclusions on factors that contribute to sick building syndrome. Based on all information and evidence gathered, a strategic solution may be developed. Pollution source removal and air cleaning would be the basic approach. Proper ventilation rates and air distribution can help minimise SBS. Effective communication between building occupants, management and maintenance personnel can help find the causes and consequences of sick building syndrome. Awareness about indoor air quality issues can aid in overcoming the sick building syndrome.

Monitoring And Documenting Air Quality

Monitoring and documenting air quality, especially in hospitals, pharmaceutical, cosmetics, and food industries environments is very important. Contamination of these environments can originate from nearby or far away sewage plants, landfill sites, and waste separation plants. Therefore, monitoring on a regular basis of air quality in operating rooms, production lines, and other controlled areas is critical.

To assess the level of microbial contamination in the air, air is sampled for analysis by direct microscopy (sometimes referred to as nonviable analyses) or by culture analysis. For direct microscopy, the air is sampled using various cassettes including Air O Cell, Allergenco, Millipore filters and others. The samples are examined at between 600 and 900X magnification.  Fungal spores and mycelial/hyphal fragments are enumerated. Millipore filters are first cleared using acetone and fixed with triacetine and then analysed in a similar manner as the Air-O-Cell or Allergenco samples. The filters have a major advantage over the other spore traps in that, having a large surface area, they can be used in highly contaminated environments, where other spore traps would easily be overloaded with dust thus rendering them difficult to analyse.

Direct microscopic analysis of air samples allows determination of total spore counts regardless of whether the spores were dead or alive. In hospital environments both dead and living spores are of concern because even if the spores were dead, they could be as toxigenic or allergenic just like living spores.

To sample air for culture analysis requires the air to be impacted on suitable agar media. Commonly used types of samplers are the Reuter Centrifugal Sampler (RCS) and the Andersen samplers. However there are many other samplers.  The air is impacted on media such as MEA and DG18. Culturable air samples are incubated for 3-5 days and the resulting colonies counted. The colonies are then transferred onto suitable agar media for identification. In general, number of fungal propagules determined by cultural method is far much smaller (1-50% of total counts in some cases) than the total number of spores and fungal propagules determined by direct microscopic examination.

To assesss air for bacterial contamination, a general purpose media such as Tryptic Soy Agar (TSA) can be used. However, if sampling for a specific type of bacterium such as Legionella spp, then a selective media such as Buffered Charcoal Yeast Extract (BCYE) Agar is recommended.

Exposure limits to black mold

Many times we’re asked the exposure limits to black mold. Unlike other indoor pollutants, there are no exposure limits to mold. Exposure limits to mold would be difficult to set because human beings differ in their susceptibility to mold. Similarly, the molds themselves differ in their ability to cause health problems.

Molds may affect human beings in three different ways:

  • Allergenicity
  • Infection
  • Toxicity

As concerns common indoor molds the most likely effect is allergenicity. Very few fungi (molds and yeasts) are known to cause infection to healthy individuals. Toxicity is most likely to occur if one eats food contaminated with the fungal toxins. While toxicity is also possible through inhalation of spores or dust containing toxins, little is known about this possibility. 

Generally, elderly people, infants, sick people and other individuals with weak immune systems are at higher risk of suffering from mold exposure related diseases than healthy people.

How To Test For Mold

Mold testing has 2 components:

  • Assessment of the extent of mold growth in the building
  • Laboratory testing of the samples collected during the building assessment

Assessment of the extent of mold growth

This component of mold testing is very important because the results of this assessment are used to determine the level of remediation required. Mold assessment in a building should be performed by a qualified professional.

Laboratory Testing Of Samples

Laboratory testing of samples for mold is necessary especially in situations where mold is suspected to be the cause of illness to the building occupants. The samples tested for mold include the following:

  • Bulk and Surface Samples: These include samples such as pieces of carpet, carpet dust, drywall, wallpaper, swabs, tape lift samples or any other material suspected of mold contamination.
  • Air Samples. Air samples may be collected on culture media or on inert non-culture media depending on the objectives of the mold investigation.