Hazards Perpetuated by the Indoor Built Environment

We spend lengthy amounts of time each day indoors, in our offices, homes, schools, health care facilities, aged care or in other private or public buildings.

Ability to breathe healthy indoor air in buildings is recognized as a basic human right, and it is an important determinant of continued health and well-being.  There are serious health risks associated to dampness, microbial growth and contamination of indoor spaces. Especially true for hospitals, day care centres, retirement homes and other special environments, where population groups tend to be profoundly vulnerable, due to their age or health status and as a result, even more affected by indoor air pollution and contaminants

Most buildings, commercial and/or residential, have the same sorts of issues, just they will differ in magnitude. Do you ever wonder about quality of the air being breathed in those buildings? And why, when people go off to hospital, they will occasionally return home sicker or reinfected in some other way?

People’s knowledge of building science is gaining momentum. We are far more aware now of how buildings “breathe” and function. Greater understanding of building-related diseases; symptoms of diagnosable illnesses which can be identified and directly attributed to airborne indoor building contaminants.


Sick building syndrome (SBS) is a major occupational hazard. The cause, management and prevention of SBS must be taken very seriously by all businesses. 

Comprising a range of non-specific symptoms; usually found in building’s occupants as they begin to experience ill health effects. Culprit, more often than not, inadequately poorly maintained, controlled indoor air – known now to be perpetrator of high number of health burdens. Yet Building Sickness Syndrome remains so poorly understood.

With wider knowledge of poor indoor air quality and contributing factors -the opportunity exists for stakeholders to focus and take action. Building owners, developers, architects, users, occupants and building managers – all these groups right now are zeroing in on producing and maintaining cleaner, healthier indoor air for their occupants. Here’s why that’s so critical.

Complexity & Interplay of Events Leading to Biological Contamination of Indoor Air

Let’s explore connection between ventilation, ergonomics, building design, physical and chemical influences inside a business. There is interplay between a range of aetiological factors like temperature, humidity, air flow movement, internal pollutants, dust, bacteria, as do other elements like heat, gas, lighting; all those play their part to effect your building’s IAQ.

In fact, there is a complex chain of events connected to biological contamination of indoor built environments – linked to:

a) inadequate ventilation;

b) water penetration indoors;

c) excessive moisture feeding biological growth;

d) physical, chemical degradation;

e) emissions; off-gasing of hazardous biological, chemical agents from new building fit outs and

f) whole host of other contributory factors, unmentioned, like surface condensation etc.

Excessive moisture on most indoor materials leads to growth of microbes.

Mould, fungi and bacteria, which subsequently emit spores, cells, fragments and volatile organic compounds into indoor air. Dampness, along with occasional biological degradation of materials, and chemical reactions initiate even more pollution through that indoor air.

Buildings, esp. in hot and humid climates, will face dire issues in their indoor built environments over most others. Biological agents present more commonly through the humid environments as they are more prone to dampness and inadequate ventilation.  

Raft of issues pertains to those two things; which only are time consuming to rectify,but very costly to mitigate if left unaddressed.

Dampness is strongest, most consistent risk indicator of asthma and respiratory symptoms. Our motto? “Keep it dry, Keep it clean”.

Ventilation (HVAC) Systems  

Look at the image above. This Ventilation system, or HVAC by another name (heating, ventilation, air conditioning system.) has contaminated air ducts? Sort of unhealthy air people can breathe in unknowingly.

Any area in a building where there’s an air-conditioner remains the greatest passage for pollutants to enter and spread through the entire space/indoor building environment.

Here’s a recent video we made to demonstrate how HVAC systems (or any form ventilation systems; big or small) are main carriers of bacteria, pollutants resulting in ill-health effects.

Ever notice sometimes on leaving the office, just how much sinuses open back up? You seem to get the ability to breathe much easier, almost within an hour of leaving a building?

And what we don’t see, our body certainly tells us…

HVACs are known to cause benign symptoms such as congestion and reactions like itchy eyes, stuffy noses, to far more serious health complications like increased prevalence of respiratory symptoms, allergies, asthma, along with perturbation of a person’s immunological system.

Unhealthy Air and Mould

Mould is Dangerous

Mould spores float through the air, in and out of buildings, growing as they land in moist environments. That makes heating and cooling (HVAC) systems; ductwork, AC evaporator coils, drip-pans near-on perfect environment for mould growth. 

Indoor mould is/ can be dangerous; it produces mycotoxins (toxic mould/black mould) known to be extremely harmful to workplace occupants. At very least, can lead to sicknesses, absenteeism, decreased worker productivity etc. At the worst, clinical evidence points to mould exposure and damp-related microbial agents as increasing the risk of rarer conditions, like hypersensitivity pneumonitis, allergic alveolitis, chronic rhinosinusitis and allergic fungal sinusitis.

Daily exposure to certain kinds of moulds can even bring on severe health issues like brain complications, even death in cases.

So it is really quite staggering why more companies don’t take the decontamination of their ventilation systems far more seriously…. to have its hygiene investigated and addressed regularly.

Even when we service our cars, now mechanics clean the AC; rarely did this happen seven years ago, such is the importance of maintaining clean air to alleviate associated health problems.

And we aren’t only talking hygiene here either.

There are sizable savings to be found in terms of energy costs, following decontamination/cleaning of HVAC / Ventilation systems, they become markedly more energy-efficient, dramatically saving on power usage too.

Mould: Not The Biggest Problem (How It Got There Is)

Mold/Mould basically grows anywhere and these microbial pollutions are the central element of indoor air pollution. Indoor Air Quality (IAQ) and environmental toxicology are complex sciences, they require the expertise of different disciplines. With certain best practice processes needed for management and remediation/mitigation of mould, esp. if you want to minimize and/or prevent cross-contamination.

Selecting appropriate materials is important too, to help prevent accumulation of dirt, moisture penetration and/or the mould growth caused by hundreds of species of bacteria and fungi. Particularly filamentous fungi growing indoors wherever there is sufficient moisture/food sources available.

Micro-organisms are ubiquitous – they propagate rapidly with the available nutrient sources (like water, dust and dirt). And let’s face it, those are commonly found in indoor spaces right?

Only sound cleaning practices and regular decontamination can rid a building or workplace of sources that support extensive microbial growth.

Mould Testing and Sampling

With countless types of mould out there, visual mould needs to be tested for species identification.

To prevent adverse health effects from inside buildings, necessary to prevent (or minimize) persistent dampness and microbial growth on interior surfaces, or building structures or cavities. Most worrying is that even these days, most country’s building standards and regulations (regarding comfort and human health) still DO NOT sufficiently emphasise this requirement.

IAQ/Mould specialists assess and perform IAQ assessment, specifically conducting Mold/Mould investigations and assessments in their own right. Mould is so dangerous, the utmost care and attention is required. Testing, prior to necessary removal and sanitation of the cavity, HVAC or other affected areas or equipment along with the certainty of “before and after” clearance testing.

Peace of mind comes from contacting a Ventilation professional and/or Mould specialist who can appropriately advise you on existing conditions, pre-determine any presence of mould, test and introduce most optimal mould remediation, removal measures.

Sure, mould-testing isn’t cheap. Neither is full scale remediation of large scale mould problem either – esp. if it has been left untreated. Even more expensive exercise to rectify then.

Anti-microbial professionals still are your best choice for your total confidence in all HVACs and ductwork being are free of harmful mould.

And while we are on the subject of mould – quick word on using Bleach too. Will not work the way you think it will. Doesn’t kill mould, only whitens it. Makes it less visible.

With the multiple number of mould/mold types around these days; super resistant (even to high heat and chemicals) bleach isn’t the answer, far from it. Add to this, it is also a known carcinogen (cancer-causer) in humans.

So always use natural-based cleaning products in your home and in the workplace for safe, superior outcomes.

For example; tea-tree based hygiene products from Healthy Building Systems Australia are powerful, non-toxic sanitisers.

Importance of Cleaning Carpets Well  

IAQ (Indoor Air Quality) requires a holistic approach; beginning at the ground level with soft or hard floorings.  When it comes to treating soft flooring/ carpets – one size does not fit al, they aren’t all the same….

Carpets (hygiene and quality) is rarely examined in any real depth. Commercial buildings will go out to Tender for carpet hygiene programs, and commonly found in the Tender is a requirement for carpets to undergo shampooing occasionally. Most floor hygiene programs happen ‘after hours’ – generally those planned works are not always facilitated by highly trained staff either. This is an unregulated industry, so one never quite knows just what they will get. Here is an example.

In first photo, we applied only clean, tempered water directly onto the carpet in a workplace. Then used a slow speed scrubber with soft Nylon 225 fibre brush, and began to gently agitate the carpet.

Now look at this.

The grey foam on top of the carpet….it’s pure chemical residue coming out of that carpet patch.

Basically people in this room were breathing this in ….every.single.day

We left the carpet for ten minutes and observed the excess chemical residue subside back into the carpet.

Sort of thing most people are not privy to when they have their carpet hygiene programs carried out by unregulated, unskilled operators.

Carpet fibres need to be carefully clean-rinsed or better still using non-toxic chemicals on each job. Quite honestly, 90% of carpet cleaning companies out there will not do this.


When flooring isn’t performing, there is tendency for Facilities Managers, Owners to not inquire about their options, there is this invariable “replace” mentality – cycle continues through to next time flooring is addressed. As environmental hygiene specialists, we see this a lot. Managers looking to replace carpets, sometimes as young as three years old, when in such a scenario, the carpet manufacturer would have offered them a warranty of up to 15 years.

Still, on it goes, companies shampooing through to next floor replacement time – same old practices and them blaming the flooring for ‘not performing’.

Even bigger concern here is what happens when they aren’t recycled?

Goes into landfill; still with all the toxic shampoo left behind. There’s real environmental consequences to that (algal bloom.)

Similarly, for people’s homes – what occurs to a home’s carpets treated over time when they too become all dried up and crunchy to walk on?


So to the decision makers of the right quality (optimal) flooring for a building?

Interior designers, decorators, architects etc regularly making the decision on type of flooring to use, would have rarely had any first-hand experience of what’s involved when it comes to flooring treatment processes and decontamination of it.

Same with their choice of flooring? Carpets (soft floorings) over vinyl or wood (hard flooring) will be a wise choice – why? Because predominantly soft flooring (depending on where they are manufactured) will have lower VOCs, lower chemicals over hard flooring. Carpets make better filters, trapping dust, and providing higher degree of safety against falls, reducing noise and air leakage etc.

Soft flooring’s (carpets) are also far easier and cheaper to maintain. Hard floors require four (4) times amount of labour to upkeep, treat and maintain over soft flooring. CRI Soft floor investigation USA relays labour aside, carpets remain cheaper to keep clean, no relentless mopping required and contaminants trapped more securely, over hard floors. Wide array of soft flooring on market today, certainly one to suit just about any indoor requirement/ specification or foot-traffic scenario.

From health risk perspective and duty of care, facilities managers and building owners need to be choosing flooring wisely. Similarly, when caring and treating those carpets regularly; because they are integral to achieving and maintaining healthier indoor built environments.


We’re sure FM’s, building owners and landlords sit there wondering just how much water is being wasted when the organisation’s carpets are being shampooed. Concerns like these (water-use) sometimes aren’t even addressed in most Tenders (… usually because when it comes to a Tender; the “cheapest price” wins.)

Building Refurbishment / Fit-outs

Interesting that during building refurbishment and fit-outs – rarely are the specifics, or impact of, heating or air conditioning choices seriously considered. Often office /building fit-outs are undertaken and AC vents aren’t ever closed off so as to minimize fit-out dust – and this results in contaminants being carried throughout the entire building.

During and after construction, you can take your pick from any number of VOCs – incl. gyprock dust (silica), timber dust, paint fumes – contaminants transmitted through HVAC / AC units to different parts of your building. Such materials, compounds can inflame respiratory issues, coupled with furniture off-gassing or water ingress situations in buildings during construction, and you have a potentially hazardous cocktail of issues. Scary because sometimes it isn’t immediate either but further down the line; like when the building is finally sealed up and occupied.

Isolating any / all ventilation and HVAC assets is absolutely critical during construction or fit out phases.


In closing, environmental risks pose as serious challenges at each stage of a business’ life-cycle. This we all know. So it will come down to how your company evaluates, manages and resolves those environmental influences we’ve discussed here.


IAQ affects many outcomes on multiple number of levels: occupant health, longevity and sustainability of your asset, duty of care, building damage (structural, paintwork, furnishings), risk management aspects, even has longer range impact upon company reputation, financial performance, sometimes competitive advantage.

Sure, we understand more about the nature of internal built environment and its effects – but we still have a long way to go… USA have moved to introduce Healthy Housing Instituteto examine Indoor Air Quality-related aforementioned issues because they recognise the impact of building materials, chemicals and unsanitary workplace conditions profound effect on human health.

More emphasis (regulation) is being placed upon IEQ (indoor environmental quality) and IAQ (indoor air quality). To this end, companies can expect closer scrutiny of their facilities and operations by health authorities. Air quality standards set new guidelines/ requirements for companies to monitor, better control levels of indoor air contamination and pollution and to assume a rigorous focus on hygiene and duty of care to all building occupants,so:

a)      Understand it’s the building owner’s/FM’s responsibility to provide healthy workplaces (living environments) free of excess moisture and mould. Considerations being proper building construction initially, regular careful hygiene maintenance, and management of water use, twice annually sanitizing of all ventilation and HVAC appliances, in manner where it does not encourage damp and/or mould growth;.

b)     Minimise dampness, microbial growth on interior surfaces and in building structures;

c)      Take action at any indication of dampness or microbial growth. Be looking for condensation on surfaces, in structures, visible mould or any mouldy odours, water leaks or water damage. With any sort of water penetration – get onto it. Inspect, measure, assess the damage and remediate to prevent cross contamination microbial growth.

d) Indoors, using only products that are safe, high quality for all hygiene or decontamination works.

Dampness, mould and remediation to prevent adverse exposure is the top priority.

Remember, prevention is better than cure.  If you see any of these get professionals in fastto mitigate / remediate immediately (best practice) or size of your issue will increase (with it, risk of hazardous exposure to microbes and chemicals) and not to mention, exponential cost to that if the situation has been left too long before it is rectified.

By |2018-11-01T09:54:09+00:00October 31st, 2018|Carpet Hygiene, HVAC, Indoor Air, Indoor Air Quality, Mould|0 Comments