How Microbiological Contamination Affects Indoor Air Quality

In this expert guide the air quality specialists at WTS examine the effects of microbiological contamination on indoor air quality and look at the main culprits and what can be done to manage the risks to ensure clean, safe indoor environments can be maintained.

Having clean air to breathe is something which many of us take for granted. It’s only when the quality of our indoor air dips that we notice that there’s a problem. The air found inside buildings contains all sorts of chemicals and particles and it would be wrong to think that they all cause problems or can be damaging to health. However, there are some microbiological contaminants including bacteria, moulds, fungi and viruses, in our air which can cause real health issues and should be tackled promptly when indoor air testing indicates their presence.

Controlling legionella bacteria

One of the microbiological contaminants which has the highest level of public awareness is Legionella bacteria, which can lead to the serious, and potentially fatal condition called Legionnaires’ disease.

Legionnaires’ disease is a serious lung infection similar to pneumonia which is caused when by someone breathes in air contaminated with water droplets (an aerosol) containing legionella bacteria.

Not all air and water contains legionella; it’s particularly associated with man-made water systems such as hot water tanks, showers, spa pools, cooling towers in industry and large air conditioning units such as those found in hotels or offices.

Prevention is better than cure when it comes to controlling the risks posed by Legionella bacteria. If your organisation operates any kind of water system (and most do) or carries out activities which use processes involving water or cooling towers, you should have plans in place to identify and then control the risks from legionella and Legionnaires’ disease. This would normally involve carrying out a legionella risk assessment, implementing measures to keep the water systems under control and managing these precautions to ensure they remain effective to keep people safe.

Learn more about legionella risk assessments

Air contamination caused by mould and fungus

A fungal spore can’t be seen by the naked eye, and is the way in which fungus reproduce. There are a range of fungal spores which cause problems with indoor air quality in the UK.

High levels of spores in the air can cause breathing difficulties such as wheezing, sneezing, headache or coughs. It is estimated that around 4% of the UK population are particularly sensitive to spores in the air.

The presence of some fungal spores in the air is unavoidable, as plants and trees go through their life cycle – the level of spores tends to peak during the summer months. Of particular concern to many businesses and homeowners is what is called toxic black mould (Stachybotrys) and its related spores. The spores from black mould are more likely to be found in the air in areas which are damp and humid such as bathrooms or kitchens, or where ventilation is poor. Treating this type of mould is usually done by improving ventilation rates in the affected areas. This can be achieved by improving ventilation rates, by adding extra windows or air bricks, introducing dehumidifiers or moving appliances such as tumble dryers.

Learn more about mould testing

Airborne bacteria and its effect on indoor air quality

Bacteria are everywhere and in most cases, having some bacteria in an indoor environment isn’t anything to worry about. Legionella is one particularly nasty type of airborne bacteria but there are others, such as tuberculosis and staphylococcus.

In a healthy family home or office, low levels of bacteria are unlikely to cause health issues, but if you are running a hospital, care home or other healthcare facility looking after people who are recovering from surgery or who have a compromised immune system, then it’s important to keep levels of airborne bacteria under control as much as possible.

Testing for bacteria in the air usually involves samples being taken and then cultivated in a laboratory using a petri dish to see what grows. Employers can also do their bit in keeping levels of bacteria under control by having strict infection control and cleaning protocols in place.

What about airborne viruses and their effect on human health

We’ve all seen the health advertisements about keeping clear of the flu, and the old slogan “coughs and sneezes spread diseases”. This is certainly true and there are many illnesses, from flu to chickenpox, norovirus or whooping cough which are spread by airborne viruses. Research indicates that flu particles can survive in the air for two to three hours, and even longer if they fall to rest on hard surfaces.

Again, for your average family home or office environment, following basic hygiene protocols of sneezing into a tissue then throwing it in the bin and regular hand washing is going to minimise the chances of falling ill and stopping the viruses getting into the air in the first place.

People operating healthcare businesses might want to take additional precautions to reduce the levels of viruses in the air as their patients will be less able to fight off illness than healthy adults.

Microbiological air testing for indoor environments

There are lots of different ways of testing indoor air quality to see whether microbes in the air could potentially cause a problem for your organisation, or even at home. One of the most common methods is using “settle plates”, which are special petri dishes filled with an agar jelly. These are left open at specific points around a room or internal space for a set period, giving time for any bacteria, viruses or spores to settle on the dishes. The dishes are then sealed, taken back to the lab and incubated at 25^oC for a week to see what grows on the dishes. A specialist microbiologist will then examine the dishes under a microscope to determine what microbes are present.

What is indoor air quality testing?

This isn’t the only way of testing indoor air quality though. However, with issues like mould it’s sometimes very obvious and visible, and it may not be necessary to test to determine what spores are present. Once you’ve taken steps to tackle the problems of microbes in the air, the air testing procedures can then be repeated to work out whether your improvements have successfully reduced the number of microbes in the air.

Expert indoor air quality testing solutions

Contact WTS today to learn how our expert indoor air quality testing and monitoring solutions can help you improve workplace health and well-being, employee comfort, attendance and productivity issues.

With offices in London serving the South and South East England, Manchester (North West), Birmingham (Midlands), Bristol (South East England and Wales), Leeds (North and North East) and Glasgow (Scotland), supported by regional teams of specially trained technicians and air quality specialists we can offer professional, cost effective engineering solutions across the whole of the UK and Ireland.

Contact us today for more information or for your FREE, no obligation quote.