It's getting cold outside -- we're turning up our heating, closing our doors and windows and trying to retain as much heat as possible.
But in our attempts to keep our house toasty warm we're creating environments for a grungy, greenish-black fungus to start growing. You guessed it -- mould.
Feeling slightly short of breath, wondering what that strange alcohol-like smell is or finding yourself with an irritating cough? Mould could be the perpetrator and it might be time to check your home for the presence of this potentially deadly household pest.
What is mould?
Mould is a term referring to a class of microscopic, multicellular organisms that are found in association with water, which is why you commonly find mould in your bathrooms.
Dr Cameron Jones, CEO of Biological Health Services, told HuffPost Australia mould can grow anywhere where there is available water, the right temperature and a food source.
"You'll commonly find them in bathrooms that have inadequate ventilation, ground floor apartments with poor insulation resistance which show condensation and following unexpected water from leaking roofs, a plumbing defect, or from dilapidation of buildings," Jones said.
"Any building material that can become damp, and similarly any non-porous surface like tiles and grout which become damp regularly can provide the right adhesion for the mould to grow."
Jones explains approximately 60 percent of homes have a water problem each year meaning they are likely to have the conditions where a mould allergy could become a realistic problem.
Why is the presence of mould worse in winter?
While in winter we try to make our homes warmer in an environmentally friendly manner, homes with poor thermal insulation resistance (the ability of heat to transfer from hot to cold) are losing heat inside the house through windows and window frames, causing condensation. Jones refers to this process as the 'Coke can effect'.
"In summer if you have a cold can of coke you'll get beads of condensation on that, especially when you go outside into the heat, and that will turn to liquid," Jones said.
"In winter when you are heating your house, if it's cold outside and the warm air inside hits your window glass, you'll get condensation forming like the Coke can effect."
This buildup of condensation can dampen walls and carpet surrounding the window -- and if the window frames are wooden, you're almost guaranteed mould will begin to grow.
Identification of condensation, poor ventilation, leaks -- that sort of thing is another indicator that you're likely to have a problem.
However while the heat indoors clashes with the cold window causing condensation and therefore a damp environment, Jones explains winter is a common time for wet weather to also creep inside.
"Most people are unaware moisture can penetrate from the outside environment inside -- think frost and ice on a winter morning."
Types of mould and how we can identify them
But as it turns out, these are some of the most common strains of fungi that produce mycotoxins -- a toxic substance created by fungi organisms that can cause disease in humans -- that are found in water-damaged environments.
"There are literally millions of different strains or genres of fungi -- several hundred that are pathogenic to humans," Jones said.
"But humans in many cases have an allergic or immune response to these ones, hence why these different types of mould, when found in water damaged interiors, are commonly allergenic to people."
Most of us notice mould because it looks like, well, mould. But while not all moulds are black or green (like many of us assume) it turns out the colour is actually irrelevant and is just a way of describing how the organism appears on your water damaged wallpaper or damp plasterboard.
So, aside from physical appearance, how else can we identify mould that is invading our homes and causing us to feel unwell?
"Odour is an excellent criterion and the reason odour is significant is that it is related to something called 'microbial volatile organic compounds' and these smell to us because they're usually an alcohol based chemical," Jones said.
"Identification of condensation, poor ventilation, leaks -- that sort of thing is another indicator that you're likely to have a problem."
However Jones explains by the time mould becomes visible, you'll usually already have a serious indoor air quality and mould problem.
How to remove mould from your home
- Increase ventilation: Your hot, steamy showers might be just what you need when you step in from an icy winter's day, but enclosing the heat causes condensation build up, which creates damp surfaces and voila -- mould is born.
- Clean regularly: Mould is often found in collections of dust so cleaning regularly will help minimise dust build up and reduce the chance of mould developing.
- Purchase a dehumidifier: According to Jones, humidity in all rooms in your house should be less than or equal to 60 percent. If you're climbing over this, it's time to invest in a dehumidifier and stop mould before it starts.
- Dry your carpet: "If carpet has become water damaged it should be dried in the first 24-48 hours -- if it's left wet after 48 hours, there will be a guaranteed mould problem developing in it, under it and around it," Jones said.
- Replace and remove the affected area: New carpet or floorboards might not seem necessary right now, but in the long run it'll work out better for your budget and better for your health
- Use chemical disinfectants: "Hospital grade disinfectants which are anti-fungal and sporicidal are different to domestic grade household disinfectants -- they're what a health care environment would use to treat a mould-affected problem area," Jones said.
- Remain vigilant.
Vinegar and water to remove existing mould
For a do-if-yourself guide to killing mould in your home, try using white wine vinegar and applying it to the affected area with a cloth or a spray bottle.
If the smell of vinegar isn't too overpowering, leave the affected surface without rinsing with water -- this will help prevent mould from coming back again.
Alternatively, if you're concerned about smell or about vinegar staining your flooring, leave the vinegar to sit for half an hour, then wipe the surface with water.
For a more powerful, effective mould remover, mix vinegar with baking soda or salt.
What if I rent?
Renters can find themselves going around in circles when it comes to removing mould from their current property.
Along with the concern about the mould itself, the health problems it can create and the unsightly look is presents, renters may also face dispute over who is responsible and allegations by the landlord the renter is at fault due to lifestyle habits.
While it may not be a long-term fix, Jones suggests covering up the affected area with sticky contact paper, the type you would cover school books with, to encapsulate the area and create an impermeable barrier between the occupants and the mould.
What problems can mould cause and how serious are they?
While it may look like nothing more than a fuzzy substance found in between our bathroom and kitchen tiles, mould can present a very realistic heath concern.
"The primary way in which people have a response is usually respiratory distress -- what they term adult onset or atopic asthma is the most common response which happens when there is irritation caused by the presence of spores in the air," Jones said.
"While the mould from the wall may be removed, the carpet in the problem area may remain damp and therefore the house occupants continue to suffer an allergic response so I would always cite respiratory issues as being the number one indicator, but mycotoxins can also cause neurological issues over time."
Neurological symptoms can mirror symptoms of other neurologic disorders including pain syndrome, dementia and lack of balance and coordination, but can also include muscle weakness and numbness.
Jones points out that while mould grows on water damaged elements, mould organisms reproduce both sexually and asexually. This means that although the mould may be in one area of the house, the asexual spores that become airborne can become distributed around the house through human movement, causing irritation and leading to serious infections.
It's not all bad though -- listen up cheese lovers.
The mould in our delicious blue cheese cannot produce damaging toxins and the acidity, salinity and density of the environment created by cheese means a slice of your favourite stilton, gorgonzola or Danish blue is perfectly healthy.
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