As we gear up to spend even more time in our homes, Gem McLuckie explains it couldn’t be a worse time for allergy sufferers as dust mite season is upon us, which begs the question – do we really know what’s lurking in our homes?
6 October 2020
House dust mites are microscopic arachnids that can be found in homes all around the world. Their average lifecycle is 65-100 days and during that time they will produce approximately 2,000 faecal pellets and secrete even more proteins through their saliva – both of which can trigger allergies and impact your wellbeing.
In fact, dust mite allergens are the most relevant inducers of allergic diseases worldwide, and extensive exposure in early childhood to indoor allergens, including house dust mites has been associated with asthma.
From May-October, dust mite breeding season takes place over which time the female of the species lays between 60-100 eggs. This drives up the numbers of dust mites in your home and can increase the concentration of allergenic material in your home. But even though mites die off in the winter, the allergenic material they produce – including faeces, body parts and saliva – is left behind.
“As the weather cools, we tend to spend more of our time indoors and ventilate our homes less frequently,” says Gem McLuckie, Lead Research Scientist in Microbiology at Dyson.
"What’s more, dust is light enough to become airborne. When we turn our heating systems on, convectional currents can move dust mite faeces and allergen around the air in our home which is why many dust mite allergy sufferers may find that their symptoms worsen in the winter months.
“The start of autumn is a perfect time to reset the dust levels in your home, removing dust and allergenic material so as to support your wellbeing. In fact, Autumn cleaning is just as important as Spring cleaning,” says Gem McLuckie.
Dust mites primarily feed on dander or dead skin cells shed by humans and animals. On average, humans shed two grams of skin per day, and even more at night where friction from bedding causes dead cells to shed. They can also get the nutrients they need from other household debris, like fish food, fungi and food crumbs.
“Wherever you spend the most time and shed the most skin, that’s where you’re most likely to find dust mites,” says Gem McLuckie, “and we spend one third of our lives in our beds. In fact, most of us are probably sleeping in a bed full of dust mite faeces.”
Indeed, there can be millions of dust mites in a single mattress. A 2003 study found detectable dust mite allergen in the beds of about 84 per cent of surveyed American homes and in Europe, detectable allergen was found in 68 per cent of homes.
“Its also common to find more mites in the beds and bedding of people who suffer from dry skin, as their discarded skin cells have reduced lipid content, which are dust mites’ favourite meal,” adds McLuckie.
House dust mites thrive in warm, damp and dark conditions, particularly where humidity levels are around 70 per cent and temperatures rise above 25 degrees Celsius. That means that areas where we sweat, breathe and share our body heat are perfect homes for mites. Sofas, mattresses, pet beds and other soft furnishings are fertile ground for dust mites, particularly in their breeding season. But there are other daily tasks that can have an impact too.
Gem McLuckie, Dyson Microbiologist
McLuckie works as a Lead Research Scientist in Dyson's RDD facilities in Malmesbury, UK
“The start of autumn is a perfect time to reset the dust levels in your home, removing dust and allergenic material so as to support your wellbeing. In fact, Autumn cleaning is just as important as Spring cleaning,” says Gem McLuckie.
"Dust mites are not dangerous,” assures McLuckie. “The harmful allergen they create comes from the proteins present in their faecal pellets and body fragments. And that can have a considerable wellbeing impact for those living in homes where dust mite colonies are present.”
Many of us may be familiar with a runny nose, watery eyes and an itchy throat after moving old dusty clothes, which would constitute a mild reaction to dust mite allergens. But the impact can be more serious in certain individuals.
Positive tests for dust mite allergies are extremely common among people with asthma, types of dermatitis and frequent sinus infections. Studies also suggest that exposure to high levels of dust mites, especially early in life, increases your risk of developing a mite allergy and asthma too.
“At Dyson, we farm our own dust mites so that we can collect their faeces. This means we can learn more about dust mite allergen and understand how our vacuums can best remove it from your home,” explains McLuckie. “It also means we know a thing or two about the conditions in which they thrive!”
1. Starve your dust mites – reducing the amount of skin cell debris in your home minimises the primary food source of dust mites, inhibitng them from reproducing exponentially during dust mite season. Vacuum your mattress on both sides with a machine with an advanced filtration system, as well as your sofa and other upholstery.
2. Manage humidity levels – dust mites hydrate themselves by absorbing water from the air, so keeping relative humidity levels below 45 per cent at room temperature will kill most of them off. Air out bedding and blankets frequently, as well as ventilating your home by opening the window or using a HEPA-filtered air purifier. Don’t forget to use the extractor fan after showering or while cooking too, as even raising the humidity levels for an hour and a half a day can enable house dust mites to survive.
3. Control the temperature – dust mites thrive at temperatures of 25 degrees Celsius, so ensure you vacuum warmer areas in your home frequently to control levels of dust mites, like pet baskets, sofas or mattresses. Washing bedding or other soft furnishing at 60-90 degrees Celsius will break up allergens too.
4. Top tips – don’t forget that dust mites and their faeces are microscopic. If you can see dust in your home, dust mites may already be thriving!
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22 degrees Celsius. Optimal relative humidity levels will depend on temperature.
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