What is Mite?

House dust mites are diverse small arthropodsthat are microscopic--1/4-1/3mm long, about the size of a sharp pencil dot. The only harm they cause is to those who are allergic to them, sparking the typical symptoms of allergy--sneezing, sniffling, itchy and watery eyes, scratchy throat, stuffy nose, eczema and rash. House dust mites have also been implicated in asthma, causing wheezing, coughing, and shortness of breath. Susceptibility to house dust mites is increasing as people spend more time indoors. Newer houses are more air tight than older constructions are contributing to increased dust mite allergies.

House dust mites live all over the world. Mites need food, heat and humidity to thrive. Their diet includes human skin scales, fungi growing on skin, molds, insect bodies or fragments, pollen grains, bacteria, plant material and house dust. Optimum growth conditions are 20-25°C and 70-80% humidity.
Dust mites are hardy creatures who live where skin is most prevalent. They can be found in old clothing, blankets, upholstery, heavy curtains and stuffed animals.

Carpeting is susceptible to dust mite infestation, especially long, loose-pile carpets, where food and moisture can accumulate and mites can burrow deep into the fibers, protecting themselves from vacuum removal. Bed mattresses and pillows (particularly foam and feather) provide the ideal environment for mites. Typically, 2-3 million dust mites reside in mattresses and box springs.

House dust mites have nothing to do with cleanliness or the presence of animals in the home. More likely, the factors contributing to their presence are humidity and the amount of fabric placed in susceptible areas.

 Dust Mite Allergy

Cause of Allergies
Dust mites themselves are not usually the cause of allergies in people. The protein that they produce in fecal pellets is really the main cause of allergenic reactions. Rhinitis, wheezing, coughing, itchy and runny eyes and constant congestion of the nose and ears are some of the more common signs of a dust mite allergy. If symptoms improve outside of living quarters or worsen when linens are changed, vacuuming, or dusting occur, there may be a more serious infestation of dust mites in your house.

On Channel 4 in the UK a program called "Dispatches" featured a documentary on "How to beat your kid's asthma", the program helped families improve their indoor environment and living. The main way in avoiding asthma was the detection and neutralization of the dust mite.

The families where given a little cartoon booklet on what dust mites are, suggestions on improving their indoor environment and minimising the allergy caused by these invisible creatures droppings which cause so much damage to asthma sufferers.

The booklet can be downloaded from this site House Dust Mite by following the purchasing instructions. Also available are the charts of tasks given to both parents and children as a daily and weekly cleaning regime. The purchase price of the booklet and charts is 2.99 including VAT.

House dust mites receive the majority of their nutritional needs (food and moisture) from dead human skin scales which are shed daily. Because of environmental and feeding requirements, dust mites prefer humid conditions (above 55% humidity) with an ambient room temperature of 72°-79°. This explains their high concentration in pillows and mattresses. When humidity levels are maintained below 50%, most adult mites will die within 7-10 days.

 

In homes, the highest concentration of dust mites can be found in mattresses and upholstered furniture. A typical profile of dust mite allergen location might be 10,000 nanograms per gram (ng/g) – mattress, 8,000 ng/g – upholstered chair, 2,000 ng/g – carpet, 1,000 ng/g – draperies. As many as 2,000,000 live mites may inhabit the average mattress. With the average pillow, 30% of its weight is comprised of dead human skins scales and dust mite allergen. Can you imagine how much heavier your mattress has become?

A related study was performed to evaluate the airborne release of dust mite allergen and to evaluate equipment used.