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Sample from Organic Control of 

Household Pests

A sample: Dust Mites


Asthma, hayfever and eczema are often at least partially due to the dust mite Dermatophagoides pteronyssius, or to dust mite residues. Perhaps one in three people have some allergic reaction to dust mites. Dust mites are tiny - just visible to the naked eye - and need warm moist living conditions.

Dust mites may trigger an attack of asthma or eczema; they may also make it worse or predispose you to other triggers. There is some evidence that the more you can reduce dust mites the more a child's asthma will be reduced. Even if you can't rid your house entirely - and you probably can't - the more you can reduce the dust mite population, the more the asthma will respond.

As an asthmatic I've noticed that when I go into houses of other asthmatics I often start to wheeze - dust mites in the air. I've also noticed that my son's sunnies fog up when he unpacks his suitcase - from the dust mite residues in the clothes.


We avoid wall to wall carpets in our house. Instead we have tiles, cork tiles and polished wood floors with small and large mats. These can be taken outside and hung in the sun regularly - sunlight is a good, old fashioned dust mite control.


This will kill about 85% of the dust mites.

Hang wet clothes in strong sunlight, or use a dryer - long, slow drying lets dust mites survive.

NEVER fill a washing machine more than half full; and use VERY hot water washes too.


As well:

• avoid long curtains that sweep the floor - and wash curtains regularly. Venetian blinds or wooden slats or plasticised fabric or oilcloth may be better in asthmatic’s bedrooms.

• vacuum mattresses regularly.

• cover mattresses with plastic sheets; even better, cover mattresses with zippered plastic or canvas dust coats.

• vacuum every day, especially under beds and sofas; mop floors with a damp mop every day; mop skirtings too. Close textured carpets can also be damp mopped if you use discretion.

• take all rugs outside at least once a week; beat them thoroughly away from tthe house and leave an hour or two in the sun.

• avoid air conditioning and central heating . Dust mites love central heating. There is evidence that dust mites are a worse problem since most houses began to be heated through winter - cold houses reduced populations; now they overwinter and numbers continue to grow all year round.

• in humid areas make sure your house has plenty of cross ventilation.

• take all removable blankets, mats etc outside in the sun for the day every ten days.

• old houses appear to have the worst dust mite problems. If you have wooden floors (not a concrete slab) make sure they are well sealed. If necessary get a sealing gun and do it yourself. Also seal along crevices around skirting boards and cornices - any cracks where mites can accumulate and breed. This should also be done for controlling other pests, and to prevent insulation fibres or under floor pest residues affecting anyone in the house

• dacron or foam rubber is best for children's toys or uphlstered chairs - cut them open and change the stuffing if you can (restuffing a teddy bear may seem daunting but it's easier than it seems, even for someone who can't sew well, like me).

• avoid feather pillows

• remember that there will be more mites in hot humid weather, and strengthen preventative controls accordingly.

Dust mites breed in old hair and skin - both of which are shed by pets. (You may also be allergic to the pet itself.)

If you do have a pet:

• try and restrict it to certain areas such as the kitchen, laundry, verandah or any area that doesn't have carpets and is easily swept

• don't let pets sit on sofas and beds. If you want them up there, cover sofas with washable blankets - and wash at least once a week.

• be prepared for daily sweeping or vacuuming - and vacuum long curtains too.

• brush and wash your pet regularly - outside.


Dust Mites and Sex
Dust mites breed very rapidly on semen residues left after sex. Unromantic as it sounds, if you have asthma and enjoy sex it may be advisable to use a plastic sheet under your normal sheets and wash it every few days. Otherwise the mattresses or mattress cover may become impregnated. The same goes for interludes on bear skin rugs by the fire, on the sofa or picnic blankets. If there's a wet patch, wash it.


Industrial Strength Vacuum cleaners
These are reputed to eradicate dust mites. They don't - but they will reduce the numbers. Make sure you empty the bag outside. The stronger the vacuum cleaner the more effective it will be - but even the strongest vacuum cleaner isn't as good as sealed floors like cork tiles or sealed wood and small mats that can be beaten outside.


Room Ionisers
These are said to generate charged particles - negative ions - into the air. The negative ions are said to bind to particles in the air like pollen and dust mites. If this occurs it will happen in only a very small area around the ioniser. Room ionisers appear to have little effect on allergic reactions.


Air Filters
These may help a lot, especially in the bedroom. The most appropriate air filters use glass fibre to trap pollens and dust and mite residues. Some air filter models with electrostatic precipitators emit ozone and can precipitate coughing fits or cause nose and eye irritation. If you are considering an air filter hire one first to check its effectiveness.


They are very effective if used correctly, though prevention must still be rigorously used to prevent further build up. 
Their effects may still be preferable to the often fatal effects of asthma. On the other hand, if you reorganise you house correctly, miticides shouldn't be necessary.

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