Microscopic hazards in your home this winter

Allergies are traditionally associated with spring and summer, when high pollen counts fill the air and leave hay fever sufferers sneezing and scratching at sore eyes. But winter brings its own allergens, with dust mites and mold spores spelling misery for a whole new batch of sufferers.

Allergic reactions occur when the immune system responds to the presence of a foreign substance. When it suspects an invasion, the immune system produces proteins called antibodies.

However, it can go into overdrive and perceive substances as harmful when they are not, producing an immune response, such as a runny nose, in an attempt to flush out the invader.

But the figures are not to be sneezed at. A 2005 report by the National Institute of Allergy and Infectious Diseases (NIAID) states that allergies are the sixth leading cause of chronic disease in the US, with health care costs in excess of $18 billion a year.

The organization also notes that allergic diseases affect about 50 million people a year and that about half of all Americans test positive for at least one of the 10 most common allergens, listing those as:

  • Ragweed
  • Bermuda grass
  • Rye grass
  • White oak
  • Russian thistle
  • Alternaria alternata mold
  • Pet dander
  • House dust mites
  • German cockroach
  • Peanuts.

Sleeping with the enemy

Dust mites
You may be sharing your bed with millions of microscopic dust mites. While they do not carry diseases, some people react to their excrement and display allergic reactions.

The Mayo Clinic describes dust mites as microscopically small bugs that thrive in house dust. Bedding, carpets and upholstered furniture are ideal homes for dust mites, and they love warm, humid conditions. So when the heating gets switched on, dust mites enjoy the perfect environment in which to breed.

The severity of a reaction to dust mites differs between people. Those with a mild reaction may have occasional bouts of sneezing, watery eyes and a runny nose. For some unlucky people, the condition is chronic, leaving them with persistent sneezing, congestion, facial pressure and a cough.

People with asthma may experience tightness in the chest and hear an audible wheezing sound when breathing out. To further compound their misery, they may also have trouble sleeping as they struggle to catch their breath or endure bouts of coughing.

Sinus infections are another complication of dust mite allergies. Chronic inflammation of the tissues in the nasal passages can block sinuses – hollow spaces connecting the nasal passages. This increases the likelihood of developing sinusitis and other infections.

While many individuals may see their beds as a sanctuary, dust mites may be guilty of the same. Depending on the age of a mattress, it may be home to between 1 million and 10 million dust mites.

And even more frightening, the weight of mattress can double in 10 years due to a dust mite infestation. A pillow also collects its fair share – with its weight increasing by about 10% after one year.

The American Academy of Allergy, Asthma & Immunology (AAAAI) estimates that 27% of Americans are sensitive to dust mites.

Living with mold

Mold and dampness next to window
Mold thrives in warm and humid locations, such as damp bathroom surfaces or even around a window.

Spores from the fungi Alternaria alternata are also known to provoke allergic reactions. A report published by the National Institutes of Health (NIH) showed that this is common in US homes, with the researchers claiming to have found it in 95-99% of dust samples taken from 831 housing units in 75 different locations.

Mold species also thrive in warm and humid conditions, and again this is a versatile and adaptive species. Damp bathroom surfaces, carpet pads, towels, even soap-coated grout can be a “bijou residence” for mold.

When ready to breed, the mold releases spores into the air. These may make new homes on other damp surfaces, or they may be breathed in by people.

However, the AAAAI notes that mold spore allergy is not as common as other airborne allergens, it rarely occurs in isolation. Luckily, many of the steps individuals can take to reduce one allergen are just as effective on others.

Many people claim to be allergic to cats or dogs, but in reality, it is not the fur they are allergic to but an allergen found in the animal’s saliva or dander (dead skin cells).

Most people react almost immediately to the allergens, with symptoms appearing within a few minutes of exposure. But some see their symptoms building up over a few hours, usually peaking 8 to 12 hours after contact with the animal.

Living with the symptoms

For most people, allergies are an annoyance rather than a major health hazard. But for people with other conditions, including asthma, an allergic reaction may cause complications.

Mold is known to case infections in the skin or mucus membranes, and on rare occasions it can cause hypersensitivity pneumonitis, where the airborne spores inflame the lungs.

Health care professionals can help treat the symptoms of allergies such as these with an array of decongestants, antihistamines, corticosteroids, oral drops and even immunotherapy – a series of allergy shots that has proven beneficial for hay fever sufferers.

While there is no “cure” for an allergy, there are simple tips individuals can follow to reduce the risk of exposure:

  • Turn on the extractor/exhaust fan when showering or cooking to remove excess humidity and odors. Leave them running for 30 minutes, but open a window slightly so the fans do not “suck” air from wall cavities or crawl spaces, dragging pollutants with it.
  • Vaccum carpets and upholstered furniture to decrease dust mites and pet allergen levels. Mopping floors can be very effective as well.
  • Wash hands frequently, especially after playing with the family pet to reduce exposure to pet allergens.
  • Launder bed linens and pajamas in hot water (above 130 degrees F) once a week to kill dust mites.
  • Many allergens are carried into our homes on shoes and transported around the house as we move. Remove shoes and boots at the front door and change into “indoor shoes” or slippers.
  • Treat the bedroom as the allergy “sanctuary” of the home. A bedroom should have the fewest allergy triggers, so keep pets, carpets, rugs and plants out of this room to avoid dust mites and mold from decaying plants. Encase pillows and mattress in a special cover to reduce the number of dust mites.
  • Install high-efficiency furnace filters, which capture 30 times more allergens, and make sure the furnace fan is always on.
  • Keep the indoor humidity level between 30-40% with the help of a humidifier or dehumidifier to help prevent the growth of mold and mites.
  • Wipe up any condensation after showering or washing dishes, and allow area to dry thoroughly.
  • Change water and filters in the humidifier according to manufacturer recommendations to avoid contamination by mold and bacteria.
  • Conduct an indoor and outdoor survey of the house every month to look for visible mold and identify areas that are at high risk for mold formation.
  • Do not lay carpets in bathrooms or basements, or other rooms where they would sit directly on top of concrete flooring.