Your dream living room...or is it?
Environmental agencies and scientists seem to agree that however hard we try, it is almost impossible to totally eliminate or even evaluate indoor pollution.
The World Health Organization (WHO) estimate that 4.3 million people a year die from exposure to household air pollution.
From cooking on wood fires in poorly ventilated dwellings to the overuse of chemicals fed by an obsession with hygiene, the potential health problems stemming from indoor pollution range from sneezing to cancer.
The US Environmental Protection Agency (EPA) define indoor air quality (IAQ) as "the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants."
This article will look at some of the issues relating to air pollution in the home.
How sick can you get from indoor air pollution?
Do you find that your eyes, nose and throat become irritated, your head aches, you feel dizzy or fatigued after spending time indoors, only to discover that, on leaving the house, they disappear? These could be the short-term effects of indoor air pollution.
Reactions to pollutants depend on a number of factors, including age, individual sensitivity and existing conditions. Children, pregnant women, elderly people - who, one study says, spend an average of 19-20 hours a day indoors - and those with cardiovascular or respiratory diseases tend to be more susceptible.
The new sofa looks chic, but it is triggering your asthma?
Some substances, like lead or tobacco smoke, may affect children more than adults. Children are more likely to have asthma, too, which can be exacerbated by indoor pollution.
Pollutants with immediate effects can be dangerous, but they are often easy to recognize and remove.
Long-term effects, such as chronic respiratory conditions, heart disease and cancer, can take years to manifest. By then, it may be too late.
With more than 900 chemical substances potentially floating around American homes, knowing what causes a problem and how to regulate it can be a minefield.
First, there is no such thing as a "typical indoor environment." Each home contains a different and complex mix of potential pollutants that change with time. Individuals also have different reactions.
Second, even if scientists can analyze one substance, combinations interact differently, potentially causing more, or less, noxious effects than each chemical does on its own. Very little is known about the combined effects of indoor air pollutants.
Common pollutants include mold, dust and dander, insects, tobacco smoke, cleaning products and pesticides, gases such as radon, nitrogen dioxide (NO2), carbon monoxide (CO) and building materials, such as formaldehyde and lead. Furniture, floor coverings and air conditioners or heaters can also harbor particles of pollution.
Where do they come from and what do they do?
Mold, damp and ambient temperature
Dryness, humidity, lack of ventilation and high or low temperatures increase the risk of indoor air pollution.
High temperatures and dryness can cause eye and skin irritation, rashes, dry skin and dry nose.
Airtight windows give rise to damp and mold.
Damp can come from leaks, condensation or the ground. It lurks in ill-ventilated kitchens - where steam is released from cooking - in bathrooms, after a shower, or in places where laundry hangs up to dry.
It promotes the growth of microorganisms such as molds and bacteria that release pollutants into the air.
These can enter the respiratory system, causing irritation of the mucous membranes, breathing problems and infections or diseases such as asthma and allergy.
Weatherizing has been promoted in recent years to reduce fuel consumption, but it also decreases ventilation, trapping humidity inside and exacerbating indoor pollution.
If you are planning on weatherizing but already have signs of indoor pollution, the EPA recommend dealing with these first.
Signs to look out for include moisture or condensation on walls or windows, smelly or stuffy air, dirty central heating or air cooling equipment and mold in ill-ventilated areas.
Medical News Today previously published an article giving more details on the dangers of mold in the home.
What about air purifiers?
Designed to kill mold and bacteria, air purifiers produce large amounts of ozone.
When inhaled, ozone can react chemically with biological molecules in the respiratory tract, leading to adverse health effects, such as reduced lung function, inflammation of the airways, coughing, wheezing and, in severe cases, death.
Ozone is a key component of smog. Do we want it in our homes?
Dust is really any kind of waste particle, from outdoor soil to fibers from bedding to flakes of skin or insects. Dust can include lead particles, mold spores, animal dander, insect feces and other pollutants.
Skin rash? It could be a cockroach allergy.
Pets and pests, such as dust mites, cockroaches and mice, are important indoor sources of allergens, leading to diseases of the airways, rhinitis and asthma.
Cockroaches contain potent allergens, and their waste and bodies are a common cause of asthma and allergic reactions, such as skin rashes.
Not only do curtains, carpets and soft furnishings trap dust, but toxic gases in the air can stick to small particles, which enter the lungs on becoming airborne during vacuuming, sitting on the couch, or walking or playing on the carpet.
To minimize the dangers of dust, the American Lung Association (ALA) recommend using a high-efficiency particle air (HEPA) vacuum cleaner at least three times a week and avoiding carpets where possible, especially in places prone to mold.
When dusting, use a damp cloth where possible to remove particles rather than just moving them on.
Tobacco smoke contains more than 7,000 chemicals; hundreds are toxic and about 70 are carcinogenic.
In adults, passive smoking can cause irritation, aggravated respiratory symptoms and coronary heart disease.
In children, it can also lead to ear infections and sudden infant death syndrome (SIDS).
The Centers for Disease Control and Prevention (CDC) estimate that since 1964, approximately 2,500,000 non-smokers have died from health problems caused by exposure to secondhand smoke in the US.
On the next page, we look at the health risks of cleaning products, gases, lead and solvents.