Pollutants that can affect air quality in a home fall into the two broad categories:

• Particulate matter includes dust, smoke, pollen, animal dander (skin flakes from an animal’s hair or fur), tobacco smoke, particles generated from combustion appliances such as cooking stoves, and particles associated with microorganisms such as dust mites, moulds, bacteria, and viruses.
• Gaseous pollutants come from combustion processes. Sources include gas cooking stoves, vehicle exhaust, and tobacco smoke. They also come from building materials, furnishings, and the use of products such as adhesives, paints, varnishes, cleaning products, and pesticides.

Ironically, the seemingly cleanest homes or offices may actually have the worst air quality due to the fastidious use of cleaning products and air fresheners that release harmful VOCs. Synthetic fragrances are the biggest culprits.

Research by a team from the University of Washington on 25 common fragranced consumer products —laundry products, personal care products, cleaning supplies and air fresheners, many of them top sellers in their categories— found 133 different VOCs emitted from the products, with an average of 17 VOCs per product. Of these 133 VOCs, 24 are classified as toxic or hazardous under US federal laws, and each product emitted at least one of these compounds. Among them are probable carcinogens (cancer causing) acetaldehydea, formaldehyde and methylene chloride.

Biological air pollutants are found to some degree in every home, school, and workplace. Sources include outdoor air; and human occupants who shed viruses and bacteria (e.g. influenza, measles, chicken pox); pets, dust mites and other pests (e.g. cockroaches) that shed allergens; toxins released by moulds and mildews; as well as indoor surfaces and water reservoirs where fungi and bacteria can grow.

Building dampness were determined to be associated with 30% to 50% increases in a variety of respiratory and asthma-related health outcomes. In Malaysia, where the average relative humidity is way above 80%, we have to take extra precautions to prevent these biological contaminants from spreading.

WHO estimates that tobacco kills around 6 million people each year — more than 5 million due to direct tobacco use and more than 600,000 are the result of non-smokers being exposed to ETS. ETS a dynamic complex mixture of more than 7,000 chemicals found in both vapour and particle phases, more than 70 of which are known to cause cancer in humans or animals, and many of which are strong irritants.

Despite the ban on indoor smoking in public places, we still see smoking in some worksites, many restaurants and other “hangout” places such as pubs and karaoke joints. Alas, you can ban smoking in your home and still be exposed to ETS. According to the US Centers for Disease Control and Prevention (CDC), there is no risk-free level of ETS exposure; even brief exposure can be harmful to health.

Just because the room seems well ventilated with hardly any smoky smell does not mean ETS is not silently killing you anyway. Research has led to the conclusion that total removal of ETS through general ventilation is not feasible.

In fact, one should not rely on odour to determine what is good or safe. Some things that smell, like vinegar, are harmless. Some odourless things—like radon and carbon monoxide— are very harmful. Sometimes, chemicals can cause you to feel sick before you notice any odour. Some people also experience “olfactory fatigue,” which is a deadening of the sense of smell. This can happen soon after the first odour sensation occurs, especially if it is a very strong odour.

Bad indoor air quality kills. The new Blueair Aware is an air monitoring device designed to quickly detect hundreds of different types of airborne particles in your indoor environment, including everything from fine particulate matter (PM2.5) to VOCs. It also tracks room humidity and temperature. Monitor your indoor air quality in real-time, track the data, and get alerts on your smartphone with the Blueair Friend App.