FROM THE EXPERTS

Why indoor air pollution may be worse than it is outdoors

The inside story on air pollution, and five simple steps to improve air quality

PUBLISHED : Monday, 15 June, 2015, 6:08am
UPDATED : Friday, 10 June, 2016, 3:03pm

Let's be honest: the air we breathe leaves a lot to be desired. There are harmful carbon dioxide emissions and toxic petrol fumes. And don't forget we are destroying the ozone layer on a daily basis.

It's enough to make you want to stay indoors, where you might think you're safe. But what you face indoors may be even more damaging.

Indoor air pollution, the degradation of indoor air quality by harmful chemicals and other materials, can be up to 10 times worse than outdoor air pollution. This is because contained areas enable potential pollutants to build up more than open spaces do.

Air pollution, be it the indoor variety or the more visible outdoor type, is bad for your health. The thing many people tend to overlook is that it can also make you look older.

There's no doubt that air pollution has a detrimental effect on the skin. It's been scientifically proven to be one of the main sources of skin damage; toxins in the air cause skin to age prematurely, especially on the face, neck and hands. It's important to recognise the problem, identify the danger signs and look at simple ways to either prevent, or at least minimise, damage.

Indoor pollutants in dust and air are often generated from sources such as environmental tobacco smoke, building materials, furniture, cleaning and hygiene products, air fresheners, computers, printers, cooking and other indoor activities, and from people themselves.

Air pollutants of current interest among researchers include ozone, nitrogen oxides, and bioaerosols. The mechanisms of pollutant activity depend on the particle size, solubility, site of deposit and specific chemical properties.

Recent studies have shown that different pollutants provoke different immunological and non-immunological responses in those exposed. Interaction between air pollutants and allergens can take place outside the exposed person, within the allergen itself, or inside the organism on mucous membranes and skin.

Five simple steps to improve indoor air quality are:

  • Keep your floors fresh
  • Maintain a healthy level of humidity
  • Make your home a no-smoking zone
  • Test for radon. Whether you have a new or old home, you could have a problem
  • Smell good naturally. Avoid synthetic fragrances

As you age your skin naturally begins to lose moisture and elasticity, but there are changes we can make to slow down the skin ageing process.

For example, it's been shown that indoor air pollution from cooking with coal or firewood accelerates skin ageing in northern Chinese women. It was significantly associated with an increased appearance of wrinkles on the forehead, under the eyes and on the backs of arms and hands.

Particulate matter, chemicals such as phthalates and organic compounds such as polycyclic aromatic hydrocarbons (PAHs) can also have a detrimental effect on skin.

Recent studies have identified links between the concentration of phthalates in indoor dust and allergic symptoms in the skin. One of the main sources of phthalate esters indoors are plasticised polyvinyl chloride (PVC) materials used in floor and wall covering materials, shower curtains, adhesives, synthetic leather, toys, cosmetics and other consumer products.

Phthalates are constantly being emitted into the air and indoor dust because they are not chemically bound to the PVC structure. Because the indoor environment is protected from environmental degradation, PAHs associated with dust persist for long periods. So concentrations in indoor dust are much higher than they are in outdoor dust and soil.

Particulate matter causes strong oxidative stress to skin, leading to premature skin ageing, while research shows that indoor contributions of particulate matters are much higher when open windows are exposed to traffic fumes.

Recognition of pollutant sources, environmental control and avoidance remain the most effective countermeasures. Regular cleaning of air conditioners and filters will help. You should avoid pollutants from traffic emissions through open windows and consider using antioxidants, moisturisers and barrier protecting skincare products.

Dr Kong Ching-boon is a Hong Kong-based doctor