If you live in a city, chances are that you suffer from the pollution in your city. Especially if you live in Asia, in some cities, the pollution levels can be life threatening. A close friend I know is actually moving cities just to avoid being exposed to pollution. As a citizen there may not be much that you can do about this in your city. However, there is a lot you can do about the pollution inside your house.
Beyond the obvious, which is just keeping your house clean as it does accumulate a lot of dust, there are a number of steps that you can take to prevent pollution building up. Your cooking can cause a lot of pollutants in the house and ensuring that you have good ventilation in the house helps. Also, and this was new to me, if the nozzles of your cooking stove is not clean, the gas (assuming you are using gas) burns uncleanly and this can cause a lot of pollution. Induction stoves are therefore preferred over gas in many countries. Your cleaning agents including the surfactants that you are using, depending on the chemicals they contain can leave pollutants in your house. It is advisable to check the ingredients of your cleaning agent and research the chemical properties as many famous brands can also be guilty. Lead has been a known pollutant and despite various steps, it still does creep into the products that we use everyday. Watching for lead is therefore an important step toward reducing pollution. Dust, mould and fungus build up in humid and warm places and in tropical countries this needs specialised cleaning as moulds and fungus do not get eliminated with regular cleaning or scrubbing. It may need UV rays to eliminate certain bacteria and fungus. Watch our for air ducts, air conditioners and other recesses that these harmful agents may be hiding.
Hopefully no one in your house smokes, but regardless it is useful to invest in an ioniser. Ionisers send an electrically charged particle into the air that either traps the pollution in the closest wall or in a unit attached to the ioniser.