Usually the most effective way to improve indoor air
pollution control is to eliminate individual sources of pollution or to reduce their
emissions. Some sources, like those that contain asbestos, can be sealed or enclosed;
others, like gas stoves, can be adjusted to decrease the amount of emissions. In many
cases, taking care of the source is also a more cost-efficient approach to protecting the
indoor environment than increasing ventilation because increasing ventilation can increase
Another approach to lowering the concentrations of indoor
pollutants in your home is to increase the amount of outdoor sources coming indoors. Most
home heating and cooling systems, do not mechanically bring fresh air into the house.
Opening windows and doors, operating window or attic fans, when the weather permits, or
running a window cooling units with the vent control open increases the outdoor
ventilation rate. Local bathroom or kitchen fans that exhaust outdoors remove contaminants
directly from the room where the fan is located and also increase the outdoor ventilation
It is particularly important to take as many of these steps
as possible while you are involved in short-term activities that can generate high levels
of pollutants - for example, painting, paint stripping, heating with kerosene heaters,
cooking, or engaging in maintenance and hobby activities such as welding, soldering, or
sanding. You might also choose to do some of these activities outdoors, if you can and if
There are many types and sizes of air cleaners on the
market, ranging from relatively inexpensive table-top models to sophisticated and
expensive whole-house systems. Some air cleaners are highly effective at particle removal,
while others, including most table-top models, are much less so. These cleaners are
generally not designed to remove gaseous pollutants.
The effectiveness of a cleaner depends on how well it
collects pollutants from the indoor environment (expressed as a percentage efficiency
rate) and how much it draws through the cleaning or filtering element (expressed in cubic
feet per minute). A very efficient collector with a low circulation rate will not be
effective, nor will a cleaner with a high circulation rate but a less efficient collector.
The long-term performance of any unit depends on maintaining it according to the
Another important factor in determining the effectiveness
of these units is the strength of the pollutant source. Table-top units, in particular,
may not remove satisfactory amounts of pollutants from strong nearby sources. People with
a sensitivity to particular sources may find that these units are helpful only in
conjunction with concerted efforts to remove the source.
Over the past few years, there has been some publicity
suggesting that houseplants have been shown to reduce levels of some chemicals in
laboratory experiments. There is currently no evidence, however, that a reasonable number
of houseplants remove significant quantities of pollutants in homes and offices. Indoor
houseplants should not be over-watered because overly damp soil may promote the growth of
microorganisms which can affect allergic individuals.
At present, EPA does not recommend using cleaning systems
to reduce levels of radon and its decay products. The effectiveness of these devices in
achieving air pollution control is uncertain because they only partially remove the radon
decay products and do not diminish the amount of radon entering the home.