KEEPING WARM 
Indoor Air Pollution 
Your cozy fireplace may involve risks 
you do not know about 
by Colin High 
If you live in a cold climate, where 
frigid night winds blow in one side of 
your house and out the other and your 
heating bills make you think you must 
be heating the whole outdoors, you prob- 
ably realize a wise move would be to fill 
in the cracks and cut down on the drafts 
in the house. There is no doubt that for 
the average older home, reducing the 
air-infiltration rate, by caulking, 
weather-stripping, and installing storm 
doors and windows, is the most cost- 
effective way of reducing winter heating 
bills. In areas of high heat costs in the 
northern states, many kinds of weather- 
proofing repay their expense in one or 
two heating seasons. 
But as more and more homeowners 
wisely save energy by sealing up the 
cracks in their houses, another problem 
is giving them cause for concern, name- 
ly, indoor air pollution. A house may 
contain numerous potential sources of 
gaseous and particulate air pollution, 
such as smoke and/or particles from 
cigarettes, a working fireplace, a wood- 
burning stove, or a gas cooking stove. As 
the rate of air exchange between the 
inside and the outside of the house is 
reduced, the possibility that some or all 
of these pollutants will accumulate is 
increased. 
Indoor air pollution is not a new phe- 
nomenon. On the contrary, today’s 
houses are probably far more healthful 
than those of a century ago, when open 
fires and poorly ventilated coal- and 
wood-burning cookstoves created high 
levels of indoor air pollution. In particu- 
lar, housewives working in the kitchen 
may have been exposed to more than 
their fair share of pollution. The quality 
of the air in pioneers’ huts, Indian te- 
pees, and sod houses, which were often 
built without chimneys, was certainly 
far worse than the quality of the air 
found in modem houses. Fortunately, 
the inhabitants of the earlier structures 
spent a good deal of their time outdoors. 
Today, however, much more time is 
spent indoors, especially in the winter, 
and young children may spend most of 
their time inside the house. 
The problem of indoor air pollution 
has only recently been recognized. That 
recognition began when skyrocketing 
fuel prices drove homeowners to employ 
energy conservation measures that, in 
turn, often reduced the air- exchange 
rates in the houses. The open fireplace, 
the traditional heat source and symbol 
of warmth, comfort, and hospitality, is 
probably the most serious cause of in- 
door air pollution. Wood and coal fires 
release high concentrations of very 
small particles, including ash and un- 
bumed hydrocarbons. The most worri- 
some of these particles are the small 
polycyclic organic materials, known as 
POMs, whose molecules are arranged in 
rings. The general class of POMs in- 
cludes more than a thousand identifi- 
able organic compounds found in wood, 
coal, and cigarette smoke, and in auto 
and truck emissions. Many of these 
POMs, such as those from wood, coal, 
and cigarette smoke, have been found to 
be carcinogenic and therefore a serious 
cause for concern. Tests in some typical 
American homes with working open 
fireplaces show that concentrations of 
particulates, which include POMs, may 
be four or five times higher than they 
are outdoors. Wood stoves of the airtight 
variety, with controlled airflow and 
properly installed chimneys, release 
fewer particles into the house than fire- 
places and, in consequence, are a less 
serious source of harmful indoor pollu- 
tion. Considering that most Americans 
view an open fireplace as a desirable 
feature, it is ironic that this symbol of 
coziness has so little to recommend it 
from the point of view of health. Not 
only are fireplaces a serious source of 
indoor air pollution but they may also be 
An airtight wood-burning stove, 
equipped with a properly installed 
chimney, releases fewer particulate 
pollutants into the interior of a 
house than an open fireplace does. 
Robert Perron 
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