The Health bulletin [serial] - University of North Carolina at Chapel Hill

February, 192'i The Health Bulletin* 31
HEALTHFUL VENTILATION
Many conflicting ideas exist regarding ventilation and its relation to
health, comfort and efficiency. This article outlines very brieflj' the results
of many experiments and careful studies of this subject made by the New
York State Commission on Ventilation whose report has aroused nationwide
interest.
UNDREDS of years ago it was discovered that the
air in which we hve is a nicely balanced mixture
of gases— principally nitrogen, oxygen and carbon
dioxide. In the vast out-of-doors nature
maintains this balance but, when air is breathed,
some of the oxygen is used up by the body and a
waste product—carbon dioxide—is breathed out.
Old theories of ventilation called for frequent
change of air in densely populated rooms so as to
keep the carbon dioxide content down to a low
figure. Repeated tests on animals and people
have shown, however, that the proportions of
oxygen and carbon dioxide can vary through a
wide range without apparent harmful or distressing results.*
Recently it has been learned that the phvsical prop- i
erties of air, particularly TEMPERATURE, HUMID-
ITY and MOTION, are of much greater importance
than any natural variation in its chemical make-up.
TEMPERATURE is
the most important element in
healthful ventilation except in certain industries
where injurious dusts and gases are produced. If, during
this winter, you wish to keep the air in your home,
office, church or school in the condition most favorable 68^68
for those who breathe it, get a good thermometer, hang
it where it will record average conditions, and keep the
temperature at 68° F. Doii't let it go higher.
The increase of colds,
sore throats, pneumonia and
similar diseases in the winter appears to be due largely
to quick changes of temperature of the air breathed.
Going from overheated rooms to the very cold out-ofdoors
weakens the delicate linings of the nose and
throat, making them susceptible to the attack of the
germs which cause disease.
A HEALTHY CHILD OR YOUNG ADULT WHO FEELS COLD WITH
THE THERMOMETER AT 68° PROBABLY NEEDS MORE CLOTHING
* Carbon Dioxide should not be confused with Carbon MONoxide,
which is a part of the exhaust gas from gasoline engines and is very
poisonous even in small quantities.
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