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VTII
EFFECTS OF INFER ~~=ION ON HAN PELF - E
.Indoors. is the place of escape from extremes of temperature,
humidity, and environmental conditions and from exposure to some
pollutants found in the ~outdoors.. It is The place where rest,
relaxation, and the general welfare afforded by bodily comforts are
sought. It is known that attempts to reduce energy consumption in
buildings can affect the quality of indoor environments. This chapter
discusses some of the effects on human welfare--e.g., discomfort,
decreased productivity, soiling, corrosion, and maintenance and
housekeeping needs--caused by alterations in environmental control
systems.
Discomfort is the result of undesirable sensory stimuli. such as
noise, malodors, glare, and extremes of humidity and temperature.
These often invoke a human response, identified as ~discomfort,. that
is straightforward and physical and that may sometimes be relieved by
attenuation of the stimulus. However, mere attenuation of the sensory
stimulus sometimes does not suffice. Discomfort is a sensitive
indicator of the need for adjustments in environmental quality control.
The relationships between indoor pollution and productivity can be
evaluated only after one carefully def ines productivity and determines
how it is to be assessed. Originaly, productivity was conceived simply
as quantity of output; but it has come to be addressed in terms of
economy--the cost per unit of production. This chapter discusses some
a ttempts to measure the effects of environmental quality, with
productivity as a tool.
Indoor air pollution is a source of soiling and contr ibutes to the
deter ioration and corrosion of equipment, furnishings, and appliances .
Soiling increases needs for maintenance and housekeeping and for some
equipment in the ventilation system.
RELATIONSHIPS BEEN S=IO=ON~C STATUS AD I~R POLLUTION
The relationships between housing characteristics and the health of
the occupants among the various socioeconomic groups are not well
known. The available information t although limited r iS important if we
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are to understand and identify the problems involved and if we are to
learn the relationships between housing types, housing quality. indoor
environmental quality, and pollutant types, on the one hand, and the
health and welfare of the people in the several socioeconomic groups,
especially those in the lower groups, on the other hand.
A comprehensive treatment of socioeconomic status (SES) and indoor
air pollution may be important to the formulation of control strategies
(local, state, or federal) in matter. that influence indoor pollution,
such as energy-conservation assistance programs and low-income and
rent-subsidy programs.
Housing characteristics are related to social status or income
level.' 5 S ~ ~ ~ Status and income often have been shown to be related
to health and probably constitute an intervening variable in the
relationship between selected housing characteristics and health. ~ ~ 5
The role of hous ing itself in determining health in still
unclear . 33 ~5 S' `, l' Crowding indoors is thought to be an
important contributor to the spread of infectious diseases and a
potential source of physiologic stress. 51 67 l' A substantially
higher proportion of persons in low-income groups have chronic health
conditions that limit their activities ~ ~ and keep them indoors.
Some character rustics of hous ing constitute def inite r isks to
health--e.g., carbon monoxide poisoning from faulty venting of
space-heating systemS72 and lead poisoning from paints.~. The two
mentioned are also related to low-income houses, which often have
greater rates of air inf titration and, because they are close to
sources of pollution, transport pollution more freely from outdoors to
indoors. as 5. Spivey and "dfordSt found that a high proportion of
gas stoves and gas space-heaters (60% in lower-SES homes in east
Baltimore) had higher indoor than outdoor concentrations of carbon
monoxide (8-8.9 ppm versus 5.5-6.1 ppm). In two sets of homes studied,
the amount of passive smoking did not appear to be related to any
differences observed in indoor carbon monoxide concentrations e In over
70% of these homes, the lead content in dust and paint samples exceeded
currently recommended standards. Blood lead contents are lower in
persons who live in SES-~uivalent houses with air-conditioning than
without. 2 ° Binder et a`. ~ 2 found that indoor respirable-particle
concentrations were higher in homes with higher ratios of persons to
room volume.
The following tentative conclusions can be drawn: Momes with
controlled ventilation systems, air filtration, good maintenance, and
properly working appliances have lower concentrations of indoor
pollutants. That implies that the middle and upper socioeconomic
groups are at lower risk. However, there are sources of pollution
other than those mentioned in upper-income houses, specifically, newer
and more carpets, curtains, and furniture. Low-income housing is more
likely to have improper ventilation, poor maintenance, defective
appliances {such as improperly operating stoves and space-heaters), and
lead-based paint--all of which contribute to higher indoor
concentrations of pollutants. 2 0 S ~ S ~ ~ ~ Furthermore, persons in the
low-income groups are more likely to live in mobile homes or
apartments,' which frequently are crowded (high ratio of persons to
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volume). 5 ~ Mobile homes generally are very airtight, and crowding
can result in high concentrations of indoor pollutants.S. .°
Recreational vans and trailers have many of the physical
characteristics of mobile homes and can have similar pollution
problems . Those who can af ford to ~ tighten ~ the i r conventional home s
for energy conservation may also have higher indoor concentrations of
some pollutants, although one would expect on eventual balance between
tightening ~ and proper ventilation in those homes .
HUMAN DISCOMFORT
The incentive to control the indoor environment is derived as much
from consideration of human comfort as from consideration of health.
Discomfort provides an immediate incentive to control the quality of
the indoor environment. Undesirable sensory signals (e.g., noise,
glare, and cold ~ register as discomfort . These signals have
s traightforward physical correlates (e . ~ ., sound pressure , contrast
ratio, and temperature) with the need for controls, such as the
installation of sound-absorbing tiles. A person annoyed initially by
the loud conversation of co-workers may eventually become annoyed even
by whispered exhanges; thus, mere attentuation of noise may not
suffice. A person annoyed frequently by sidestream cigarette smoke
from the person at the next desk may eventually become angered by the
slightest trace of tobacco-smoke odor. Such time-dependent changes in
sensitivity show a cognitive contribution to discomfort. Some persons
can become annoyed merely by the information carried by a stimulus, and
this reaction can be as important as a reaction to the stimulus itself.
Whether discomfort is caused by the intensity of stimulation or by
the condi~cioned response resulting from sensitization, the questions
ar ise: Will avoidance or elimination of discomfort ensure a reasonably
healthful indoor climate? Does endurance of discomfort take a
psychologic or physiologic toll?
Our senses are remarkably adaptive. Therefore, they do not provide
infallible sensory signals about the safety of the environment, owing
to their inability to register some types of energy or potential
stimuli . For instance, a person may view a solar eclipse without
knowledge that the ultraviolet rays, unregistered by the photon
receptors, may damage the eye. A person may bask in the warmth of the
summer sun without awareness that ultraviolet rays, poorly registered
in this case by cutaneous receptors, may cause serious, even lethal
burns . S. imilarly, a person may eat a baster ia-laden, although
delicious, meal without any sensory warning of the ptomaine toxins
present. The sense of smell also fails to register some harmful
stimuli, such as carbon monoxide. With only a limited number of
notable exceptions, however, the absence of annoying stimuli indoors
may be misleading, but generally does signify safe conditions of
occupancy.
Regarding the endurance of discomfort, possible long-term effects
include irritability, depression, inability to concentrate, anxiety,
indigestion, headaches, back pain, and insomnia. s7 Short-term
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effects of discomfort are often rather specific to a particular
modality. Hence, n~alodors may cause symp tome of digestive upset, poor
lighting may cause headaches, and cold drafts may cause muscle
stiffness. Objective verification of direct causes of these various
symptoms is difficult. For this reason, the symptoms, even when
severe, fail to qualify as adverse health effects.
This section briefly discusses some of the indoor-polution aspects
of discomfort.
MALODORS
The olfactory senses signal the presence of some harmful airborne
stimuli, but sometimes they fail to do so, and there are frequent
~ false alarms. ~ As mentioned in Chapter IV, people have historically
avoided bad-smelling air for fear that it signaled illness-causing
conditions. In the nineteenth century, the criteria for ventilation
commonly arose from the notion that odorous air contained harmful
ingredients known variously as crowd poison, morbific matter, and
anthropotoxin. ~. For instance, Russell stated in The Atmosphere in
Relation to Human Life and Health: s 2
Organic matter is given off from the lungs and skin, of
which neither the exact amount nor the composition has been
hitherto ascertained. Their quantity is very small, but of
its importance there can be no doubt. . . . Since this organic
matter has been proved to be highly poisonous, even apart from
carbon dioxide and vapor, we may safely infer that much of the
mischief resulting from the inspiration of rebreathed air is
due to the special poisons exhaled by the body.
In the absence of ins trumentation to detect the presence of small
amounts of odorous organic vapors, the nose remains a sensitive
ind icator . Surpr is ingly, even today there are no good rules for laymen
or scientists to relate perceived odor quality to toxicity. Some
odorous signals are used to warn about toxic hazards (e.g., mercaptans
a re used in natural gas to s ignal leaks ~ . We may know f tom exper fence
that some foul-smelling living spaces pose no overt danger, but people
will still avoid such places. We may argue that this avoidance is
derived from mere discomfort, but occupants may fail to see the
s ituation in such benign term.
In the early twentieth century, the New York State Commission on
Ventilation performed a set of experiments regarding the effect" of
occupancy odor on human comfort and performance. In a popular
synopsis of this 8-yr effort, Winslow7° stated:
We may summarize our discussion of the physiology of
ventilation as follows: The chemical vitiation of the air of
an occupied room (unless poison '3 or dusts from industrial
processes or defective heating appliances are involved) is of
relatively slight importance. The organic substances present,
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manifest as body odors, may exert a depressing effect upon
inclination to work and upon appetite; therefore, occupied
rooms should be free from body odors which are obvious to
anyone~entering from without. {Such odors are never perceived
by those who have been continuously in the room while they
have been accumulating. ~ Objectionable effects of this sort
have only been demonstrated, however ! with a carbon dioxide
content of over .2 per cent, which would correspond to an air
change of less than 6 cubic feet per person per minute.
During the 1930s, Winslow and Berrington, ~ demonstrated that adult
odor. similar to that from a heating system could also depress appetite.
Winslow implied that the olfactory sense generally adapts to
prevailing odorous stimulation in such a way as to reduce discomfort.
Similarly, Cain reported that a temporary reduction in olfactory
sensitivity, perhaps in conjunction with affective habituation,
presumably explains why workers in some malodorous industries
eventually find the odorous atmosphere unobjectionable.' In
contrast, people who live near malodorous sources of pollution seem to
exper fence adverse olfactory reactions of constant or even increasing
severity. For example, residents exposed frequently to malodorous
emiss ion of factor ies complained of chronic headaches, nausea,
coughing, disturbance of sleep, and loss of appetite. `. Those
adverse reactions seem to arise as a consequence of industrial odors
that are more or less unremitting and are beyond the residents '
control. But when the source is in the occupied space, some control
{or avoidance ~ may well be possible . {Tobacco smoke, traditionally the
most bothersome odorant, is a common exception. ~
Complaints about irritation of the eyes, throat, and nose are
common and increasing among people in newly constructed or newly
renovated offices.. These complaints may arise from a confluence of
low, energy-conserving races of ventilation and emission of odorous or
irritating substances, such as formaldehyde, from new furnishings.
Tobacco smoke may exacerbate the problem. The course of the reaction
of the common chemical sense of those exposed may vary considerably.)'
One person may notice irritation immediately; another may notice it
only after occupying a space for a few hours, but continue to
experience it long after leaving the space and possibly fail to
associate the irritation with its source. As a further complication,
it has long been suspected that formaldehyde acts as an olfactory
anesthetic. S.
NOISE
Discomfort due to noise has received more attention than that
related To any other type of sensory stimulation. Noise-induced
discomfort occurs in a great variety of situations, ranging from
disturbance of sleep to difficulty in hearing in the workplace. Noise
s tandards and regulations abound: for outdoor noises, for sound
insulation in buildings, for controlling the risk of occupation-related
deafness, and for guarding against hear ing dif f iculty and annoyance in
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offices, schools, and hospitals. The context can have a strong bearing
on the degree of annoyance. Nemecek and Grandjean.5 surveyed a large
office and found that most of the employees were disturbed by noise
that was considered well within professional design standards. The
~noise. came from conversations, and it was content, rather than
intensity, that was the disturbing attribute .
Exper ireents in both human beings and animals have shown that
stressful effects from nondeafening noise arise without respect to the
~meaning. of the auditory stimulation. ~ 2 Physical attributes that
seem particularly relevant to annoyance include intensity,
concentration of energy within high frequencies, temporal and spectral
complexity, duration, and the suddenness of sounds.~. Table VIII-1
shows results of a survey made to determine the importance of var ious
physical and perceived attributes of annoying sounds. 2 ~ The
respondents judged loudness the most important attribute, with
suddenness next in line. The next three most important attributes
comprised cognitive features (sound is man-made, sound cannot be turned
off, sound is unnecessary). The preeminence of loudness in the
determination of annoyance has led to recommendations, such as those in
Table VIII-2, for tolerable maximal loudness in various types of
rooms. The loudness value. listed here refer to continuous noise
in the period between 7 a.me and 10 p.m.
Both human and animal laboratory exper iments have shown hormonal
effects of noxious, although nondeafen~ng, noise exposure. Even
exposures of about 70 dB can increase the output of adrenal
corticosteroids. ~ 2 ~ Sound intensity this low can also cause
constriction of peripheral blood vessels. 38 Such changes, and other
physiologic manifestations, usually fail to outlast the stimulus, but
do cause concern that noise might eventually lead to more chronic
symptoms of stress or af feet sleep. Frequent interruption of sleep or
a iteration in the normal progress ion of sleep patterns may be thought
to jeopardize physical or mental health eventually. Fortunately,
adaptive alterations in the pattern of sleep seem to minimize most
short-term consequences of disruption by noise.32
In addition to physiologic manifestations, noise exposure produces
adverse behavioral manifestations. Experimental exposure to noise
diminished the quality of interpersonal contact,iS increased
aggressiveness, 2' and impaired willingness to help persons in
need. Loud noise, particularly intermittent noise, may alter
productivity. The effect may be facilitative, rather than inhibitory;
that has led to the speculation that noise may interact with other
environmental factors and with personal factors to achieve a degree of
arousal desirable for work. 2'
TEMPERATURE
There is little scientific information on the connection between
thermal conditions and productivity. In laboratory experiments at
65-85°F (18-29°C), productivity often reached a peak at nonpreferred
temperatures. In an apparel factory. productivity (i.e.,
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TABLE lIII I-1
Contributions of Various Characteristics of Sound to Annoyancea
Sound Characteristic
Steady hig}~-pitched sounds
Steady low-pitched sounds
Int erm i ttent high-p i tched sound s
Intermit tent low-pi tched sounds
Loudnes s of sounds
Suddennes s of sounds
Feeling that a sound cannot be turned of f
Feeling that a sound is unnecessary
Feeli ng that a sound comes from a source
of lit tie benefit
Sounds that clash (unharmonious ~
Sounds that catch one 's attention at a
di stance and then ge t louder and louder
Sound i s man-made
aData from Dunn. 23
Relative Annoyance
~ Scale Value
3 e 94
Be 66
4e 54
Be 81
Be 46
5e 80
5e 55
5e 38
4 e 81
4e 43
5e 23
5e 65
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TABLE VIII-2
Suggested Maximal Tolerable Intensities in Various Indoor Locations
for More or Less Continuous Noise between 7 a.m. and 10 p.m.a
Type of Space
B road cas t s tudi o
Concert hall
Legitimate Cheater ~ 500 seats5 no amplification)
Music room
Schoolroom (no amplification)
Apartments, hotel
As semb ly hal 1
Home
Mot ion-pict ure theater
Hospital
Chur ch
Courtroom
Library
Of f ice
Exe cut ive
Secretarial (mostly typing)
Draf tiny
Meeting room ~ sound amplification)
Re tail s tore
Restaurant
aData f ram Kryter 3
Intensity,
dB(A)
28
28
33
35
35
38
38
40
40
40
40
40
40
35
50
45
45
47
55
.
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piecework ~ var fed 1 ittle, if at all, with thermal conditions (note,
however, that workers were paid by the piece) . ~ ~ When given the
opportunity to express an opinion, people will be consistent in their
preference regarding environmental conditions. The Comfort vote. has
1 iteral meaning in research on thermal acceptability. It refers to a
sub jective rating on a seven-point scale of comfort, on which the
midpoint signifies thermal neutrality. A large body of research has
made it possible to determine, by means of Comfort equations, ~ the
combinations of several factors--notably air temperature, humidity,
radiant temperature, air velocity, degree of activity, and type of
clothing--that will minimize discomfort. The range of acceptable
combinations of environmental conditions Is known as the Comfort zone.
Figure VIII-1 depicts summer and winter comfort zones adopted in
1981 by The American Society of Heating, Refrigerating, and
Air~Conditioning Engineers (ASHRAE) . 2 ~ A The comfort zones show the
relationship of comfort to temperature and humidity during ~light.
activity. At least 809 of occupants should feel comfortable--no more
than slightly warm or slightly cool--in these zones. The comfort zone
is different between summer and winter, because people wear more
clothing during the winter. The thermal resistance of a clothing
ensemble can be measured precisely in Clog units . Table vIII-3 offer s
an example of how a change in clothing will be reflected quantitatively
in clo values and optimal operative temperatures. Operative
temperature is determined on the basis of air temperature and average
radiant temperature. In an interior zone with only a slight radiant
component, the operative temperature approximately equals dry-bulb
temperature.
Insulation f rom slouching and degree of activity interact in
determining acceptable temperature. The ASHRAE standard therefore
offers an equation to convert acceptable operative temperature TIC) for
sedentary occupancy (1 .2 mets ~ to that for Ire active occupancy (e . g .,
housework at 2 mets , garage work at 3 mets ): to Active ~ =
to~sedentary, - 3 (1 + clo) (met - 1.1), where to represents
operative temperature. In addition to steady-state features of the
thermal environment, the standard considers temporal nonuniformities
(e.g., temperature cycling) and spatial nonuniformities (e.g., vertical
temperature differences). Some limited nonuniformities, such as
monotonic temperature drifts, may prove both economical and
acceptable. ~ ~
Conditions for thermal comfort seem to vary little, if at all, with
such factors as geographic location, sex, body build, ethnic
background, and even age.24 The effects of aging seem to merit some
special consideration. Basal metabolic rate decreases progressively
with age, but, according to Fanger, 24 evaporative heat loss does,
also. The two changes seem to of feet each other, although the elderly
spend much more time than the young in sedentary activi ties .
Furthermore, wi th the lower temperatures now common indoors dur ing
winter, the elderly seem to have a narrower temperature range over
which they can increase their thermal resistance. s 3 Because of
sensory adaptation, a sedentary old person may fail to notice the
symptoms of impending hypothermia until it becomes severe. Adequate
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~W
w
fir
50
at
o
3 35
o
62.F;4
-15.C
by/
~~.~=
.
. ~
L~ ~
it/'
_
He'
3~
hi,
2C,
25
! I ~ ~ ~ ~ t t
80
fit ~
0.0
IF
~0
OPERATIV £ TE MPE RAT UR E
0.01S
O.OtO
o
-
can
-
0.005 ~
FIGURE VIII-l Acceptable ranges of operative temperature and humidity
for persons wearing typical summer clothing and typical winter clothing.
These "comfort zones" assume that occupants are engaged in only light
activity. Reprinted with permission from American Society of Heating,
Refrigerating, and Air-Conditioning Engineers.
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Representative terms from entire chapter:
operative temperature
429
TABLE VIII-3
l
Temperatures for Thermal Acceptabili Icy (Comf art ~ o f Sedentary or Slightly
Active Persons (
439
comparatively short time; particles smaller than 1 Um may remain
suspended for hours, unless they become attached to other particles,
walls, or surfaces. Dairies has reviewed deposition from moving
aerosols. 22
Electrostatic and thermal precipitation are two important
mechanisms by which particles are deposited. Penney and Ziesse47
have measured the nobilities of airborne dust particles under the
influence of thermal and electrostatic gradients and have estimated an
average effective thermal mobility of 2.4 x 10 8 m2/°C.s and an
effective electric mobility of about 11 x 10 8 m2/v m. These
values can vary widely for different dust particles, but they are
useful approximations for the design of dust-collecting equipment.
Penney and Ziesse also noted that an electrostatic precipitator that
does not capture all particles causes more soiling than an air-cleaner
of the same efficiency that does not charge particles. Apparently, the
particles become electrically charged, and that causes them to attach
to surfaces more readily. Thus, it is important that the precipitator
be des igned for maximal capture .
The force of attraction between two molecules (London-Van der Waals
force ~ varies as the inverse of the 7th power of the distance between
them ~ ' and plays a role in interparticle adhesion or adhesion to
surfaces. The electrostatic attraction of particles to surface. is
very strong at distances of a few angstroms, but diminishes rapidly
with increasing distance. From the standpoint of soiling, London-Van
der Weals forces are probably important in particle retention after a
particle contacts a surface. Corns' calculated the electrostatic
attraction between a charged particle 1 ~ in diameter and an
adhering particle or surface in which it induces an equal and opposite
charge. Assuming a particle charge of 15 electrostatic units
(e.s.u. --i.e., 15 x 10-9 coulombs--and a separation of 1 nm {10
Al, he estimated a force of 5.2 x 10-3 dynes, which is about 107
times the gravitational force, assuming a density of 1 g/cm3 .
However, this is only one one-thousandth of the estimated Van der Waals
force.
Capillary attraction is a mechanism of particle retention due to
adsorbed liquid f ilms . Capillary attraction is probably more important
in fouling (where air comes into contact with damp coils or pipes) or
in particle filtration (where adhesive liquids are applied to the
filter} than in most everyday soiling of walls and surfaces. When the
radius of the liquid film at the point of contact is small, compared
with the radius of the particle, the force of attraction between a
sphere and a plane surface, with a film of liquid interposed, may be
expressed by the relationship ~ ~ 48yr, where ~ is the capillary
force, ~ is the surface tension of the liquid, and r is the particle
radius . 2 S Corn ~ ~ has suggested that that equation is approached
only at relative humidities near 100%, where water is in the liquid
phase. An lower vapor pressures, the force is less .
The surface-to~volume relationship of particles increases
dramatically an particles become very small, and this relationship za
important in soiling. Surface force'; have a much greater role in
determining soiling properties of small partic3 es than of larger
440
particles. Very fine particles cling to a glans slide when the elide
is inverted. Walker and Fishy ~ demonstrated that repouring small
particles by either liquids, airstreams, brushing, or gravity was more
difficult than removing large particles.
Human activities can cause agitation that resuspends de - sited
particles. Primarily, it is the larger particles that are more readily
redispersed by this means. Bunt, ~ ~ in experiments using a light-
scatterinq-particle counter, showed that vacowe-cleaning a rug or
operating an electric fan caused a severalfold increase in the number
of particles larger than 3 ~m, but only a slight perturbation in the
number of smaller particles. But other acti~ritie~--such as smoking,
heating, or cooking--produced primarily submicrometer particles. Also,
aerosols in this size range are probably produced by condensation from
the vapor phase, rather than by dispersing preexisting particles from
surfaces or from a powder.
MOI STORE AND Ft3NGAL GROWTH
Fungal growth is another cause of soiling and deterioration that
generally occurs in areas with high humidity and low ventilation.
Microbial slimes in air-cooling and -humidifying units, plumbing
fixtures, condensation trays, and drains cause serious and often costly
mechanical problems. These and other airborne organisms can discolor
paint, weaken fabrics, and degrade foodstuffs. Microorganisms can also
lead to odors, such as the musty smell of a damp bat.
SchafferSS has reviewed many of the effects of moisture in buildings,
including the promotion of fungal growth. Moisture can be generated
internally from combustion during heating and cooking, drying clothes,
bathing, and even breathing, and it can come from the outside during
per iods of high humidity a Moisture generated indoors can result in
high humidities when there is no dehumidification, when ventilation
rates are low, or when a structure has tight vapor barriers in walls
and partitions. Fungal growth in ducts or on walls and surfaces has
been observed after the use of large amounts of outside sir for
ventilation during damp periods.
Water vapor is not ordinarily regarded as a pollutant. Not only is
it essential to support the growth of microorganisms, but, if it in
present in excessive amounts, it can cause more visible effects. such
as peeling of paint and wallpaper. It also has an effect on comfort
(as discussed earlier), and it can enhance the effect of other
pollutant". Hermance et al., ~ ° for example, hare noted this in
steadying damage to telephone contacts by airborne nitrates.
GASEOUS POLLUTANTS
The important gaseous pollutants--such as ozone, sulfur dioxide,
oxides of nitrogen, and carbon monoxide--affect the corrosion and
deterioration of materials. Ozone can cause cracking of rubber and
some other elastomers. The amount or rate of cracking of stretched
441
rubber bands has been used as a method for determining low
concentrations of ozone. 53 Not only does ozone occur in the
outdoor air, but trace amounts Can be produced indoors by arcing of
electric motors in tools and appliances and by corona discharges of
electrostatic air-cleaners. Sulfur dioxide and oxides of nitrogen may
also contribute to corrosion and deterioration, but they are more often
considered as potential health hazards. Carbon monoxide is
comparatively inert and does not react on surfaces; although it is a
hazard to health and safety, i t does not normally cause soiling or
deter "oration .
EFFECTS OF TIGHT CONSTRUCTION
. . .
Reduc~cion of inf titration resulting from tighter construction
decreases the amounts of pollutants coming from outside, but can cause
increases in the concentrations of those generated indoors, unless
there is a change in ventilation rate . To achieve the full benef it of
t ight construction without increasing soiling, corrosion, and
deterioration, provision must be made to abate or eliminate indoor-
generated moisture and the indoor pollutants at their source.
Particles and moisture are probably the most important agents that
affect the rates of soiling, corrosion, and deterioration. Particle
counts are usually lower indoors, 9 but not always. Cooking,
cleaning, and other indoor activities intermittently distribute
particles, as well as moisture . Sources of many other pollutants are
discussed in Chapter IV.
As mentioned earlier, increased tightness of buildings can result
in increased moisture indoors. Previously, moisture generated indoors
has leaked out through the building structure, but, as these paths of
elimination are reduced, it may be necessary to use dehumidif iers .
EFFECTS ON MAINTENANCE FOR CORROSION AND DETERIORATION
Andrews S estimated that the cost of corrosion in the United
States exceeds S25 billion per year. This expense is reported to be
due to additional fuel, maintenance, or replacement costs. Although
the f Faction of these costs caused by indoor pollution was not
reported, it can be assumed that even a small percentage could
represent a great f inancial impact over the lifetime of a building.
Four types of corrosion, which must be controlled in building
environmental control sys~cems, are shown in Table VIII-4, with some
methods of prevention.
~ f the quality of the indoor a ir is degraded, the increased
concentration of contaminants can aggravate scaling of heat-exchanger
surfaces. s For example, the air in a space with relatively high
moisture content often is recirculated across a cooling coil for
dehumidifications Increased carbon dioxide and sulfur dioxide of the
indoor air may react with the condensed water and accelerate corrosion
on the cooling coil.
442
TABLE VIII~4
Types of Corrosion and Methods of Environmental Control in Buildingsa
Type of Corrosion Resul t Maintenance Action
Unifo rm
Pitting
Galvanic
Direct chemical attack
Local deposits of parti-
cles on metal surfaces
Electrochemical reaction
between dissimilar
metals ~ less noble metal
is corroded ~
Stress Corrosion attacks stress- Replace
weakened metal
aData from And rews.
Apply protective coatings
Inspect and remove solid
deposits
Remove solids in suspension
Apply such coatings as
plastics, paints, and
asphaltum (protect both
metals with same material)
Apply appropriate chemical
inhibito ~ s
443
Report of increased maintenance of heat-exchangers or rotating
equipment necessitated by degradation of indoor air quality were not
found in the literature, but the appropriate conditions for increased
corrosion have been reported. s ~. IS ~ ~ 47 IS For example, Her~nce
et al. 3° reported that telephone switching equipment required
increased maintenance because of nitrates.
Inasmuch as nitrogen oxides and sulfur oxides can be present in
indoor environments, either from indoor source. or from outdoors, the
potential exists for corrosion of electric components in most indoor
environments .
EFFECTS ON HOUSEKEEPING
.
Cleaning and care of materials and properties in institutional
spaces represent approximately 15-2096 of the total annual operating
costs of these facilities (W. W. Whitman, personal communication). In
turn, annual operating costs can be approximately 50-75% of the
annualized initial investment of buildings.* Thus, any degradation of
the indoor air quality that causes an increase in housekeeping can
seriously affect the life-cycle cost of a building.
As buildings have become more energy-efficient, the moisture
content has been generally reported to have increased, owing to
decreased infiltration. Is Additionally, the concentrations of smoke
particles and other contaminants from smoking and other indoor
activities have increased thee Chapter IV). Thus, the rates of soiling
and deterioration of exposed surfaces may be accelerated. as a result
of degradation of indoor air quality.
Windows are a pr imary s ite for accelerated soiling, especially
dur ing the heating season . Because resistance to heat transfer through
windows is usually one-tenth to one-third that of adjacent walls, the
inside surface temperatures of the windows will be much lower than
those of the walls. I f the inside surface temperatures of the windows
are lower than the dewpoint temperature of the occupied space,
condensation will occur at these surface.. Particles and gaseous
contaminants in equilibrium with the water vapor will be deposited on
the window surfaces with the condensate. As the condensate leaves the
windows by evaporation or draining, the other contaminants will be left
on the surfaces as residue, thus increasing the required frequency of
cleaning. Boyce~3 reported that, when windows are not thoroughly
cleaned periodically, a cloudy film builds up that can be removed only
with muriatic acid. To combat pollution in L;os Angeles, Boyce stated,
aluminum mullions and transoms on the Con Park Plaza Building must be
cleaned annually with mild steel wool and oil must then be applied to
protect the metal . ~ f outdoor pollutants are transported indoors, or
if similar pollutants are generated indoors, the interior surfaces of
windows might require similar treatment.
.
*The annualized initial investment is based on a present cost of
S70/ft2 amortized over 50 yr at an inflation rate of 9~. Current
annual operating costs are approximately S3/ft2.
444
Indoor lighting efficiency is also affected by indoor air quality.
Williams66 reported that dirt accumulations on lamps and fixtures can
reduce light output by 10-50. over the rated ~end~of-life. of the
lamps. Thus, as dirt and film accumulate on fixtures and lops,
cleaning and relamping frequencies must be increased to maintain proper
illumination .
Another major category of housekeeping expense is related to the
care of floors and carpeting. Darlings reported that, on a national
average, 40-60% of the working hours of cleaning crew. is required for
floors and carpeting and that carpeting soils more quickly in
industrial centers than in suburban areas, where air pollution is lens
severe.
Furniture, paintings, sculptures, and musical instruments are also
af fected by indoor air quality. The special requirements for
environmental control in museum, art galleries, and auditoriums are
indicative of the care that is required to protect these properties. '
METROS) OF TREATMENT
There are ways to reduce the indoor pollution that causes soiling
and deterioration . For example, sir f titration reduces the amount of ~
a irborne dust . Most central heating and air-conditioning systems
contain air filters. Although these are usually not of high
efficiency, they do reduce dust. An electronic a~r-cleaner designed
for a specific system can remove still mare particles.
The visible effects of undesirable thermal precipitation of dust on
walls near grilles and radiators may be reduced by shields that direct
air away from walls.
Dehumidifiers remove excessive moisture. However, during the
heating season, humidity is often low indoors, and it may be necessary
to add moisture to the air, to prevent stress cracking in furniture and
other wood products due to excessive drying. (The relationship between
human comfort and humidity and temperature is discussed earlier in this
chapter and in Chapter IV.) Tobacco-amoking places an added burden on
a jr-cleaning and ventilation systems. In public buildings, smoking is
often prohibited or restricted to specified areas.
Particles and other airborne materials generated in cooking nay be
largely repoured by exhaust systems near the point of generation.
Activated carbon and other adsorbent air-cleanere are sometimes
used in buildings in high-pollution areas to remove gaseous
pollutants. However, these are not in general use, and they present
some special problems. For example, it is harder to determine when an
adsorbent filter needs to be changed than a particulate filter (see
also Chapter ~X).
RECOMMENDATI ONS
Some of the commonly recognized agents that produce soiling and
deterioration have been discussed in the foregoing paragraphs, but
445
additional questions need investigation. With regard to removal of
indoor particles, where is the point of diminishing returns in
improving the eff iciency of particulate f ilters? Likewise, where is
the point of diminishing returns reached in increasing the rate at
which air is removed from an occupied space and filtered? Dust
composition may also be important. There have been a few analyses of
indoor dust, 2 ~ ~ ~ but much less work that has tried to relate
soiling, corrosion, or other deleterious effects to dust composition
and particle size. Thus, the effectiveness of dust removal technology
and the specific nature of the dust, as they relate to soiling and
deter ioration, need f urther investigation.
Information on the role of gaseous pollutants in soiling or
corrosion is lacking.
REFERENCES
American Society of Heating, Ref. rigerating and Air~Conditioning
Engineers. Symposium Bulletin. Air Conditioning Criteria for Man's
Living Environment, Louisville, Kentucky, June 24-28, 1973. New
York: American Society of Heating, Refrigerating and Air-
Conditioning Engineers, Inc., 1973. .33 pp.
2. American Society of Heating, Refrigerating and Air-Conditioning
Engineers. ASEIRAE Draft Standard 55-74R. Thermal Environmental
Conditions for Human Occupancy. New York: American Society of
Heating, Refrigerating and Air~ond~tioning Engineers, Inc., April
198 0 .
3. American Society of Heating, Refrigerating and Air~onditioning
Engineers. Commercial and public buildings, pp. 3 .1-3 . 16. In ASHRAE
Handbook and Product Directory. 1978 Applications. New York:
American Society of Heating, Refrigerating, and Air Conditioning
Engineers, Inc., 1978.
4. Andersen, I. Formaldehyde In the indoor environment--Health
implications and the setting of standards, pp. 65-77, and
discussion, pp. 77-87. In P. O. Fanger and O. V¢1 bjorn, EdS. Indoor
Climate. Effects on Human Comfort, Performance, and Health in
Residential, Commercial, and Light-Industry Buildings. Proceedings
of the First International Indoor Climate Symposium, Copenhagen,
August 30-September 1, 1978. Copenhagen: Danish Building Research
Institute, 1979.
5. Andrews, F. T. Building Mechanical Systems, pp. 117-124. New York:
McGraw-Hill Book Company, 1977.
6. Arguelles, A. E., D. Ibeas, J. P. Ottone, and M. Chekherdemian.
Pituitary-adrenal stimulation by sound of different frequencies. J.
Clin. Endocrinol. Me tab. 22: 846-852, 1962.
Austin, P. R., and S. W. Tzmmerman. Design and Operation of Clean
}looms 1965, pp. 96-135. Birmingham, Mich.: Business News Publishing
Company, I96 5.
8. Axelsen, O. Influence of heat exposure on productivity. Work
Environ. Health 11:94-99, 1974.
446
A.
Benson, F. B., J. J. Henderson, and D. E. Caldwell. Indoor-Outdoor
Pollutant Relationabips: A Literature Review. U.S. Environmental
Protection Agency (National Environmental Research Center ~ .
Publication No. AP-112. Washington, D.C.: U.S. Government Printing
Office, 1972. 73 pp.
. Berglund, L. G. New horizons for 55-74: Implications for energy
conservation and comfort. ASHRAE Trans. 86 (Pt. 13:507-515, 1980.
11. Berglund, L. G., and R. R. Gonzalez. Application of acceptable
temperature drifts to built environments as a mode of energy
conservation. ASHRAE Trans. 84 (Pt. 11:110-121, 1978.
12. Binder , R. E., C. A. Mitchell, H. R. Hosein, and A. Bouhuys .
Importance of the indoor environment in air pollution exposure.
Arch . Environ . Health 31: 277-279, 1976.
13. Boyce, S. Reflections on a clean glass building, pp. 36-37. In
Maintenance Guide for Commercial Buildings. Cedar Rapids: Stamats
Publishing Co., 1975.
14. Bradley, E. C., and A. J. Haagen-Smit. The application of rubber in
the quantitative determination of ozone. rubber Chem. Technol.
24: 750-755, 1951.
15. Broadbent, D. E. Noise in relation to annoyance, performance, and
mental health. J. Acoustical Soc. America 68 :15-17, 1980.
16. Cain, W. S. Contribution of the trigeminal nerve to perceived odor
magnitude. Ann. N.Y. Acad. Sci . 237: 28-34, 1974 .
17. Cain, W. S. Lability of odor pleasantness, pp. 303-315. In J. H. A.
Kroeze, Ed. Preference Behaviour and Chemoreception. London:
Information Retrieval Ltd., 1979.
18. Cain, W. S., L. G. Berglund, R. A. Duffee, and A. Turk. Ventilation
and odor control: Prospects for energy ef f iciency . Lawrence
Ber keley Laboratory Repor t IL-9578 . Berkeley , Cal .: Lawrence
Berkeley Laboratory, Energy and Environment Division, 1979. 61 pp.
19 . Corn, M. Adhesion of particles, pp. 359-392 . In C. N. Davies, Ed.
Aerosol Science. New York: Academic Press, Inc., 1966 0
20 . Daises , R. H., D. W. Smith , A. Feliciano, and J. R. Trout. Air
levels of lead inside and outride of homes. Ind. Med. 41~10) :26-28,
1972.
_. Darling, W. E. A lot more of what you 're looking for on carpet
care, pp. 22-25. In Maintenance Guide for Commercial Buildings.
Cedar Rapids, Iowa: Stamats Publishing Company, 1975.
22. Davies, C. N. Deposition from moving aerosols, pp. 393-446. In C.
N. Davies, Ed. Aerosol Science. New York: Academic Press, Inc.,
1966.
2 3 . Dunn, B . E . The noise environment of man, pp. 193-257. In H. W.
Jones, Ed. Noise in the Human Environment. Vol. 2. Edmonton,
Alberta: Environment Council of Alberta, 1979.
24. Fanger, P. 0. Thermal Comfort. Analysis and Applications in
Environmental Engineering. Copenhagen: Danish Technical Press,
1972. 244 pp.
25. Fuchs, N. A. The Mechanics of Aerosols, p. 362. New York: Pergamon
Press, 1964.
26. Geber, W. F., T. A. Anderson, and B. Van Dyne. Physiologic
responses of the albino rat to chronic noise stress. Arch. Environ.
Health 12:751-754, 1966.
447
27. Geen, R. G., and E. C. Ordeal. Activation of cue-elicited
aggression by general arousal. J. Personality Sac. Paychol.
11: 289-292, 1969 .
2 8 . Gieseke, J. A., E. R. glosser , and R. B. Reif . Collection and
characterization of airborne particulate matter in buildings
ASHRAE Trans. 84 (Pt. 1) :572-589, 1978.
29 . Glans, D. C., and J. E. Singer. Urban Stress. Experiments on Noise
and Social Stressors. New York: Academic Press, Inc., 1972. 182 pp.
30 . Hermance, H. W., C. A. Russell, E. J . Bauer, T. F. Egan, and }I. V.
Wadlow. Relation of airborne nitrate to telephone equipment damage.
Environ . Sci . Technol . 5: 781-785, 1971.
31. Hunt, C. M. Simple Observations of Some Common Indoor Activities ss
Producers of Airborne Particulates. Paper presented at ASHRAE
Symposium on Cleaner Indoor Air--Progress and Problems Cl-72-1,
Cincinnati, Ohio, October 19-22, 1972.
3 2. Jovanovi6, U. J. Normal Sleep in Man. An Experimental Contribution
to Our Knowledge of the Phenomenology of Sleep. Stuttgart:
Hippokrates Verlag Gmblt., 1971. 327 pp.
33. Kasl, S. V. The effects of the residential environment on health
and behavior : A review, pp. 65-127. In L. E. Hinkle, Jr., and W. C.
I`oring, Eds. The Effect of the Man-Made Environment on Bealth and
Behavior . DREW Publication No. (CDC) 77-8318 . U. S. Department of
Health, Education, and Welfare, Center for Disease Control.
Washington, O.C.: U.S. Government Printing Office, 1977.
34 e Kryter, K . D. The Ef feats of Noise on Man . New York: Academic
Press, Inc., 1970. 633 pp.
35. Lebowitz, M. D. A critical examination of factorial ecology and
social area analysis for epidemiological research. Ariz. Acad. Sci.
1 2 (2~: 86-90, 1977.
3 6 . Lebowitz, [M. ~ D. Social environment and health. Public Bealth Rev.
4: 327-351, 1975.
37. Lebowitz, M. D. The relationship of socio-environmental factors to
the prevalence of obstructive lung diseases and ocher chronic
conditions . J. Chron. Dis . 30: 599-611, 1977.
38 . Lehmann , (;., and J . Tamm. t3ber Vertinderungen der Rreislaufdynamik
des rohenden Menschen unter Einwirkung van Gerauschen. Int. Z.
Angew. Physiol. einschl. Arbeitsphysiol. 16: 217-227, 1956. (in
Ge rman ~
3 9 . Lennard-Jone~, J . E . Cohes ion . Proc . Phys ical Soc . (London )
43: 461-482, 1931.
4 0. Lin-Fu, J. S. Vulnerability of children to lead exposure and
toxicity (First of two parts ~ . N. Eng1 . J . Med . 289 :1229-1233, 1973 .
4 1. Mathews , X. E., Jr ., and L. K. Canon. Environmental noise level as
a determinant of helping behavior. J. Personality Soc. Psychol.
3 2: 511-577, 1975.
4 2. McNall, P. E., Jr . The relation of thermal comfort to learning and
performance : A state~of-the-art report. ASHRAE Trans. 85 {Pt. 1),
7 59-767, 1979.
4 3 . Moschandreas , D. J ., J. W. Winchester , J. W. Nelson, and R. M.
Burton. Fine particle residential indoor air pollution. Atone.
Environ. 13 :1413-1418, 1;979.
~8
44. National Center for Bealth Statistice. Medical Care, Bealth Status
and Family Income. Series 10, - . 9. Washington , D.C.: U.S.
Government Pr inting Of f ice, 1964.
Hemecek, J., and E:. Grand dean . Results of an ergonomic
investigation of large~space offices. muon Factors 15:111-124,
1973.
46. New York S"te Commission on ventilation. Ventilation. Hew York:
Du~cton, 19 23 .
47. Penney, G. W., and N. G. Zlesse. Soiling of surfaces by fine
particles. ASEiRAE Transe 74{Pt. 11:vI.3.1-VI.3.13, 1968.
48. Pepler, R. D. A study of productivity and abeenteeism in an apparel
factory with and without sir conditioning. ASERAE Trane. 79lPt.
2} s81-86. 1973.
49. Pepler, R. D., and R. B. Wamer. Temperature sad learning: An
experimental study. ASHORE Trans. 74{Pt. 2)s211, 1968.
50. Prosbansky, B. M., W. a. Tttelson, and L`. G. RivItn. The influence
of the physical environment on behaviors Some basic assumptions,
pp. 27-37. In B. M. Proshanaky, W. B. Ittelson, and L. G. Riming
Ede. Environmental Psychology: Man and Bis Physical Setting. New
York: Belt, Rinehart and Winston, Inc., 1970.
51. Redford, E. P. Bealth aspects of housing. J. Occup. Hed.
18: 105-108, 1976.
52. Russell, F. A. R. The Ataospbere in Relation to fin Life and
Health. Publication No. 1072. Washington, D.C.: Smithsonian
Institution, 1896. Compiled in Smithsonian Misc. collections
39:Article ITI, 1899. 148 pp.
53. Sacber, G. A. Energy metabolism and tbermoregulation in old age.
ASBRAE Trans. 85tPt. 1) :775-783, 1979.
5 4. Schaefer , v. J., V. A. Mohnen , and v. R. Heirs . Air quality of
American homes. Science 175 :173-175, 1972.
55. Schaffer, }3. die A survey of some moisture and other problems
influenced b`< building tightness. ASTM-DOE Symposium on Air
Infiltration and Air Change Rate Measurement, Washington, D.C.,
March 16, 1978 (in prese).
56. Schaplowsky, A. F., L. G. Polk, F. 8. Ogleabay, J. B. ISorrison, R.
E. Gallagher, and W. Berman. Carbon monoxide contamination of the
living environment: A national survey of home air specimens and
children's blood samples. Presented at American Public Health
Association Meeting, November 7, 1973. U.S. Deparmen~c of Bealth,
Education, and Welfare, Center for Disease Control.
57. Selye, B. One Stress of Life. rev. ed. New York: McGraw-Eill Book
Company, Inc., 1976. 516 pp.
58. Speal~n, C. R. Odors, odorants, and deodorants in aviation. Ann.
N. Y. Acad . Sci . 58: 40-43, 1954.
59. Spivey, G. M., and E. P. Radford. Inner~city housing and
respiratory disease in children: A pilot study. Arch. Environ.
Bealeb 34 s 23-29, 1979.
60. Sterling, T. D., and D. M. Robaysshi. Exposure to pollutants in
enclosed slicing Spaces. ~ Environ. Res. 13s1-3S. 1977.
449
61. U.S. Depart~nt of Bealth, Education, and Welfare, National
Institute for Occupational Safety and Bealth. National Occupational
Hazard Survey. Pilot Study. Dow (NTOSH} Publication No. 75-162.
Washington, D.C.: U.S. Department of Bealth, Education, and
Welfare, May 197S.
62. U.S. Environmental Protection Agency, Office of Noise Abatement and
Control. Information on l~evele of Environmental Noise Requisite to
protect R,blic Bealth and Welfare with an Adequate Margin of
Safety. U.S. Environmental Protection Agency B - port No.
5 50/9-74-004. Washington , D. C.: U. S. Environmental Protection
Agency, 1974. 46 pp. ~ appendices.
63. Vega, T., and C. J. Seymour. ~ simplified method for determining
ozone levels in community air pollution surveys. J. Air Po3~1ut.
Control Assoc. 11:28-33,44, 1961.
64. Walker, R. L., and B. R. Fish. Adhesion of Particles to Surfaces in
Liquid and Gaseous Environ~nente. Paper presented at 4th Annual
Meeting of the American Association for Contamination Control,
Miami, Fla., May 25-28, 1965.
65. Williams, H. Developing a table of relaxation allowances. Ind. Eng.
5~12) :18-22, 1973.
66. Williams, B. G. More light with less manpower, pp. 56-68. In
Maintenance Guide for Commercial Buildings. Cedar Spider Stamats
Publishing Co;, 1975.
67. Wilner, R., R. Walkey, T. Pinkerton, and M. Tayback. The Musing
Environment and Family Life. Baltimore: me Johns Bopkins Press,
1962. 338 pp.
6 8. Winneke, G., and J. Ra~tka . Odor pollution and odor annoyance
reactions in industrial areas of the Rhine-Ruhr region, pp.
471-479. In J. Le Magnen and P. Hack, ode. Proceedings of the
Sixth International Symposium on Olfaction and Taste. tendons
Information Retrieval Ltd., 1977.
69. W`nnick, L. American musing and Its Use s The Demand for Shelter
Space. Census Monograph Series. New York: John Wiley ~ Sons, Inc.,
1957. 143 pp.
70. Winslow, C.-E. A. Fresh Air and Ventilation. New York: B. P. Dut ton
& Company, 1926. 182pp.
71. Winslow, C.-E. A., and L. P. Berr$ngton. The influence of odor upon
appetite. Aaa. J. Hyg. 23:143-156, 1936.
. World Bealth Organization. Health Bazards of the Busasn Environment.
Genera: World Bealth Organization, 1972. 387 pp.
7 3. Wyon, D. P. Human productivity in thermal environments between 6SF
and 85F (18-30C), pp. 192-216. In J. A. J. Stolwijk, Ed. Energy
Conservation Strategies in Buildings. New Barren s John B. Pierce
Foundation of Connecticut, Inc., 1978.
7 4 e Wyon, D. P. me role of the environment in buildings today s Thermal
aspects. Factors affecting the choice of ~ suitable room
temperature. Build Int. 6: 39-54, 1973.
