United States
                   Environmental Protection
                   Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
                   Research and Development
EPA/600/S9-86/020 Sept. 1986
&EPA         Project  Summary
                  Proceedings  of an  Engineering
                  Foundation  Conference  on
                  Management  of Atmospheres
                  in Tightly  Enclosed  Spaces
                  J. E. Janssen
                    Indoor air pollution is rapidly being
                  recognized as a major problem in build-
                  ings. An Engineering Foundation Con-
                  ference was held in Santa Barbara in
                  October 1983 to assess the state of
                  knowledge about management of at-
                  mospheres in  tightly enclosed spaces
                  and to discuss newer methods for miti-
                  gation of indoor pollutants. Approxi-
                  mately 25 invited speakers represent-
                  ing most of the groups doing significant
                  work in this area and 20 interested col-
                  leagues attended. ASHRAE sponsored
                  the conference with interest stemming
                  from its Standard 62-1981, "Ventilation
                  for Acceptable Indoor Air Quality." DOE
                  and EPA were cosponsors with interest
                  in energy requirements for the ventila-
                  tion of buildings and for better defini-
                  tion of indoor air quality problems and
                  related control technology. Specific ob-
                  jectives for this conference were the as-
                  sessment of the state of knowledge for
                  consideration in the revision of
                  ASHRAE Standard 62-1981 and provid-
                  ing background information for both
                  DOE and EPA in planning their pro-
                  grams for improving indoor air quality.
                    Conference arrangements were coor-
                  dinated by the Engineering Foundation,
                  endowed with a grant from Ambrose E.
                  Swasey (a successful machine tool
                  manufacturer) in 1914 "for the further-
                  ing of research in Science and Engineer-
                  ing and for the advancement of the pro-
                  fession of engineering and the good of
                  mankind."
                    This Project Summary was devel-
                  oped by EPA's Air and Energy Engineer-
                  ing Research Laboratory, Research Tri-
                  angle Park,  NC,  to  announce  key
findings of the research project that is
fully documented in a separate report
of the same title (see Project Report
ordering information at back).

The Conference
  The conference program was divided
into two parts: the first, devoted to
defining major pollution problems in
buildings; and the  second, assessing
the state of the art of control techniques.
James Frazier, National Research Coun-
cil, discussed several indoor pollutants
and the relationship of exposure, dose,
and advance health effects and the need
for documentation in Standard 62-1981.
Many of the pollutants in indoor air re-
sult in an accumulative dose from expo-
sure to their various sources. Often the
very young and the very old spend most
of their time in the home. Workers, on
the other hand are exposed in the work
place 8 hours a day, 5 days a week.
Thus, the dose accumulated by an indi-
vidual may be substantially greater in
the home even though contaminant lev-
els there are much lower  than in the
work place or in outdoor ambient air.
Thus, the work place threshold limit val-
ues (TLVs) cannot be used  as limits for
exposure in the home in the same way
they are used in the work place. Stand-
ard 62-1981 has used a reduction factor
of 1/10 of the TLV for several pollutants.
The rationale for using this factor was
that there are four times as many hours
of exposure in the indoor environment
as in the work place. The safety factor of
1/10 of the TLV concentration was intro-
duced because infants and the aged
may be less able to tolerate stress in-

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duced by contaminants. This is an un-
certain practice that has no data  base
upon which the extrapolation of work
place TLVs can be proven to be accept-
able. There is  a critical need to accu-
rately and objectively assess the health
risks to all occupants thus exposed to
known hazardous indoor pollutants. It
was also noted that the human nose is
most sensitive  to the presence of odor-
ous pollutants;  this recognition can lead
to complaints about indoor pollution. It
is important to have  knowledgeable
people with appropriate instruments
who can follow, up on complaints and
obtain the facts about the nature, char-
acter, and concentrations of the pollu-
tants.
  Greg Traynor,  Lawrence Berkeley
Laboratory, reported on the use of un-
vented combustion systems. Kerosene
and gas fired space heaters can be di-
vided into two classes,  radiant and con-
vective. Radiant heaters cool the flame
and reduce nitrogen oxide emission.
This flame quenching tends to produce
more carbon monoxide, however. Con-
vective heaters tend to produce less car-
bon monoxide but more nitrogen ox-
ides. Carbon monoxide emissions tend
to decrease as operating time increases.
This is probably due to a gradual  in-
crease in flame temperature with oper-
ating time.
  Wood stoves, even though they are
vented, tend to smoke and leak combus-
tion products  into a home, especially
during start-up. Ventilation  rates for uin-
vented combustion systems need to be
established.
  Much progress has been made in re-
ducing formaldehyde emission rates
from plywood and particle board  ac-
cording to C. Beat Meyer, Professor of
Chemistry,  Washington State Univer-
sity. Differences greater than ten-fold in
the formaldehyde emission from differ-
ent manufacturers' particle boards have
been measured. The molar ratio of the
reactants in urea  formaldehyde resins
has a marked influence on the amount
of unreacted formaldehyde. Manufac-
tured homes (e.g., mobile homes) may
contain as much as 1 Ib (0.5 kg) of unre-
acted formaldehyde.
  While there is a 5% cost penalty and
some problems with supplies of particle
board and plywood with low formalde-
hyde emission rates, it appears that the
industry  is working quietly to reduce
formaldehyde  emission rates in manu-
factured homes. It also appears that the
0.1 ppm recommended limit for
formaldehyde is achievable and reason-
able based on documented comfort
criteria.
  Thomas Mathews, Oak Ridge  Na-
tional Laboratory, also discussed the
emission of formaldehyde from wood
products. He  has measured emission
rates as a function of temperature and
humidity in a special Teflon-lined cham-
ber. Teflon was required to minimize
the collection of  formaldehyde
molecules on the walls of the chamber.
Emission rates were found to be a func-
tion of the thickness of the material
(e.g., chipboard, plywood), the temper-
ature, the humidity, and the ambient
concentration of vapor in the air. Mod-
els have been developed for describing
internal formaldehyde concentration
gradients in terms of temperature, hu-
midity, and ambient formaldehyde
vapor pressure. The interaction of ambi-
ent conditions with the materials  pro-
duces variable emission rates that upset
a simple ventilation model based on a
constant emission rate. Increasing the
ventilation rate to reduce  ambient
formaldehyde concentration increases
the emission rate. Thus, the reduction in
ambient formaldehyde concentration is
not linear with respect  to ventilation
rate. Other measures (e.g., more opti-
mum  formulation of  the adhesives or
sealing (passification) of the surfaces)
also may be needed. Manufacturers ap-
pear to be making progress in this direc-
tion.
  P. Ole Fanger from the University of
Denmark described work on ventilation
to control odor. His group has been re-
peating Yaglou's classic work  carried
out in the early 1930s. Fanger has used
relatively large groups  of college stu-
dents in larger rooms than Yaglou used.
Unlike Yaglou,  Fanger finds no corre-
spondence between ventilation rate and
space per person for odor control. Both
Fanger and W. Cain, J.B. Pierce Labora-
tory, Yale University have found a slight
correlation between  odor dissatisfac-
tion and C02 level. There is greater dis-
satisfaction as the  C02  rises.  Both
Fanger's and  Cain's experiments have
been  carried out with visitors (i.e., the
subjects were  brought from a "clean"
space into the test space, where condi-
tions had been established by other oc-
cupants), and asked  to vote immedi-
ately on acceptability. The  present
outdoor air flow rate of 2.5 L/S specified
in Standard 62-1981  will satisfy  only
50% of the visitors. A flow rate of 8 L/S
(16 cfm) is needed to  satisfy 80% of the
visitors. Adapted occupants in a space
(i.e., those who have  been there for 15
min) find 2.5 L/S generally acceptable.
Thus, it appears that the ventilation
standard should consider the difference
between visitors and adapted occu-
pants in various applications.
  Fanger also discussed some of Cain's
data on smoking. Cain has  found that
80% acceptance will require 120 m3/hr
(33.3 L/S or 70 cfm) of ventilation per
cigarette. With the normal smoking rate
of 0.6 cigarette per occupant (both
smokers and non-smokers),  this corre-
sponds to a required ventilation rate of
around 20  L/S per occupant, not far
from the 17.5 L/S per occupant (35 cfm)
recommended in 62-1981.  J. Repace
pointed out that people with allergic dis-
eases respond to tobacco smoke differ-
ently and are generally much more sen-
sitive.
  James Repace, EPA, reviewed the his-
tory of the knowledge of smoking dan-
gers. The first report of the Surgeon
General implicating tobacco  as a cause
of cancer came out in  1964. By 1979
there was overwhelming knowledge of
the health risk related to tobacco smoke.
Approximately 30% of the adult popula-
tion smoke two  cigarettes/hour at 10
min per cigarette. Thus,  30% smoking
30% of time means that 11 %  of the pop-
ulation is always smoking. Repace has
related health risks to ventilation  rate
and finds that 9.5 L/S minimum outdoor
air  produces  a health risk of  about
1.5  x 10~3. This is higher than the ideal
risk of 10~5 realized for many dangers,
but is less than the risk accepted for haz-
ards such as automobile travel. The 9.5
L/S value is about at the point of dimin-
ishing returns. A 10~5 risk would require
550 L/S of outdoor air per person. Ignor-
ing the smoking risk and using the min-
imum outdoor air flow rate of 2.4 L/S
raises the risk to a clearly unacceptable
level. Repace expects to publish his rec-
ommendations for tobacco smoke con-
trol soon.
  Robert Trietman, Harvard, also dis-
cussed the  problem of  "side smoke."
Smokers tend to  hold their cigarettes
away from their own person when not
actually inhaling. The Harvard Air Pollu-
tion/Lung Study found that although
30% of the adult population smoke, be-
tween 50 and 75% of the children in the
study live in homes where at least one
person smokes. These children show in-
creased pulmonary disease  and  differ-
ence in lung function. It has been found
in Japan that non-smoking women who
live with husbands who  smoke have
twice the cancer risk as those who live
with non-smoking husbands. Studies in

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 Greece showed a 2.4 times risk increase
 when  husbands smoked one  pack  of
 cigarettes  per  day and 3.4 times in-
 crease for two packs per day. There are
 insufficient data to reveal  any differ-
 ences in health  risk associated with the
 type of heating system or use  of elec-
 tronic air cleaners.
  A. (Tony) Nero of Lawrence Berkeley
 Laboratory discussed the radon prob-
 lem. He feels that the present standard,
 while recognizing radon as  a contami-
 nant of concern, oversimplifies the con-
 trol problem. The radon concentration
 may be somewhat independent of infil-
 tration since stack effect, which in-
 creases infiltration, also draws radon
 from the soil into the structure.  He also
finds that radon concentration in water
 does not necessarily correlate with its
 usual distribution in the soil. Filters that
 remove particulates do reduce radon
 progeny. The risk factor associated with
 radon  is  about 2 x 10~4 per working
 level month (WLM). One pico currie per.
 liter of air  is equivalent to 0.2 WLM.
 Nero feels that ventilation alone is insuf-
 ficient for proper control of radon.
  James Jaax of Johnson Space Center
 discussed the special problems of creat-
 ing an acceptable spacecraft environ-
 ment. Temperatures around 26°C with
 relative humidity of 50% or less have
 been found acceptable. The  absence of
 gravity has no effect as long as forced
 circulation is maintained. Air circulation
 rates of around 7.6 m/min are desirable.
 (This is consistent with change from
 natural to forced  convection over the
 human body in an earthbound environ-
 ment.)
  Carbon  dioxide levels of 1% have
 been used  in the  space shuttle. Space
 stations are expected to be held to 0.5%.
 Odor is something of a problem, how-
 ever; there is a buildup of trace meta-
 bolic products in the air.
  Preston McNall of NBS discussed the
 issue of building codes in the U.S.
 Thirty-five states have statewide build-
 ing codes. Thirty-two of these are based
 on one of three model  building codes.
The Building Officials Code Administra-
tion (BOCA) code  is used in the north-
 eastern and midwestern U.S. The Inter-
 national  Conference of Building
 Officials (ICBO) code is used in the west-
 ern U.S. The Southern Building Code
 Congress (SBCC)  code is used in the
 south. In addition 80% of the cities with
over 500,000 population use the model
 codes. These codes all use at least parts
 of the ASHRAE Standard 62-73.  Several
states are considering  use of Standard
62-1981 as recommended in ASHRAE's
position statement on ventilation. The
codes vary considerably in their treat-
ment of such things as tobacco smoke.
The Southern code, for example, ig-
nores tobacco smoke as a special con-
sideration. In general, codes  are en-
forced by review of building designs.
There are no performance inspections.
A few codes require a positive source of
combustion air for furnaces and fire-
places, but there is title enforcement of
ventilation codes in single family resi-
dences.
  John Carlton-Foss discussed relation-
ships between psychological, thermal
comfort, and physiological approaches
to testing  responses of people to envi-
ronmental conditions in the laboratory
or in the field. He showed the evolution
of the ballots used to measure subjects'
evaluations  of thermal environments.
He emphasized that Rohles had  used a
semantic differential  ballot with multi-
ple scales for the experiments which led
to the comfort zone in ASHRAE Stand-
ard 55-1981, and that a similar ballot
should be used in work with comfort
and indoor air quality. He said that indi-
vidual differences play  an important
role in thermal comfort and can be ex-
pected to play a similar role in response
to pollutants in  indoor air. He cited a
field study  in which  personality was
found to be the  most significant factor
in occupants' satisfaction or dissatisfac-
tion with the "stuffiness" of indoor air.
The subjective  responses measured
with such  ballots can also be quantified
through measuring the impacts of in-
door air pollutants on people's perform-
ance. There are specific and general ef-
fects, and he cited his recent study on
seating and performance as an example
of measuring the impact of general
stress on  performance.  He cautioned
that investigators should be aware of
complex, and sometimes confusing, in-
teractions between  many variables;
e.g., psychological and  ergonomic
ones. There are methods for separating
the variables, and these should be taken
into consideration when designing new
work, or when reviewing work that does
not explicitly include them.
  Harvey Sachs, National Indoor Envi-
ronmental Institute, presented two pa-
pers on the  subject or radon. The first
was a discussion of a study of the preva-
lence of radon  in homes in eastern
Pennsylvania. His study of  10 homes in
one town showed that older homes
tend to have less radon than new
homes due to generally  lower infiltra-
tion (ventilation) rates in newer con-
struction. Local geology is an important
predictor of radon contamination. Soil
permeability and source strength influ-
ence radon  level in the  homes. Sachs
stated that there are several orders of
magnitude variation in radon exposure
for people living  in the U.S. and that the
radon level in a home often is an indica-
tion of soil radon level and permeability.
His conclusion was that, although expo-
sure to radon in the eastern U.S. is rela-
tively high, little excess lung cancer is to
be expected now. The  highest expo-
sures are in the stock of new  houses.
The cumulative population dose will re-
main low for the next 20 years. It would
appear that  this  may be a time bomb
waiting for the  future.  U.S. data  on
radon problems  are still sketchy.
  In his second paper, Sachs described
an  experiment in which  radon  was re-
moved from the soil under the floor slab
of a house by ventilation of the soil. In
one house an open unlined sump in the
basement floor was  sealed and fined
with an exhaust  fan vented to the out-
doors. This depressurized the soil under
the floor  and decreased the radon con-
centration in the  basement by 90%. In a
second case,  a  basementless, earth-
sheltered house  had sub-slab air ducts
which  brought  in large amounts of
radon. A partial vacuum on the per-
forated parameter drain pipe reduced
radon concentrations by 80% without
sealing the  ducts. Ventilating  a drain
pipe around the foundation of a third
house also gave an 80% reduction in
radon. Depressurization  of the soil
under and around the foundation sub-
stantially reduced  radon levels in  all
three houses.
  Dean Baker, UCLA School of Public
Health, discussed his investigations of
"sick buildings" when he was health in-
vestigator for NIOSH before his present
appointment at  UCLA. Measurements
were made by questionnaires and inter-
views. Efforts then were made to corre-
late subjective data with factors such as
location inside the building and location
of the building in the community; time
of day, week, or season; and similar
variables in  an effort to find possible
cause/effect relationships. Specific sub-
jective  symptoms were complaints of
"stuffiness" of the  building environ-
ment and absenteeism caused by vari-
ous illnesses attributed to the building
environment. Physical measurements
showed a plethora of chemical contami-
nants usually well below recommended
concentration limits. Thermal discom-

-------
fort was a common factor. The NBC
building in New York City was an exam-
ple. Nineteen contaminants were identi-
fied, but all were below the lowest rec-
ommended industrial limits, but use of
industrial limits has been questioned.
Building ventilation  was not measured
but was estimated to be 35% below the
recommended ventilation rate. Incom-
plete detailed measurement of all perti-
nent factors is a problem in much of the
data on sick buildings. There is consid-
erable interaction between chemical,
physical, biological,  and social factors.
Acute symptoms include hypersensitiv-
ity to pneumonltis  (humidifier fever),
dermatitis, and  non-specific  (sick at
home) complaints. Chronic symptoms
include chronic respiratory disease,
neurasthenia, and  possibly  cancer.
Baker said that the effects of large parti-
cles of fiberous glass, which cause der-
matitis, do not correlate well with venti-
lation rate.  Problems are  often due to
perception  of conditions.  Physical re-
sponse to contaminants occurred in the
first 4 weeks of exposure. Reports of
multiple symptoms followed. Baker rec-
ommended creation  of an environmen-
tal committee to deal with complaints.
  David Harris,  National Institute of
Building Sciences, discussed mitigation
of problems through the use of substi-
tute materials. NIBS  conducted a study,
in 1983, to compile and organize a com-
prehensive list of building materials,
products, and systems typically used to
construct office buildings, schools, and
homes for the elderly since 1970 in the
Washington D.C. area. Typical activities
which occur in these buildings were
also listed, as were organizational refer-
ence sources for more detailed informa-
tion on each subject area. The effect of
these materials and activities on indoor
air quality for each of the three building
types will be further  studied by the EPA
as part of the Agency's total exposure
monitoring  program. While the data
and analyses are far from complete, this
approach appears to be a good effort to
identify some sources of indoor air pol-
lutants.
  Brian Krafthefer, Honeywell,  pre-
sented data showing the effect of an
electronic air cleaner on radon progeny
concentrations. Measurements of radon
progeny in the basement of a  home in
Minneapolis revealed an inverse corre-
lation with barometric pressure and a
diurnal variation  with  temperature
when the furnace was not operating and
the fan and air cleaner were off. Activity
levels up to about 0.03 Wl, three times
the limit specified in Standard 62-1981,
were measured.  Operation of the fur-
nace fan reduced the peaks by 50%. Op-
eration of the electronic air cleaner held
the activity level  to less than 0.005 Wl,
half of the recommended limit. At this
level there was no apparent correlation
with barometric  pressure or tempera-
ture.
  J. Donald Cummins, Purafil Inc., dis-
cussed the use of adsorbing and oxidiz-
ing filters. Activated carbon has a sur-
face area of about 735,000 m2/kg of
material. Vapor  molecules contacting
this surface are held by Van der Waals
forces. Adsorption is proportional to
molecular weight. Thus, materials such
as activated carbon and activated alu-
mina are much more effective in remov-
ing large organic molecules than they
are in trapping small gas molecules like
CO. Removal efficiency can be en-
hanced by adding reactive  chemicals
which combine with  the trapped
molecules. Potassium permanganate
added to activated alumina is very effec-
tive on oxidizable vapors. The adsorbed
molecules are oxidized by the perman-
ganate. Vapors such as  hydrogen sul-
fide and formaldehyde can be efficiently
removed from air by this material. The
filter medium has a finite life, however,
but the cost is often an attractive alter-
nate  to  other air cleaning methods
when special problems exist.
  Amos  Turk, New York City College,
discussed  the five different physical
processes of using granular materials
for air cleaning.  Molecules may be
physically adsorbed  on  the  surface of
porous materials such as activated car-
bon or alumina.  The addition of various
reagents  can  cause the adsorbed
molecules (P) to be neutralized (N), oxi-
dized  (O), complexed (C), or decom-
posed (D).
  The typical means of gas/vapor filtra-
tion with granular media are:
                         Possible
 Pollutant            Filtration Means
 Body Odor
 Cosmetics
 Plasticizers
 Radon
 Tobacco Odors
 Fecal, Urine Odors
 N02, SO2
 Ozone
 Peroxides
 Ethylene
 Mercury Vapor
 Metal Hydrizes
 Fumigants (EDB)
P, N
P
P
P
P,0
P, N, O, C
P, N, 0
D
P, D
C
C
P, 0
P
Except for the decomposition of ozone
or peroxides,  the reagents are con-
sumed with use, and the filtration mate-
rial must be replaced or rejuvenated pe-
riodically.
  James E. Woods, Iowa State Univer-
sity (recently joined Honeywell), dis-
cussed some of the compromises be-
tween air quality  and cost. Doing
nothing to humidifiers and ducts, which
may sometimes  be wet,  introduces a
prohibitive cost due to the danger of Le-
gionnaires' disease. Rigorous  mainte-
nance and special treatments to im-
prove indoor air quality are required.
Biological  contaminants are not
presently  spelled  out in Standard 62-
1981, but should be considered. Woods
also questioned the acceptability of
2500 ppm  of C02- European and
Japanese  standards limit C02  to 1000
ppm. Woods suggested that ventilation
systems might be rated as to effective-
ness, perhaps on a scale of 1 to 10.
  J. E. Janssen discussed the problem
of ventilation or air mixing efficiency.
Standard  62-1981 assumes that  all of
the outdoor air that is inducted into a
building is effective in diluting the con-
taminants. Tracer gas tests and flow
models show that this is a poor assump-
tion. When the supply outlets and return
inlets of a  ventilating system are both in
the ceiling, as they commonly are, and if
the exhaust air is taken from the recircu-
lating air  stream, as it usually is, it is
possible for a significant amount of out-
door air to be inducted into the supply,
bypass directly from the supply outlet to
the return, and be exhausted without
ever  mixing at the occupied  level, ft
model has  been  devised  to  calculate
this wasted ventilation. Tracer gas
decay measurements at the return inlei
and  at the occupied level provide the
needed data. Mixing efficiencies of onl>
50% may  be common.
   Robert Macriss, Institute of Gas Tech
nology, discussed infiltration in residen
tial structures. Infiltration is the mair
passive means of controlling air quality
in residences.  IGT data show that infil
tration can  vary  from 0.01  to 1.0 ai
change per  hour in a given house, IG'
has procedures and a model for extrap
olating single point measurements
They have  found that the concentre
tions  of  contaminants from  interne
sources are  more a function of interzon
mixing than of infiltration rate. Both th
LBL and IGT models confirm the usefu
ness of single cell models.
   William Fisk, Lawrence Berkeley Lat
oratory, reviewed the use of mechanic!

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ventilation systems in residences. Dur-
ing the past 5 years,  15,000 to 20,000
units per year have been sold. This is a
small fraction of the homes that have
been built. Mechanical ventilation is ef-
fective against both  radon and  its
progeny. Enthalpy type air-to-air heat
exchangers conserve humidity in cold
climates but also tend to conserve dis-
solved formaldehyde. Air-to-air heat ex-
changers have  discouraging econom-
ics: first cost may  be upward of $500;
fan power ranges fom 0.7 to 3.6 W/0.5
L-s; thermal efficiencies, from 50  to
70%; air flow rates, from 40 to 120 US;
and payback periods in climates like
Minneapolis, from  12 to more than 30
years. In Washington, D.C., the payback
period ranges from 16 to more than 30
years. Leakage between air streams re-
duces efficiency, and cold weather op-
eration can produce  icing problems.
Good maintenance is required to pre-
vent biological contamination and a
possible source of  legionellosis.
  E. Sterling, TDS, Ltd., discussed a
data base he has on air quality and ven-
tilation  in 143 buildings. Unfortunately
ventilation rates were not  always  re-
ported with measured contaminant lev-
els. Sterling believes that occupancy is
the best measure of contaminant load in
office buildings. He also found poor cor-
relation between the building design
and actual occupancy. Since code en-
forcement is usually based on design, it
is likely that many buildings are oper-
ated well outside the recommendations
of the ventilation standard.
  D. Moschandreas, Illinois Institute  of
Technology, Research Institute, re-
viewed measurements of emissions
from gas cooking  ranges. Tests were
made in a chamber with a ventilation
rate of 50 L7S (consistent with Standard
62-1981). Three different ranges were
tested, each in two different extremes of
air/fuel  mixture: a normal stoichiomet-
ric, blue flame, and a yellow, diffusion
flame  representing a malfunctioning
burner. Formaldehyde emission rates of
1200 to 8000 |i.g/hr were measured.
  Tom Phillips discussed public health
considerations in the development  of
residential building standards in Califor-
nia. The standard was adopted in 1978.
This standard required caulking around
the sole plate and wall outlets, sealing
of ducts in unconditioned spaces, and
caulking around windows and doors.
Outside venting of  cooking ranges was
recommended. This residential stand-
ard was implemented through the use
of an extensive questionnaire to be an-
swered by the building contractor. New
design targets are 0.4 air changes per
hour (ach). Houses achieving 0.3 ach are
to have heat exchangers and dehumidi-
fiers. The code is the result of much tes-
timony and compromise.
  Robert Treitman, Harvard University,
also reviewed experimental techniques
for paniculate measurements. The Har-
vard group has used high volume and
dichotomous samplers. Aerosol mass
balance  instruments  have been  less
successful for low concentrations found
in residences.
  Nagda, Geomet, reviewed the status
of their current project with EPRI. Two
"identical"  130 m2 houses  have been
built and are being used for studies of
indoor generated pollutants. The
houses are unoccupied, and one is used
as a control. Typical household activi-
ties such as cooking on  a gas  range,
vacuum cleaning, and clothes launder-
ing generate pollutants to be measured.
Measurements include CO, NOX, radon,
formaldehyde, particulates, and C02. In-
filtration  is  measured with SF6 tracer
gas. Carbon monoxide rose to 7.5 ppm
upstairs after 2 hours of operation of the
gas range with the furnace fan off and
5 ppm with  the fan  on. Sealing of the
structure to  achieve 40% reduction (by
blower door test) had little effect on CO
concentration.
  P. 0. Fanger, Technical  University of
Denmark, reviewed recent studies of
the effect of drafts on comfort. The test
chamber consisted of a room in which
subjects  were exposed to air velocity
fluctuations  as they occur in normally
ventilated spaces. Fluctuating velocities
have been found to be more objection-
able than steady velocities. Tempera-
tures  of 20, 23, and 26°C have been in-
vestigated. Surprisingly,  short  haired
subjects complained less than long
haired. Twenty percent of the subjects
felt a  mean  velocity of 0.15 m/s (30 ft/
min) as uncomfortable at 20°C. This in-
dicates a  need to review the Air Diffuser
Performance Index which defines 0.35
m/s (70 ft/min) as the threshold  of dis-
comfort.
  The final session  of the conference
addressed the  questions  of how
ASHRAE  Ventilation Standard 62-1981
should respond to new data. It was sug-
gested that  the Air  Quality Procedure
could be based on health risk. People
accept personal risk of 10~1 to 10~2.
Lifetime smoking risk  is 10"1, lifetime
risk for driving an automobile is 10~2,
and occupational  risks are generally in
the range of 10~2 to  10~3.  Environmen-
tal risks are generally less than  10~3,
and some are as low as 10~5. The cur-
rent level of risk in the home is in the
range of 10~2 to 10~3. It is probably im-
practical to try to reduce home  risk be-
low 10~3.  Commercial buildings  have
risk factors in the range of 10~3 which
may be a reasonable level. Risk factors
are politically difficult to accept, and in-
voluntary risk must  be lower than vol-
untary risk.
  The consensus seemed to be that the
Ventilation  Rate Procedure in Standard
62-1981 should be maintained.  The Air
Quality option could be modified. Per-
mission  for innovative procedures
should be  maintained. The standard
should specify important pollutants and
define maximum permissible levels.
The standard should tell  the designer
how to use the information.
  Specific recommendations and  prob-
lems were:
 1. ASHRAE needs guidance on accept-
   able  risks—is  10~3  acceptable?
    Morbidity risk, rather than mortality
    risk, should be used.  Rationale for
    risk should not, however, be  in-
    cluded  in the standard. Simply stay-
    ing at  home  should  not increase
    personal risk.
 2. There is a need to define risk in the
    home. Larger samples are needed.
 3.  Optimum environmental  condi-
   tions for productivity need to be de-
   fined.
 4.  Indoor air pollutants need to  be
   characterized on a broader scale.
 5.  Methods are needed to verify venti-
    lation  rates specified in  Standard
   62-1981.
 6. Ventilation effectiveness in build-
    ings must be determined.
 7. The effectiveness of air quality con-
   trol options  needs to be evaluated.
 8.  Human  detection limits for
   formaldehyde need to be improved.
 9. Health effects related to IAQ need to
   be investigated.
10. Improved  instrumentation  is
    needed both for research and for
   compliance tests.
11.  Should occupational or environ-
   mental  standards apply to indoor
   environments?
12.  How  can we achieve  implementa-
   tion of, and  compliance  with, the
   standard?
13. There is a need  to model pollutant
   behavior in  buildings. What is the
   relationship  between  comfort, en-
   ergy, health, and productivity?
14. The acceptability of body odor and
   tobacco smoke needs to be defined.

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    How should the differences be-
    tween visitors  and adapted occu-
    pants be handled?
15.  There is a need to coordinate with
    other organizations and trade
    unions.
16.  How should sensitive groups (e.g.,
    allergic or sick subjects) be consid-
    ered?
17.  Causes of, and remedies for, sick
    buildings need to be identified.
J. E. Janssen is with Honeywell, Inc., Technology Strategy Center, Roseville, MN
  55109.
W. Gene Tucker is the EPA Project Officer (see below).
The complete report,  entitled "Proceedings  of an Engineering  Foundation
  Conference on Management of Atmospheres in  Tightly Enclosed Spaces,"
  (Order No. PB 86-219  193/AS; Cost: $16.95, subject to change)  will  be
  available only from:
        National Technical Information Service
        5285 Port Royal Road
        Springfield, VA 22161
        Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
        Air and Energy Engineering Research Laboratory
        U.S. Environmental Protection Agency
        Research Triangle Park, NC 27711

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United States
Environmental Protection
Agency
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                                       Information
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Official Business
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EPA/600/S9-86/020
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