Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
An Air Quality Survey of Respirable Particles and
Particulate Carcinogens in Boston Pubs
Before and After a Smoking Ban
James Repace, MSc.
Health Physicist
Repace Associates, Inc.,
Secondhand Smoke Consultants
101 Felicia Lane, Bowie MD 20720
Phone:1- 301-262-9131; Fax: 1-301-353-8457
Email: repace@comcast.net ; website: www.repace.com
Executive Summary
Using state-of-the-art air pollution monitoring equipment, air quality was assessed
in 7 Boston hospitality venues before and after a workplace smoking ban issued by the
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Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
Board of the Boston Public Health Commission (BPHC) on May 5th, 2003. The pubs
were sampled on Friday evening, April 18, 2003, under conditions of unrestricted
smoking, and again on Friday evening, October 17, 2003, less than 6 months after going
smoke-free. Measurements were made of respirable particulate air pollution (RSP) and
particulate polycyclic aromatic hydrocarbons (PPAH), pollutants known to increase risk
of respiratory disease, cancer, heart disease, and stroke. Environmental indicators,
including carbon monoxide (CO), carbon dioxide (CO2), temperature, and relative
humidity were also measured. Prior to the smoking ban, all venues were heavily
polluted, with indoor RSP concentrations averaging 10 times higher than outdoors, and
indoor PPAH concentrations averaging 4 times higher than outdoors.
Pre-smoking-ban Pub RSP levels were 23 times higher than post-ban levels,
violating the annual National Ambient Air Quality Standard (NAAQS) for fine particle
pollution (PM2.5) by nearly 4-fold. Pre-ban indoor PPAH averaged nearly 12 times
higher than post-ban levels, quadrupling workers’ daily carcinogenic PPAH exposure.
By contrast, after the smoking ban, indoor air quality levels for both pollutants were,
except for RSP in one venue, indistinguishable from outdoors, and in compliance with
the NAAQS. Secondhand smoke (SHS) contributed on average, 95% of the RSP air
pollution during smoking, and 90% of the carcinogenic PPAH, when the post-ban indoor
pollution levels were chosen as a reference level (Figure ES). This occurred despite a
pub smoking prevalence averaging only 12%, less than 2/3 of the current 19.7% Statewide prevalence. One pub had much lower post-ban PPAH levels than pre-ban, but much
higher post-ban RSP levels than pre-ban. This pub was found to have significantly
elevated levels of CO relative to other pubs, indicative of an additional air quality
problem apparently unrecognized by its owners. This pub’s data was excluded from the
averages.
Ventilation practices in these pubs failed to limit workers’ exposures to SHS-RSP
to comply with the health-based National Ambient Air Quality Standard (NAAQS), even
for those pubs that had estimated ventilation rates per occupant close to or exceeding
standard ventilation engineering design criteria. Averaged over all pubs, increasing
ventilation to limit SHS-RSP to NAAQS levels for workers pre-smoking ban would have
required an unachievable 242 air changes per hour (a 100-fold increase over the mean
value measured for six of seven pubs) despite the low smoking prevalence. This air
quality survey demonstrates conclusively that the health of Boston hospitality workers
and patrons has been endangered by secondhand smoke pollution. The Boston Clean
Indoor Air Regulation’s ban on smoking in hospitality workplaces eliminates that hazard,
and is well-justified regardless of any real or imagined economic impact.
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Repace Associates, Inc.
Boston's S moke-free Law Clears the Air
200
200
Cancer-Causing PPAH, ng/m3
150
150
100
100
smoking
50
50
smokefree
smokefree
0
PPAH
1
0
Harmful Fine Particulate RSP, g/m3
smoking
PPAH pre-ban
PPAH post-ban
RSP Pre-Ban
RSP Post-ban
RSP
FIGURE ES. AVERAGE INDOOR AIR POLLUTION LEVELS IN 6 DOWNTOWN PUBS
BEFORE AND AFTER BOSTON’S SMOKE-FREE WORKPLACE LAW: BANNING SMOKING
DECREASED CARCINOGEN (PPAH) LEVELS BY 90%, AND DECREASED RESPIRABLE
PARTICLE (RSP) LEVELS BY 95%.
(Repace Associates, Inc., 2003).
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Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
Introduction: The Massachusetts Coalition For a Healthy Future commissioned a study
in order to compare the level of pollution from tobacco smoke in the smoking areas of
typical hospitality venues under actual ventilation practices to the level of pollution in
those same venues in a smoke-free condition following the promulgation of Boston’s
Clean Indoor Air Regulation (BPHP, 2003). This report describes that study, and
presents the results of air quality monitoring in 7 hospitality venues in the City of
Boston, Massachusetts, before and after the May 5th, 2003 smoking ban. All venues were
mechanically-ventilated bars or bar/restaurants, as described in Table 1. Boston has a
population of 589,500, of whom 447,000 were aged 21 years or over, i.e., old enough to
be bar patrons (U.S. Census, 2002). Its population density is 11,500 persons per square
mile. Greater Boston's five leading industries are: financial services, health care, high
technology, higher education, consulting, and tourism, accounting for over half of all
employment (Boston Chamber of Commerce, 2003).
Secondhand smoke (SHS), also known as environmental tobacco smoke (ETS), is
air pollution caused by the burning of tobacco products. SHS is a mixture of exhaled
mainstream smoke, and sidestream smoke. Mainstream smoke is the aerosol drawn into
the mouth of a smoker from a cigarette, pipe, or cigar through the cigarette. Exhaled
mainstream smoke is formed when this aerosol is exhaled by the smoker, minus a
fraction that is retained in the smokers’ respiratory tract. Sidestream smoke is the
aerosol which escapes directly into the air from the burning part of a tobacco product.
Due to proximity to the source, the smoker is exposed to greater amounts of SHS than a
nonsmoker who breathes this air pollution. (NAS, 1986)
The presence of toxins and carcinogens in ambient air polluted with tobacco
smoke is largely due to the sidestream emissions from the smoldering tobacco products.
Levels of these toxins and carcinogens in secondhand smoke often exceed the
concentrations in mainstream smoke. Secondhand smoke contains about 4000 chemical
compounds, including known carcinogens such as polycyclic aromatic hydrocarbons
(PAH), aromatic amines, volatile- and tobacco-specific nitrosamines, as well as a variety
of other toxic or irritating compounds, including carbon monoxide, benzene,
formaldehyde, hydrogen cyanide, ammonia, formic acid, nicotine, nitrogen oxides,
acrolein and respirable particulate matter. (Hoffman and Hoffman, 1987). ETS contains 5
regulated hazardous air pollutants, 47 hazardous wastes, and more than 100 chemical
poisons (Repace, 2000).
Secondhand smoke (SHS) has been condemned as a health hazard by all U.S.
environmental health, occupational health, and public health authorities, including the
National Toxicology Program (2000), the National Cancer Institute (1993; 1995), OSHA
(1994), the Environmental Protection Agency (1992), the National Institute for
Occupational Safety and Health (1990), the Surgeon General (1986), and the National
Academy of Sciences(1986).
Nevertheless, because of repeated Congressional admonitions that SHS is an issue
best handled by States, federal regulatory agencies have been discouraged from
undertaking rulemaking or research efforts to protect private-sector workers and the
public. However, States have been slow to take action, especially in the hospitality
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industry sector. Maryland Occupational Safety and Health banned smoking in all
workplaces in 1994, but in 1995, the State legislature overrode the rule before it took
effect, exempting bars and restaurant bars, apparently in the belief that hospitality
industry workers did not warrant the same protection from secondhand smoke as other
workers. In 1995, California banned smoking in all restaurants and other workplaces,
and in 1998 extended the ban to include all bars. Delaware followed suit in 2002. In
2003, both New York City and Boston banned smoking in bars. New York State,
Connecticut, and Maine also banned smoking in all workplaces, bringing the total of
states to ban smoking to five. Five months after Boston implemented an indoor smoking
prohibition, 94 Massachusetts cities and towns have eliminated smoking from all
workplaces, including bars and other nightspots (Smith, 2003). As of this writing, the bicameral Massachusetts State Legislature has passed two different versions of a Statewide law just before adjourning until January 2004; the Governor has indicated he would
sign the conference committee’s final compromise, whose details remain undecided (AP,
Nov. 22, 2003).
There are approximately 85,000 restaurant & bar workers in
Massachusetts (Mass DET, 2000), as shown in Table 0. As of April, 2003, prior to
Boston’s smoking ban, Massachusetts State Law provided only that smoking not be
permitted in any restaurant that seats more than 75 persons, except in a specifically
designated smoking area of not less than 200 ft2 area (Mass TCP, 2003). About 61% of
Massachusetts residents resided in areas where smoking was not permitted in any dining
room. However, only 34% resided in areas where smoking was not permitted in any
restaurant including bar areas. It has been estimated that only 15% of the 85,000
hospitality workers worked in entirely smoke-free workplaces in 2002 (Skeer & Seigel,
2003), and thus 72,250 did not.
Table 0. Hospitality workers in Massachusetts, 2000 (Mass DET, 2000).
Occupational Title
Current Jobs, Number
Current Jobs, %
Hosts/Hostesses: Rest./Lounge
6,600
0.2
Bartenders
13,280
0.4
Waiters & Waitresses
57,780
1.7
Dining Rm/Cafe Attds/Bar Helpers
7,790
0.2
Total
85,450
2.5
The Ventilation Issue:
Despite that fact that ventilation was long ago demonstrated to be unable to
control secondhand smoke (Repace and Lowrey, 1980; 1985), the tobacco industry and
its allies in the hospitality industry continue to assert that “ventilation” controls
secondhand smoke and that smoke-free laws are unnecessary. Such vague claims do not
specify the level of exposure corresponding to de minimis risk, and thus ignore SHS risks
to health of workers and patrons. For example, the Philip Morris website (2003) asserts
that:
“Business owners who choose to accommodate smoking should reduce
secondhand smoke through designating separate areas or separate rooms
for non-smokers and smokers and through the use of high-quality
ventilation systems to minimize [emphasis mine] smoke in the air.
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The R.J. Reynolds Tobacco Company website (2003) asserts a similar philosophy:
“There are … a number of ways to allow smokers and nonsmokers to
peacefully coexist in public places without resorting to smoking bans.
Common courtesy and common sense -- coupled with adequate
ventilation and filtration, and designated smoking areas [emphasis mine]- can often accommodate the wishes of smokers and nonsmokers alike.
We believe that business owners know best how to satisfy their customers,
and they, rather than the government, should be allowed to decide whether
to allow, restrict or ban smoking in their establishments.”
However, such claims, aimed only at protecting tobacco industry profits, are often
adopted uncritically by the hospitality industry, and are vague and unscientific, because •
they do not define any legally acceptable level of SHS exposure, • they never define the
current risk or risk reduction offered at a given smoker density by a given ventilation rate,
and • they never offer any comparison of ventilation to smoke-free laws in controlling
secondhand smoke. Key terms like “minimize,” “accommodate,” or “adequate” remain
undefined, and are worse than useless for protecting either the health of workers in
designated smoking areas, or that of nonsmoking patrons who sit in designated
nonsmoking areas and affected by recirculated or drifting SHS.
Nonsmoking majority avoids smoky premises: The hospitality industry
continues to raise an economic argument against smoking bans despite the long-term
increase in sales following the California smoking ban. Such arguments ignore the
adverse economic effects on this industry caused by nonsmokers’ well-documented
aversion to tobacco smoke, illustrated by the following survey. In 1995-96, Biener et al.
(1999) at the University of Massachusetts (Boston), surveyed a representative sample of
4929 Massachusetts adults to assess who avoids smoky restaurants and bars, and why. In
1996, the adult population of Massachusetts (>18 years) was 4.54 million, of whom 3.57
million (79%) were non-smokers, and . Biener et al.’s survey found that 76% of the
nonsmokers were bothered by tobacco smoke, and that 46% of nonsmokers reported that
they avoided smoky places due to offensive odors or health worries.
Biener et al. estimated that, in 1996, of these 3.57 million nonsmokers, 515,405
adult nonsmokers (14.4%), avoided patronizing smoky restaurants and 364,400
nonsmokers (10.2%) avoided patronizing bars, due to secondhand smoke concerns,.
Scaling these data to year 2000, Massachusetts smoking prevalence had declined to about
19.7% (±1%) (MMWR, 2003), and the adult population (>18 years) had increased to 4.85
million, of whom 955,500 were smokers, and 3.895 million were nonsmokers. Thus in
2000, if 14.4% of adult nonsmokers avoided smoky restaurants and 10.2% avoided
smoky bars, then an estimated total of [(0.144)(3.8945) + (0.102)(3.895)] = 958,000
nonsmokers’ trade was lost to the Massachusetts hospitality industry due to SHS. In
other words, the fraction of nonsmokers who avoid hospitality venues in Massachusetts
because of secondhand smoke appears to be greater than the total number of smokers in
the State, leading to the conclusion that secondhand smoke loses trade.
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Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
Principal Investigator: This study was designed by James Repace, MSc., of
Repace Associates, Inc., a health physicist and an international secondhand smoke
consultant with 60 published scientific papers on the hazard, exposure, dose, risk, and
control of secondhand smoke. He has earned numerous national honors, including the
Flight Attendant Medical Research Institute Distinguished Professor Award, the Robert
Wood Johnson Foundation Innovator Award, and the Surgeon General’s Medallion. He
is a Visiting Assistant Clinical Professor at the Tufts University School of Medicine. He
was a senior policy analyst and scientist with the U.S. Environmental Protection Agency,
and served as a consultant to OSHA on its proposed rule to regulate secondhand smoke
and indoor air quality. He also served as a research physicist at the Naval Research
Laboratory in the Ocean Sciences and Electronics Divisions. His full curriculum vitae
may be viewed at www.repace.com.
Methods: The first monitoring phase was conducted on Friday evening, April 18,
2003, prior to enactment of the May 5th smoke-free law. The criteria for the April 18
venues to be sampled included the presence of visible smoking, all within walking
distance, and representing a broad variety of hospitality venues, ranging from
neighborhood bar serving food to tourist bar serving raw shellfish. Two bar/restaurant
venues on the list of candidates were rejected because no-one could be found smoking.
The venues selected are described in Table 1. The second monitoring phase was
conducted six months later, on Friday evening, October 17, 2003, after compliance with
the law had been amply demonstrated, and the temperature was sufficiently cool such that
the venues were not open to the outdoor air and the baseline indoor air quality could be
assessed in the absence of smoking. The same venues were sampled at the same time of
night. Both phases of this study were conducted in collaboration with Prof. James Hyde
of the Tufts University Dept. of Medicine, a Boston resident, who identified the venues to
be sampled, and Ms. Meghan Birch and Ms. Russet Morrow, of the Massachusetts
Coalition who served as observers and assisted with logistics.
In order to assess indoor and outdoor air quality, two fractions of the particulate
phase of secondhand smoke were chosen for measurement: respirable particles (RSP),
consisting of airborne particulate matter in the combustion size range below 3.5 microns
in diameter (PM3.5), and particulate polycyclic aromatic hydrocarbons (PPAH).
Cigarettes, pipes, and cigars are major emitters of RSP and PPAH (Repace and Lowrey,
1980; 1982; Repace et al., 1998). RSP was chosen in part because there are relevant
federal health-based outdoor air quality standards for a very similar fraction of RSP
called PM2.5 (Wallace, 1996; USEPA, 1997). EPA’s outdoor air standards are widely
accepted as a basis for judging the quality of indoor air (e.g., see ASHRAE Standard 621981, 1989, 1999). PM3.5 was also selected in part to compare directly to previouslypublished PM3.5 measurements of tobacco smoke pollution by this and other investigators
(Repace, 1987). Many epidemiological studies have shown that increases in daily
average RSP levels are associated with increased morbidity and mortality from all causes
and from cardiovascular and respiratory diseases (Ware, 2000; Samet et al., 2000).
Moreover, there is new evidence that even shorter-term exposures can have cardiopulmonary health effects (Pope and Dockery, 1999; Lanki, et al., 2002), SHS included
(Repace, 2002). While daily average concentrations can readily be assessed by pumpand-filter gravimetric sampling, these are not adaptable to multiple short-term
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measurements of the order of 1/2 hour because it is difficult to collect sufficient sample
for analysis, and they yield only time-integrated readings as opposed to minute by minute
readings. Short-term one-minute average exposures can be assessed only by “real-time”
monitors that can record simultaneous measurements of concentration and time.
Lightweight, easily concealed, battery-powered monitors for respirable particles, such as
the pDR 1200 laser photometer chosen for these experiments, have been developed,
calibrated against standard pump-and-filter gravimetric methods, and deployed in
environmental epidemiology studies (Lanki et al., 2002; Repace, 2003).
PPAH was chosen in part because it consists of a mixture of well-known
carcinogens present in tobacco smoke, as well as diesel exhaust, and wood smoke
(Hoffmann & Hoffmann, 1987). PPAH have been implicated in heart disease and stroke
mechanisms as well (Glantz & Parmley, 1991). Total PAH include both gaseous and
particulate phase compounds. The classic PPAH compound is benzo(a)pyrene, which is
a known human lung carcinogen (Danissenko, et al., 1996). There are >100 PAH
molecules; measurement of PPAH underestimates the total number of toxic PAH in the
air. Portable real-time PAH monitors have been developed, calibrated against standard
gas-chromatography /mass spectrometry methods, and deployed in environmental
epidemiology studies (Zhiqiang et al., 2000; Chuang et al., 1999; McBride et al., 1999;
Repace et al., 1998; Ott et al., 1994). A lightweight battery-powered version of these
real-time respirable PPAH monitors, the EcoChem PAS2000CE, is deployed in these
experiments.
In order to assess ventilation, two methods were used: the first method involved
measuring carbon dioxide (CO2) using a Langan T15 Personal Exposure Measurer
(Langan Instruments, San Francisco, CA), which measures concentrations in real time. If
the number of persons in the establishment is counted, and the space volume measured,
the ventilation rate per occupant can be estimated from the difference between the indoor
and outdoor CO2 levels by using an equation given by The American Society of Heating
Refrigerating, and Air Conditioning Engineers (ASHRAE) in ASHRAE Standard 621999,Ventilation for Acceptable Indoor Air Quality. This method is based on carbon
dioxide levels in exhaled breath, which will build up in an indoor environment limited
only by the ventilation rate. The carbon dioxide method may be limited in accuracy by
variation in the contribution of outdoor sources of CO2, such as automotive traffic, or if
the CO2 level has not attained equilibrium. Another limitation is that the ventilation rate
per occupant defines the rate of supply of outdoor air per occupant of the space, and does
not directly measure the rate of pollutant removal. Because of this limitation, a second
method, the air exchange rate method, is used to assess the actual rate of pollutant
removal. The air exchange rate method calculates the actual air exchange rate for
secondhand smoke removal using the mass-balance model (Repace and Lowrey, 1980;
Ott, 1999). The air exchange rate is defined as the rate of replacement of polluted air
with unpolluted air, and is an index of how fast the secondhand smoke is removed by the
air handling system. These are described in more detail below.
Controlled Experiments for Equipment Calibration. The air quality monitoring
equipment used in these studies was calibrated in other studies conducted in collaboration
with Prof. Wayne Ott at the Department of Statistics, Stanford University, which were
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presented at ISEA 2003, the International Conference on Exposure Analysis (Repace,
2003; Ott & Repace, 2003). We used several different types of real-time and integrated
air monitors in controlled experiments in a home with a smoldered Marlboro Medium
cigarette as a source, and compared our results to a mathematical model. We measured
carbon monoxide (CO), respirable suspended particles (RSP or PM2.5 and PM3.5), and
surface-bound particulate polycyclic aromatic hydrocarbons (PPAH) in a real home. The
monitors included:  one Langan T-15 Personal Exposure Measurer for carbon monoxide
(CO), carbon dioxide (CO2), relative humidity (RH%) and temperature (oC);  two MIE
Personal DataRam 1200 Laser Photometer (MIE);  two Kanomax 3511 Piezoelectric
Microbalance (Piezobalance; PZB)  four EcoChem PAS2000ce PAH Photoionization
Monitors, and  two Cyclone Mass Collection Pump & Filter Monitors developed at
Stanford University for outdoor air quality measurements. The MIE and EcoChem
monitors were employed in the Boston Field Study described in this report. The
piezobalances were deployed by Repace and Lowrey (1980) in past experiments, and the
Cyclone devices are the “gold standard” reference units for the calibration. More than
one of each type of monitor was used to determine the measurement precision of the
devices. The cigarettes were ignited in a 41m3 bedroom and allowed to burn a specified
time, then extinguished, and the air monitors were operated side by side indoors with
readings taken once per minute. With four cigarettes smoked at the same time in a
bedroom on March 10, 2003, we found that MIE laser photometric monitors, set to
measure PM3.5, agreed well with each other but gave readings 31.2% and 29.6% higher
than the Cyclone particle mass collection filters, which were set to measure PM2.2 (Table
4). By comparison, the factory-calibrated piezobalances, also set to measure PM3.5,
gave readings that were only 9.6% and 6.3% above the mass filter collection methods,
suggesting a precision of + 5%. The PM3.5 size-cut was selected to compare with
previous studies by Repace and Lowrey (1980), using the piezobalance.
On March 11, 2003, the above experiment was repeated, with the laser
photometers and piezobalances set to measure a size range more consistent with that
measured by the Cyclones. We studied 7 cigarettes smolder-smoked for ten minutes
every hour, and analyzed the results using the Sequential Cigarette Exposure Model
(SCEM) mathematical model based on the mass balance equation for a 7 cigarette
smoking pattern for an actual cigarette smoker (Figure 5). The SCEM model requires
information on the starting and ending time of each cigarette, the cigarette’s emission rate
(1.4 mg/min), the particle decay rate, and the physical volume of the facility. Only the
decay rate was estimated from the measured data after the last cigarette was extinguished.
On this second set of experiments with the sequence of 7 cigarettes, the MIE Personal
DataRam’s average particle concentration set to measure PM2.5 was only 17% above the
mass collection results based on filter weighings (Table 2). The piezobalance readings
also set at PM2.5, remained 9.6% higher than the mass filter weighings. The mean
concentration of the SCEM multiple-cigarette indoor model was 32% higher than the
mass collection monitors, but the shapes of the curve agreed well with the MIE Personal
DataRam monitors. Because an actual cigarette smoker emits exhaled mainstream as
well as sidestream smoke, some overestimation is not surprising. The decay rates of the
RSP from the piezobalance and the MIE were found to be closely aligned, with
regression fits showing decays of 0.77 [R2 = 0.997] and 0.82 air changes per hour (h-1)
[R2 = 0.99] respectively. In contrast, the decay rate of the PPAH from the EcoChem PAS
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was 1.8 times greater, at 1.46 h-1 [R2 = 0.90], an important finding, suggesting that the
PPAH tar particles absorbed faster than the less sticky RSP on the surfaces of this closed
unventilated room (Ott & Repace, 2003; Repace, 2003).
Part I: Air Quality Measurements Prior to the Boston Smoke-Free Law
Repace and Lowrey (1980) pioneered the use of real-time measurements to study
air pollution from secondhand smoke in the hospitality industry; the present survey was
conducted according to protocols they developed (Repace, 1987a,b), but using current
state-of-the-art equipment. Accordingly, an air quality monitoring instrument package
was assembled and first deployed on Friday, April 18, 2003 in selected Boston hospitality
venues, as listed in Table 1.
Boston Weather: Weather conditions measured at Logan Airport on the Harbor
on Friday evening April 18 (6 PM to Midnight) were fair and cold, with barometric
pressure between 30.57 and 30.54 inches of mercury. The outdoor temperature was 41 oF
(5oC) at 6 PM, decreasing to 39oF (4oC) by Midnight. Winds were 15 mph at 6 PM,
diminishing to 6.9 mph by Midnight. Outdoor relative humidity ranged from 76% to
87% during the same hours [www.wunderground.com]. However, the environmental
parameters inside the monitoring package were measured using the Langan Personal
Exposure measurer, which was deployed in the Downtown Boston area during this
survey, were less extreme, with temperature varying from 12.7oC to 20.9oC, with a mean
17.3 oC, and relative humidity ranging from 25% to 64%, with a mean of 43.5%.
Survey Methods: Each venue was visited for an average of about 36 minutes
(range, 20 to 59 min). RSP (PM3.5) was recorded using a pump-driven ThermoMIE
personalDataRAM model pDR-1200 real-time aerosol monitor (ThermoAndersen, Inc.,
Smyrna, GA), and PPAH were sampled using a pump-driven EcoChem PAS2000CE
real-time particle-bound polycyclic aromatic hydrocarbon monitor (EcoChem Analytics,
Inc., League City, TX). The pDR1200 was used with a factory calibration of 1.00; the
instrument was HEPA-zeroed and the calibration rechecked prior to each day’s sampling.
The PAS2000CE was also used as factory calibrated. Both devices incorporate data
loggers and can output mass concentration and time to a computer; both were
synchronized and set for 1-minute averaging times. Outdoor and in-transit locations were
sampled before and after each venue, as well as a nonsmoking hotel room before and
after the pub survey. The miniaturized monitors were concealed, and sampling was
discreet in order not to disturb occupants’ normal behavior. All venues were wellpatronized during the measurements.
The monitoring package was generally
unobtrusively located along a wall, or beneath a table, ~2 ft from the floor.
Each pub’s dimensions were measured using a Calculated Industries Dimension
Master ultrasonic digital ruler (range 2 ft – 50 ft, resolution ± 1%), by a Bushnell
Yardage Pro Sport Compact infrared laser Rangefinder (range 10 yd to 700 yd, resolution
± 1 yd), or estimated by pacing, if the venue was too crowded or irregular in shape. The
total number of persons and the number of burning cigarettes was counted every ten
minutes, including the beginning and end of the sampling period. The clock time upon
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entering and leaving each establishment was recorded in a time-activity pattern diary, so
that each venue’s concentration could be identified by time recorded in the data.
Results During Smoking: Table 2 organizes the April 18 pre-ban study results.
The April 18 RSP and PPAH data are plotted in Figure 1. Figure 1 shows a characteristic
pattern of low outdoor RSP and PPAH levels is evident, with indoor RSP and PPAH
levels in all pubs significantly elevated with respect to the outdoors. Pub # 6 results show
that the RSP-to-PPAH ratio is significantly greater than for the other pubs. Pub # 6 also
has a carbon monoxide (CO) level twice as high as the other pubs, which have CO levels
on average comparable to outdoors. Figure 3 shows a plot of the RSP levels vs. the
PPAH levels, excluding Pub #6 [further justification for this exclusion will be given in
discussion of the second air quality survey]. Fig. 3 shows a linear relationship (R = 0.93)
between RSP and PPAH in the pubs indicating that the PPAH carcinogens are reflecting
the effect of smoking, as shown in the controlled experiments of Fig. 5, which show that
the PPAH levels track the RSP levels, and that both are elevated during smoking and
decay toward background levels when the cigarettes are extinguished. The pattern of
peaks and valleys is not regular in the pubs because smoking occurs randomly, as
opposed to regularly in the controlled experiments. Again excluding Pub #6, the indoor
levels of RSP average 179 g/m3, ~10 times higher than the outdoor RSP levels, which
averaged 18.6 g/m3, and ~28 times higher than in the hotel room. Similarly, the PPAH
levels, again excluding Pub #6, average 65.1 ng/ m3 in the pubs, ~4 times higher than the
outdoor levels, which averaged 15.8 g/m3, and 23 times higher than the hotel room.
These results suggest that smoking causes (179-18.6)/179 = 90% of the RSP levels, and
(65.1-15.8)/65.1 = 76.1% of the PPAH levels, assuming the background RSP and PPAH
are the same as on the street as opposed to the hotel room. If the levels in the hotel room
represent the true background level, then smoking causes 96% of the RSP and 96% of the
PPAH.
Part II: Air Quality Measurements After the Boston Smoke-Free Law
Boston Weather: Weather (6 PM to Midnight) was overcast and mild, with
barometric pressure between 30.09 inches of mercury to 30.12 inches of mercury. The
outdoor temperature was 48.2 oF (9oC) at 6 PM, increasing to 50.0 oF (10oC) by
midnight. Winds were 10.4 mph at 6 PM, and lowered to 0.0 mph by midnight. Relative
humidity ranged from 58% to 62% during the same period [www.wunderground.com].
Survey Methods: All hospitality venues were re-measured after the smoking ban
took effect, and it was judged that their compliance with the ban was satisfactory. On
Friday evening, Friday, October 17th, 2003, ~6 months after the Boston pub smoking ban,
continuous measurements of respirable particles (RSP), in the particle size range less than
3.5 microns in diameter (PM3.5) and carcinogenic particulate polycyclic aromatic
hydrocarbons (PPAH), were again made from 6 PM to 12 AM, in the same 7 venues as
prior to the ban, in the same order and at about the same time of night. As in the pre-ban
field study, control measurements were performed outdoors, in transit, and in a nonsmoking room on the same floor at the same hotel.
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Results: Table 3 organizes the Oct. 17 post-ban study results. The Oct. 17 RSP
and PPAH data are plotted in Figure 2. Figure 2 shows a characteristic pattern of low
indoor and outdoor RSP and PPAH levels, except for the RSP levels in Pub # 6. Pub # 6
results show that the RSP is significantly greater than for the other pubs, while the PPAH
levels are the same. This indicates that the smoking created the elevated PPAH levels
shown in Figure 1 for Pub # 6, but that there is another source for the RSP. As in Table
2, Table 3 shows that Pub # 6 also has an elevated carbon monoxide (CO) level, 6 times
that of the mean for the other pubs, which again have CO levels on average comparable
to outdoors. Again excluding Pub #6, the indoor levels of RSP average 7.73 g/m3,
~99% of the outdoor RSP levels, which averaged 7.82 g/m3, and only ~4 times higher
than in the hotel room. Similarly, the PPAH levels, again excluding Pub #6, average 5.64
ng/m3 in the pubs, ~62% of the outdoor levels, which averaged 9.05 ng/m 3, and 2.2 times
higher than the hotel room. These results suggest that smoking caused (179-7.73)/179 =
96% of the RSP levels measured during the first survey, and (65.1-9.05)/65.1 = 86% of
the PPAH levels, assuming the background RSP and PPAH are the same as in the pubs.
The hotel room RSP levels were 3 times higher on April 18 than on Oct. 17, but still
relatively low, on both surveys, and PPAH levels were essentially the same on both
occasions.
Discussion and Analysis
Generalizing Measured Values: Data were collected in the April 18th survey so
that values for area and volume, smoker density, air exchange rate, average concentration
of the measured pollutant, and the estimated SHS contribution could be calculated. It is
important to note that SHS concentrations can be both predicted and generalized by
published mathematical models (as the SCEM model illustrates in Figure 5), by
comparing measured values with those calculated using the Habitual Smoker model of
Repace and Lowrey (1980; 1982; 1985). This is done by using statewide smoking
prevalence, default occupancy and ventilation rates specified for bars and restaurants by
the American Society of Heating, Refrigeration, and Ventilation Engineers (ASHRAE).
ASHRAE Standard 62-1989, Ventilation for Acceptable Indoor Air Quality, specified
ventilation rates for odor control “to accommodate a moderate amount of smoking” for
premises in which smoking was allowed. [N.B.: A subsequent edition of ASHRAE
Standard 62, issued in 1999, repealed the former recommendation for ventilation rates in
smoking buildings, stating that “since 1989, numerous cognizant authorities have
determined that environmental tobacco smoke is harmful to human health. These
authorities include among others, the United States Environmental Protection Agency,
World Health Organization, American Medical Association, American Lung Association,
National Institute of Occupational Safety and Health, National Academy of Sciences,
Occupational Safety and Health Administration, and the Office of the U.S. Surgeon
General.”]
Predicted SHS-RSP Concentrations for a model Pub, and Restaurant/Bar occupied
and ventilated according to ASHRAE Standard 62 Default Conditions Using the
Habitual Smoker Model:
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1. ASHRAE Standard 62-1989 Default design ventilation rate and building occupancy:
Ventilation rates are specified by ventilation engineers and codified under the American
Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) Standard
62, Ventilation for Acceptable Indoor Air Quality. The ventilation rates specified in
Standard 62 are designed to provide dilution air to occupied spaces such as offices, bars,
and restaurants. This dilution air is supplied for the purpose of controlling odors and
carbon dioxide levels from human metabolism, and is generally recirculated at higher
flow rates for the purpose of delivering heating, ventilation, and air conditioning with
good mixing efficiencies. Recirculated air, unless it is filtered for both particles and
gases, does not control indoor air pollution. These design ventilation rates are generally
adopted by regional and local building codes, and installed equipment capable of
supplying the specified amount of air is required for a certificate of building occupancy.
However, once installed, these rates are not enforced, and building owners and operators
routinely reduce the amount of outdoor air supplied to save on operating expenses
(Repace and Lowrey, 1980). Because the actual building occupancy of a pub will
fluctuate during the day, at a time of low occupancy, an adequate amount of ventilation
air may be supplied, but at higher occupancies, this amount may be inadequate. For
localized sources of air pollution, such as restrooms and kitchens, localized exhaust must
be supplied in an amount which is adequate to control odors and smoke. If a pub is
stuffy, or has objectionable odors, the ventilation is poor.
ASHRAE Design Ventilation Rates for Bars & Restaurants: outdoor air
ventilation rate, 30 cubic feet per minute per occupant [cfm/occ] (15 liters/sec per
occupant [Lps/occ]); maximum (default) occupancy, 100 persons per 1000 ft2 of floor
area. Restaurants: 20 cfm/occ (10 Lps/occ) for outdoor ventilation air, for a maximum
occupancy of 70 persons per 1000 ft2. At maximum occupancy for a restaurant which
encloses a bar (as do the several of the venues in this study), ventilation rates between 10
and 15 Lps/occ might be anticipated where the bar is incidental to the restaurant business,
and for a bar where food is incidental to beverage service, a ventilation rate of 15 Lps/occ
would be expected. At less-than-maximum occupancy, ventilation rates per occupant
should be higher than design because fewer persons would be generating CO2.
2. Predicted Design Air Exchange Rates: The air exchange rate of a room is rate at
which an entire room volume of air is replaced by outdoor air. The air exchange rate
directly determines the rate of pollutant dilution in a room. For example, 1 air change per
hour in a pub of 100 cubic meters (m3) volume supplies 100 m3 of outdoor air to the pub
each hour. Air exchange with the outdoors dilutes the indoor pollutant concentration, but
does not remove all the pollution in the pub in one hour, particularly if the pollution is
being steadily generated by a constant source such as smoking. At one air change per
hour, the smoke from a single cigarette will be reduced to 37% of its initial peak after one
hour. However, if smoking occurs steadily, air exchange can only dilute the smoke
concentration to some steady-state level, oscillating between some maximum and
minimum concentration, as the peaks and valleys of a controlled experiment illustrate in
Figure 5. Where smoking occurs randomly, as in a pub, some peaks will be higher than
others, and some valleys lower than others. For tobacco smoke, Equation 1 shows that
the time-weighted average pollutant concentration is directly proportional to the density
of smokers in the pub, and inversely proportional to its air exchange rate. Thus, doubling
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the air exchange rate will halve the secondhand smoke (SHS) concentration in the room
for a given smoker density (number of smokers in a room of a given size). The air
exchange rate for pollutant dilution is calculated from the product of the ventilation rate
per occupant Vo and the occupant density P/V for a typical pub as follows:
Design ventilation rates must be based on maximum expected occupancy.
Default conditions for occupancy and corresponding ventilation rates are specified in
ASHRAE Standard 62. Taking the example of Pub # 4 in Table 2, which has a 10-foot
ceiling and a floor area of 1440 ft2, the default design ventilation rate for a pub is 30
ft3/min-occ, and the equivalent air exchange rate is: Cv = (Vo)(P/V) = (30 ft3/minocc)(100 occ/14,400 ft3)(60 min/hr) = 12.5 air changes per hour (h-1). This is a very high
air exchange rate, signifying that an amount of air equal to the volume of the room is
replaced 12-1/2 times per hour, or every 4.8 minutes.
3. Predicted Active Smoking Prevalence: The current Massachusetts average adult
habitual smoking prevalence is 19.7% (±1%) (MMWR, 2003). Thus in a group of adult
Massachusans consisting of mixed smokers and nonsmokers according to the Statewide
smoking prevalence, 19.7% of the entire group would be expected to be habitual
smokers. Of those, 1/3, or ~6.6% would be expected to be observed actively smoking at
any one time (Repace & Lowrey, 1980; Repace, 1987). In other words, the physical
observable in a field survey is not the number of habitual smokers, but rather the number
of burning cigarettes averaged over the measurement period. Thus in a field survey of a
venue in Massachusetts the prevalence of active smoking would be expected to be 6.6%
of persons present if the smoking prevalence is representative of that in the larger state
population. However, as Table 1 shows, this is 50% higher than the mean 4.04% (SD
1.6%) active smoking prevalence actually observed for all 7 venues sampled.
4. Predicted Active Smoker Density: Also, if a bar has a percentage of smokers equal to
the current Massachusetts prevalence rate, it would have a default smoker density of
(0.197 smokers/occ)(100 occ/10,000 ft3) = 19.7 smokers per 10,000 ft3, or in metric units,
19.7 smokers per 283 cubic meters (m3), of whom 1/3 would be expected to be actively
smoking at any one time (Repace & Lowrey, 1980), which yields an active smoker
density of Ds = (1/3)(19.7)/2.83 = 2.32 active smokers (i.e., burning cigarettes (BC) per
100 m3.
5. The SHS-RSP Modeling Equation: Repace and Lowrey (1980) and Repace (1987)
derived an equation, called the “habitual smoker model” for the calculation, in units of
micrograms of pollutant per cubic meter of air (g/m3) of uniformly-mixed timeaveraged SHS-RSP levels in a building as a function of the active smoker density Ds, in
units of burning cigarettes per hundred cubic meters (BC/100m3) in the building and the
building’s air exchange rate Cv, in units of air changes per hour (h-1):
RSPETS  650

Ds
Cv

g/m3
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(Eq. 1),
Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
where SHS-RSP decay rate increasing Cv by 20% is incorporated to account for particle
removal by surfaces, and assumes a steady state. Each cigarette is assumed to be smoked
at a national average rate of 2 per hour, and to produce SHS-RSP at an average emission
of 14 mg. This model is in good agreement with the predictions of the time-averaged
values of the time-series model of Ott (1999). It is important to note that because Eq. 1
represents a uniform dilution model, it may underestimate the SHS dose for persons, such
as bartenders, who must work in close proximity to sources of secondhand smoke.
Using Eq. 1, the predicted respirable smoke particulate (RSP) concentration
(PM3.5) for Boston Pub #4 under the default assumptions is calculated as:
SHS-RSPpub = 650(2.32)/(12.5) = 121 g/m3.
Similarly, the associated PPAH level may be estimated from the 2000:1 ratio found in
both this and the Delaware Survey of Repace (2003): 60.5 ng/m3.
These are the expected values for the default conditions of ventilation and smoker
density.
Adjusting for measured smoker density, this estimate decreases by the ratio
(0.98/2.32) to account for the actual smoker density observed during the field observation
period, yields (121)(0.98/2.32) = 51 g/m3. However, the observed level was actually 338
g/m3. This is likely due to a less-than-design ventilation rate. The air exchange rate can
be calculated by subtracting an estimated background RSP concentration of the order of
18.6 g/m3 observed on the street from outdoor non-SHS sources, yield an estimated
SHS-RSP concentration in Pub # 4 of 338-18.6 = 319 g/m3. Using Eq. 1, the estimated
air exchange rate in this pub was ~2 h-1. This compares to 12.5 h-1 calculated above.
This is why the calculated SHS-RSP level is lower than the measured level. The next
question to be answered is was the pub being ventilated according to code? To answer
this, we must look to the measured CO2 levels and the actual occupancy, to estimate the
ventilation rate per occupant.
Data Analysis: Ventilation
Measurement of Carbon Dioxide (CO2) levels to evaluate the ventilation rate
per occupant. CO2 is a waste product of human metabolism, and will buildup in the air
proportionally to the number of persons in the building environment. The design
ventilation engineer’s guideline for ventilation rates in buildings is ASHRAE Standard
62-1999, Ventilation for Acceptable Indoor Air Quality, published by the American
society for Heating, Refrigerating and Air Conditioning Engineers (ASHRAE).
ASHRAE Standard 62 specifies rates of ventilation for the design engineer to supply in
order to limit CO2 buildup to no more than 700 parts per million (ppm) above outdoor
levels, in order to limit the odors from human bioeffluents to levels that will satisfy about
80% of unadapted persons (visitors) to a space. Thus, measurement of CO2 allows
assessment of the ventilation rate per actual occupant for comparison with the design
ventilation rate, which is generally specified by the local building code, and is a measure
of ventilation adequacy. Ventilation rates should be adequate for the maximum number
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of occupants of a restaurant or bar, and the maximum default occupancy is specified in
the Standard.
Equation 2 is typically used to estimate the ventilation adequacy based upon an
indoor CO2 measurement. Eq. 2 is given in Appendix C of ASHRAE Standard 62
(ASHRAE, 1999), and specifies the estimation of Cs, the equilibrium CO2 levels in parts
per million (ppm) in a venue:
Cs 
N
 Co
Vo
(Eq. 2),
where N is the CO2 generation rate per person (N = 0.30 L/min, corresponding to office
work), Vo is the outdoor air flow rate per occupant in L/s, and Co is the CO2 concentration
(expressed in parts per million or ppm) in the outdoor air. Application of this equation
assumes that the equipment is appropriately calibrated, that indoor or outdoor
concentrations are not influenced by other combustion sources, that the air handling
system is constant, that the number of persons is fixed, that they are adults of average
size, generate CO2 at a minimal level of activity (1 met), corresponding to being seated
with no or light activity, and that the concentration has reached its equilibrium level
(Persily, 1997). If these conditions are not met the ventilation rate estimated will only be
approximate.
The number of persons was counted every 10 minutes and averaged. Continuous
monitoring of CO2, as conducted in this study, enables evaluation of equilibrium status.
Note that if the space has not reached equilibrium, Eq. 2 will underestimate Cs, and thus
underestimate Vo. Equilibrium is the point at which the rate of generation of CO2
balances its rate of removal by ventilation, and thus the. concentration has reached its
peak, and is unchanging. The choice of an appropriate background level, Co, for CO2 is
sometimes difficult. CO2 in the outdoor air in the most pristine location is about 380
ppm; however, outdoor levels may also be influenced by local human activities such as
traffic or vegetation (Keeling & Whorf, 2002). A cumulative frequency plot (not shown)
shows that the lowest 8% of the data are relatively flat, with mean of 473 ppm (SD 6.4).
I will estimate Co ~ 473 ppm as the outdoor background, and N = 5000 ppm-L/soccupant. Similarly, during the Oct. 17 study, the lowest 8% of the data had a mean of
487 ppm (SD 23).
The mean outdoor background level during the April 18 field study was 729 ppm;
this however, was higher than the mean level in Pub #7; using this value for Co in Eq. 2
would lead to an unphysical negative value for Vo for this pub. Moreover, assessment of
CO2 levels outside an establishment at street level may not accurately reflect indoor
background CO2 levels, which will be determined by the level at the rooftop air fresh-air
intake, which is less influenced by the CO2 emissions of street traffic. Moreover because
the monitoring package was on the street for sometimes only 5 minutes, and the CO2
monitor was inside a closed zipper pouch, the time constant for the CO2 to decrease to
outdoor background appears to have been insufficient, as shown in Fig. 7. In the cases
where the monitors were on the street for lengthier periods, as between pub visits 1 & 2
and 3 and 4 and 6 & 7, we see the deepest valleys, and for short outdoor tours, as between
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pubs 2 & 3, 4 & 5, we see the shallowest valleys. Thus it is prudent to use the lowest
measured CO2 value for the background. Also equilibrium does not appear to have been
attained for Pubs #1, #2 and #3 (whereas for the remaining pubs it appears to be
reasonably close to equilibrium), and thus the ventilation rate estimated from the CO2
level may be overestimated for pubs 1,2, and 3, and it is prudent to use the peak CO 2
levels as closest to equilibrium. The minimum observed value during the April 18 field
measurement was 461 ppm, and during the October 17 study, 450 ppm. Thus, assuming
a Co value of ~480 ppm as the background CO2 level for the pre-ban and post-ban data
may underestimate the ventilation rate per occupant somewhat, yielding overestimated
values.
Figure 7 suggests that on April 18, 3 of the 7 pubs were underventilated at the
given occupancy, and even pubs # 2 and #7, which had the lowest CO2 levels, would
have been underventilated at maximum occupancy according to ASHRAE Standard rates
on April 18. Figure 8 shows that on October 17, only three pubs ( 3, 6, and 7) appear to
be near equilibrium; the ventilation rates Vo calculated from non-equilibrium values will
be overestimated for these pubs. This suggests that the typical pub would be
underventilated at maximum occupancy. This is not surprising, since operational
ventilation rates are not enforced, and reducing outdoor ventilation rates saves on energy
consumption and costs. The ventilation rate per occupant recommended by the ASHRAE
Standard 62 for bars is 15 Lps/occ. Of the 7 pubs, 5 met or exceeded that, largely
because of a much lower than maximum occupancy of 26 persons per 1000 ft2.
Nevertheless, this did not result in acceptable SHS concentrations. For example, Pub #7
had a ventilation rate per occupant of 20.2 Lps/occ, but also had an RSP level of 117
g/m3, (117/1.49) = ~79 times the level observed after the smoking ban, and for PPAH, a
level of 15.3 ng/m3, or (15.3/2.14) = 7 times higher than before the ban. Thus, even when
the ventilation rate met or exceeded that recommended by ASHRAE, the levels of SHSrelated pollutants far exceeded the levels afforded by the smoke-free law.
But there was one major exception: Pub # 6, which had a higher RSP level after
the smoking ban than before (although the PPAH level was much lower). Repace et al.
(1980) found that cooking smoke could contribute significantly to indoor air pollution.
Kitchens are supposed to remain under negative pressure to contain cooking fumes
(ASHRAE, 1996). However, Table 2 shows that Pub #6’s CO level on April 18 was
[(5.5-2.16)/(0.38)] = 8.8 standard deviations beyond the mean of the other pubs.
Similarly, Table 3 shows that Pub #6’s CO level on Oct. 17 was also high, at [(7.941.24)/(0.85)] = 7.9 standard deviations beyond the mean of the others. This suggests that
Pub # 6 had an indoor air quality problem of another type. The Boston Public Health
Commission was alerted, and conducted an investigation. The investigation discovered
that a gas-fired deep-fat fryer had a yellowish flame instead of the expected blue, as a
result of the burner being plugged with grease. These yellow flames emitted 50 ppm of
CO into the kitchen, which permeated the rest of the premises, although the kitchen
exhaust hoods were functioning (L. Bethune, BPHC, Office of Environmental Health,
personal communication).
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Data Analysis: Air Quality
Time Series Pollutant Analysis: Figure 3 plots the pre-ban RSP vs. the pre-ban
PPAH. A regression analysis yields a good linear fit (R = 0.93) with a 2000:1 ratio
between RSP and PPAH. This is in good qualitative agreement with the calibration
experiments of Fig. 5, which shows that during smoking, the cigarette PPAH tracks the
RSP very well, but has a higher decay rate. Figure 4 plots the background-subtracted
RSP vs. the background-subtracted PPAH values as a function of burning cigarette
density and SHS-RSP air exchange rate using the habitual smoker model. It shows that
the SHS-PPAH levels are removed at higher air exchange rates than SHS-RSP, in
agreement with Fig. 5, likely the result of a higher removal rate by surface adhesion.
Thus it appears that the PPAH carcinogens (see Table 5) are largely generated by
smoking.
By how much are the RSP and PPAH levels reduced by the smoking ban? From
Table 2, excluding Pub # 6, which had the IAQ problem, the pre-ban pub RSP levels
average 179 g/m3. From Table 3, the post-ban pub RSP levels, again excluding Pub #6,
average 7.7 g/m3, a decrease by 96%. Similarly, From Table 2, excluding Pub # 6, the
pre-ban pub PPAH levels average 65.1 ng/m3. From Table 3, the post-ban pub PPAH
levels, again excluding Pub #6, average 6.32 ng/m3, a decrease by 90%. If the
calculations are referenced to the indoor/outdoor levels on April 18, the estimated SHSRSP contribution is [(179-18.6)/179] = 90%, and the estimated SHS-PPAH level
contribution is [(65.1-15.8)/65.1] = 76%. However the latter calculation may be an
underestimate, since the PPAH level in the pubs on Oct. 17, 6.32 ng/m3, was about 70%
of the outdoor level; if the PPAH outdoor level on April 18 is adjusted downward to 70%
of its value (0.70)(15.8) = 11 ng/m3, and the estimated SHS-PPAH concentration
recalculated, [(65.1-11)/65.1] = is 83%. Thus, a conservative inference from the data
would be that SHS contributed about 90% to 95% of the RSP levels during smoking, and
80% to 90% of the PPAH levels during smoking, with an average smoking prevalence of
about 12%. This compares to a state-wide smoking prevalence of 19.7% in 1999, as
reported above.
How do these air quality measurements compare with other studies? For the
outdoor levels, Levy et al. (2003) measured RSP (PM2.5) using a TSI Dust Trak and
PPAH (using the same EcoChem PAS 2000CE used in this study) in Roxbury, a
neighborhood of Boston with significant diesel and gasoline-fueled traffic. The Dust
Trak is reported to overestimate RSP levels by factors of 2 to 3 relative to integrated mass
measurements. Levy et al. measured RSP and PPAH continuously during the daytime
hours 9:30 AM to 4:30 PM, and reported levels during July and August of 2001 over nine
sites which averaged 52 g/m3 (SD 21) for the RSP; adjusting for overestimation, this
would yield estimated RSP levels of from 17 to 26 g/m3 and a range of medians across
sites from 11 to 86 g/m3. By contrast, the mean outdoor values measured on the preand post-ban field studies reported here, were 8 g/m3 and 19 g/m3 respectively. For
PPAH, the mean level in the Roxbury Study was 18 ng/m3 (SD 21), and the range of
medians across sites was from 4 to 57 ng/m3. Similarly, the outdoor PPAH values
measured on the pre- and post-ban field studies reported here, were 6 ng/m3 and 16 ng/m3
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respectively. The outdoor levels of RSP and PPAH reported in this field survey are
consistent with but somewhat lower than, the Roxbury study, which was conducted in a
part of Boston more influenced by heavy traffic than the downtown area which was
investigated in this survey.
In a very similar air quality survey to that reported on here, Repace (2003)
measured RSP and PPAH in Wilmington, DE in 8 hospitality venues, a casino, 6 pubs,
and a pool-hall. In the Wilmington study, SHS contributed 90% to 95% of the RSP air
pollution during smoking, and 85% to 95% of the carcinogenic PPAH, with an average
smoking prevalence of 15%. Outdoor RSP levels pre- and post-ban were: 11 g/m3 (SD
3.2) and 7.4 g/m3 (SD 8.9), and outdoor PPAH levels pre- and post-ban were: 27 ng /m3
(SD 28) and 7.9 ng /m3 (SD 11.5), respectively. These PPAH results are also similar to
those found in the Wilmington air quality study.
Ventilation Rate per Occupant: The estimated ventilation rates per occupant Vo
are derived from the peak carbon dioxide levels as shown in Figs. 7 and 8 using Eq. 2,
and are given in Tables 2 and 3. These rates may be overestimated if the peak value is
less that the equilibrium value, which is the highest concentration achievable, and reflects
a balance between the rate of generation of carbon dioxide by pub occupants and its
removal rate by ventilation. On April 18, it appears that Pubs 3 and 7 are in equilibrium;
Pub 8 probably is, and the remainder are unclear. Averaged over all pubs but #6, the
mean ventilation rate per occupant on both April 18 and Oct. 17 Vom = ~15 Lps/occ,
while the mean area person density was 39 persons per 1000 ft2 averaged over all pubs.
Since the default ventilation rate and default occupancy for a restaurant are 10 Lps/occ
and 70 persons per 1000 ft2 respectively, and for a bar they are 15 Lps/occ and 100
persons per 1000 ft2 respectively, it appears that overall the typical establishment may be
roughly in compliance with the ASHRAE Standard at the lower-than-maximum person
densities encountered during these surveys. However, 3 of the 7 pubs are underventilated
at the actual occupancy. Moreover, it appears that ASHRAE design ventilation rates
would not be complied in any of the pubs during times of maximum occupancy. There is
a very good correlation between the pre- and post-ban Vo for 5 of the 7 pubs. For pubs 2
and 5, the agreement is poor. Figure 8 suggests sufficient time may not have elapsed to
reach equilibrium for these two. This is likely due to the fact that the CO2 monitor did
not have an active pump, but rather relied on diffusion through a zipper into its
compartment, resulting in a long time constant to equilibrium relative to the sampling
time.
On average, the air exchange rate for SHS removal in these pubs results in RSP
concentrations which are ten to fifteen times the 15 g/m3 level of the federal air quality
standard. Thus, while the ventilation rate per occupant is roughly sufficient to control
CO2 in most pubs at the encountered occupancy, the air exchange rates in all pubs are
inadequate to control SHS at the encountered level of smoking. In other words, the
ventilation rate can be “adequate” by design standards because it is designed to control
CO2, but inadequate for SHS because ventilation is not designed for SHS control. It is
important not to confuse the two.
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The U.S. Annual National Ambient Air Quality Standard (NAAQS) for RSP.
To place the predicted and observed levels of RSP into perspective, consider the NAAQS
for particulate matter 2.5 microns in diameter or less (PM2.5), which encompasses
combustion-related fine particulate by-products such as tobacco smoke, chimney smoke,
and diesel exhaust. In 1997, the EPA promulgated a 24-hour NAAQS for PM2.5, of 65
µg/m3, not to be exceeded more than once per year, and an annual NAAQS for PM 2.5 of
15 µg/m3, based on protecting human health (Fed. Reg., 1997; Ware, 2000). The
NAAQS for PM2.5 is designed to protect against such respirable particle health effects as
premature death, increased hospital admissions, and emergency room visits (primarily the
elderly and individuals with cardiopulmonary disease); increased respiratory symptoms
and disease (children and individuals with cardiopulmonary disease); decreased lung
function (particularly in children and individuals with asthma); and against alterations in
lung tissue and structure and in respiratory tract defense mechanisms in all persons. (Fed.
Reg., 1997). PM2.5 and PM3.5 are closely related (Wallace, 1996).
Compliance with the NAAQS using Ventilation: How much ventilation would
be required to bring the default pub into compliance with the federal air quality standard?
The annual average PM2.5 level for Boston (City Square) for 2001 was: 13.25 g/m3 (MA
DEP, 2003). The average pre-ban SHS PM2.5 level in the 6 pubs (excluding Pub #6) was
179 g/m3, and post-ban 7.73 g/m3. Subtracting post-ban background, and assuming
pub staff work 260 days per year, 8 hrs per day, they are exposed to an annual average of
(171 g/m3)(260 d/365 d)(8 hr/24hr) = 40.6 g/m3 from SHS, and to an annual average
background level of 13.25 g/m3 from outdoor non-SHS sources. Assuming that these
averages are sustained over the required 3 year averaging period, SHS causes a violation
of the 15 g/m3 Annual National Ambient Air Quality Standard by a factor of (40.6 +
13.25)/15 = 3.6. Carcinogenic and other toxic risk aside, to reduce the PM2.5 level in the
typical pub to achieve compliance with the NAAQS would require that the level in the
pub average no more than {15 g/m3– 13.25 g/m3} = 1.75 g/m3. To reduce the
average level in the pub from 171 g/m3 to 1.75 g/m3 by ventilation would require a
more than 100-fold increase in the air exchange rate, from 2.48 h-1 to [(171/1.75)(2.48)] =
242 air changes per hour. Expressed in terms of the ventilation rate per occupant, this
would require an increase from ~15 Lps/occ to 150 Lps/occ, assuming no increase in
smoker density. These calculations illustrate that, despite observed ventilation rates per
occupant for most pubs close to that recommended by ASHRAE, secondhand smoke
levels were not controlled, even though smoker prevalences averaged 60% of the
Massachusetts state-wide level. Without even getting into questions of carcinogenic risk,
this illustrates that as a control measure for SHS, ventilation is futile.
It should be noted that tobacco industry-funded research has typically reported
“combustion aerosol” estimated from such standard tobacco industry-used atmospheric
markers as UVPM, FPM, and Sol-PM used as surrogates for SHS-RSP. In the most
recent study of this type, Bohanon et al. (2003) conclude after making measurements of
tobacco smoke in 34 restaurants in Asia, Europe, and North America, that “RSP does not
correlate well with levels of particulate matter that are highly specific to tobacco smoke.”
Recourse to figures 1 through 6 in this report demonstrates to the contrary, that in places
where tobacco is smoked, nearly all of the RSP is due to smoking, and tobacco industry-20-
Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
funded research into SHS in hospitality venues is not scientifically credible and appears
to be mainly designed to stave off smoking bans such as those in Boston.
Insofar as PPAH are concerned, although no standards have been set for PPAH,
assuming an 8-hr workday, on a 24-hr average basis for the 7 venues sampled, pre-ban
PPAH exceeded post-ban PPAH levels by a factor of [(65.1/3) + 6.32)]/6.32 = 4.1,
significantly increasing exposure of workers to substances known to be implicated in the
causation of cancer, heart disease, and stroke.
Discussion: Figures 1, 2, 3, and 5 taken together demonstrate conclusively that
secondhand smoke causes most or a significant fraction of the massive RSP and PPAH
pollution elevations shown in 6 of 7 hospitality venues of Figure 6. Smoking in these
Massachusetts hospitality venues caused levels of respirable particles and particle-bound
PAH carcinogens exposure to increase by six-to-ten-fold. The models developed from
Equation 1 generalize the results to other hospitality venues. What are the likely health
consequences of such pollution? According to the Agency for Toxic Substances and
Disease Registry (ATSDR, 2003), “animal studies have shown that PAH exposure
increased the rate of birth defects in test animals, and reduced their ability to fight
disease, even after short-term exposure. It is not known whether these effects occur in
people. However, people exposed to PAHs for prolonged periods have developed cancer.
Animal studies have demonstrated that some PAHs have caused lung cancer, stomach
cancer, and skin cancer.” Ten carcinogenic particulate-phase PAHs have been identified
in tobacco smoke as listed in Table 5; this is one-sixth of known tobacco smoke
carcinogens (Hoffmann and Hoffmann, 1998).
A body of evidence connecting exposure to SHS to premature death has
accumulated during the past two decades, and has been summarized in several
authoritative reports compiled by panels of scientific and medical experts. The U.S.
National Toxicology Program has included SHS on its list of known human carcinogens
(NTP, 2000), a list which includes asbestos, coal tar dyes, and mustard gas, reaffirming
the landmark judgment of the U.S. Environmental Protection Agency in 1992 (USEPA,
1992).
Thus, the reduction in carcinogenic PAHs caused by the Boston smoking ban
as shown by this study, has demonstrably reduced the risk of cancer for hospitality
workers, managers, and patrons.
Concerning RSP pollution, Samet et al. (2000) concluded that there is consistent
evidence that the levels of fine particulate matter in the air are quantitatively associated
with the risk of death from all causes and from cardiovascular and respiratory illnesses.
Other indicators of impaired respiratory health, such as upper and lower respiratory
symptoms, and decrements in lung function also occur with increasing particulate air
pollution. Secondhand smoke has been linked to both cardiovascular and respiratory
disease mortality (NCI, 1997). Long-term repeated exposure to particulate air pollution,
like that experienced by workers in the hospitality industry, is known to increase the risk
of chronic respiratory disease and the risk of cardiorespiratory mortality. Short-term
exposures to particulate air pollution, like that experienced by hospitality industry
-21-
Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
patrons, can aggravate existing cardiovascular and pulmonary disease and increase the
number of persons in a population who become symptomatic, require medical attention,
or die (Pope and Dockery, 1999). Thus it may be confidently stated that the smoking ban
in the Boston hospitality industry has decreased the risk of these diseases in both workers
and patrons, as the levels of fine particle air pollution in these venues has decreased by
ten-fold to background levels.
Finally, the elevated carbon monoxide levels and heavy RSP pollution in Pub #6
before and after the smoking ban suggest that the kitchen exhaust equipment has broken
down and grilling fumes are being pulled into the dining room along with cooking gas
fumes from an improperly adjusted range. This illustrates the reality that some
hospitality business owners appear to be either incapable of recognizing -- or indifferent
to -- a breakdown in their ventilation systems, and a complex regulatory system would be
required to routinely inspect these systems for proper operation and code compliance. On
the other hand, the smoke-free bar law has reduced the pub’s SHS emissions to zero,
requiring only the stroke of a pen.
-22-
Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
CONCLUSIONS:
1. An air quality survey of indoor and outdoor fine-particle air pollution (PM3.5 RSP)
and carcinogenic particulate-phase polycyclic aromatic hydrocarbons (PPAH) in
seven Boston, Massachusetts pubs indicates that depending upon whether indoorto-outdoor or indoor-to-indoor ratios are used, the Boston smoke-free law reduced
RSP pollution by 90% to 95% and PPAH pollution by 80% to 90%.
2. The estimated smoking prevalence in the pubs at 12%, was 40% lower than the
estimated state-wide smoking prevalence of 19.7%.
3. One pub had an ongoing indoor air pollution problem due to its cooking and
maintenance practices causing elevated indoor carbon monoxide and respirable
particulate levels, before and after the smoking ban. This pub was excluded from
the air quality averages.
4. A very high correlation was found between the RSP and PPAH levels from
secondhand smoke (SHS) when smoking was still permitted.
5. The PPAH levels appear to be removed by rooms surfaces much faster than RSP
levels, indicating that SHS which contaminates room surfaces is enriched in
carcinogens.
6. Both RSP and PPAH were proportional to the density of burning cigarettes prior
to the smoking ban.
7. Analysis of CO2 data using a mathematical model indicates that while the
supplied ventilation rate was generally in compliance with design ventilation rates
for pubs at the measured occupancy, at maximum occupancies it would appear
not to meet ASHRAE recommendations.
8. The RSP levels measured during smoking violated the National Ambient Air
Quality Standard (NAAQS) for hospitality workers by nearly 4-fold.
9. The PPAH levels measured during smoking quadruple workers’ daily exposures
to these carcinogens.
10. Carcinogenic risk apart, analysis of the RSP data using a mathematical model
indicates that the ventilation supplied was incapable of controlling RSP to meet
the NAAQS without more than a one-hundred-fold increase in ventilation rates.
11. Smoke-polluted pubs in Boston had average levels of fine particles and
particulate carcinogens which were ten-fold and ~four-fold higher than in Boston
sites heavily polluted with truck and bus traffic.
-23-
Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
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FIGURES & TABLES
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Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
Table 1. 7 Downtown Boston bar/restaurants where air quality was measured. Smoking was permitted in the bar areas under the
existing Boston regulations during the April 18, 2003 measurements, and was banned when the October 17, 2003 measurements
were made . The monitors’ inlets were ~ 1 m from the floor for all measurements. Venue numbers are keyed to Figures 1 and 2.
Venue
Description
1. Bar/Restaurant
A large “horseshoe” bar area dominates one large room. A small room opens out to the front.
Bar caters to young singles clientele who gather after work. Food is also available but not
central. Monitoring equipment was placed ~15 ft. from the bar against an outer wall in the bar
area for both measurements.
2. Bar/Restaurant
A long rectangular bar dominates this famous bar/restaurant. One large open room. Wide
variety of patrons from young singles, older couples and some tourists. Monitoring equipment
was positioned against a wall ~6 ft. from one end of the bar and ~10 ft. from the front door in a
virtually identical position for both measurements.
3. Bar/Restaurant
A large complex area dominated by a centrally located bar and stand-up eating area. This
bar/restaurant is part of a chain well known for bar and traditional “pub-style” food. Patrons
include both tourists and locals of diverse ages. On both occasions monitoring devices were
placed in identical locations about 8 feet from the bar against a 5 ft. wall in the stand-up area.
4. Bar/Restaurant
A noisy and crowded venue. Patrons are almost exclusively 20 to 30 year old singles who
gather from late afternoon to late at night. Bar food is available and served throughout both in
the bar area and smaller dining room. Monitors were placed ~20 ft. from the bar against a
windowed wall during the first (April visit), and against the bar for the return (October) visit.
5. Bar/Restaurant
A small, crowded, neighborhood bar/restaurant. The narrow bar area is ~15 ft. wide and ~40
ft. long with another ~20 ft. devoted to dining booths contiguous to the bar. Monitors were
placed about 6 feet from the bar’s middle against a wall in identical locations for each visit.
6. Bar/Restaurant
Grilled and sizzling-hot ethnic food is the main attraction of this bar/restaurant. The bar is
contiguous to dining area #1, and ~10 ft. distant and open to dining area #2. Monitors were
placed adjacent to tables in dining area #1 in April, and in dining area #2 in October.
7. Bar/Restaurant
Well-known upscale bar/restaurant chain frequented by both locals and tourists. The large
rectangular raw shellfish bar area is separated from the main dining room by corridors but also
has large dining tables encircling the bar. Monitors were placed against a wall adjacent to a
dining table at ~12 ft. from the bar, and at adjacent tables for the two visits.
-29-
Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
Table 2. April 18, 2003 Boston Indoor/Outdoor Pre-Ban Air Quality Survey Results
Venue
Pub #1
Area
(ft2)
1600
Ceiling
Ht. (ft)
13
Volume
(m3)
589
Ave. #
Persons
Present+
()+
Ave. #
Persons
per
1000 ft2
78.3
49
(11.2)
Pub #2
4550
12.83
1653
131
5041
11
1570
111
29
1440
10
408
98
22
900
7.5
191
54
68
2037
9.58
552
40.8
60
1655
9
422
43.5
20
79.5
(35.2)
26
1.5
1.15
3.67
3.3
9.9
4.0
4.08
12.2
2.5
4.63
13.9
2.25
5.51
16.5
2.75
6.32
19.0
(0.5)
39
(19.5)
Mean all
but # 6
Hotel
Rm
Outdoors in
transit ¶
0.5
(0.5)
(2.1)
Mean All
8.93
(0.71)
(9.25)
Pub #7
2.98
(1.73)
(1.4)
Pub #6
2.33
(0.14)
(2.7)
Pub #5
Estimated
Smoker
Prevalence
% of all
Persons
(0.58)
(51.2)
Pub #4
% of
Persons
Actively
Smoking+
(0.58)
(34)
Pub #3
Ave. #
Burning
Cigarettes+
1
-

2.57
(1.13)
4.04
(1.6)
11.65
(5.8)
Ave.+
RSP,
g/m3
Ave. +
PPAH,
ng/m3
197
62
(55)
(23)
43
6.4
(23)
(11.5)
57
38
(49)
(21)
338
160
(120)
(59)
323
(113)
308
109
41.1
(80)
(68)
117
15.3
(39)
(9.0)
Ds, Active
Smoker
Density
Cv, Est.c
RSP Air
changes
per hour
(h-1)
0.40
1.4
198
61.7
(54.9)
179
65.1
(129)
(59.3)
6.45*
2.81**
(1.36)
(1.59)
18.6
15.8
(11.7)
(11.7)
CO2
ppm
(Peak)
Vo
L/soccg
1.86
1100
7.9
680
29.1
800
15.3
900
11.7
1480
5.0
1150
7.4
720
20.2
976
(286)
950
(301)
625
13.8
(8.5)
14.8
(8.8)
(0.13)
0.03
0.75
1.90
(0.14)
0.23
3.74
2.08
(0.06)
0.98
1.98
2.47
(0.21)
1.31
2.78
2.77
(0.33)
(68)
(128)
CO
ppm
(ave.)
0.41
0.91
5.50
(1.05)
0.65
4.23
1.89
(0.07)
0.57
(0.44)
0
0
2.26
(1.37)
2.48
(1.35)
2.63
(1.31)
2.16
(0.38)
1.32
(0.045)
(19)
2.14
729A
(0.45)
(Ds in units of burning cigarettes per 100 m3); * 77 minute average (68 min before and 9 min after all Venue sampling); **73 minute average (65 min before, 8 min
after sampling); c(Using Habitual Smoker Model of Repace & Lowrey (1985):assumes 2 cigarettes per smoker-hour & 1.43 mg RSP/cig: ETS-RSP = 650
Ds/Cv);†(excluding RSP and PPAH values from Pub #6). #Ave. of 3 measurements~ ten minutes apart. +(standard deviations of measurments in parentheses). RH%:
25%-64%, mean 43.5% (9). ToC range: 12.7-20.9; mean 17.3 (2.3); AWeighted mean, minimum outdoor CO2 value: 461 ppm). g(assumes Co = 473 ppm)
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Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
Boston, MA, Pub Air Quality Study: Before Smoking Ban, Friday Apr. 18, 2003
0
30
60
700
90
120
7 :00 PM
6:0 0 PM
150
180
8 :00 PM
210
650
RSP, micrograms per cubic meter (g/m3)
g/m 3
300
330
360
700
12:00 AM
11 :00 PM
10 :00 PM
650
600
550
550
PPAH ng/m
3
500
500
Pub
#6
450
SMOKING
400
350
450
400
350
Pub
#1
300
300
250
200
250
Pub
#7
Pub
#3
200
Pub
#2
150
150
100
50
50
0
0
0
30
60
90
120
150
180
210
240
270
300
330
360
Elapsed Time, minutes
Repace Associates, 2003 , <www.repa ce.com >
Figure 1. Measurements of respirable particle pollution (RSP) and carcinogen pollution (particulate PAH) as a
function of time before the Boston smoking ban on Friday, April 18, 2003 from 6 PM to 12 AM in 7 hospitality venues.
-31-
3)
100
PPAH Carcinogens, nanograms per cubic meter (ng/m
RSP A
270
Pub
#5
Pub
#4
600
240
9 :00 PM
Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
Table 3. October 17, 2003 Boston Indoor/Outdoor Air Quality Survey Results Smoke-Free Post-Ban+
Venue
Pub #1
Area
(ft2)
Ceiling
Ht. (ft)
Volume
(m3)
1600
13
589
Ave. #
Persons
Present+
Ave. #
Persons
per
1000 ft2
54.6
34
(1.15)
Pub #2
4550
12.83
1653
99.3
5041
11
1570
123
21.8
1440
10
408
92.7
24.4
900
7.5
191
69
64.4
2037
9.58
552
50.3
76.7
1655
9
422
48.3
24.7
6.26
13.5
525
29.0
1.49
76.7
39
81.6
(22)
(196)
7.73
(6.13)
8.56
13.8
1.61
5.98
1.9
12.2
25.2
7.45
15.7
1.55
7.6
2.14
6.8
5.64
3.8
6.32
900
12.1
800
16.0
950
10.8
940
11.0
1260
6.5
720
21.5
2.89
1.30
0.82
0.92
7.94
14.0
0.48
(0.19)
9.1
10.2
2.20
931
12.7
(2.64)
(169)
(4.78)
1.24
877
13.7
(0.85)
(96)
(4.3)
Non-smoking
1
2.14*
2.42**
33
86
0.56
573
Hotel Rm
(1.16)
(1.54)
(0.037)
(44)
A
A
Outdoors/
7.82
9.05
666B
42
57
1.32
In Transit¶
† †
( (excluding Pub #6). #Ave. of 3 measurements ~ten min apart; *(91 min Ave., 68 min before venues, 23 min after); **(85 min Ave., 65 min before venues, 20
min after); A(Time-weighted mean). c(based on ASHRAE 62 formula). (¶ On sidewalks; crossing streets). Range in air temperature: 17.5 –21.8 oC, mean 19.8 oC;
range in relative humidity: 28%-48%, mean 38%. +(standard deviations of measurements in parentheses) B(weighted mean); g(assumes Co = 487 ppm)
-32-
(4.02)
10.8
(1.48)
(4.09)
4.3
950
(0.09)
(1.24)
41
1.04
(0.18)
(3.82)
1.2
Vo,
L/s-occg
(0.24)
(4.00)
170
CO2
ppm
(peak)
(0.37)
(5.13)
4.2
CO
ppm
(ave.)
(0.084)
(13.7)
(0.96)
(28.8)
Mean all
but # 6†
2.4
(274)
(11.0)
Mean
All Venues
1.39
% of
Pre-ban
PPAH
Level
(2.14)
(3.16)
(2.08)
Pub #7
38
(1.05)
(1.73)
Pub #6
16.3
Ave. + PPAH,
ng/m3
(4.99)
(1.44)
(22.5)
Pub #5
3.8
(4.75)
(20.6)
Pub #4
7.47
% of
Pre-ban
RSP
Level
(1.46)
(26)
Pub #3
Ave.+ RSP,
g/m3
Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
Boston, MA, Pub Air Quality Study: After Smoking Ban, Friday Oct. 17, 2003
0
30
60
90
120
150
180
210
240
270
300
330
360
700
700
10:00
12 :00
AM 650
11 :00
PM
RSP
PPAH
600
Respirable Particle Pollution (RSP) g/m3
9 :00
600
550
550
500
500
450
450
SMOKE-FREE
400
400
350
350
300
300
250
250
200
Pub
#1
150
Carcinogen Pollution (PPAH) ng/m3
650
8 :00
7 :00
6:00
PM
200
Pub
#2
Pub
#3
Pub
#5
Pub
#4
Pub
#6
Pub
#7
150
100
100
50
50
0
0
0
30
60
90
120
150
180
210
240
270
300
330
360
Elapsed Time, minutes
Repac e Assoc iates , 2003, <www.repace.com>
Figure 2. Measurements of respirable particle pollution (RSP) and carcinogen pollution (particulate PAH) as a function of time
after the Boston smoking ban on Friday, October 17, 2003 from 6 PM to 12 AM in the same 7 hospitality venues shown in Figure 1.
Pub #6 had high carbon monoxide levels before and after the ban, suggesting the peak above is due to backdrafting of cooking
fumes from a malfunctioning kitchen exhaust.
-33-
Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
Ratio, RSP/PPAH, Boston AQ Study
RSP g/m 3 = 2.030 PPAH ng/m 3 + 46.988 r = 0.932
RSP (micrograms per cubic meter)
350
300
250
200
150
100
50
0
0
50
100
150
200
PPAH (nanograms per cubic meter)
Repace Associates, Inc. 2003
Figure 3. The ratio of respirable particle pollution to carcinogen pollution in 6 of 7 Boston pubs studied before the smoking ban.
Pub # 6 is excluded due to apparent contamination from kitchen fumes. The ratio for RSP/PPAH in the same units is about 2000:1.
This is the same RSP/PPAH ratio found in the Wilmington, Delaware study (Repace, 2003). This suggests that, on a time-averaged
basis, the PPAH carcinogen levels can be estimated from the measured SHS-RSP levels or calculated for SHS using the massbalance model.
-34-
Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
Boston SHS-RSP, PPAH vs. D s, Cv
Estimated SHS-RSP ( g/m 3)
350
0.75
ach
300
1.98
ach
250
200
RS P - B
150
PPAH - B'
4.23
ach
100
50
0
0
0.5
1
1.5
Burning Cigarette Density, Ds, per 100 m3
Figure 4. Pre-ban secondhand smoke respirable particulate, SHS-RSP, (total measured RSP – background RSP) in micrograms per
cubic meter and SHS-PPAH concentration (total measured PPAH – background PPAH) in nanograms per cubic meter versus
burning cigarette density Ds (active smokers observed per hundred cubic meters of space volume) and air exchange rate C v in units
of air changes per hour (ach) as calculated from RSP using the model of Repace & Lowrey (1980). Note that the decay rates of the
PPAH are much higher than for RSP, as found in the calibration experiments. This suggests that the PPAH carcinogens
contaminate room surfaces to a greater extent than the remainder of the particulate phase. Background-subtraction values are
arbitrarily chosen from measured hotel room values. Data from Pub # 6 are omitted from this plot.
-35-
Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
-1
SCEM+BKGND
SCEM Assumptions: ACH = 0.8 h ; g = 1.4 mg ETS-RSP/min;
3
3
V = 41 m ; background = 6.38 g/m . Repace, Ott, & Kim, 2003.
PZBR1
MIEA
Silicon Valley Calibration Experiments, March 11, 2003 Expt.
800
800
600
600
400
400
200
3
Cyclones
PPAH Concentration, ng/m
Model, PZB, MIE Concentration, g/m
3
PPAH
200
PZB Cleaned
0
0
0
3:50 PM
60
120
5:50 PM
180
240
300
360
9:50 PM
420
480
11:50 PM
ELAPSED TIME, MINUTES
Figure 5. Calibration of real-time MIE Laser photometer and Piezobalance (PZB) vs. time-averaged Respirable Mass Filters
(cyclones). The EcoChem Photoelectric Aerosol Sampler is shown for comparison, as is the theoretical SCEM model for a smoker
of Ott et al. (1992). Numerical results are given in Table 4 (Repace and Ott, 2003).
-36-
Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
Calibration of MIE photometers
against Piezobalances & Filters
Continuous Mass (PM3.5) Monitors vs. Integrated Filter Mass (PM2.2)
measurements (units, g/m3), during decay period.* March 10, 2003
Silicon Valley Experiments. (JL Repace, WR Ott, & Y Kim, 2003)
Statistic
MIE A
pDR 1200
PM3.5
MIE B
pDR 1200
PM3.5
PZB R1
PM3.5
impactor
PZB S2
PM3.5
impactor
Integrated
Filter†
mass;
flow rate:
25 Lp m;
PM2.2
Minimum
419.00
412.00
316.48
335
Maximum
1053.00
1012.00
1077.50
979
Mean
672.20
664.28
561.84
545
512.5
Median
629.00
620.00
507.84
500
St. Dev.
180.62
176.00
193.85
165
21.51
% Diff. of
+31.2%
+29.6%
+9.6%
+6.3%
0%
mean with
Filter mass
* Factory Calibration Factors for PZB R1 Factor 7.36 g/Hz-mi n; PZB S2 factor 2000x0.00278 = 5.56. J L
Repace analysis 7/7/03. †Two Ge lman Teflo 2 mi cron pore size filters. MIE internal factory calibration
factor, 100% . MIE Fl ow-rate settings measured by Gili brator: MIE A (n = 16): 2.913 (SD 0.013 ) Lpm;
MIE B (n = 15): 2.863 (SD 0.014) Lp m. Room Vo lume: 41 m3; 4 Marlboro medium 100s cigarettes
smoldered; net tobacco burned: 1.7 g; cigarette burning time: 10 mi n. 100 m in averaging period begins 20
mi n post ignition, 10 min post ext inguishing.
see also: Modeling and Measuring Indoor Air Pollution from Multiple Cigarettes Smoked in Residential Settings, WR Ott & JL Repace, ISEA 2003.
Table 4. Calibration data for the real-time MIE Laser photometer and Piezobalance (PZB) set to measure PM3.5, vs. time-averaged
Respirable Mass Filters (cyclones) set to measure PM2.2. Experimental results shown in Fig. 5.
-37-
Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
Table 5. Carcinogenic PPAH, IARC Status, Amount in Cigarette Smoke
Particulate Phase PAH
IARC
IARC
Amount
Reference
(PPAH)
Carcinogen Carcinogen
Measured
In
In Humans
In SHS
Laboratory
Animals
(ng/cig)*
Benz(a)anthracene
Benzo(b)fluoranthene
Benzo(j)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Dibenzo(a,i)pyrene
Dibenz(a,h)anthracene
Dibenzo(a,l)pyrene
Indeno(1,2,3-cd)pyrene
5-methylchrysene
All PPAH in SHS
All PAH in SHS
Sufficient
Sufficient
Sufficient
Sufficient
Sufficient
Sufficient
Sufficient
Sufficient
Sufficient
Sufficient
412
132
32
Sufficient
74
1,067
13,500
A,B
A,B
A,B
A
A,B
A
A
A
A
A
B
C
Inhaled dose of PPAH to a cigarette smoker
200
D
References: A. Hoffmann & Hoffmann (1998); B. Gundel et al. (1995);
C. Rogge et al. (1994); *ng/cig = nanograms per cigarette. Blank cells
indicate no data available; IARC = International Agency for Research on Cancer.
D. Siegmann & Siegmann (1998) – Molecular precursor of soot and quantification of
the associated health risk. In: Current problems in Condensed Matter, Maran-Lopez, Ed.
Plenum Press, NY.
-38-
Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
200
200
150
150
100
100
50
0
0
PPAH
1
50
RSP, micrograms per cubic meter
PPAH nanograms per cubic meter
Boston Pub RSP & PPAH, pre- and post-smoke-free law
PP AH p re-ban
PP AH p ost-ban
RSP Pre-Ban
RSP Post-ban
RSP
Figure 6. Indoor Air Pollution Levels Before (Friday, April 18, 2003) and After (Friday, October 17, 2003) Boston’s May 5th, 2003
Smoke-free Law: Comparison of indoor Carcinogenic PPAH and fine particulate RSP Levels in 6 of 7 pubs (excluding Pub #6,
which had ventilation problems) shows that after the Boston Pub Smoking Ban, PPAH levels decreased by 90%, and RSP levels
decreased by 95%. Indoor levels post-ban were at (for RSP), or below (for PPAH), outdoor levels.
(Repace Associates, Inc., 2003).
-39-
Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
BOSTON ENVIRONMENTAL: CARBON DIOXIDE IN 7 PUBS, APRIL 18, 2003
1500
1500
CO2 PPM 041803
PUB # 5
1400
1400
1300
1300
PUB # 6
1200
1200
CO2 PPM
PUB #1
1100
1100
1000
1000
PUB # 4
900
900
PUB # 3
800
800
PUB # 7
PUB # 2
700
700
600
600
500
500
400
400
6:00:00 PM
7:00:00 PM
8:00:00 PM
9:00:00 PM
10:00:00 PM
11:00:00 PM
12:00:00 AM
CLOCK TIME
Figure 7. Carbon Dioxide vs. Time in 7 Boston Pubs and Outdoors, April 18, 2003. The valleys occur on the city streets, the peaks
occur during pub visits. Pubs 3, 5, 6, and 7 are near equilibrium. Ventilation rates based on non-equilibrium values will be
underestimated.
-40-
Boston, Massachusetts Air Quality Study
Repace Associates, Inc.
Boston Environmental: Carbon Dioxide, Oct. 17, 2003
1500
1500
Carbon Dioxide Level (parts per million)
CO2 101703
1400
1400
1300
1300
PUB # 6
1200
1200
1100
1100
PUB # 1
1000
PUB # 4
1000
PUB # 5
PUB # 2
900
900
PUB # 3
800
800
PUB # 7
700
700
600
600
500
500
400
400
6:00:00 PM
7:00:00 PM
8:00:00 PM
9:00:00 PM
10:00:00 PM
11:00:00 PM
12:00:00 AM
Clock Time
Figure 8. Carbon Dioxide vs. Time in 7 Boston Pubs and Outdoors, October 17, 2003. The valleys occur on the city streets, the
peaks occur during pub visits. Only Pubs #3, #6, and # 7 appears to have attained near equilibrium.
-41-