The chemical composition of environmental tobacco smoke III. Identification of conservative tracers of environmental tobacco smoke

Eswironr~nt International, Vol. 15, pp. 19-28, 1989 Printed in the U.S.A. All rishts reseated.

0160-4120/8953.00 +.00 Copyright @1989 Pergamon Press pie

THE CHEMICAL COMPOSITION OF ENVIRONMENTAL TOBACCO SMOKE III. IDENTIFICATION OF CONSERVATIVE TRACERS OF ENVIRONMENTAL TOBACCO SMOKE D. J. Eatough, C. L. Benner, H. Tang, V. Landon, G. Richards, F. M. Caka, J. Crawford E. A. Lewis, and L. D. Hansen Chemistry Department, Brigham Young University, Provo, UT 84602 USA

N. L. Eatough Department of Chemistry, California Polytechnic State University, San Luis Obispo, CA 93407 USA E187-500 (Received 9 November 1987; Accepted 24 May 1989) Several components of environmental tobacco smoke (ETS) have been determined in experiments conducted in a 30 m 3 Teflon chamber. The effect of residence time in the chamber on the particle size distribution, mass of particles, gas-particle equilibria, and chemical composition of both the gas and particle phases of environmental tobacco smoke has been studied. Many organic compounds present in tobacco smoke condensate are not found in the particle phase in environmental tobacco smoke but are present in the gas phase. Concentrations of several nitrogen containing organic compounds, identified in the chamber experiments, have been determined in several indoor environments where environmental tobacco smoke was present. These compounds were not found in indoor environments where environmental tobacco smoke was not present. The studies in the indoor environments indicate that gas phase nicotine and myosmine are removed from indoor environments at a much faster rate than gas phase 3-ethenylpyridine or 2-ethenylpyridine or particle-phase nicotine or cotinine. Gas-phase 3-ethenylpyridine and particle-phase nicotine are proposed as tracers of environmental tobacco smoke.

INTRODUCTION

tions were exposed. The composition and relative importance of gas-phase vs. particle-phase constituents of fresh or aged environmental tobacco smoke in an indoor environment are not known. As a result, the current epidemiologic data all have inadequate dose/response documentation (NAS 1986; DHHS 1986). Tracers of environmental tobacco smoke used in the past include respirable (or total) suspended particulate matter (RSP), CO, nitrogen oxides, nicotine, N-nitrosamines, aromatic hydrocarbons, and frequency of smoking. Recent reviews of environmental tobacco smoke by the National Academy of Sciences

Epidemiological data in the literature indicate that exposure to environmental tobacco smoke (ETS) leads to an increased incidence of respiratory disease, the impairment of lung development in children, and the development of lung cancer (NAS 1986; DHHS 1986). The reliability of the predictions made from this data is currently limited in part by the quality of the environmental tobacco smoke dose exposure measurements (NAS 1986). There are uncertainties in the actual dose of environmental tobacco smoke as compared to other pollutants to which the study popula19

D.J. Eatough et al.

20

(1986) and the U.S. Surgeon General (DHHS 1986) reach the same conclusion: the only tracers previously used that may be related to actual exposure to environmental tobacco smoke are concentrations of nicotine and RSP. As pointed out in these reviews, both of these tracers have potential problems associated with their use. The use of nicotine as a tracer of environmental tobacco smoke is complicated by the fact that nicotine is found primarily in the gas phase in the environment (Eudy et al. 1986; Thome et al. 1986; Eatough et al. 1986; Hammond et al. 1987; Eatough et al. 1987). Furthermore, nicotine is a strong base and is expected to be removed from the environment at a faster rate than particle phase nicotine or the particulate portion of environmental tobacco smoke (NAS 1986; Eudy et al. 1986; Eatough et al. 1987). Thus, the concentration of gas-phase nicotine may underestimate exposure to the particle phase of environmental tobacco smoke. Total RSP is the tracer for environmental tobacco smoke most extensively used in past studies (NAS 1986) because of the ease with which it may be measured. However, studies by Spengler et al. (1985) have shown that even though RSP is elevated in environments where smoking is present, about one half of the RSP in indoor environments where smoking is present comes from sources other than environmental tobacco smoke. RSP thus overestimates exposure to environmental tobacco smoke. As summarized in the review by the National Academy of Sciences (1986), a suitable tracer for quantifying environmental tobacco smoke concentrations should be 1. unique or nearly unique to environmental tobacco smoke, 2. easily detected in air, even at low smoking rates, 3. similar in emission rate for a variety of tobaccos, and 4. in constant proportion to compounds in ETS that affect human health. The objective of the research reported here was twofold: first, the chemical characterization of environmental tobacco smoke, with the goal of identifying components that might be used for the source attribution of both gases and particles from environmental tobacco smoke; and second, testing the use of these potential tracers in a variety of typical indoor environments. EXPERIMENTAL Environmental chamber studies

The 30 m3 Teflon chamber, associated equipment, and diffusion denuders used for the selective collec-

tion of gases in the presence of particles have been described (Eatough et al. 1986, 1988, 1989; Benner et al. 1989). Details of the experimental techniques used for the determination of the components of environmental tobacco smoke in the chamber studies are given elsewhere (Eatough et al. 1989; Benner et al. 1989). The sampling and analysis procedures used in the chamber studies included the following.

Particle phase sampling. The collection of environmental tobacco smoke is complicated by shifts in the gas-particle equilibria of volatile organic species during sampling (NAS 1986; Eatough et al. 1986, 1987). The total particle mass and concentrations of particle phase species were determined with a piezobalance and by sampling with open faced quartz, Nuclepore, and Teflon filters, as well as with filter pack sampiing systems preceded by diffusion denuders to remove acidic and basic gaseous compounds (Eatough et al. 1988, 1989). The total number concentration and size distribution of particles were determined using a condensation nucleus counter and a differential mobility size analyzer (Benner et al. 1989).

Gas-phase sampling. The basic gases (nicotine, cotinine pyridine, etc.) were collected with benzenesulfonic-acid-(BSA)-coated diffusion denuders and with an XAD-II or Tenax sorbent bed following a quartz filter (Eatough et al. 1989). The acidic gases (CH3COzH, HNO3, HNOz, SOz etc.) were collected with NaHCO3 coated diffusion denuders (Eatough et al. 1988, 1989, Benner et al. 1989). Ammonia was collected with an oxalic acid coated annular denuder (Eatough et al. 1988). The concentrations of 03, CO, NO, NOx, SOz and total gas-phase hydrocarbons were determined with real-time monitoring instruments (Eatough et al. 1986, 1989). Analytical techniques. A variety of analytical techniques were used for the determination of the gaseous-phase (Eatough et al. 1989) and particle-phase (Benner et al. 1989) constituents of environmental tobacco smoke. Organic compounds collected on filters or on sorbent beds were extracted with organic solvents and determined by capillary column gas chromatography and gas chromatography-mass spectrometry (GC-MS). Chemical class separations were performed as needed to assist in the identification of the compounds by GC-MS (Benner et al. 1989). The concentrations of nitrogen containing organic bases collected by the BSA annular denuder system were determined by extraction with water, neutralization of the acidic solution with excess NaOH, and counterextraction of the resulting solution in CH2C12 for anal-

Tracers of tobacco smoke

21

RESULTS AND DISCUSSION

ysis by GC. Water soluble anions, cations, and nicotine were determined by ion chromatography. The elemental composition of collected aerosols was determined by proton induced X-ray emission spectroscopy. All analytical results were corrected for blank concentrations. Blank samples were handled and analyzed the same way as the environmental samples, except that no air was passed through the blank sampiing system. The extraction recoveries for the various analytical procedures were determined for each compound quantified. Details of the analytical procedures have been published (Eatough et al. 1989; Benner et al. 1989).

Chamber Experiments The gas-phase and particle-phase distribution of various components of environmental tobacco smoke determined in the environmental chamber are given in Table 3. Only those compounds determined in the study (Eatough et al. 1989; Benner et al. 1989) that are representative of the various chemical classes or that have potential value as tracers of environmental tobacco smoke and are present in concentrations high enough to be useful in environmental studies are given. The values given in Table 3 are slightly different than those previously published (Eatough et al. 1987) because the data in Table 3 are summarized from the previously published results and additional studies conducted as a function of total number of cigarettes burned in the chamber experiments (Eatough et al. 1989; Benner et al. 1989). The chemical composition of environmental tobacco smoke in the chamber was determined for samples collected immediately after combustion of the cigarettes and after two to four hours of aging. Samples were collected for environ~nental tobacco smoke produced from the combustion of one, two, three, and four cigarettes. The gas-particle distribution of those compounds listed below as potential tracers of the gas and particle phases of environmental tobacco smoke did not vary substantially with time or number of cigarettes smoked. In addition, the concentrations of CO and NO x were constant with time in the chamber. The chamber experiments indicated that the following compounds attributable to environmental tobacco smoke might be suitable tracers of ETS in an indoor environment. 1. Gas phase: Nicotine, myosmine, pyridine, 2- and 3-ethenylpyridine, HNOz. 2. Particle phase: Sterols [cholesterol, stigmasterol (24-ethylcholest-5,22-dien-3~-ol), campesterol

Sampling for tracers of ETS indoors

Indoor samples were obtained both at businesses and homes where smoking was present and at similar indoor locations where there was no smoking. Both particulate and gas phase species identified in the chamber studies were determined in the indoor environments using the sampling systems given in Table 1 and the analytical techniques used in the chamber studies. The concentrations of NOx and CO in the indoor environments were obtained using commercial sorbent bed systems (Drager tubes). The flow rates for all sampling systems except the Drager tubes were controlled with Tylan mass flow controllers. The Tylan units were calibrated against a Kurz mass flow meter and a dry gas meter. The sample flow rates for the Drager tubes were controlled by a critical orifice and monitored with rotometers calibrated against a bubble flow meter. The Drager tubes purchased commercially (Dragerwerk A.G., Lubeck) were calibrated against the real-time CO, NO, and NO, instruments during sampling from the environmental chamber. The indoor environments studied are summarized in Table 2.

Table 1. Sampling systems used for the collection of the gas-phase and panicle-phase components of environmental tobacco smoke in indoor environments. System Number

Components

Sample Flow Rate (slpm)

Sample Collected

i

BSA-Coated Denuder Teflon Filter BSA-Coated Filter

20

Basic gas-phase compounds Particles Evolved basic compounds

2

NaHCO 3 Coated Denuder Teflon Filter Nylon Filter

20

Acidic gas-phase compounds Particles Evolved acidic compounds

3

0.4pm Pore Nuclepore Filter 20 Oxallc-Acid-Coated Filter

Particles, Mass, & Elements NH 3

4

Quartz Filter XAD-II Sorbent Bed

Particles, Organic Compounds Gas-Phase Organic Compounds

5

Drager Tubes

30 0.08

CO, NO x

22

D.J. Eatough et al.

Table 2. Sampling locations and concentrations of CO, NO, and fine particles (<2~tm size) for samples collected in indoor environments. Fine Part.

Location

Replicate Sample Site Samples Number of Smokers

CO. ~L/L

Home V

Living Room

2

0.19±0.01

5±0

Housetrailer

Kitchen

2

0, Wood-Burning Fireplace 0, Gas Cooking

0.31±0.12

8±3

19±3

Home S

Dining Room

i

2, Moderate Smoking

0.84

4

68

8±1

35±5

N__QOx,nL/L ~g/m 3 151

Living Room

2

I, Infrequent Smoking 0.67±0.10

Kitchen

3

2, Heavy Smoking

Kitchen

3

2, Heavy Smoking

Home L

Dining Room

i

2, Moderate Smoking

Hair Salon

Break Area

2

i, Infrequent Smoking 0.27±0.06

Business,

Office

i

3.58

42

28

Lunchroom

i

I, Heavy Smoking in a.m. 2-5, During Breaks

2.17

42

94

Library

i

0

1.21

27

31

Reception Area

I

Forecast Area

I

Office

I

2.80

51

52

Lunchroom

I

0, Next to Smoker's Office 0, Next to Reception Area I, Heavy Smoking in a.m. 2-4, During Breaks

2.59

53

76

Library

I

0

2.49

44

38

Reception Area

i

Forecast Area

i

Disco, Day 1

By Stage

i

0, Next to Smoker's 2.15 Office 0, Next to Reception 2'.30 Area 20-100 22.1

148

801

Disco, Day 2

By Stage

i

20-I00

114

774

Day i

Business,

Day 2

a

1.90

18.9

18 7±1

36 29±0

47 43

a Not determined.

(24-methylcholest-5-en-3~-ol), 13-sitosterol (24-ethylcholest-5-en-313-ol)], sterenes (24-methylcholesta-3,5,22-triene and 24-ethylcholesta-3,5-diene), nicotine, nicotyrine, and cotinine. In addition, the chamber studies indicated that the following compounds should be monitored to deter-

mine the relationships among the tracers and the major components of environmental tobacco smoke and the relative deposition rates of gas and particle phase components of ETS: 3. Gas phase: CO, NO, NO 2. 4. Particle phase: RSP, K (and other elements).

Tracers of tobacco s m o k e

23

Table 3. Gas-phase and particle-phase compounds identified in environmental tobacco s m o k e equilibrated in a 30 m s teflon chamber.

Chemical Class

Class wtt of Particle

Examples of Identified Compounds

#Mol Compound/Mol CO Particles Gas Phase

Particles Alkanes Bases

4.22±0.82g/molCO 3.6±0.5 10.9±1.2

Phytadlene n-Hentriacontane

a

393±150 14.7±1.7 10.6±3.3 17.7±7.0 < 5 < 5 < 5 6.4±2.4 12.1±6.5 9.1±7.5 5.9±1.3

0 0 0 0

8.8±8.5 6.8±3.4

0 0

0.5±0.1

Campesterol Stlgmasterol ~-Sitosterol Cholesterol

Sterenes b

0.4±0.3

24-MeC-3,5-dien 24-EtC-3,5,22-trien

<0.I

Inorganic

138± 13 93± 29

Nicotine 12 500±3600 Myosmine 375± 38 Nicotyrine 16± 6 Cotinine 18.2±9.4 Pyridine 1180± 72 3-Ethenylpyridine 1370±460 2-Ethenylpyrldine 207± 36

Sterols

PAH

~ Compound in Gas Phase

Pyrene Phenanthrene NO NO 2 HNO 3 HNO 2 SO 2 + Sulfate NH 3 Potassium Calcium

98.3±1.4 96.1±0.9 60 ±20 54.6±12.8 I00 i00 i00

0.02±0.01 0.11±0.02 36 700±3200 2520± 430 96± 127 4650±1300 71± 52 51 900±5400 0 0

0 0 92± 55 54± 40 71± 40 155± 34 840±150 340±100

i00 i00 44 ±24 98.7± 1.0 49 ±23 99.6± 0.2 0 0

a Not determined. b MeC and EtC - Methyleholesta and Ethylcholesta.

Experiments in indoor environments

Additional information on which of the compounds listed in Table 3 might be suitable as tracers of environmental tobacco smoke was obtained from studies conducted in indoor environments. The concentrations of the various species in indoor environments determined using the sampling systems described in Table 1 are given in Tables 2 and 4. The sterols and sterenes determined in the chamber experiments could not be directly determined in the environmental samples because of interference in the GC analysis by high-molecular-weight hydrocarbons not present in the chamber. The concentrations of the sterols and sterenes were too low to be quantified reliably using the fractionation techniques previously described (Benner et al. 1989). However, many of the basic nitrogen-containing organic compounds could be reliably determined in these samples, as indicated in Table 4. Nicotine, myosmine, cotinine, pyridine, 3-ethenylpyridine, and 2-ethenylpyridine were seen in all in-

door environmentswhere smoking was present. Nicotyrine was detected in samples from the environments with high concentrations of nicotine and 3-ethenylpyridine. Equally important, the various nitrogen-containing basic compounds seen in environmental tobacco smoke were not detected in the indoor environments where smoking was not present. In the home with emissions from a wood fireplace, but not from tobacco smoking, the wood smoke was allowed to vent partially into the room during the sampling, resulting in the observed high concentrations of particulate matter. In the house trailer with the gas stove, cooking was done during the sample collection period. Thus, both of these samples represent substantial, rather than minor, contributions from these two nontobacco sources. The data suggest that interference in the correct identification of environmental tobacco smoke from production of pyridine, 3-ethenylpyridine, and/or 2-ethenylpyridine from other

D. L Eatough et al.

24

Table 4. Concentrations of nitrogen-containing organic compounds of environmental tobacco smoke for samples collected in indoor environments. The locations are the same as those detailed in Table 2.

Chemical Compocents of l~iL~,~,tal Td~aceo Smoke (nmo]./m3) Location

Nicotine Myosmlr~ Cotininv Pyrldia~ 3-EtyPyra 2-EtyPyra Gaseous Particle C~se~us ]?articleGaseous Particle Gaseous Casects Gaseous ~).I

~).I




<13.1


Ho,.setrailer




<13.1



<13.1


<%).i

H~eS

19.8

4.8



<~.I

0.5

14.2

38.0

4.6

2.1~0.I 0.2~).2


I.~V

O. L~O. 1
5.(~0.6

Hm~ L Hair Salon

84.~_14

17.4_+4.0 0.7+~).3
25.7+~.3

iO.~.4

44.9

4.2

b
0.8:K).3
~ ~.I

3.9+~0.9 0.7~0.4 0.2~0.0 <~.i


0.2


~).I

1.2d~).8 26.~.9

2.~0.4 37.6t17

0.5~0.0 4.~.I

ll.2t~l.l ll.ld~l.6

1.5~0.2

11.7

6.0

0.5~0.7

~4.7 1.3~0.9


Bos~,

48.3

3.0

2.4

<~.i

i.i

0.9

I0.i

22.7

2.0

ray1

37.4

10.8

2.3

~0.i

~).i

0.8

15.0

27.1

1.8

0.8

i.i

0.3

<13.1

0.2

<~.I

3.9

0.3

23.6

6.5

0.5

<~.i


0.5

4.6

17.8

0.6

7.7

2.2

0.5


0.3

<13.1

3.1

7.4

0.6

Business, 25.4

2.9

0.9

0.I

0.8

0.5

14.3

1.1

Day 2

2.7

1.2

0.3

1.2

0.8

26.1

1.8

Disco,

33.7 2.0

0.9

0.2

<13.1

0.6


6.8

0.5

23.1

4.8

1.1

<13.1

0.5

1.5

22.2

2.1

7.7

1.6

0.5

<13.1

0.3

0.3

8.7

3.4

1.4

707

32.0

25.9


8.5

4.0

216

173

12.2

592

27.9

16.7

3.9

4.3

3.7

158

146

9.8

Day1 ~ ,

ray2

a EtyPyr - Ethenylpyrldine. b Not determined.

sources can be expected to be minimal, if not zero, in most indoor environments. Additional insights into the possible use of the nitrogen-containing basic organic compounds as tracers of environmental tobacco smoke can be gained from looking at the mole to mole ratios of the various compounds to each other and to other constituents in the environments studied. Suspended fine particulate matter (>211m diameter), CO, and NO x are three species that have been considered as potential tracers of environmental tobacco smoke (NAS 1986; DHHS 1986). The weight to mole or mole to mole ratios of these various spe-

cies to particle-phase nicotine as a function of the concentration of particle-phase nicotine in the indoor environments with environmental tobacco smoke is shown in Fig. 1. The solid horizontal line in Fig. 1 is the grams of particles to mole particle phase nicotine (10.7g/mole) obtained in the chamber studies, with the dashed horizontal lines being the observed deviation of this ratio in environmental tobacco smoke in the chamber. The mole to mole ratios of CO and NO z to particle-phase nicotine in Fig. 1 have boon scaled to this same ratio using the values given in the figure, based on the results given in Table 3. At concentrations of particle-phase nicotine greater than about

Tracers of tobacco smoke

,--1000,... Io Q. 0 °0 ~

100 Ratio

~og

¢,m

Found

Chamber

in

Studies ~

100

~

--A[i -~ . . . . . . . .

lO

b•

¢.-

°

o

o

°0 ~

8~ t, °

z °~

25

,

Z~-. . . . . . . . . . .

~I ..........

~__~. . . . . . . , - - ~ - - I ~

10

z

•

z~. . . . . . . .

._~

•

1

Q.

o C0-0.00422 NOx*0.108

0.1

0

5

10

15

[Nicotine(p)],

20

25

...........................

30

35

nmol/m3

_

/

!:~

/

C

°

: Ratio Found in -Chamber Studies 0

5

10

15

[Nicotine(p)],

0

i ~ ,ico ii;,, ................. :: o Myosmine*32.0 i • Pyridine* 10,6 ;......................................

2'0

2'5

3'0

35

nmol/m3

Fig. l. Ratio of ~tg fine panicles, nmol CO*0.00422, and nmol NO=*0.108 to nmol particle-phase nicotine as a function of the concentration of particle-phase nicotine in indoor environments with environmental tobacco smoke.

Fig. 2. Ratio of mol gas-phase nicotine, reel total myosmine*32.0, and tool pyridine* 10.6 t o mol panicle-phase nicotine as a function of the concentration of panicle-phase nicotine in indoor environments with environmental tobacco smoke.

5 nmol/m 3, three of the four species (particle-phase nicotine, fine particles, NO x) are related at the ratios predicted from the chamber experiments. This indicates that each of these species is a suitable tracer of environmental tobacco smoke at high concentrations in the environments studied. The concentrations of CO were higher than expected for all samples. At lower concentrations of particle-phase nicotine, the mole ratio of NOx to particle-phase nicotine also becomes much greater than predicted from the chamber experiments. The concentrations of fine particles show more infrequent and smaller deviations from the predicted values. This increase in the observed ratio of these species to particlephase nicotine at low concentrations of particle-phase nicotine is probably due to an increase in the relative amount of fine particles, CO, and/or NO~ from other sources as the concentration of environmental tobacco smoke decreases and the more rapid deposition of tobacco smoke aerosol compared to the deposition or loss of CO and NO x. Since the deposition loss of NO x in indoor environments should be more rapid than that for CO, the data in Fig. 1 show that, for many of the homes studied, there were other sources of both CO and NO~. It can be assumed that the increase in fine particles compared to particle-phase nicotine at low concentrations is due to contributions from other sources. Based on this assumption, the data in Fig. I indicate that the percent of total fine particle mass due to smoking in the indoor environments varied from an assumed near 100% for the disco to only 20% to 30% for the rooms in the office

building remote from areas where people were smoking. Excluding the special case of the disco, which had heavy environmental tobacco smoke exposure, the average contribution of environmental tobacco smoke to total fine particles in the indoor environments where environmental tobacco smoke was present was 53%. This is in agreement with previous results observed in the large studies conducted by Spengler et al. (1985). Myosmine, pyridine, and gas-phase nicotine all are removed from the environment at rates higher than that for the removal of particle-phase nicotine. This is consistent with previous observations in experimental chambers with active surfaces for the removal of the basic compounds (Theme et al. 1986; Curvall et al. 1987). The mole ratio of these various species to particle-phase nicotine as a function of the concentration of particle-phase nicotine in the indoor environments with environmental tobacco smoke is shown in Fig. 2. The solid and dashed horizontal lines in Fig. 2 are the average mole ratio and deviations in the ratio for gas-phase and particle-phase nicotine from the data in Table 3. The concentrations of myosmine and pyridine have been scaled to this same ratio using the values given in Table 3. The observed mole ratio of gas-phase nicotine to particlephase nicotine in the indoor environments averaged 6.9 + 5.8 compared to 31.8 for the environmental tobacco smoke collected in the Teflon experimental chamber. The percentage of nicotine in the gas-phase in the indoor environments varied from 40% to 96% of the total and averaged 81 + 12%. The value ob-

26

tained in the chamber was 98.3 % gas-phase nicotine. Correspondingly, the amount of myosmine and pyridine compared to particle-phase nicotine is reduced in the indoor samples, being 0.33 + 0.26 mole myosmine/mole of particle-phase nicotine and 2.3+ 1.7 mole pyridine/mole of particle-phase nicotine. Excluding the disco, the mole ratio of pyridine to particle-phase nicotine was 1.8 + 1.1. The corresponding values from the chamber studies are 0.99 and 3.0 mole myosmine and pyridine per mole particle-phase nicotine, respectively. The data in Fig. 2 indicate that the relative removal rates for the three gas-phase species are in the order nicotine myosmine pyridine. The relative removal rates for gasphase nicotine and pyridine are in agreement with results which have been reported for an experimental chamber that absorbs gaseous bases (Thome et al. 1986). The ratio of fine particles or RSP to total nicotine has been reported by several investigators. Comparison of these results with those obtained in this study provides further insights into the relative deposition rates for gas-phase nicotine and the particle-phase of environmental tobacco smoke in indoor environments. The data in Table 3 give a ratio of 2.0 g particles/g nicotine in environmental tobacco smoke. Values determined in sidestream smoke emissions vary from 2 to 4 g particles/g nicotine (Guerin et al. 1986; Klus and Kuhn 1982; Sakuma et al. 1984; Rickert et al. 1984). However, in studies conducted in environmental chambers that have reactive surfaces, the values are higher. This is probably due to the more rapid removal of gas-phase nicotine (Thome et al. 1986). Thus, for example, in an unventilated room, ratios of 8 to 13 g particles/g nicotine have been determined, and the ratio was observed to increase with increasing residence time in the room (Curvall et al. 1987). Extrapolation of the data to time zero predicts a value of about 5 g particles/g nicotine. Steady-state experiments in ventilated chambers give values of around 12 to 15 g particles/g nicotine, if it is assumed that the deposition rate of nicotine is equal to the measured deposition rate of particles (Hammond et al. 1987; Lewtas et al. 1987). Measured deposition rates of nicotine in a different chamber (Thome et al. 1986) suggest that this assumption can result in a sizable positive error. Chamber experiments thus indicate that the observed ratio of particles to nicotine from environmental tobacco smoke increases with increases in adsorptive surfaces and in residence time. Experiments conducted in indoor environments indicate that the observed ratio of particles to nicotine present in environments dominated by smoking vary

D.J. Eatough et al.

t-

120

,m

O

z

._o

80 Ratio Found in Chamber Studies 40

t~ 13.

0

•. = : * : ~ i : =

0

z.:=.:¥~:.-~_

5

10

=

15

=

~._-::=::=-

20

r-----

25

=i .=::-.-.::

30

35

[Nicotine(p)], nmol/m3 Fig. 3. Ratio of g fine particulate matter (>2~m in size)/g total nicotine as a function of the concentration of particle-phase nicotine in indoor environments with environmental tobacco smoke.

from 6 to 50 g particles/g nicotine (McCurdy et al. 1987; Hammond and Coghlin 1987; Eudy et al. 1987; Klus et al. 1987; McCarthy et al. 1987) with the ratio generally increasing with increased residence time and/or decreased total concentrations in the indoor environments studied. The corresponding values found in the study reported here varied from 3 to 100 g fine particles/g total nicotine and were inversely related to the concentration of nicotine, Fig. 3. The combined results of the various studies reported to date show that gas-phase nicotine (or total nicotine) is not a good marker of the particle-phase of environmental tobacco smoke due to its rapid removal from indoor environments. The mole ratios of 3°ethenylpyridine and 2-ethenylpyridine (and possibly cotinine) to particle-phase nicotine in this study are similar for both the chamber and indoor environment studies, Fig. 4. The y axis in Fig. 4 gives the actual mole ratio of 3-ethenylpyridine to particle-phase nicotine, the other ratios have been scaled according to the values given in Table 2. The data become more scattered at the very low concentrations and there is some indication that, at low concentrations, the relative amount of cotinine increases. This may be due to the formation of cotinine with time (Benner et al. 1989) in the indoor environment. However, the data do show that the deposition losses of 3-ethenylpyridine and particlephase nicotine are similar in indoor environments. The concentrations of these two species are correlated, and with a linear regression line (r2=0.75) comparable to that predicted from the chamber data in Table 3, shown as the solid and dashed lines, re-

Tracers of tobacco smoke

27

~100 Q.

Ratio Found in Chamber Studies

¢,-

o 0 z 0 ¢) Q.

I

...

" ~

•

. . . .

•

.........

•

I • •

oO

..................

'-

3-Ethenylpyridine 2 - Ethenylpyridine* 6.6 2 Cotinine* 3 8.2

UJ

~"

5

10

15

20

25

30

35

[Nicotine(p)], nmol/m3 Fig. 4. Ratioof mol 3-ethenylpyridine,mol 2-ethenylpyridine*6.62, and mol total cotinine*38.2 to mol particle-phase nicotine as a function of the concentration of particle-phase nicotine in indoor environments with environmental tobacco smoke.

spectively, in Fig. 5. Since in the indoor environments the actual concentration of 3-ethenylpyridine and gas-phase nicotine are similar (Table 4), the data in Fig. 5 indicate that 3-ethenylpyridine may be a suitable gas-phase tracer that can be monitored with passive sampling devices (Eatough et al. 1987; Hammond et al. 1987) and provide an accurate assessment of exposure to particles from environmental tobacco smoke. ~ Appreciation is expressed to R.J. Reynolds Tobacco, USA for support of this research through a grant to Hart Scientific Inc., and to Brenda Sedar, Michael J. Eatough and Laura Lewis for technical assistance.

Acknowledgment

REFERENCES Benner, C.L.; Bayona, J.M.; Caka, M.M.; Tang, H.; Lewis, L.; Crawford, J.; Lamb, J.D.; Lee, M.L.; Lewis, E.A.; Hansan, L.D.; Eatough, D.J. The chemical composition of environmental tobacco smoke. II. particle phase. Environ. Sci. Technol. 23:688-499; 1989. Curvali, M.; Kazemi-Vala, E.; Enzell, C.R.; Olander, L.; Johansson, J. Inhaled amount of tobacco smoke during passive smoking. Seifert, B.; Esdorn, H.; Fischer, M.; Rtlden, H.; Wejner, J., eds. Proceedings, 4th International Conference on Indoor Air Quality and Climate. Berlin, Institute for Water, Soil and Air Hygiene. 2:57-60; 1987. D.H.H.S. The health consequences of involuntary smoking, a report of the Surgeon General.; U.S. Dept of Health and Human Services, Washington, D.C.; 1986. Eatough, D.J.; Benner, C.L.; Bayona, J.M.; Caka, F.M.; Richards, G.; Lamb, J.D.; Lewis, E.A.; Hansen, L.D. The chemical corn-

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Fig. 5. Concentration of particle-phase nicotine vs. gas phase 3-ethenylpyridine in indoor environments with environmental tobacco smoke. position of environmental tobacco smoke: I. gas phase acids and bases. Environ. Sci. Technol. 23:679-687; 1989. Ratough, N.L.; McGregor, S.; Lewis, E.A.; Eatough, DJ.; Huang, A.A.; Ellis, E.C. Comparison of six denuder methods and a filter pack for the collection of ambient HNO3(g) and HNO2(g) in the 1985 NSMC study. Atmos. Environ. 2:1601-1618; 1988. Eatough, DJ.; Benner, C.L.; Bayona, J.M.; Caka, F.M.; Tang, H.; Lewis, L.; Lamb, J.D.; Lee, M.L.; Lewis, E.A.; Hansen, L.D. Sampling for gas and particle phase nicotine in environmental tobacco smoke with a diffusion denuder and a passive sampler. Proceedings, EPA/APCA Symposium on Measurement of Toxic and Related Air Pollutants. Pittsburg, PA, Air Pollut. Contr. Assoc. 132-139; 1987. Eatough, DJ.; Benner, C.L.; Bayona, J.M.; Caka, F.M.; Mooney, R.L.; Lemb~J.D.; Lee, M.L.; Lewis, E.A.; Hansen, L.D.; Eatough, N.L. Identification of conservative tracers of environmental tobacco smoke. Seifert, B.; Esdorn, H.; Fischer, M.; Rfiden, H.; Wejner, J., eds. Proceedings, 4th International Conference on Indoor Air Quality and Climate. Berlin, Institute for Water, Soil and Air Hygiene. 2:3-7; 1987. Eatough, D.J.; Benner, C.; Mooney, R.L.; Bartholomew, D.; Steiner, D.S.; Hansen, L.D.; Lamb, J.D.; Lewis, E.A. Gas and particle phase nicotine in environmental tobacco smoke. Proceedings, 79th Annual Meeting of the Air Pollut. Contr. Assoc. Paper 86-68.5, Pittsburgh, PA; 1986. Eudy, L.W.; Theme, F.A.; Heavner, D.K.; Green, C.R.; Ingebrethsen, B . J . Studies on the vapor-particulate phase distribution of environmental nicotine by selective trapping and detection methods. Proceedings, 79th Annual Meeting of the Air Pollution Control Association. Paper 86-38.7, Pittsburgh, PA; 1986. Eudy, L.; Heavner, D.; Stancill, M.; Simmons, I.S.; McConnell, B. Measurement of selected constitutents of environmental tobacco smoke in a Winston-Salem, North Carolina restaurant. Seifert, B.; Esdorn, H.; Fischer, M.; RiJden, H.; Wejner, J., eds. Proceedings, 4th International Conference on Indoor Air Quality and Climate. Berlin, Institute for Water, Soil and Air Hygiene. 2:126-130; 1987. Guerin, M.R.; Higgins, C.E.; Jenkins, R.A. Measuring environmental emissions from tobacco combustion: sidestream ciga-

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rette smoke literature review. Atmos. Environ. 21:291-297; 1986. Hammond, S.K.; Leaderer, B.P.; Roche, A.C.; Schenker, M. collection and analysis of nicotine as a marker for environmental tobacco smoke. Atmos. Environ.; 21:457-462; 1987. Hammond, S.K.; Coghlin, J. Field study of passive smoking exposure with passive sampler. Seifert, E.; Esdorn, H.; Fischer, M.; Rflden, H.; Wejner, J., eds. Proceedings, 4th International Conference on Indoor Air Quality and Climate. Berlin, Institute for Water, Soil and Air Hygiene. 2:131-136; 1987. Klus, H.; Kuhn, H. Verteilun8 verschledner Tabakrauchbestandteile anf Haupt-und Nebenstromrauch (Eine Ubersicht). Beitr. Tabakforsch. 11:229-265; 1982. Klus, H.; Begutter, H.; Ball, M.; Intorp, M. Environmentaltobacco smoke in real life situations. Seifert, B.; Esdorn, H.; Fischer, M.; Rfiden, H.; Wejner, J., eds. Proceedings, 4th International Conference on Indoor Air Quality and Climate. Berlin, Institute for Water, Soil and Air Hygiene. 2:137-141; 1987. Lewtas0 J.; Williams, K.; Lofroth, G.; Hammond, K.; Leaderer, B. Environmental tobacco smoke: mutagenic emission rates and their relationship to other emission factors. Seifert, B.; Esdorn, H.; Fischer, M.; Rflden, H.; Wejner, J., eds. Proceedings, 4th International Conference on Indoor Air Quality and Climate. Berlin, Institute for Water, Soil and Air Hygiene. 2:8-12; 1987. McCarthy, J.; Spengler, J.; Chang, B-H.; Coultas, D.; Samet, I. A personal monitoring study to assess exposure to environmental tobacco smoke. Seifert, B.; Esdorn, H.; Fischer, M.; Rfiden, H.; Wejner, J., eds. Proceedings, 4th International Conference on

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Indoor Air Quality and Climate. Berlin, Institute for Water, Soil and Air Hygiene. 2:142-146; 1987. McCurdy, S.A.; Kado, N.Y.; Sohenker, M.B.; Hammond, S.K.; Benowitz, N.L. Measurement of personal exposure to mutagens in environmental tobacco smoke. Seifert, B.; Esdorn, H.; Fischer, M.; Rflden, H.; Wejner, J.0 eds. Proceedings, 4th International Conference on Indoor Air Quality and Climate. Berlin, Institute for Water, Soil and Air Hygiene. 2:91-96; 1987. N.A.S. Environmental tobacco smoke. Measuring exposure and assessing health effects. National Academy Press, Washington; 1986. Rickert0 W.S.; Robinson, J.C.; Collishaw, N. Yields of tar, nicotine and carbon monoxide in the sidestream smoke from 15 brands of canadian cigarettes. Amer. J. Public Health 74:228-231; 1984. Sakuma, H. Kusama, M.; Yamaguchi, K.; Sugawara, S. The distribution of cigarette smoke components between mainstream and sidestream smoke. Beitr. Tabakforsch. Inter. 12:251-258; 1984. Spengler, J.D.; Treitman, R.D.; Testeson, T.D.; Mage, D.T.; Soczak, M.L. Personal exposures to respirable particulates and implications for air poUutlon epidemiology. Environ. Sci. Tech. 19:700707; 1985. Thome, F.A.; H~avner, D.L.; Ingebrethsen, B.J.; Eudy, L.W.; Green, C.R. Environmental tobacco smoke monitoring with an atmospheric pressure chemical ionization mass spectrometer/mass spectrometer coupled to a test chamber. Proceedings, 79th Annual Meeting of the Air Pollution Control Association. Paper 86-37.6, Pittsburgh, PA; 1986.