Determination of Emission Factors for Cigarettes and Electronic Cigarettes

Transcription

1 Determination of Emission Factors for Cigarettes and Electronic Cigarettes Paul R. Nelson, John W. Caraway, Tao Jin, and Eckhardt Schmidt 69 th Tobacco Science Research Conference 21-September

2 What is an emission factor? How are emission factors determined? Topics Cigarette emission factors Electronic cigarette emission factors Conclusions / Limitations 2

3 What is an emission factor? An emission factor is a measure of the average amount of a specific pollutant or material discharged into the atmosphere by a specific process, fuel, equipment or source. 1 The term is commonly used with reference to outdoor pollutant sources, but is also applicable for indoor sources; e.g., ozone emissions from copiers, formaldehyde emissions from furniture, etc

4 Emission factor examples 2012 Toyota Prius g CO 2 per mile Electricity in Florida Lb. of CO 2 per KWHr New permanent press shirt µg formaldehyde/m 2 /hr Cigarette mg RSP/cigarette 4 Martin et al. (1997). Environment International, 23,

5 How are emission factors used? Emission factors can be used for modeling, for example: If you have a well-mixed indoor space occupied by two people and ventilated at 204 m 3 hr -1 in which 4 cigarettes per hour are smoked, what is the expected steady-state particulate concentration? 4 cig hr -1 x 13.7 mg cig -1 x 1000 µg mg m 3 hr -1 = 269 µg m -3 5

6 How are emission factors determined? Can be determined in static (unventilated) or dynamic (ventilated) environmental chambers For tobacco products, focus has been on use of static chambers Product is smoked in chamber; then concentrations are measured 6

7 Calculation of Emission Factor from Real-Time Data Background Corrected CO (ppm) Time (min) Profile of CO measured in an environmental chamber following smoking of a cigarette Background corrected data shown in plot 7

8 Calculation of Emission Factor from Real-Time Data Peak Profile of CO measured in an environmental Chamber following smoking of a cigarette Emission factor calculated from peak concentration Emission factor = Peak Concentration x Chamber Volume # Cigarettes Smoked 8

9 Calculation of Emission Factor from Time- Weighted Average Data (Historical) Peak (8.02) TWA (6.85) For analytes collected on sorbent tubes, etc. ( min), only a single average value is available Time-weighted average (TWA) concentrations are less than the peak concentration Emission factors calculated from TWA data will underestimate actual emission factor 9

10 Calculation of Emission Factor from Time- Weighted Average Data (Historical) Assume that measured analyte follows CO decay (ideal assumption) Calculate Peak:TWA ratio for CO Correct emission factor for TWA analyte based upon CO Peak:TWA ratio Emission Factor (EF) calculation (amount per product used) EEEE = PPPPPPPP TTTTTT TTTTTT BBBB CCCCCCCCCCCCC VVVVVVVVVVVV # pppppppppppppppp uuuuuuuu 10

11 What about electronic cigarettes? Electronic cigarettes don t generate CO traditional method for correction will not work A new approach is needed to properly apply correction Approach is based upon measured decay of CO 2 Approach can also be applied to combustible cigarettes where high resolution CO measurements are not available 11

12 Calculation of Emission Factor from Time-Weighted Average Data (New) CO2 (ppm) Time (min) Simulated CO 2 concentration in environmental chamber Non-zero background levels CO 2 rises while subjects are in chamber due to exhaled CO 2 Slow decay after subjects leave chamber due to leakage 12

13 Calculation of Emission Factor from Time-Weighted Average Data (New) Bkg-corrected CO2 (ppm) Time (min) Background-corrected CO 2 concentration 0-2 min used for background correction 13

14 Calculation of Emission Factor from Time-Weighted Average Data (New) Bkg-corrected CO2 (ppm) C 0 C t = C 0 e -kt Time (min) C 0 is peak concentration (@ 20 min) CO 2 decays following first order kinetics 14

15 Calculation of Emission Factor from Time-Weighted Average Data (New) Bkg-corrected CO2 (ppm) C 0 is peak concentration (@ 20 min) TWA = CCoo ee kkkk dddd C Time (min) where t=0 begins at 20 min on graph 15

16 Calculation of Emission Factor from Time-Weighted Average Data (New) Bkg-corrected CO2 (ppm) C Time (min) C 0 is peak concentration (@ 20 min) TWA = CCoo ee kkkk dddd PPPPPPPP TTTTTT = 120 CC CC oo ee kkkk dddd

17 Calculation of Emission Factor from Time-Weighted Average Data (New) PPPPPPPP TTTTTT = CC CC oo ee kktt dddd

18 Calculation of Emission Factor from Time-Weighted Average Data (New) PPPPPPPP TTTTTT = PPPPPPPP TTTTTT = CC CC oo ee kktt dddd kk 11 ee kk 18

19 Calculation of Emission Factor from Time-Weighted Average Data (New) ln ([CO2]) Slope = -k Time (min) PPPPPPPP TTTTTT = PPPPPPPP TTTTTT = CC CC oo ee kktt dddd kk 11 ee kk Slope of ln([co 2 ]) vs time = k 19

20 Calculation of Emission Factor from Time-Weighted Average Data (New) ln ([CO2]) Slope = -k Time (min) PPPPPPPP TTTTTT = PPPPPPPP TTTTTT = CC CC oo ee kktt dddd kk 11 ee kk Slope of ln([co 2 ]) vs time = k Air exchange rate (ACH) determined from k ACH = k * 60 20

21 Calculation of Emission Factor from Time-Weighted Average Data (New) Assume that measured analyte follows CO 2 decay (ideal assumption) Calculate Peak:TWA ratio for CO 2 Correct emission factor for TWA analyte based upon CO 2 Peak:TWA ratio Emission Factor (EF) calculation (amount per product used) EEEE = PPPPPPPP TTTTTT TTTTTT BBBB CCCCCCCCCCCCC VVVVVVVVVVVV # pppppppppppppppp uuuuuuuu Emission Factor (EF) calculation (amount per mg e-liquid) EEEE = PPPPPPPP TTTTTT TTTTTT BBBB CCCCCCCCCCCCC VVVVVVVVVVVV mmmm ee llllllllllll cccccccccccccccc 21

22 Cigarette Emission Factors Emission factors calculated from recent study of emissions from electronic cigarettes using historical and new methods 25 secondhand smoke components were measured Chamber concentrations 40+ times higher than typical smoking environments 1 1 Nelson et. al. (1998) J. Air & Waste Manag. Assoc., 48,

23 Cigarette Emission Factors Component Marlboro Gold mg/cig (SD) (Historical Method) Marlboro Gold mg/cig (SD) (New Method) Marlboro Lights mg/cig (SD) 1997 Particulate <2.5 µm 13.2 (2.0) 12.0 (2) 14.5 (0.6) Nicotine* 1.2 (0.2) 1.2 (0.2) n/a Acetaldehyde 2.1 (.1) 1.9 (0.1) 2.5 (0.1) Formaldehyde 1.1 (0.2) 1.0 (0.2) 0.88 (0.07) Phenol 0.18 (0.07) 0.16 (0.06).115 (.007) Benzene 0.27 (0.09) 0.25 (0.08).31 (.04) Styrene 0.11 (0.04) 0.10 (0.4).092 (.007) Ammonia 2.9 (1.6) 2.7 (1.6) 3.5 (.2) *Nicotine does not follow first order decay kinetics; emission factor underestimates true emission factor. 23

24 Cigarette Emission Factors Component Newport mg/cig (SD) (Historical Method) Newport mg/cig (SD) (New Method) Particulate <2.5 µm 12.7 (1.3) 11.6 (1.1) Nicotine* 1.2 (0.2) 1.1 (0.2) Acetaldehyde 2.12 (0.05) 1.94 (0.03) Formaldehyde 1.0 (0.1) 0.9 (0.1) Phenol 0.18 (0.02) 0.16 (0.02) Benzene 0.28 (0.02) 0.26 (0.02) Styrene (0.007) (0.006) Ammonia 2.6 (0.9) 2.3 (0.8) *Nicotine does not follow first order decay kinetics; emission factor underestimates true emission factor. 24

25 Electronic Cigarette Emission Factors Emission factors calculated from recent study of emissions from electronic cigarettes Chamber concentrations 40+ times higher than typical smoking environments 1 No measurable contribution from electronic cigarettes in typical smoking environments for analytes not significantly different (nsd) from background Emission factors provided only for components above background (3 of 25) 1 Nelson et. al. (1998) J. Air & Waste Manag. Assoc., 48,

26 Electronic Cigarette Emission Factors Component VUSE Original mg/10 min use (SD) VUSE Menthol mg/10 min use (SD) Market Sample mg/10 min use (SD) Glycerol 0.75 (0.56) 0.87 (0.50) n/a Propylene Glycol 0.74 (0.43) 7.3 (3.3) n/a Nicotine* (0.015) (0.080) (0.006) Component VUSE Original µg/mg e-liquid (SD) VUSE Menthol µg/mg e-liquid (SD) Glycerol 22 (14) 20 (5) Propylene Glycol 22 (13) 171 (11) Nicotine* 2.4 (0.4) 3.0 (0.6) *Nicotine does not follow first order decay kinetics; emission factor underestimates true emission factor. 26

27 Emission Factor Comparison Component Marlboro Gold mg/cig (SD) VUSE Original mg/10 min use (SD) Market Sample mg/10 min use (SD) Glycerol n/a 0.75 (0.56) n/a Propylene Glycol 1.7 (0.9) 0.74 (0.43) n/a Nicotine* 1.2 (0.2) (0.015) (0.006) Component Newport mg/cig (SD) VUSE Menthol mg/10 min use (SD) Market Sample mg/10 min use (SD) Glycerol n/a 0.87 (0.50) n/a Propylene Glycol 0.74 (0.43) 7.3 (3.3) n/a Nicotine* 1.1 (0.2) (0.080) (0.006) *Nicotine does not follow first order decay kinetics; emission factor underestimates true emission factor. 27

28 Conclusions New method for determining emission factors works with products that do not emit CO Emission factors for cigarettes using new method are comparable to those obtained using historical method Cigarette emission factors measured in recent study are similar to those measured 18 years ago Most emissions from electronic cigarettes are so low (nsd vs. blank) that they cannot be reliably determined. 28

29 Limitations Emission factors calculated based upon CO 2 decay can slightly underestimate true emission factor due to exfiltration of smoke as smokers leave chamber Some compounds may adsorb on surfaces (e.g., nicotine) leading to underestimation of emission factors Incorrect baseline correction (overestimation) for CO 2 can artificially inflate emission factor 29

30 Acknowledgements Stephen Sears (RJRT) Bellomy Research Clinical Research Atlanta Covance MAS 30