Fire Fighters: Respiratory
Protection and Lung Injury
Jefferey L. Burgess, MD, MPH
Associate Professor, Environmental and
...
Smoke exposure
Acrolein
Benzene
Carbon Monoxide
Hydrogen chloride
Hydrogen cyanide
Nitrogen dioxide
Particulates
Polycycli...
Firefighter heatlh
Older studies demonstrated accelerated
rates of decline in pulmonary function
Recent longitudinal studi...
Phases of firefighting
Entinguishment (knockdown)
Entry/ventilation
Rescue
Support/standby
Overhaul
Questions
Self-contained breathing apparatus
(SCBA): how much protection do they
provide?
Is spirometry alone adequate for...
SCBA performance
NIOSH recommended PF of 10,000
When inhalation rate exceeds respirator
supply, facepiece pressure will be...
Fit-testing
102 of 440 firefighters were fit-tested
during fourteen shifts at eight stations.
Virtually all the firefighte...
CNP Fit-tests for Tucson*
Mean Leak (cc/min) All (%) Large (%)
<2.5 66 68
2.6-10 15 16
10.1-50 9 8
50.1-100 3 8
101-500 5 ...
Treadmill testing
Firefighters previously fit for personal
facepieces using irritant smoke.
Firefighters fitted with a lar...
Conclusions
All 10 firefighters studied on the
treadmill overbreathed their respirators.
Facepiece fit was excellent in mo...
Medical surveillance
Seattle Fire Department since 1988
Voluntary for 1,108 uniformed firefighters
Annual pulmonary functi...
DLCO by exam year
80
90
100
110
1989 1990 1991 1992 1993 1994 1995 1996
%PredictedDLCO(Crapo)
Non-smokers
Smokers
Decline in DLCO: possible causes
Machine error
Changes in firefighter population (age,
race, smoking, FEV1, etc.)
Smoke ex...
Instrument testing
Firefighters were tested on both the regular
DLCO unit and a second similar unit
22 paired measurements...
Hospital testing
11 of 18 firefighters with DLCO <70%
were retested
No statistically significant difference in
the measure...
Firefighter characteristics
Year 1989 1990 1991 1992 1993 1994 1995 1996
Age 39 38 37 37 35 35 34 34
Male (%) 94 94 94 93 ...
DLCO Regression model (n = 812)
Parameter Estimate Std Error p
Intercept -6.448 4.168 0.1223
Age (years) -0.124 0.023 0.00...
DLCO Regression model (continued)
Parameter Estimate Std Error p
Time -0.913 0.291 0.0017
Age*time 0.017 0.004 0.0001
Fema...
DLCO Discussion
-1.02 ml/min/mmHg associated with year
of measurement v. -0.006 ml/min/mmHg
associated with number of fire...
Overhaul (OH)
Phase after the flames have been doused
when firefighters (FF) search for and
extinguish hidden sources of c...
Methods-biomarkers
Baseline and 1 hour post-OH
measurements
FVC and FEV1
Serum Clara cell protein (CC16)
Surfactant associ...
Methods-overhaul
Phoenix FF wore air purifying respirators
(APR)
Tucson FF wore no respiratory protection
Monitored for sm...
Results-FF participants
Tucson (n=25) Phoenix (n=26)
Age 39.6 ± 6.7 39.3 ± 8.1
Male gender 24 (96%) 25 (96%)
non-Hisp. Whi...
Results-smoke exposure (ppm)
Analyte n* Tucson n* Phoenix
Formaldehyde 21/22 0.11±0.18 19/19 0.26 ±0.25
Acetaldehyde 5/23 ...
Results-smoke exposure (ppm)
Analyte n Tucson n Phoenix
Carbon monoxide 18 12.2±10.5 13 34.1±34.7
Nitrogen dioxide 18 0.00...
Results-biomarkers
Group n CC16* SP-A* n FVC (L) FEV1 (L)
TFD 25 8.9±3.5 287±144 19 5.42±0.72 4.10±0.62
TFD-OH 25 12.3±3.6...
Interleukins
IL-10 supresses inflammation
IL-8 and TNF-α are pro-inflammatory
Relative to non-smokers, sputum IL-10
concen...
Sputum cytokines
Group TNF-α IL-8 IL-10
PFD 9.8±12.4 600±795 69.2±72.5
PFD-OH 10.6±12.0 768±953 13.7±25.2*
p<0.01
Firefigh...
Sputum IL-10
0
20
40
60
80
100
120
140
160
180
200
baseline overhaul
IL-10concentration(pg/L).
Discussion
Phoenix FF had significant reductions in
spirometry and increase in lung
permeability following OH
OH exposures...
Recommendations
Either
Use self-contained breathing apparatus
during overhaul
or
Increase the time interval between
exting...
References
Burgess JL and Crutchfield CD. Tucson fire fighter exposure to products of
combustion: A risk assessment. Appli...
Fire Fighters: Respiratory Protection and Lung Injury
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Fire Fighters: Respiratory Protection and Lung Injury

  1. 1. Fire Fighters: Respiratory Protection and Lung Injury Jefferey L. Burgess, MD, MPH Associate Professor, Environmental and Occupational Health University of Arizona College of Public Health
  2. 2. Smoke exposure Acrolein Benzene Carbon Monoxide Hydrogen chloride Hydrogen cyanide Nitrogen dioxide Particulates Polycyclic aromatic hydrocarbons (PAHs) Sulfur dioxide and thousands more
  3. 3. Firefighter heatlh Older studies demonstrated accelerated rates of decline in pulmonary function Recent longitudinal studies demonstrate stable spirometry results Continuing exposure to products of combustion Continued concern over elevated cancer rates
  4. 4. Phases of firefighting Entinguishment (knockdown) Entry/ventilation Rescue Support/standby Overhaul
  5. 5. Questions Self-contained breathing apparatus (SCBA): how much protection do they provide? Is spirometry alone adequate for medical surveillance of firefighters? What type of respiratory protection is needed for firefighters during overhaul?
  6. 6. SCBA performance NIOSH recommended PF of 10,000 When inhalation rate exceeds respirator supply, facepiece pressure will become transiently negative. If there is a leak, contamination with products of combustion may occur. The degree of contamination will depend on facepiece fit and extent of negative pressure excursions.
  7. 7. Fit-testing 102 of 440 firefighters were fit-tested during fourteen shifts at eight stations. Virtually all the firefighters present in each station volunteered for fit-testing. Fit-testing used a single Scott AV-2000 large facepiece and a Dynatech Nevada FitTester.
  8. 8. CNP Fit-tests for Tucson* Mean Leak (cc/min) All (%) Large (%) <2.5 66 68 2.6-10 15 16 10.1-50 9 8 50.1-100 3 8 101-500 5 8 >500 4 2 *Fit-testing using a large facepiece. All refers to all firefighters tested, large refers to firefighters fit with a large facepiece
  9. 9. Treadmill testing Firefighters previously fit for personal facepieces using irritant smoke. Firefighters fitted with a large facepiece were eligible for the treadmill study. 90% volunteered for testing. Ten of the 51 eligible firefighters were randomly selected for the treadmill tests. Treadmill 3.5 mph and 16% gradient.
  10. 10. Conclusions All 10 firefighters studied on the treadmill overbreathed their respirators. Facepiece fit was excellent in most firefighters. Only one of the 51 firefighters fit for a large facepiece could potentially have had a respirator PF of less than 10,000.
  11. 11. Medical surveillance Seattle Fire Department since 1988 Voluntary for 1,108 uniformed firefighters Annual pulmonary function tests including forced vital capacity (FVC), forced expiratory volume- 1 second (FEV1) and diffusing capacity of the lung to carbon monoxide (DLCO)
  12. 12. DLCO by exam year 80 90 100 110 1989 1990 1991 1992 1993 1994 1995 1996 %PredictedDLCO(Crapo) Non-smokers Smokers
  13. 13. Decline in DLCO: possible causes Machine error Changes in firefighter population (age, race, smoking, FEV1, etc.) Smoke exposure or other workplace exposure
  14. 14. Instrument testing Firefighters were tested on both the regular DLCO unit and a second similar unit 22 paired measurements were compared No statistically significant difference was found
  15. 15. Hospital testing 11 of 18 firefighters with DLCO <70% were retested No statistically significant difference in the measurements 4 of the 11 firefighters were exercised tested, and 3 of 4 tests were normal
  16. 16. Firefighter characteristics Year 1989 1990 1991 1992 1993 1994 1995 1996 Age 39 38 37 37 35 35 34 34 Male (%) 94 94 94 93 91 91 92 90 Minority (%) 11 12 12 13 14 13 14 13 Smoker (%) 19 19 17 15 14 12 10 10 Annual fires 20 20 19 19 17 17 16 16 Respirator use (%): extinguish 76 78 77 78 78 77 77 78 entry/vent 69 71 69 70 70 70 70 70 standby 30 28 27 27 25 25 25 25 overhaul 47 48 46 48 48 49 50 50
  17. 17. DLCO Regression model (n = 812) Parameter Estimate Std Error p Intercept -6.448 4.168 0.1223 Age (years) -0.124 0.023 0.0001 Height (m) 19.956 2.362 0.0001 Female -4.966 0.694 0.0001 Minority -2.184 0.432 0.0001 FVC 2.400 0.200 0.0001 Pack-years -0.060 0.017 0.0005 Smoking -2.065 0.483 0.0001 AVEFIRE 0.050 0.015 0.0013
  18. 18. DLCO Regression model (continued) Parameter Estimate Std Error p Time -0.913 0.291 0.0017 Age*time 0.017 0.004 0.0001 Female*time 0.230 0.115 0.0467 FVC*time -0.111 0.035 0.0006 Smoking*time 0.241 0.075 0.0014 AVEFIRE*time -0.006 0.003 0.0333
  19. 19. DLCO Discussion -1.02 ml/min/mmHg associated with year of measurement v. -0.006 ml/min/mmHg associated with number of fires fought. Actual extent of smoke exposure could not be directly or quantitatively determined. Is DLCO useful for medical surveillance?
  20. 20. Overhaul (OH) Phase after the flames have been doused when firefighters (FF) search for and extinguish hidden sources of combustion Usually no visible smoke Firefighters often remove respirators Recent study (Bolstad-Johnson et al., 2000) suggests potential for significant exposure
  21. 21. Methods-biomarkers Baseline and 1 hour post-OH measurements FVC and FEV1 Serum Clara cell protein (CC16) Surfactant associated protein A (SPA)
  22. 22. Methods-overhaul Phoenix FF wore air purifying respirators (APR) Tucson FF wore no respiratory protection Monitored for smoke exposure during OH
  23. 23. Results-FF participants Tucson (n=25) Phoenix (n=26) Age 39.6 ± 6.7 39.3 ± 8.1 Male gender 24 (96%) 25 (96%) non-Hisp. White 15 (60%) 14 (54%) Hispanic 8 (32%) 11 (42%) Black 0 1 ( 4%) Other 2 ( 8%) 0 Current smoker 1 ( 4%) 1 ( 4%)
  24. 24. Results-smoke exposure (ppm) Analyte n* Tucson n* Phoenix Formaldehyde 21/22 0.11±0.18 19/19 0.26 ±0.25 Acetaldehyde 5/23 0.16±0.01 18/19 0.38±0.49 Respirable dust† 0/24 11/19 6.18±7.80 Benzene 0/23 10/20 0.56±0.47 HCl 6/23 0.21±0.11 9/19 0.89±0.62 H2SO4 † 4/23 0.27±0.01 10/19 3.40±3.63 * Number of measurements exceeding LOD / number of samples collected † Measurements in mg/m3 , all other values given in ppm
  25. 25. Results-smoke exposure (ppm) Analyte n Tucson n Phoenix Carbon monoxide 18 12.2±10.5 13 34.1±34.7 Nitrogen dioxide 18 0.003±0.005 13 0.008±0.007 Sulfur dioxide 18 0.45±0.40 13 1.52±1.42
  26. 26. Results-biomarkers Group n CC16* SP-A* n FVC (L) FEV1 (L) TFD 25 8.9±3.5 287±144 19 5.42±0.72 4.10±0.62 TFD-OH 25 12.3±3.6† 306±157 19 5.36±0.73 3.94±0.65 PFD 26 9.6±3.5 250±117 26 5.44±0.68 4.22±0.51 PFD-OH 26 14.6±5.2† 334±141† 26 5.29±0.74† 4.09±0.56† * units µg/L † p <0.01
  27. 27. Interleukins IL-10 supresses inflammation IL-8 and TNF-α are pro-inflammatory Relative to non-smokers, sputum IL-10 concentrations in healthy smokers are decreased 25% and smokers with COPD 75%
  28. 28. Sputum cytokines Group TNF-α IL-8 IL-10 PFD 9.8±12.4 600±795 69.2±72.5 PFD-OH 10.6±12.0 768±953 13.7±25.2* p<0.01 Firefighters with rapid rates of longitudinal decline in lung function had a 27% lower sputum IL-10 concentration than slow decliners (p=0.59)
  29. 29. Sputum IL-10 0 20 40 60 80 100 120 140 160 180 200 baseline overhaul IL-10concentration(pg/L).
  30. 30. Discussion Phoenix FF had significant reductions in spirometry and increase in lung permeability following OH OH exposures greater in Phoenix Use of APR did not protect against changes in biomarkers
  31. 31. Recommendations Either Use self-contained breathing apparatus during overhaul or Increase the time interval between extinguishment and start of overhaul, maximizing structure ventilation
  32. 32. References Burgess JL and Crutchfield CD. Tucson fire fighter exposure to products of combustion: A risk assessment. Applied Occupational and Environmental Hygiene 1995; 10: 37-42. Burgess JL and Crutchfield CD. Quantitative respirator fit tests of Tucson fire fighters and measurement of negative pressure excursions during exertion. Applied Occupational and Environmental Hygiene 1995; 10: 29-36. Burgess JL, Brodkin CA, Daniell WE, Pappas GP, Keifer MC, Stover BD, Edland SD, Barnhart S. Longitudinal decline in measured firefighter single-breath diffusing capacity of carbon monoxide values: A respiratory surveillance dilemma. American Journal of Respiratory and Critical Care Medicine 1999;159:119-124. Bolstad-Johnson DM, Burgess JL, Crutchfield CD, Storment SB, Gerkin RD. Characterization of firefighter exposures during fire overhaul. American Industrial Hygiene Association Journal 2000;61:636-641. Burgess JL, Nanson CJ, Bolstad-Johnson DM, Gerkin R, Hysong TA, Lantz RC, Sherrill DL, Crutchfield CD, Quan SF, Bernard AM, Witten ML. Adverse respiratory effects following overhaul in firefighters. Journal of Occupational and Environmental Medicine 2001;43:467-473. Burgess JL, Nanson CJ, Gerkin R, Witten ML, Hysong TA, Lantz RC. Rapid decline in sputum IL-10 concentration following occupational smoke exposure. Inhalation Toxicology 2002;14:133-140.

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