Analysis of Real-time Particulate Monitoring in Career, Volunteer, and Mixed Career-Volunteer Fire Stations
Abstract No:
1544
Abstract Type:
Student Poster
Authors:
M Chaudhari1, R Taylor1
Institutions:
1Western Kentucky University, Bowling Green, KY
Presenter:
Mamata Chaudhari
Western Kentucky University
Western Kentucky University
Faculty Advisor:
Dr. Ritchie Taylor, Ph.D, M.S.
Western Kentucky University
Western Kentucky University
Description:
During this study, the investigators carried out real-time particulate concentration monitoring at a series of 23 fire stations in a primarily rural area of the mid-south, with the intent of measuring any adverse exposures to particulate (especially diesel particulate from vehicle exhaust) that firefighters and other personnel may be exposed to while operating and working around fire apparatus and other equipment in these confined areas.
The use of real-time monitoring equipment, as opposed to the more common air pump filtration technique codified in NIOSH method 5040, allowed the investigators to view inflection points where particulate levels temporarily increased far above the norm. This allowed the investigators to evaluate whether elevated particulate levels could arise in reaction to specific fire station operations or other environmental factors.
The use of real-time monitoring equipment, as opposed to the more common air pump filtration technique codified in NIOSH method 5040, allowed the investigators to view inflection points where particulate levels temporarily increased far above the norm. This allowed the investigators to evaluate whether elevated particulate levels could arise in reaction to specific fire station operations or other environmental factors.
Situation/Problem:
While the direct hazards firefighters experience during fire suppression are well-known, secondary or indirect exposures may be overlooked in the current firefighting landscape wherein structural fires are increasingly rare and most firefighting activity relates to other types of emergency. Some of these indirect exposures may occur at the fire station facilities where firefighting personnel spend most of their time.
During day-to-day operations at a fire station, there may be many occasions when combustion engines are operated inside the station. Personnel remaining in the station after this operation may then be exposed to harmful combustion exhaust products such as carbon monoxide gas, PAHs, and carbon particulate.
Existing research on this topic tends to focus on larger metropolitan fire departments (which do not represent a majority of firefighters nationally), and, when measuring aerosol particulate, tends to utilize the NIOSH-recommended air pump filtration method, which is only capable of indicating exposure as a lengthy time-weighted average. Additionally, because of the long turnaround time on sampling using air pump filtration, many studies of particulate air contamination in fire stations have been hampered by small sample sizes.
In this study, the investigators utilized real-time sampling methods to expand their sample size and evaluate rural volunteer and mixed fire departments as well as urban professional departments, with the intent of seeing whether exposures at these stations are comparable to those at the more oft-studied metropolitan stations.
During day-to-day operations at a fire station, there may be many occasions when combustion engines are operated inside the station. Personnel remaining in the station after this operation may then be exposed to harmful combustion exhaust products such as carbon monoxide gas, PAHs, and carbon particulate.
Existing research on this topic tends to focus on larger metropolitan fire departments (which do not represent a majority of firefighters nationally), and, when measuring aerosol particulate, tends to utilize the NIOSH-recommended air pump filtration method, which is only capable of indicating exposure as a lengthy time-weighted average. Additionally, because of the long turnaround time on sampling using air pump filtration, many studies of particulate air contamination in fire stations have been hampered by small sample sizes.
In this study, the investigators utilized real-time sampling methods to expand their sample size and evaluate rural volunteer and mixed fire departments as well as urban professional departments, with the intent of seeing whether exposures at these stations are comparable to those at the more oft-studied metropolitan stations.
Methods:
The two primary instruments used in this study were the DRX Dust-trak Aerosol Monitor and the OPS 3330 Particle Sizer. Both of these instruments utilize optical methods to evaluate particulate concentrations in real time, with the Dust-trak device measuring particle mass-concentration and the OPS device measuring particle count. Both devices are able to sort and measure particulate of different sizes, which is relevant in the occupational health context because finer particulate is accounted as a greater respiratory health risk.
During sampling, the DRX device was placed in the engine bay of each fire station, while the OPS device was placed in the day room or, if no day-room was present, the most populated social area within the station. Each device was programmed to sample at 60-second intervals for a 4-hour time period at each station, with the beginning of each 4-hour period beginning prior to each station's morning engine check, the one period of operation when engine ignitions were guaranteed at all facilities.
Firefighters at each station were consulted for contextual information about the fire station environment and the fire apparatus present, but no biodata or procedural data was gathered, so no IRB was submitted. Workers on-site were simply used as a resource for site identification and categorization.
Data sets were normalized through logarithmic transform, and additional manipulations were carried out, comparing each reading to a baseline derived from the median of readings from the same location. This was because the goal of the study was not simply to see which stations had the highest average or median particulate concentrations, but to try to identify when, why, and for how long elevated particulate concentrations occurred, necessitating a means of comparison within as well as across datasets from each station. The primary statistical tool used for this purpose was the t-test of independent means.
One weakness of this methodology is that it is sufficiently different from the normal particulate sampling methodology used in occupational health that the results cannot be compared directly with those of most prior studies. Additionally, the use of two disparate instruments to measure two different parts of the fire station environment means that the results from those two environments cannot be compared directly. The lack of duplicate instrumentation also prevented the investigators from taking concurrent ambient readings from outside the fire station environment.
During sampling, the DRX device was placed in the engine bay of each fire station, while the OPS device was placed in the day room or, if no day-room was present, the most populated social area within the station. Each device was programmed to sample at 60-second intervals for a 4-hour time period at each station, with the beginning of each 4-hour period beginning prior to each station's morning engine check, the one period of operation when engine ignitions were guaranteed at all facilities.
Firefighters at each station were consulted for contextual information about the fire station environment and the fire apparatus present, but no biodata or procedural data was gathered, so no IRB was submitted. Workers on-site were simply used as a resource for site identification and categorization.
Data sets were normalized through logarithmic transform, and additional manipulations were carried out, comparing each reading to a baseline derived from the median of readings from the same location. This was because the goal of the study was not simply to see which stations had the highest average or median particulate concentrations, but to try to identify when, why, and for how long elevated particulate concentrations occurred, necessitating a means of comparison within as well as across datasets from each station. The primary statistical tool used for this purpose was the t-test of independent means.
One weakness of this methodology is that it is sufficiently different from the normal particulate sampling methodology used in occupational health that the results cannot be compared directly with those of most prior studies. Additionally, the use of two disparate instruments to measure two different parts of the fire station environment means that the results from those two environments cannot be compared directly. The lack of duplicate instrumentation also prevented the investigators from taking concurrent ambient readings from outside the fire station environment.
Results / Conclusions:
No fire station exhibited average or median readings indicating that the OSHA occupational exposure limit for particulate (0.5 micrograms per cubic meter as an 8-hour TWA) were exceeded. However, two stations did exceed this concentration for brief periods, and two others were within the same order of magnitude. Overall there is no indication of the occupational exposure limit being exceeded.
Career stations typically had higher activity levels than non-career stations, resulting in more frequent engine ignitions producing more exhaust. However, career stations were not seen to have significantly greater particulate concentrations on average than the typically less-active non-career stations. There was no statistically significant difference in mean particle concentrations (p = 0.598, p > 0.05, p > 0.1) between the two categories (career vs. non-career) of fire station evaluated, though all of the stations which did record anomalously higher (>1 stdev) particulate readings were non-career. Overall, there is no indication that activity level increases particulate exposure at fire stations.
Career stations typically had higher activity levels than non-career stations, resulting in more frequent engine ignitions producing more exhaust. However, career stations were not seen to have significantly greater particulate concentrations on average than the typically less-active non-career stations. There was no statistically significant difference in mean particle concentrations (p = 0.598, p > 0.05, p > 0.1) between the two categories (career vs. non-career) of fire station evaluated, though all of the stations which did record anomalously higher (>1 stdev) particulate readings were non-career. Overall, there is no indication that activity level increases particulate exposure at fire stations.
Primary Topic:
Indoor Environmental Quality/Indoor Air Quality
Secondary Topics:
Aerosols
Engineering Controls and Ventilation
Co-Authors
Please add your co-authors below. Co-authors are listed for professional courtesy and will not be communicated with regarding the decision notification or any on-site logistics, if accepted. Only the primary presenter listed is expected to attend and present the content on-site.
Acknowledgements and References
List any additional people who worked on the project or provided guidance and support along with details on the role they played in the research. (Please include first name, last name, organization, city, state and country).
Batt. Chief Gabe Heatherly, Danville Fire Department, Danville, KY, USA
Chief Leslie Goodrun, Franklin-Simpson Fire & Rescue, Franklin, KY, USA
Practical Application
How will this help advance the science of IH/OH?
By providing a larger sample size and categorization of firefighting facilities than many other studies of its type, this will hopefully prove a good resource for fire departments when conducting research to apply for grants for particulate-control apparatus, or when reviewing indoor air quality SoP.