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1 저작자표시 - 비영리 - 변경금지 2.0 대한민국 이용자는아래의조건을따르는경우에한하여자유롭게 이저작물을복제, 배포, 전송, 전시, 공연및방송할수있습니다. 다음과같은조건을따라야합니다 : 저작자표시. 귀하는원저작자를표시하여야합니다. 비영리. 귀하는이저작물을영리목적으로이용할수없습니다. 변경금지. 귀하는이저작물을개작, 변형또는가공할수없습니다. 귀하는, 이저작물의재이용이나배포의경우, 이저작물에적용된이용허락조건을명확하게나타내어야합니다. 저작권자로부터별도의허가를받으면이러한조건들은적용되지않습니다. 저작권법에따른이용자의권리는위의내용에의하여영향을받지않습니다. 이것은이용허락규약 (Legal Code) 을이해하기쉽게요약한것입니다. Disclaimer

2 보건학석사학위논문 Characterization of Firefighter Exposures According to Task in Fireplace 화재현장에서소방관직무에따른 유해인자노출특성 2014 년 8 월 서울대학교보건대학원 환경보건학과산업보건전공 진수현

3 Characterization of Firefighter Exposures According to Task in Fireplace 화재현장에서소방관직무에따른유해인자 노출특성 지도교수윤충식 이논문을보건학석사학위논문으로제출함 2014 년 4 월 서울대학교보건대학원 환경보건학과산업보건전공 진수현 진수현의보건학석사학위논문을인준함 2014 년 6 월 위원장백도명 ( 인 ) 부위원장조경덕 ( 인 ) 위원윤충식 ( 인 )

4 ABSTRACT Characterization of Firefighter Exposures According to Task in Fireplace Suhyun Jin Department of Environmental Health Graduate School of Public Health Seoul National University, Korea Advisor Chungsik Yoon, Ph.D., CIH Objective The high mortality rates and safety and health problems among firefighters have gained attention and highlighted the need to improve safety. Firefighters are known to be exposed to a variety of toxic and carcinogenic substances such as benzene, benzo(a)pyrene, and asbestos. The International Agency for Research on Cancer (IARC) classifies firefighters as Group 2B (potentially cancer-causing occupation). Although firefighters are classified as a high-risk group, little information is available about the hazardous agents they are exposed to during fire extinguishing activities. The aim of this study

5 was to evaluate firefighter exposure to these hazardous agents during various fire extinguishing tasks. Methods Personal breathing zone samples of polynuclear aromatic hydrocarbons (PAHs), benzene, toluene, ethylbenzene, xylene (BTEX), metals, particulates, and asbestos were collected from firefighters to characterize firefighter exposure levels. We classified firefighting tasks into fire extinguishing, overhaul, and fire investigation activities. A total of 14 fire activities were surveyed in this study: five fire extinguishing, six overhaul, and three fire investigations. Sampling areas included a laundry, outlet store, temporary building, underground parking lot, sauna in a public bath, apartment, printing house, restaurant congested buildings. Results Firefighters were exposed to carcinogenic substances such as PAH, benzene, benzo(a)pyrene, and asbestos. Although no substance exceeded the ACGIH TLV, PAHs were detected in every sample. Naphthalene (Group 2B by the IARC) ranged from 0.24~ mg/m 3 (median 49.6 mg/m 3 ) and benzo(a)pyrene was detected in one overhaul case at µg/m 3. Benzene ( ppm) was detected in every task and exceeded the ACGIH TLV (0.5 ppm) at two fire extinguishing, two overhaul, and one fire investigation activity. Respirable particles were detected ( mg/m 3 ) and exceeded the ACGIH TLV (3 mg/m 3 ) at two fire extinguishing and one overhaul case. Conclusion These results indicate that all firefighting tasks generated various hazardous combustion products, including known and possible

6 carcinogens and particulate matter. Peak exposure to benzene and respirable particles may be very high during all three kinds of tasks. Although the environment during overhaul and fire investigation may not appear dangerous, firefighters are actually exposed to a variety of hazardous substances. Key word: Firefighters exposure, Overhaul, Investigation, Characterization of hazards during fire Student ID:

7 Contents ABSTRACT i Contents iii List of Tables v 1. Introduction Materials and methods Survey outline Sampling and analytical methods Quality control Results Discussion Conclusion... 36

8 6. References Appendix 국문초록

9 List of Tables Table 1. Information on the sampling substance 12 Table 2. OELs and IARC carcinogenic grades for major toxic substances targeted in this study 13 Table 3. Analytical method and media and instrument 17 Table 4. Summary of the measured firefighting area 22 Table 5. PAH concentration according to the task 24 Table 6. VOC concentrations according to the task 25 Table 7. Metals concentrations according to the task 26 Table 8. Particulates concentrations according to the task 27 Table 9. Asbestos concentrations according to the task 27 Table 10. The result of comparison of two tasks 28 Table 11. Confinement state associated with concentrations 29 Table 12. Comparison of preceding firefighters exposure studies with this study and health effects of substances 33

10 List of Appendix Appendix 1. Xad-2 and filter concentration of PAH during fire extinguish 41 Appendix 2. Xad-2 and filter concentration of PAH during overhaul 42 Appendix 3. Xad-2 and filter concentration of PAH during fire investigation 43 Appendix 4. Recovery efficiency of metals 44 Appendix 5. Desorption efficiency of BTEX 44 Appendix 6. Summary data for fire extinguishing PAHs samples 45 Appendix 7. Summary data for overhaul PAHs samples 46 Appendix 8. Summary data for investigation PAHs samples 47 Appendix 9. Summary data for fire extinguishing VOCs samples 48 Appendix 10. Summary data for overhaul VOCs samples 48 Appendix 11. Summary data for fire extinguishing VOCs samples 48 Appendix 12. Summary data for fire extinguishing metals samples 49 Appendix 13. Summary data for overhaul metals samples 49 Appendix 14. Summary data for investigation metals samples 50 Appendix 15. Summary data for fire extinguishing particulate samples 51 Appendix 16. Summary data for overhaul particulate samples 51 Appendix 17. Summary data for investigation particulate samples 51 Appendix 18. Summary of Sample site concentration 52

11 1. Introduction Firefighters are exposed to various risks such as falling, collision, high temperatures, and harmful gases. Recently, the risks have increased as residential spaces and industrial buildings are being built taller or underground as a result of dense populations and facilities. Additionally, the use of new construction materials may release unknown harmful gases with high toxicity(jung, 2008). Safety and health problems have been increasing among firefighters, such as musculoskeletal disorders caused by exposure to heavy materials, which have highlighted the need for safety improvement. Firefighters perform various tasks within these harmful environments, such as emergency rescue, first aid, and fire extinguishing. Yong(2008) analyzed causes of death in the line of duty among firefighters over a 16-year period ( ) in Korea: 87 of 189 (46%) deaths were caused by internal diseases, followed by vehicle accidents (24%), fire extinguishing (13%), and safety accidents (8%).Of the firefighters who died from internal diseases, 63% had brain cardiovascular disease and 30% had cancer. Direct causes of brain cardiovascular disease for firefighters include excessive physical activity, high temperatures, emotional stress, and inhalation of harmful gases present in fire and smoke(han, 2008). Inhaling carbon monoxide at the scene of a fire is known to have a direct effect on cardiovascular disorders(guidotti, 1992), and exposure to fine dust(baxter, 2010) and polynuclear aromatic hydrocarbons are both associated with cardiovascular disorders(peters et al., 1997; Timonen et al., 2006). Damage to respiratory organs caused by inhaling smoke from 8

12 fires is the primary cause of death and disease morbidity in firefighters(rabinowitz, 2002). Cancer accounts for 30% of deaths in the line of duty, and firefighters are exposed to carcinogenic substances such as benzene, benzo(a)pyrene, asbestos, and formaldehyde(kim, 2008). Foreign studies have reported that multiple myeloma, non-hodgkin's lymphoma, prostate cancer, and testicular cancer are related to firefighting activities. Skin, brain, anal, oral, pharyngeal, stomach and colon cancer, as well as malignant melanoma and leukemia, may be related to firefighting activities(lemasters et al., 2006). The International Agency for Research on Cancer (IARC) has conducted meta-analyses of cancer among firefighters. They found that the rates of testicular cancer, prostate cancer, and non-hodgkin's lymphoma were significantly increased in firefighters, and the IARC has classified firefighters as Group 2B (potentially cancer-causing occupation) (IARC, 2010). Recent cohort studies have demonstrated that exposure to polynuclear aromatic hydrocarbons and asbestos is related to an increased risk of prostate cancer, skin cancer, and lung cancer(pukkala, 2013), as well as to respiratory cancer and malignant mesothelioma(daniels, 2013). In 2007, a national study investigated chemical exposure among firefighters at the scene of a fire; it included fire extinguishing and overhaul tasks. In 2011, a national study focused on chemical exposure during fire extinguishing. Foreign studies have focused on exposure of firefighters in various scenarios, such as forest fires(miranda, 2012; Reisen, 2008) and large building fires (Dawn, 2010). 9

13 In sum, although many studies have focused on firefighters using an occupational matrix, few have examined exposure to harmful factors during the fire extinguishing process. No studies have classified firefighting tasks into fire extinguishing, overhaul, and fire investigation tasks. Therefore, the objective of this study was to assess the harmful substances firefighters are exposed to during three kinds of tasks: fire extinguishing (general extinguishing activities and prevention of spreading); overhaul (finding and extinguishing any remaining flames or charcoals inside the walls, ceiling, and floor after a fire has been extinguished); and fire investigation (identifying the cause of the fire and estimating damage through data collection and fire investigation, which may involve questioning, on-site verification, recognition, and valuation).. 10

14 2. Materials and methods 2.1. Survey outline This study focused on fire scenes attended by the K fire station, which had the most mobilizations during 2011 in Seoul (S. M. F. D., 2012). K fire station attended 362 fire accidents, making it the busiest of the 22 fire stations administered by the Seoul Metropolitan Fire Headquarters or any other station in Korea. The jurisdiction of K station includes dense residential areas, largescale high-rise buildings, and cultural facilities at a high risk for accidents. From January 21 February 15, 2013, researchers were on standby with firefighters and accompanied them on the first fire truck mobilized to the scene. Sampling media were preloaded prior to arriving at the scene; at the scene, we removed filter plugs and broke sampling tubes. After arriving at each scene, the situation and scale of the accident was examined: simple smoke generation and small-scale fire accidents were excluded from research samples because there was insufficient time for sampling. Collected samples were classified into fire extinguishing, overhaul, and fire investigation tasks, based on the opinions of firefighters on the scene about the conditions and activities of a live fire scene. We selected target substances to examine at fire locations based on previous national and international research; Tables 1 and 2 list the target substances and summaries of published OELs and IARC carcinogenic grades for major toxic substances. 11

15 Table 1. Information on the sampling substance Type Substance Naphthalene, Acenaphthylene, Acenaphthene, Fluorene, Phenanthrene, Anthracene, Fluoranthene, PAHs Pyrene, Benzo(a)anthrancene, Chrysene, Benzo(b)fluoranthene, Benzo(k)fluoranthene, Benzo(a)pyrene, Indeno(1,2,3-c,d)pyrene, Dibenzo(a,h)anthrancene, Benzo(g,h,I)perylene Particulates Total suspended particulate, Respirable particles, Asbestos Metals Be, Cd, Co, Cr, Mn, Pb, As, Cu VOCs Benzene, Toluene, Ethyl benzene, Xylene 12

16 Table 2. OELs and IARC carcinogenic grades for major toxic substances targeted in this study Permissible NIOSH REL ACGIH Exposure Substance TWA TWA* IARC*** Limits (STEL**) (STEL**) (STEL**) Naphthalene 50 mg/m³ (75 mg/m³) 50 mg/m³ (75 mg/m³) mg/m³ (79 mg/m³) Group 2B Acenaphthene Group 3 Fluorene Group 3 Phenanthrene Group 3 Anthracene Group 3 Fluoranthene Group 3 Pyrene Group 3 Chrysene Group 2B Benzo(a)pyrene Group 1 Benzene 1 ppm (5 ppm) 0.1 ppm (1 ppm) 0.5 ppm (2.5 ppm) Group 1 Toluene 50 ppm (150 ppm) 100 ppm (150 ppm) 20 ppm Group 3 Ethyl benzene 100 ppm (125 ppm) 100 ppm (125 ppm) 20 ppm Group 2B Xylene ppm (150 ppm) 100 ppm (150 ppm) Group 3 Beryllium mg/m³ (0.01 mg/m³) mg/m³ mg/m³ Group 1 Cadmium 0.01 mg/m³ mg/m³ Group 1 Coblat 0.02 mg/m³ 0.05 mg/m³ 0.02 mg/m³ Group 2B Chromium 0.5 mg/m³ 0.5 mg/m³ 0.5 mg/m³ Group 3 Manganese 1 mg/m³ 1 mg/m³ (3 mg/m³) 0.2 mg/m³ - Lead 0.05 mg/m³ 0.05 mg/m³ 0.05 mg/m³ Group 2B Arsenic 0.01 mg/m³ mg/m³ 0.01 mg/m³ Group 1 Copper 1 mg/m³ 1 mg/m³ 1 mg/m³ - Asbestos 0.1 fiber/cm3 0.1 fiber/cm3 0.1 fiber/cm3 Group 1 Total suspended particulate Respirable particles 10 mg/m³ - 10 mg/m³ mg/m³ - *Time Weighted Average(TWA) : The time-weighted average concentration limit for a normal 8-hour workday and a 40-hour workweek to which nearly all workers may be repeatedly exposed, day after day, without adverse effect **Short Time Exposure Limit(STEL) : A 15 minute TWA exposure that should not be exceeded at any time during a workday, even if the 8-hour TWA is within the TLV-TWA ***International Agency for Research on Cancer (IARC) Group 1 : carcinogenic to humans, Group 2A : Probably carcinogenic to humans, Group 2B : possibly carcinogenic to humans, Group 3 : not classifiable as to its carcinogenicity in humans, Group 4 : Probably not carcinogenic to humans.

17 2.2. Sampling and analytical methods We monitored the personal exposure of firefighters to the target substances during their various tasks. The firefighters wearing the sampling equipment did not directly perform firefighting activities, but instead shadowed working firefighters or positioned themselves in rooms during firefighting activities. Considering the occupational requirement for vigorous activity and large movements at fire scenes, pumps were placed inside the bag to minimize limiting firefighter activity and the tube was put outside of the bag to be within the breathing zone of the researcher. Air sampling pumps were charged and calibrated every day. Researchers classified activities at the fire scene as fire extinguishing, overhaul, and fire investigation, and collected firefighter personal exposure samples. Each sample was recorded with its location, sample time, and sampling duration. Any samples that could be lost due to volatilization were maintained in a cooler before being moved to the laboratory. Polynuclear Aromatic Hydrocarbons (PAHs) PAH samples were collected using a high-volume flow rate pump (GilAir-5 Air, Gilian, USA) equipped with a PTFE filter (2.0 μm, 37 mm, Gelman Zefluor, Milipore, USA) and connected to a XAD-2 (150 mg/75 mg, SKC, USA) using PVC tubing. The pumps were calibrated to 2.0 L/min. The filter and XAD-2 were wrapped in aluminum foil to protect against light exposure. Samples were shipped to the laboratory in an insulated container with bagged 14

18 refrigerant after collection. Samples were analyzed according to the NIOSH method 5515 using gas chromatography-mass spectrometry (GC-MS). BTEX BTEX samples were collected using a low-volume flow rate pump (LFS113, Gillian, USA) equipped with Coconut Charcoal Tubes (SKC, USA). Pumps were calibrated to 0.2 L/min. Samples were shipped to the laboratory in an insulated container with bagged refrigerant after collection. Samples were collected and analyzed according to the NIOSH method 1501 using GC-FID. Metals Metals samples were collected using PVC filter (0.5 μm, SKC, USA) with a high volume pump to evaluate metal concentrations. The pumps were calibrated to 2.0 L/min. Samples were collected and analyzed according to the NIOSH method 7300 using ICP-OES (inductively coupled plasma-optical emission spectroscopy; ICP- OES, Perkin Elmer, USA). Particulates Total suspended particulates (TSP) and respirable particle concentrations were presented as gravimetric measurements. TSP sampling was performed using the NIOSH method 0500 with a high-volume pump calibrated to 2.0 L/min and PVC filter. For respirable particles, an aluminum cyclone (SKC, USA) pump was calibrated to 2.5 L/min with a high-volume pump. Respirable 15

19 particles samples were monitored in accordance with NIOSH method Filters were weighed before and after the sampling using a microbalance with a detection limit of mg (XP6, Mettler Toledo, USA). Asbestos was monitored in accordance with the NIOSH method 7400 using MCE COWL 0.8 µm pore size filters (SKC, USA). Samples were analyzed using phase contrast microscopy (PCM). 16

20 Table 3. Analytical method and media and instrument Analyte Media Flow rate (LPM) Analysis Ref. Method PAHs 37 mm, 2 μm PTFE +washed XAD GC/MS NIOSH 5515 BTEX Charcoal 0.2 GC/FID NIOSH 1501 Metals PVC filter in 3 piece cassette 2.0 ICP -OES NIOSH 7300 Total suspended particulate PVC filter in 3 piece cassette 2.0 Gravimetric method NIOSH 0500 Respirable dust PVC filter + Aluminum cyclone 2.5 Gravimetric method NIOSH 0600 Asbestos MCE in 28 mm cassette 2.0 PCM NIOSH

21 2.3. Quality control We performed quality control to assess the accuracy and precision of our analyses. For gaseous substances, reproducibility of the analytical instrument and recovery of spiked sample were evaluated; Appendix 1 lists the results. The limit of detection (LOD) was calculated by multiplying by 3.14 standard deviations of seven replicates of the lowest standard solution. Samples below the LOD were classified as ND (not detected). LODs were as follows: PAHs; naphthalene , acenaphthylene µg/m 3, acenaphthene µg/m 3, fluorene µg/m 3, phenanthrene µg/m 3, anthracene µg/m 3, fluoranthene µg/m 3, pyrene µg/m 3, benzo(a)anthrancene µg/m 3, chrysene µg/m 3, benzo(b)fluoranthene µg/m 3, benzo(k)fluoranthene µg/m 3, benzo(a)pyrene µg/m 3, indeno(1,2,3-c,d)pyrene µg/m 3, dibenzo(a,h)anthrancene µg/m 3, and benzo(g,h,l)perylene µg/m 3. VOCs; benzene ppm, toluene ppm, ethylbenzene ppm, m,p-xylene ppm and o-xylene ppm. Metals; Be mg/m 3, Cd mg/m 3, Co mg/m 3, Cr mg/m 3, Mn mg/m 3, Pb mg/m 3, As mg/m 3, and Cu mg/m 3. Quality control of TSP and respirable particles was performed as follows. Before measurement and analysis, all samples were stored in a desiccator for at least 48 hours to avoid moisture adsorption. All filters were weighed three times and the average weight was used as the filter weight for quality 18

22 assurance during the sampling procedure. Static electricity was controlled by treating filters on static elimination ES-100 (SDION, KOREA) prior to weighing. Quality control of asbestos was performed using the laboratory completed asbestos control program by the Korea Occupational Safety and Health Agency. 19

23 2.4. Statistical analysis To examine differences in exposure levels between fire extinguishing and overhaul, the Mann-Whitney U test was performed. A multiple regression analysis was also performed to examine any correlations between concentration and task, confinement state, burnt area size, number of people mobilized, work time, number of equipment mobilized, amount of damage, and building material. Statistical analysis was performed using SPSS-21.0 (IBM Statistics). 20

24 3. Results Personal breathing zone samples were collected from firefighters to characterize their exposure levels. Samples were collected at eight fires near the K fire station in Seoul during the study period (January 21 February 15, 2013). Locations included a laundry, outlet store, temporary building, underground parking lot, sauna in a public bath, apartment, printing house, restaurant congested buildings. Table 4 lists information about the fire scenes. Eight fire scenes were examined, including five fire extinguishing, six overhaul, and three fire investigation activities. PAHs, BTEX, metals, particulates, and asbestos were measured; 14 samples were collected during the five fire extinguishing, six overhaul, and three fire investigation cases. Sampling times ranged from minutes. The firefighting situations differed at every location, so there were limitations in measuring the series of each fire activity in all samples. Concentrations of substances differed by extreme values, which heavily influenced averages, so we used median values instead of average values for accuracy. 21

25 Table 4. Summary of the measured firefighting area Factors of fire scene confi Fire Location neme Size extinguish Overhaul Investigati Combusted material on ing nt (m 2 ) state Laundry Outlet store Apartment Temporary Building Laundry room fire to structure , Electronic Vapor Recovery System, Clothing Clothing,Fabric Upholstery material, Steel reinforcement Pipe insulation film materials, Household ceiling spaces, Textiles Refrigerator, TV, furniture, Household items, steel reinforcement Printing house Boxes, Plastic, Paper Printing Machine 1243 Underground Parking lot Plastic, Paper, Car - Sauna in Public bath Wood, pipe, Radiator, steel reinforcement 100, Restaurant congested buildings Contents of kitchen, concrete structure, steel reinforcement 3896 samples acquired no samples - no data 22

26 Polynuclear Aromatic Hydrocarbons (PAHs) Of the 16 PAHs, naphthalene was detected during all fire extinguishing and overhaul activities. Other compounds detected during fire extinguishing included benzo(a)anthrancene, chrysene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene benzo(a)anthrancene, chrysene, indeno(1,2,3-c,d)pyrene, and benzo(g,h,i)perylene. Compounds detected during overhaul included naphthalene, acenaphthylene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthrancene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, indeno(1,2,3-c,d)pyrene dibenzo(a,h)anthrancene, and benzo(g,h,i)perylene. Compounds detected during fire investigation included naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, chrysene, indeno(1,2,3-c,d)pyrene dibenzo(a,h)anthrancene, and benzo(g,h,i)perylene. Table 5 lists PAH concentrations according to asks. 23

27 Table 5. PAH concentration according to the task Fire extinguishing (N=5) Overhaul (N=6) Investigation (N=3) PAHs Median Range Median Range Median Range (µg/m³) (µg/m³) (µg/m³) (µg/m³) (µg/m³) (µg/m³) Naphthalene Acenaphthylene ** - Acenaphthene 7.28 ** - ND* ** - Fluorene ** - Phenanthrene Anthracene ** - Fluoranthene ** - Pyrene Benzo(a)anthrancene 1.57 ** ND* - Chrysene Benzo(b)fluoranthene ND* ND* - Benzo(k)fluoranthene ND* ** - ND* - Benzo(a)pyrene ND* ** - ND* - Indeno(1,2,3-c,d)pyrene 0.48 ** ** - Dibenzo(a,h)anthrancene ND* ** - Benzo(g,h,I)perylene * ND Not Detected - The values of LOD are as follows Naphthalene µg/m³, Acenaphthylene µg/m³, Acenaphthene µg/m³, Fluorene µg/m³, Phenanthrene µg/m³, Anthracene µg/m³, Fluoranthene µg/m³, Pyrene µg/m³, Benzo(a)anthrancene µg/m³, Chrysene µg/m³, Benzo(b)fluoranthene µg/m³, Benzo(k)fluoranthene µg/m³, Benzo(a)pyrene µg/m³, Indeno(1,2,3-c,d)pyrene µg/m³, Dibenzo(a,h)anthrancene µg/m³, benzo(g,h,l)perylene µg/m³ ** Detected only once 24

28 BTEX Benzene, toluene, ethylbenzene, and xylene (BTEX) were analyzed. Benzene was the major BTEX to which firefighters were exposed. Benzene was detected in all samples during all three tasks and was present at relatively higher concentrations than other BTEX. Toluene was detected in three of the five fire extinguishing activities, in two of the six overhaul activities, and two of the three investigation activities. Ethylbenzene was detected in two fire extinguishing, two overhaul, and one fire investigation. Table 6 lists BTEX concentrations according to tasks. Table 6. VOC concentrations according to the task VOCs Fire extinguishing N=5 Median (ppm) Range (ppm) Median (ppm) Benzene Overhaul N=6 Range (ppm) 4.66 Investigation N=3 Median (ppm) Range (ppm) Toluene Ethylbenzene * - m,pxylene 0.245* * * - oxylene * * - * Detected only once 25

29 Metals Beryllium, cadmium, cobalt, chromium, manganese, lead, arsenic, and copper were analyzed. Beryllium, cadmium, cobalt, manganese, lead, and arsenic were not detected in any samples, but chromium was detected in all samples and copper was detected in samples from three fire extinguishing, five overhaul, and two fire investigation activities. Table 7 lists metal concentrations according to tasks. Table 7. Metals concentrations according to the task Metals Fire extinguishing Median (mg/m³) N=5 Range (mg/m³) Overhaul Median (mg/m³) N=6 Range (mg/m³) Investigation Median (mg/m³) N=3 Range (mg/m³) Be ND - ND - ND - Cd ND - ND - ND - Co ND - ND - ND - Cr Mn ND - ND - ND - Pb ND - ND - ND - As ND - ND - ND - Cu ND Not Detected

30 Particulates The median values for the concentration of TSP during fire extinguishing, overhaul, and fire investigation activities were 2.67 mg/m³, 3.10 mg/m³, and 0.69 mg/m³, respectively. The median values of respirable particles were 2.27 mg/m³, 1.17 mg/m³ and 0.45 mg/m³, respectively. Table 8 lists concentrations according to tasks. The median values for asbestos concentrations during fire extinguishing, overhaul, and investigation activities were 0.15 fibers/cc, 0.18 fibers/cc, and 0.04 fibers/cc, respectively. Table 9 lists concentrations according to tasks. Table 8. Particulates concentrations according to the task Analyte Total suspended particulate Fire extinguishing N=5 Median (mg/m³) Range (mg/m³) Median (mg/m³) Overhaul N=6 Range (mg/m³) Investigation N=3 Median (mg/m³) Range (mg/m³) Respirable particles Table 9. Asbestos concentrations according to the task Fire extinguishing Overhaul N=5 N=6 Analyte Median (fibers/cc) Range (fibers/cc) Median (fibers/cc) Range (fibers/cc) Investigation N=3 Median (fibers/cc) Range (fibers/cc) Asbestos

31 3.1. Statistical analysis fire extinguishing Chrysene overhaul fire extinguishing Benzene overhaul fire extinguishing Toluene overhaul The Mann-Whitney U test analysis was conducted with the two groups to compare the concentration levels of frequently detected substances between the tasks, but showed no significant differences(p>0.05). The result of Mann- Whitney U test analysis was shown in table 10. Table 10. The result of comparison of two tasks Substance Task N Median Range p-value fire extinguishing Naphthalene overhaul fire TSP extinguishing overhaul

32 A multiple regression analysis was conducted to identify correlations between concentration levels and factors such as task, confinement state, number of firefighters dispatched, work time, number of mobilized equipment, property damage, and building materials as independent variables. A correlation was observed between concentration level and confinement state. Table 11 lists the results of the multiple regression analysis. Table 11. Confinement state associated with concentrations Substance Variable β Adjusted R² p-value Naphthalene Chrysene Confinement Benzene state Toluene TSP Other factor as follow; task, confinement state, number of people dispatched, work time, number of mobilized equipment, property damage, and building structure were not significant, therefore the results of multiple regression were not shown in table. 29

33 4. Discussion This study investigated the chemical hazards that firefighters are exposed to while conducting three kinds of tasks at live fire scenes. The results demonstrated that the firefighters were exposed to hazardous substances such as benzene and PAH, as well as particulates. Several previous studies have been performed during fire extinguishing or overhaul tasks, but few studies have included fire investigation. Table 12 compares concentrations according to task. PAH was detected at every fire scene. Naphthalene, which the IARC categorizes as Group 2B (possible carcinogenic substance), was present at concentrations higher than those recorded in previous studies of fire extinguishing and overhaul cases. The highest concentration of naphthalene ( µg/m 3 ) was detected in a sample from a fire extinguishing task in a sauna in a public bath. This fire scene was located in the basement, which was filled with smoke upon arrival due to poor ventilation. However, this level did not exceed the ACGIH TWA maximum value of µg/m 3. Concentrations of benzo(a)pyrene, which is a well-known carcinogen that causes lung cancer, stomach cancer, and skin cancer among the PAHs (Sadikovic, 2006), is known to range from 1 50 µg/m 3 at fire scenes. In the present study, benzo(a)pyrene was detected at a concentration of µg/m 3 during one overhaul task (in a sauna at a public bath). Benzene, which is known to cause leukemia and is categorized as a Group 1 carcinogen by the IARC, was detected in all samples collected during fire extinguishing and fire investigation tasks, and was detected in every case but 30

34 one during overhaul tasks. Benzene was detected at relatively high concentrations compared to other BTEX. Previous studies have reported that benzene concentrations during firefighting can exceed the ACGIH TLV of 0.5 ppm. In this study, a concentration of ppm was detected in a sample from one fire extinguishing activity: this significantly exceeds the ACGIH TLV maximum. This high concentration may have occurred because that the fire was in a confined underground sauna with poor ventilation. Benzene levels also exceeded the ACGIH TLV maximum in one case of fire extinguishing, two cases of overhaul, and one case of fire investigation. TSP levels in samples ranged from mg/m³. The highest concentration was detected during an overhaul task in an apartment; because all windows were closed, this fire scene was poorly ventilated. The highest level of respirable particles (7.55 mg/m 3 ) was also detected during an overhaul task in an apartment. Respirable particle levels exceeded the ACGIH TWA maximum (3 mg/m 3 ) in two fire extinguishing tasks and one overhaul task. These findings were similar to those of other studies, but Johnson (2000) reported higher concentrations of TSP and RSP: mg/m 3 and 80.1 mg/m 3, respectively. Asbestos can be released after a building collapses (Lee, 2010). Among the 14 case analyses conducted using PCM, some samples could not be identified due to black ashes collected in the filter. However, PCM analysis revealed 31

35 that two cases of fire extinguishing and four cases of overhaul exceeded the ACGIH TWA of 0.1 fibers/cc. It is important to note that the PCM technique is only used to assess the form of particles and calculate the concentration by counting the fibrous particles, which may include both asbestos fibers and non-asbestos fiber particles; therefore, overestimation is possible. 32

36 Table 12. Comparison of preceding firefighters exposure studies with this study and health effects of substances number fire extinguish overhaul investigation of fires min max min max min max Naphthelene (µg/m³) This study Kim(2007) Dawn(2000) Baxter(2014) Benzo(a)pyrene (µg/m³) This study 14 ND ND ND ND Kim(2007) 9 ND Dawn(2000) Jankovic(1991) Chrysene (µg/m³) This study Kim(2007) Dawn(2000) Jankovic(1991) Benzen (ppm) This study Kim(2007) 9 ND Dawn(2000) Austin (2001) Jankovic (1991) 22 ND 22 ND Toluen (ppm) This study Kim(2007) 9 ND Brandt-Rauf(1988) TSP (mg/m3) This study Dawn(2000) Johnson(2000) Kinnes(1998) RSP (mg/m3) This study Kim(2007) Dawn(2000) ND Not detected - Not sampled 33

37 The Mann-Whitney U test analysis (a non-parametric testing method) was used to compare concentration levels between fire extinguishing and overhaul tasks, but no significant differences were observed among the two groups (P>0.05). Multiple regression analysis was used to identify any correlations between concentration levels and factors such as task, confinement state, number of firefighters dispatched, work time, number of mobilized equipment, property damage, and building structure as independent variables. A correlation was found between concentration levels and confinement state (P<0.05). Every fire scene analyzed in this study was within a building. In modern buildings, the majority of components such as carpets, wallpaper, and furniture contain polyethylene and PVC, which produce a variety of toxic chemicals including carcinogens when burned. Firefighters entering a site to rescue victims (the highest priority among fire extinguishing activities), and those conducting fire extinguishing operations near a fire, are required to wear a self-contained breathing apparatus. However, firefighters who drive to a fire site, as well as supervisors, communications personnel, paramedics, and firefighters who maintain a distance and use fire hoses do not wear air respirators. Furthermore, firefighters may enter a scene without wearing an air respirator due to communication problems during overhaul and fire investigation, or due to physical exhaustion and heat. This means they may be directly exposed to harmful factors that may have an effect on their health. Exposure to toxic gases and particulates during fire extinguishing, overhaul, 34

38 and fire investigation tasks should therefore be considered in terms of health effects. Many toxic gases are produced during a fire and remain in the atmosphere, such benzene, respirable particles, and PAHs. The environment is not as hot or smoky during overhaul or fire investigation tasks as it is during knockdown, but it still contains products of combustion from small fires or smoldering material. Our results demonstrate that firefighters require selfcontained breathing apparatus during fire extinguishing, overhaul, and fire investigation tasks. Our results also reveal that the environment of the fire site, such as the confinement state, has more influence than concentration levels on firefighter exposure. However, differences in the level of exposure can result from a lack of firefighter awareness about exposure during different tasks (i.e., fire extinguishing, overhaul, and fire investigation), and from not wearing protection. One limitation of this study is that each fire scene has different characteristics; the type and amount of materials varies, making it difficult to identify trends within each task. Previous studies have also reported difficulties in estimating the type and amount of substance: actual fire scenes differ so greatly that direct comparison is challenging. Currently, occupational exposure limits regarding the task of the firefighters are non-existent. Evaluation of exposure at fire scenes should not be limited to one or two projects; work environments of firefighters should be regularly measured to create a database from collected data. In addition, further statistical analysis is required in future studies. 35

39 5. Conclusion This study examined hazardous substances during fire extinguishing, overhaul, and fire investigation activities. The environment during overhaul and fire investigation tasks may not appear as dangerous as during fire extinguishing tasks, but it may still contain hazardous combustion products. Therefore, firefighters may be exposed to hazardous substances exceeding safe standards not only during fire extinguishing, but also during overhaul and fire investigation. In particular, firefighters may be exposed to carcinogens such as benzene or PAHs; therefore, a self-contained breathing apparatus must be worn to minimize exposure to hazardous substances during overhaul and fire investigation. Although the fires that occurred during this study period were in different locations and it was not possible to repeat the same fire scenes due to the nature of fire accidents, these results can inform future occupational health research for firefighters working in fire scenes that are difficult to access. They may also be used to inform research about health hazards to firefighters, and may provide a basis for assessing exposure and improving the work environments of firefighters. 36

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44 Appendix Appendix 1. Xad-2 and filter concentration of PAH during fire extinguish site 1 site 2 site 3 site 4 site 5 PAH (µg/m³) Laundry Outlet store Temporary Building Underground parking lot Sauna in Public bath Xad-2 Filter Total Xad-2 Filter Total Xad-2 Filter Total Xad-2 Filter Total Xad-2 Filter Total Naphthalene ND ND ND ND Acenaphthylene ND ND ND ND ND ND ND ND ND Acenaphthene ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND Fluorene ND ND ND ND Phenanthrene ND ND ND Anthracene ND ND ND ND ND ND ND ND ND ND ND Fluoranthene ND ND ND ND ND ND Pyrene ND ND ND ND ND ND Benzo(a)anthrancene ND ND ND ND ND ND ND ND ND ND ND ND ND Chrysene ND ND ND ND ND ND ND ND ND Benzo(b)fluoranthene ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND Benzo(k)fluoranthene ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND Benzo(a)pyrene ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND Indeno(1,2,3-c,d)pyrene ND ND ND ND ND ND ND ND ND ND ND ND ND Dibenzo(a,h)anthrancene ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND Benzo(g,h,I)perylene ND ND ND ND ND ND ND ND ND ND ND ND Not Detected ND

45 Appendix 2. Xad-2 and filter concentration of PAH during overhaul PAH (µg/m³) site 1 site 2 site 3 site 4 site 5 site 6 Laundry Outlet store Apartment Temporary Building underground parking lot Sauna in Public bath Xad-2 Filter Total Xad-2 Filter Total Xad-2 Filter Total Xad-2 Filter Total Xad-2 Filter Total Xad-2 Filter Total Naphthalene ND ND ND ND ND ND Acenaphthylene ND ND ND ND ND ND ND ND ND ND ND ND Acenaphthene ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND Fluorene ND ND ND ND ND ND ND ND ND ND Phenanthrene ND ND ND ND ND ND ND ND ND ND Anthracene ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND Fluoranthene ND ND ND ND ND ND ND ND ND ND Pyrene ND ND ND ND ND ND ND ND Benzo(a)anthrancene ND ND ND ND ND ND ND ND ND ND ND ND ND ND Chrysene ND ND ND ND ND ND ND ND ND ND Benzo(b)fluoranthene ND ND ND ND ND ND ND ND ND ND ND ND Benzo(k)fluoranthene ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND Benzo(a)pyrene ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND Indeno(1,2,3- c,d)pyrene ND ND ND ND ND ND ND ND ND ND ND ND Dibenzo(a,h)anthrancene ND ND ND ND ND ND ND ND ND ND ND ND Benzo(g,h,I)perylene ND ND ND ND ND ND ND ND ND ND ND ND

46 Appendix 3. Xad-2 and filter concentration of PAH during fire investigation PAH (µg/m³) site 1 site 2 site 3 Printing house Sauna in Public bath Restaurant congested buildings Xad-2 Filter Total Xad-2 Filter Total Xad-2 Filter Total Naphthalene ND ND ND ND ND Acenaphthylene ND ND ND ND ND ND ND ND ND Acenaphthene ND ND ND ND ND ND ND ND ND Fluorene ND ND ND ND ND ND ND ND ND Phenanthrene ND ND ND ND ND Anthracene ND ND ND ND ND ND ND ND ND Fluoranthene ND ND ND ND ND ND ND Pyrene ND ND ND ND ND Benzo(a)anthrancene ND ND ND ND ND ND ND ND ND Chrysene ND ND ND ND ND Benzo(b)fluoranthene ND ND ND ND ND ND ND ND ND Benzo(k)fluoranthene ND ND ND ND ND ND ND ND ND Benzo(a)pyrene ND ND ND ND ND ND ND ND ND Indeno(1,2,3-c,d)pyrene ND ND ND ND ND ND ND Dibenzo(a,h)anthrancene ND ND ND ND ND ND ND Benzo(g,h,I)perylene ND ND ND ND ND ND Not Detected 43

47 Appendix 4. Recovery efficiency of metals Conc. ( mg ) N Recovery of filter (%) Be Cd Co Cr Mn Pb As Cu ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± 4.9 Total ± ± ± ± ± ± ± ± 9.9 Appendix 5. Desorption efficiency of BTEX Conc. N ( μl ) Total 9 Desorption efficiency of adsorbent (%) Benzene Toluene Ethylbenzene ± ± ± ± ± ± ± ± ± ± ± ± 4.2 m,pxylene 85.7 ± ± ± ± 3.9 o-xylene 83.1 ± ± ± ±

48 Appendix 6. Summary data for fire extinguishing PAHs samples Number of Analyte Samples above LOD Median(µg/m³) MIN(µg/m³) MAX(µg/m³) Naphthalene Acenaphthylene Acenaphthene Fluorene Phenanthrene Anthracene Fluoranthene Pyrene Benzo(a)anthrancene Chrysene Benzo(b)fluoranthene - ND ND ND Benzo(k)fluoranthene - ND ND ND Benzo(a)pyrene - ND ND ND Indeno(1,2,3-c,d)pyrene Dibenzo(a,h)anthrancene - ND ND ND ND Not Detected 45

49 Appendix 7. Summary data for overhaul PAHs samples Number of Analyte Samples above LOD Median(µg/m³) MIN(µg/m³) MAX(µg/m³) Naphthalene Acenaphthylene Acenaphthene - ND ND ND Fluorene Phenanthrene Anthracene Fluoranthene Pyrene Benzo(a)anthrancene Chrysene Benzo(b)fluoranthene Benzo(k)fluoranthene Benzo(a)pyrene Indeno(1,2,3-c,d)pyrene Dibenzo(a,h)anthrancene

50 Appendix 8. Summary data for investigation PAHs samples Number of Analyte Samples above LOD Median(µg/m³) MIN(µg/m³) MAX(µg/m³) Naphthalene Acenaphthylene Acenaphthene Fluorene Phenanthrene Anthracene Fluoranthene Pyrene Benzo(a)anthrancene - ND ND ND Chrysene Benzo(b)fluoranthene - ND ND ND Benzo(k)fluoranthene - ND ND ND Benzo(a)pyrene - ND ND ND Indeno(1,2,3-c,d)pyrene Dibenzo(a,h)anthrancene ND Not Detected 47