Exposure and risk assessment of BTEX in indoor air of gyms in Tehran, Iran

Microchemical Journal 150 (2019) 104135

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Exposure and risk assessment of BTEX in indoor air of gyms in Tehran, Iran Mohammad Hadi Dehghani

a,b

a

a,c,⁎

, Abbas Norouzian , Mehdi Fazlzadeh

d,⁎⁎

, Hamid Reza Ghaffari

T

a

Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Institute for Environmental Research, Center for Solid Waste Research, Tehran University of Medical Sciences, Tehran, Iran Social Determinants of Health Research Center, Ardabil University of Medical Sciences, Ardabil, Iran d Social Determinants in Health Promotion Research Center, Hormozgan Health Institute, Hormozgan University of Medical Sciences, Bandar Abbas, Iran b c

ARTICLE INFO

ABSTRACT

Keywords: BTEXs concentration Risk assessment Gyms Exposure Tehran

The objective of this study was to determine the concentrations of benzene, toluene, ethylbenzene, and xylene (BTEX) in indoor air of 50 gyms in Tehran city and to further assess the health risk due to exposure to BTEX. 10 l of air samples were collected from each gyms and The concentrations of BTEX were determined using GC-FID. Monte Carlo simulations were conducted to evaluate carcinogenic and non-cancer risk owing to BTEX exposure. The results showed that the mean ± SD concentrations of benzene, toluene, ethylbenzene and xylene in indoor air of gyms were 75.1 ± 36.2, 34.1 ± 23.8, 54.8 ± 34.9, and 19.5 ± 9.1 μg/m3, respectively. Among the BTEX, benzene has the most concentrations in the gyms. The mean of inhalation lifetime cancer risk (LTCR) for benzene in indoor air of gyms was calculated 4.1 (10−7), which is lower than the standard limit set by the US Environmental Protection Agency and world health organization. Accordingly, benzene imposes no risk for athletes in gyms investigated in this study. Also, the mean of Hazard quotients (HQ) for benzene, toluene, ethylbenzene and xylene were calculated to be 1.1 (10−2), 2.6 (10−5), 3.09 (10−4) and 7.6 (10−3), respectively, which are much lower than 1 and shows that these compounds do not threaten athletes at the gym in terms of non-carcinogenic disorders. Uncertainty analysis shows that BTEX concentrations have the highest contribution of LTCR and HQ (52.5–82.8%). Therefore, gyms can be a potential source for exposure to BTEX and increase the risk of health problems among athletes.

1. Introduction

Research on Cancer (IARC) has classified benzene, toluene, ethylbenzene and xylenes as class B1 (carcinogen to humans), class D (no carcinogen), group B2 (possibly carcinogen to humans) and class D (no carcinogen), respectively [20,21]. Exposure to BTEX compounds may have significant impact on human health [10]. They have been linked to chronic asthma, cancer and some neurological disorders and symptoms such as weakness, loss of appetite, fatigue, confusion, and nausea as well as the irritation of eyes, skin, mucous membranes and respiratory tract [12,22–25]. Furthermore, benzene negatively impacts blood-forming system, the lymphatic system and the central nervous system and can cause disorders such as hematological disorders, aplastic anemia, leukaemia, myocardial infarction, nasopharyngeal cancer, and respiratory diseases [26,27]. Also, toluene exposure impacts premature delivery, and neurobehavioral and reproductive system [28,29]. Sources for BTEX in indoor air of gyms may be include infiltration of outdoor air pollution, furnishing, cleaning products, paints, adhesives,

Individuals spend about 80–90% of their lifetime in indoor spaces, < 10% in outdoors and some inside vehicles [1]. Therefore, safe indoor air is of high importance [2,3]. Many studies have shown that indoor air pollution is more dangerous than outdoor [4–7]. gyms are among indoor spaces used by many individuals. Gyms due to the use of different flooring materials and also wide range of colors, could be a release source of different types of volatile organic compounds [8,9]. An important class of VOCs components is benzene, toluene, ethylbenzene, and xylene, collectively referred to as BTEX, which have been the focus of many toxicological studies and various health effect studies [10–13]. BTEX evaporate readily at room temperature and inhalation pathway becomes the most important route of exposure for these compounds [14,15]. Exposure to BTEX concentrations in the air pose harmful health effects such as cancers, teratogenic effects, and hematological and neurological disorders [16–19]. International Agency for

Correspondence to: M. Fazlzadeh, Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. ⁎⁎ Corresponding author. E-mail addresses: [email protected] (M. Fazlzadeh), [email protected] (H.R. Ghaffari). ⁎

https://doi.org/10.1016/j.microc.2019.104135 Received 13 June 2019; Received in revised form 23 July 2019; Accepted 24 July 2019 Available online 24 July 2019 0026-265X/ © 2019 Elsevier B.V. All rights reserved.

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heating and conditioning system and other VOC emitting materials utilized in building materials [15,25,30,31]. Many studies have shown that adverse health effects of air pollutants increase with physical activities which can effect on the lung and their players efficiency [8,9,31]. It has also been shown that diffusion capacity increases with activities, which may increase the emission of pollutants through the lung during exercise [8,9]. Strong activities increase the number of breath, and change the way of breath from nose to mouth, and thus reducing the nose ability to remove pollutants entering body [8,32]. Athletes are especially exposed to pollutants from inhalation pathway [9]. Furthermore, during activities more air enter lung through mouth and enter deep into air sacs [32,33]. Since most of sport fields (gyms) in Iran use nonstandard flooring and also due to inadequate ventilation, they have a high potential in the release of BTEX compounds indoors. Therefore, the study of air pollutants is of high priority in indoor space of gyms. Therefore, due to the importance of estimation of health effects of volatile organic compounds and also due to lack of information regarding the concentrations of these pollutants in public indoor places, this study is designed in order to evaluate the exposure of athletes to BTEX compounds, and to investigate the influential factors in gyms in Tehran.

in this research were of analytical grade. 2.4. Quality control and quality assurance The method was validated using limit of detection (LOD), limit of quantification (LOQ), and relative standard deviation (RSD). LOD and LOQ were determined using the blank method. In this sense, the concentrations of 10 Blank samples were measured in triplicate way and LOD and LOQ were calculated using Eqs.(1) and (2) [37].

LOD = Mean(B) + [3 × Standard Deviation( B)]

(1)

LOQ = Mean(B) + [10 × Standard Deviation( B)]

(2)

where B is blank sample concentration. Concentrations of BTEX compounds in blank samples ranged from 0.00 to 0.05, 0–0.07, 0–0.11, and 0.0–0.0 μg/m3 for benzene, toluene, ethylbenzene, and xylene, respectively. The LOD and LOQ were 0.02 and 0.06 μg/m3 for benzene, 0.03 and 0.09 μg/m3 for toluene, 0.04 and 0.13 μg/m3 for ethylbenzene and 0.0 and 0.0 μg/m3 for xylene, respectively. Also, Recovery of analytical method was tested by injecting 10 μg of BTEX compounds into fresh charcoal tubes. They were subjected to similar extraction and analysis methods as the field samples. Averagely, 93% recovery (ranged from 81 to 110%) was achieved for target compounds.

2. Material and method 2.1. Study area and data collection

2.5. Statistical analysis

In order to selection of sampling locations, gyms were studied for their indoor air pollution between November 2018 and March 2019 in Tehran city, Iran. All the gyms in urban area of Tehran metropolitan were listed and 50 gyms were selected using systematic random sampling method and these places were monitored for the concentrations of BTEX. In addition, information about ventilation systems (On or Off), heating systems (On or Off), number of athletes and gyms age were collected by using a questionnaire from each gym in Tehran, Iran.

The data were interpreted by the SPSS statistical software, version 22.0. Firstly, Kolmogorov-Smirnov test (KeS test or KS test) was applied to recognize normal distribution of quantitative variables. The data of BTEX concentrations were checked with variables (ventilation: On or Off; heating system: On or Off; number of athletes, gyms age, temperature, and humidity) to recognize normal distribution, which all variables was normal distribution. Additionally, for comparison mean of BTEX concentrations with qualitative variables such as heating system and ventilation were used Student t-test. The relationship between BTEX concentrations and quantitative variables such as the number of athletes, gyms age, temperature, and humidity were evaluated by Spearman's rho correlation coefficient.

2.2. Air sampling process Air samples for BTEX were taken based on the method described in the NIOSH Manual of Analytical Method number 1501 [34]. SKC personal sampling pumps were used for indoor air sampling. Air samples were performed at the flow rate of 0.2 l/min for 50 min to collect a total air volume of 10 l [34]. Charcoal sorbent tubes (SKC) were used as sampling media. The details of air sampling techniques were fully explained elsewhere. After completion of the sampling period, they were transported to the laboratory according to the manufacturer guideline, stored at −20 °C and analyzed within 72 h. Air samples were taken from standing breathing zone of athletes (height of 150 cm above the ground level). All the samples were taken between 10 am and 11 pm, when gyms have the most athletes, for each sampling day in November 2018 to March 2019. Also, during the sampling, temperature and relative humidity in indoors air gyms were measured using WBGT (WetBulb globe temperature) meter model of MK427JY.

2.6. Health risk assessment 2.6.1. Exposure assessment Exposure assessment was conducted for athletes referred to gyms to play footstool. Therefore, exposure scenario was designed as follows: The exposure time (ET) and exposure frequency (EF) of athletes were measured using a face-to-face interview method. It was assumed that these people play footstall from the age of 21 to the age of 70. Therefore, their exposure duration (ED) was considered 49 years. Exposure levels were calculated according to Eqs. (3) and (4) to be applied for the estimation of carcinogenic and non-carcinogenic risk, respectively.

C µg EC = m3

2.3. Sample preparation and analysis Briefly, the charcoal was placed into 5 ml screw-top glass vials. 2 ml of carbon disulfide (CS2) was added to each vial and then The vials containing CS2 and charcoal were shaken for thirty minutes using an ultrasonic agitation device. The extracted samples were transferred into GC vials and BTEX concentrations were determined by a gas chromatography (GC Agilent 7890) instrument equipped with a flame ionization detector (FID) using a capillary column (30 m, BD-5). Aliquots of 1 micro liters were taken from the vial and injected into a capillary column. Injector and detector temperatures were set at 250 and 300 °C, respectively. Oven temperature was programmed at 40 °C for 10 min and then 10 °C/min to 230 °C [35,36]. All chemicals and reagents used

EDI

µg

day year

h day

m3

AT (year) × 365

( ) × 24 ( ) day year

h day

(3)

mg kg. day C

=

( ) × ET ( ) × ED (year) × EF ( )

( )× µg

m3

( ) × IR ( ) × ET ( ) × ED (yaer) × EF ( ) AT (year) × 365 ( ) × 24 ( ) × BW(kg)

1 1000

mg µg

m3 day

day yera

h day

day year

h day

(4) where, C is BTEX concentration in indoor air of gyms, ET is exposure time, ED is exposure duration (yr), EF is exposure frequency (days/yr), 2

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2.7. Monte-Carlo simulation and sensitivity analysis

Table 1 Risk parameters applied for simulation of HQ and ELCR. Parameter

Probability distribution

Statistical parameters

Reference

Inhalation rate (m3/day) Benzene concentration (mg/ m3)

NA Beta

IRIS EPA This study

Toluene Concentration (mg/ m3)

Beta

Ethylbenzene concentration (mg/m3) Xylene concentration (mg/ m3) Exposure Frequency (day/ year) Exposure time (h/day)

Uniform

18.7 Min:0.10 Max:0.14 Alph: 1.11 Beta: 1.10 Min:0.00 Max:0.18 Alph: 0.97 Beta: 5.19 Min: 0.00 Max: 0.13 Min: 0.00 Max: 0.03 Min: 51.31 Max: 156.69 Min:0.20 Max:0.96 Alph: 0.71 Beta: 1.80 35 Carcinogenic: 70 Non-carcinogenic: 35 Benzene: 2 (10−6) Benzene: 3(10−2) Toluene: 5 Ethylebenzene: 1 Xylene: 1(10−1)

IRIS EPA

Uniform Uniform Beta

Exposure duration (year) Averaging time (year)

NA NA

Inhalation Unit risk (UR) (μg/m3)−1 Inhalation reference concentration (RfC) (mg/m3)

NA NA

In most of public health risk assessment, the mean, conservative or worst-case values are applied to calculate point estimate of risk which is assumed to be conservative and protective of public health. The most important limitation of this method are the lack of clarity of the conservatism degree, failure to determine the uncertainty of the final risk value, and unrealistic maximum values considered for some input variables [42]. The Monte-Carlo technique selects the values of the parameters from their distribution fitted to input data and consequently calculates both point value and the distribution of exposure and risk. The calculation process is repeated several times and estimates the average, minimum, maximum, standard deviation, percentiles and some other statistical indicators as the final results. Therefore, the results obtained from the Monte -Carlo simulation technique are more reliable and more valuable compared with point estimate method. There are many potential sources of uncertainty including, the sampling methods, experimental procedures, laboratory equipment, model structure, and humans [42,43]. Uncertainty analysis shows that the value of calculated risk with how much confidence can be placed in the real range [43]. An uncertainty analysis based on Spearman rank-order correlation was employed to understand how uncertainty and variability of input parameters can influence on uncertainty of LTCR and HQ as response variables in the models. A Monte-Carlo simulation technique with 10,000 replicates was performed using Oracle Crystal ball software to obtain the uncertainty and variability of the input parameters in LTCR and HQ calculations.

This study

This study This study This study This study

IRIS EPA IRIS EPA IRIS EPA

3. Results and discussion

NA: not applicable.

3.1. Gyms characteristics

AT is averaging time, BW is body weight, and IR is inhalation rate [38]. The values and probability distributions of parameters in Eqs. (1) and (2) are presented in Table 1.

The physical characteristics of gyms are shown in Table 2. From this table, the average age of the clubs was about three years. Of the 55 clubs, 66% of them have a ventilation system. The average number of people using the club in each shift was about 20 people. The average temperature and humidity of the stadiums was 25.4 and 8.1, respectively.

2.6.2. Carcinogenic risk assessment Carcinogenic risks of BTEX were assessed according to the methodology provided by the USEPA [39] as follows:

LTCR = EC

µg µg × UR m3 m3

3.2. BTEX concentration

1

(5)

The results of the concentrations of the BTEX compounds are shown in Fig. 1 and Table S1 (from Supplementary material). The average concentrations of benzene, toluene, ethylbenzene and xylene were found to be 75.1 ± 36.2, 34.1 ± 23.8, 54.8 ± 34.9, and 19.5 ± 9.1 μg/m3, respectively. The guideline and standard regulated values for BTEX concentrations in the gyms indoor air have not been established by the national and international institutions around the world yet. Hence, BTEX concentration measured in this study compared with the guideline values proposed by the national and international institutions for BTEX in workplaces and air indoor environments. The recommended occupational exposure limits for BTEX in workplaces and indoor environments are presented in Table S2 (from Supplementary material). The results of this work showed that the average

where, UR is cancer unit risk. The UR of benzene is presented by the Integrated Risk Information System (IRIS) of the USEPA. The UR values of 2 × 10−6 proposed for of benzene [40], were used for assessment of LTCR. Based on the World Health Organization (WHO) report, LTCR values in range of 1 × 10−5- 1 × 10−6 are considered as “an acceptable limit for humans”, but the USEPA has recommended LTCR values < 1 × 10−6 [11,22, 23]. 2.6.3. Non-carcinogenic risk assessment Also, risk assessment for the non-carcinogenic risk of BTEX was calculated using the parameter called hazard quotient (HQ), the ratio of EDI to reference dose (RfD), by using the following equation:

HQ =

EDI mg/kg RfD (m/kg

day)) day)

Table 2 Physical characteristics and ventilation condition of the gyms.

(6)

Parameter

In this study a value of 3 × 10−2 μg/m3, 5, 1 and 1 × 10−1 mg/m3 RfC of benzene, toluene, ethylbenzene and xylene, respectively were used to calculate the reference dose (RfD) for BTEX. When HQ value is above 1, the potential risk can be significant. Inversely, If HQ ≤ 1, it means as an acceptable hazard level since the dose level is lower than the reference concentration (RfC) [11]. Risk parameters used for calculating HQ and LTCR for BTEX are given in Table 1.

Descriptive statistics Minimum

Temperature Humidity User Age Ventilation

3

18.90 63.00 12.00 1.00

Maximum

Mean

25.40 21.71 81.40 73.29 26.00 19.48 4.00 3.04 Yes (66%), No (34%)

Std. deviation 1.77 3.68 3.08 0.90

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and previous studies in terms of BTEX concentrations are characteristics of the indoor environment, outdoor pollution, activity carried out in the gym, and meteorological conditions [8,55]. 3.3. The relationship between the concentration of BTEX compounds and gyms characteristics Spearman rank correlation coefficient was applied to determine the relationship between BTEX concentrations. Pairwise plot of the relationship along with the correlation coefficients and p-value are shown in Fig. S1. As shown in the figure, the relationships of benzene-toluene, benzene-ethylbenzene, and xylene- ethylbenzene are statistically significant and the relationship of benzene-xylene, toluene-ethylbenzene, and toluene-xylene are not statistically significant. The highest coefficient was found between benzene and toluene. The coefficients for all the correlations are low. The most probable explanation for a weak correlation between BTEX concentrations is different sources responsible for the emission of these compounds [56]. Concentrations can be derived from both indoor and outdoor sources. The indoor sources of these compounds can be building materials (paints) and human activities (smoking). In outer environments, these compounds originate from traffic, petrol stations and oil and petrochemical refineries [57]. The relationship between temperature and humidity of gym and BTEX concentration was assessed using spearman rank correlation coefficient. The weak correlations were found between the temperature and BTEX concentration. The correlation coefficient was ranged from 0.047 to 0.349. The relationship between temperature and ethylbenzene was statistically significant (p < 0.05) and it was insignificants for others (p > 0.05). In the urban environments, an inverse relationship has been reported between temperature and BTEX concentration. The high concentration of BTEX in the winter is associated with incomplete combustion of fuels and their low levels in the summer, can be related to the lesser emission sources and better air ventilation [13]. However, in indoor environment, there are sources other than fuel, such as paints and building materials that may release more quantities of BTEX compounds at higher temperatures. In other word, temperature mainly influences source to release BTEX rather than sink them [58]. For humidity, positive association was found for benzene (CC = 0.03 and p > 0.05) and ethylbenzene (CC = 0.09 and p > 0.05) and negative association was found for toluene (CC = 0.021 and p > 0.05) and xylene (CC = -0.052 and p > 0.05). In study by Chen Zhou et al., an increase in BTEX concentrations was observed with increase in humidity. The impact of humidity on BTEX concentrations depend on building material and type of BTEX [58] and these parameters are worthy to be further researched.

Fig. 1. The concentration of BTEX in indoor air of gyms.

concentrations of benzene (75.1 μg/m3) were lower than the NIOSH (320 μg/m3) [ 36], ACGIH (1600 μg/m3) [45], Iran (1600 μg/m3) [46] and HSE (3250 μg/m3) [47] recommended values and higher than the values proposed by IEPO (5 μg/m3) [48], HKSAR guideline (16.1 μg/ m3) [49] and ANSES guidelines (30 μg/m3) [50]. Benzene concentrations frequently exceeded the annual exposure level of 5 μg/m3 recommended by IEPO. Benzene is a carcinogen substance and no acceptable level has been recommended for its ambient and indoor air concentrations by WHO [51]. It means that any concentration, especially in long term exposure, might leave its malefic effects. However, the mean concentrations of toluene (34.1 μg/m3), ethylbenzene (54.8 μg/m3) and xylene (19.5 μg/m3) in indoor air of gyms were lower than recommended exposure values by ACGIH, HSE, NIOSH and Iran (table S2). To the best of our knowledge, there are a few studies investigating BTEX concentrations in gym. Martines et al. investigated BTEX concentration in a spinning rooms. They reported the concentrations of benzene, toluene, ethylbenzene, m + p-Xylene, and oXylene to be 1.71, 9.15, 1.87, 2.02, and 0.96 μg/m3, respectively, which are lower than BTEX concentrations measured in present study [52]. In another study by Stathopoulou et al. BTX concentration has been measured in large athletic halls. Benzene, toluene, and xylene concentrations in this study were found to be 0.44, 84, and 51 μg/m3, respectively, in a ventilated gym during an aerobics class of fitness [53]. Katsoyiannis et al. have reported total BTEX in the gyms to be 49 μg/m3 [54]. Except for toluene, the concentration of other BTEX compounds is similar in domestic and work environments. The main sources of toluene in gyms can be the materials applied to build the club and sports equipment and for BEX is outdoor air pollution [54]. Therefore, the most probable factors explaining the difference between present study Table 3 The results of carcinogenic and non-carcinogenic risk assessment of BTEX. Benzene

Mean Median Standard Deviation P10 P20 P30 P40 P50 P60 P70 P80 P90

Toluene

Ethylbenzene

Xylene

Carcinogenic

Non-carcinogenic

Non-carcinogenic

Non-carcinogenic

Non-carcinogenic

4.10E−07 3.43E−07 3.03E−07 1.03E−07 1.58E−07 2.14E−07 2.73E−07 3.42E−07 4.05E−07 4.81E−07 6.10E−07 8.23E−07

1.15E−02 9.19E−03 9.08E−03 2.78E−03 4.30E−03 5.88E−03 7.60E−03 9.19E−03 1.10E−02 1.32E−02 1.67E−02 2.33E−02

2.60E−05 1.53E−05 3.21E−05 5.34E−07 3.11E−06 6.07E−06 1.00E−05 1.53E−05 2.16E−05 2.94E−05 4.15E−05 6.51E−05

3.09E−04 2.39E−04 2.70E−04 4.30E−05 9.43E−05 1.43E−04 1.93E−04 2.39E−04 2.93E−04 3.65E−04 4.75E−04 6.77E−04

7.67E−03 5.92E−03 7.06E−03 7.92E−04 2.01E−03 3.30E−03 4.37E−03 5.92E−03 7.41E−03 9.34E−03 1.22E−02 1.68E−02

4

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M.H. Dehghani, et al.

3.4. Health risk assessment

the main source of these compounds is air pollution outside the building, suitable ventilation techniques should be used to reduce their concentrations. The concentration of pollutants in these places can be reduced through using pollutant free materials for constructing and decorating and locating gyms far enough away from highways and crowded areas of the city with high traffic and vehicles.

The results of the health risk assessment of the BTEX compounds are shown in Figs. S2, S3 and Table 3. As shown in Table 3, the LTCR for benzene is 4.1 (10−7), which is lower than the standard limit set by the US Environmental Protection Agency (US.EPA) and world health organization (WHO) [56]. Furthermore, 90th percentiles of LTCR calculated for benzene in indoor air of gyms was 8.2 (10−7), which lower than USEPA and WHO limit. The LTCR values indicating low risks due to benzene inhalation exposure in gyms. Compound with lifetime cancer risk values of > 10−4, 10−5–10−4, and 10−6–10−5 show “definite risk”, “probable risk”, and “possible risk”, respectively [55]. According to these classifications, benzene impose no risk for athletes in gyms investigated in this study. HQ values larger than one mean unacceptable exposure conditions with high chronic non-cancer risks for the target organs in human body [11, 22]. Table 3 and Fig. S3 shows that the mean HQ calculated for BTEX in indoor air of the gyms. As can be seen from the table, the mean of HQ for benzene, toluene, ethylbenzene and xylene in indoor air of gyms were calculated to be 1.1 (10−2), 2.6 (10−5), 3.09 (10−4) and 7.6 (10−3), respectively. HQ values of BTEX are much lower than 1 and shows that these compounds do not threaten athletes at the gym in terms of non-carcinogenic disorders. To the best of our knowledge, there are no studies assessing health risk of BTEX compounds in the gym. In studies conducted on outdoor air of different city of Iran, LTCR values for benzene have been reported to be in the range of 3.93 (10−7)-7 (10−1) [22,56,60]. The reason for the difference in the results of this study and other studies can be the characteristics of the area in which the gyms are located in terms of traffic, the presence of green space and the characteristics of the gym in terms of moisture content, ventilation, temperature and the number of people in the gym [22]. As there might be other carcinogens including particle matters, heavy metals, VOCs and PAHs in indoor air of gyms. These pollutants were not considered in the risk assessment process in our study. Therefore, future studies suggested to focus on them.

Acknowledgements This research has been supported by the Tehran University of Medical Sciences (# 97-02-27-39091). The authors are also grateful for the technical support from laboratory of environmental health engineering in Tehran University of Medical Sciences. Appendix A. Supplementary data Supplementary data to this article can be found online at https:// doi.org/10.1016/j.microc.2019.104135. References [1] R. Rostami, A. Zarei, B. Saranjam, H.R. Ghaffari, S. Hazrati, Y. Poureshg, M. Fazlzadeh, Exposure and risk assessment of PAHs in indoor air of waterpipe cafés in Ardebil, Iran, Build. Environ. 155 (2019) 47–57. [2] J.A. Bernstein, N. Alexis, H. Bacchus, I.L. Bernstein, P. Fritz, E. Horner, N. Li, S. Mason, A. Nel, J. Oullette, The health effects of nonindustrial indoor air pollution, J. Allergy Clin. Immunol. 121 (2008) 585–591. [3] M. Miri, A. Alahabadi, M.H. Ehrampoush, H.R. Ghaffari, M.J.Z. Sakhvidi, M. Eskandari, A. Rad, M.H. Lotfi, M.H. Sheikhha, Environmental determinants of polycyclic aromatic hydrocarbons exposure at home, at kindergartens and during a commute, Environ. Int. 118 (2018) 266–273. [4] L.A. Wallace, E.D. Pellizzari, T.D. Hartwell, V. Davis, L.C. Michael, R.W. Whitmore, The influence of personal activities on exposure to volatile organic compounds, Environ. Res. 50 (1989) 37–55. [5] J. Namieśnik, T. Górecki, J. Łukasiak, Indoor air quality (IAQ), pollutants, their sources and concentration levels, Build. Environ. 27 (1992) 339–356. [6] M. Fazlzadeh, R. Rostami, S. Hazrati, A. Rastgu, Concentrations of carbon monoxide in indoor and outdoor air of Ghalyun cafes, Atmospheric Pollution Research 6 (2015) 550–555. [7] M.R. Masjedi, F. Taghizadeh, S. Hamzehali, S. Ghaffari, M. Fazlzadeh, A.J. Jafari, S. Niazi, E.A. Mehrizi, M. Moradi, H. Pasalari, H. Arfaeinia, Air pollutants associated with smoking in indoor/outdoor of waterpipe cafés in Tehran, Iran: concentrations, affecting factors and health risk assessment, Sci. Rep. 9 (2019) 3110. [8] A. Andrade, F.H. Dominski, Indoor air quality of environments used for physical exercise and sports practice: systematic review, J. Environ. Manag. 206 (2018) 577–586. [9] C. Ramos, H. Wolterbeek, S. Almeida, Exposure to indoor air pollutants during physical activity in fitness centers, Build. Environ. 82 (2014) 349–360. [10] D.M. Fazlzadeh, R. Rostami, A. Zarei, M. Feizizadeh, M. Mahdavi, A. Mohammadi, D. Eskandari, A survey of 24 hour variations of BTEX concentration in the ambient air of Tehran, Journal of babol university of medical sciences (JBUMS) 14 (2012) 50–55. [11] M. Dehghani, M. Fazlzadeh, A. Sorooshian, H.R. Tabatabaee, M. Miri, A.N. Baghani, M. Delikhoon, A.H. Mahvi, M. Rashidi, Characteristics and health effects of BTEX in a hot spot for urban pollution, Ecotoxicology environmental safety 155 (2018) 133–143. [12] R. Moolla, C.J. Curtis, J. Knight, Assessment of occupational exposure to BTEX compounds at a bus diesel-refueling bay: a case study in Johannesburg, South Africa, Sci. Total Environ. 537 (2015) 51–57. [13] A. Masih, A.S. Lall, A. Taneja, R. Singhvi, Exposure profiles, seasonal variation and health risk assessment of BTEX in indoor air of homes at different microenvironments of a terai province of northern India, Chemosphere 176 (2017) 8–17. [14] S. Hazrati, R. Rostami, M. Fazlzadeh, BTEX in indoor air of waterpipe cafés: levels and factors influencing their concentrations, Sci. Total Environ. 524 (2015) 347–353. [15] S. Hazrati, R. Rostami, M. Farjaminezhad, M. Fazlzadeh, Preliminary assessment of BTEX concentrations in indoor air of residential buildings and atmospheric ambient air in Ardabil, Iran, Atmos. Environ. 132 (2016) 91–97. [16] ATSDR, Toxicological Profile for Ethylbenzene, in, US Department of Health and Human Services. Public Health Service. Agency for Toxic Substances and Disease Registry Atlanta, GA, (1990). [17] U.D.O. Health, H. Services, Toxicological Profile for Xylene, Atlanta: Agency for Toxic Substances and Disease Registry, (2007). [18] A.N. Baghani, A. Sorooshian, M. Heydari, R. Sheikhi, S. Golbaz, Q. Ashournejad, M. Kermani, F. Golkhorshidi, A. Barkhordari, A.J. Jafari, M. Delikhoon, A. Shahsavani, A case study of BTEX characteristics and health effects by major point sources of pollution during winter in Iran, Environ. Pollut. 247 (2019) 607–617. [19] A. Masih, A.S. Lall, A. Taneja, R. Singhvi, Exposure levels and health risk assessment

3.5. Uncertainty analysis Uncertainty analysis shows how the variability of input variables affects the uncertainty of the final response. The results of uncertainty analysis of LTCR and HQ were shown in Figs. S4, S5. As can be seen from these figures BTEX concentrations have the highest contribution in the uncertainty of LTCR and HQ. The contribution of BTEX concentrations ranged from 52.5 to 82.8%. The second rank belongs to exposure time (ET) with contribution from 12.3 to 30.5%. Exposure frequency has the least contribution in the uncertainty of simulated LTCR and HQ with values from 4.9 to 19.4%. Uncertainty comes from the estimation of both exposure and risk. The uncertainty is inherent in a quantitative risk assessment and in addition to the input parameters, there is also uncertainty in the toxicological parameters of BTEX. In this study, only the uncertainty of input parameters was examined except for the toxicology parameters. Therefore, the results of the risk assessment presented can take some degree of uncertainty. However, instead of point estimate value, different statistical parameters of risk are presented that can include a different range of conditions for input parameters. 4. Conclusion The air quality of the gym in terms of BTEX was investigated in this study. The mean concentration of benzene was higher than standard limit suggested by some international organization. A feature that distinguishes the gym from other places is a higher rate of athlete's breathing in these places, which can expose a person to a higher concentration of contaminants. Therefore, more precaution needs to be taken in the gyms to reduce the air pollutants, especially BTEX. Because 5

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M.H. Dehghani, et al.

[20] [21] [22] [23]

[24] [25] [26] [27] [28]

[29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39]

of ambient BTX at urban and rural environments of a terai region of northern India, Environ. Pollut. 242 (2018) 1678–1683. I.W.G.o.t.E.o.t.C.R.o.C.t. Humans, IARC Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans, IARC, 1993. IARC, Agents Classified by the IARC Monographs, (2014), pp. 1–120. M. Delikhoon, M. Fazlzadeh, A. Sorooshian, A.N. Baghani, M. Golaki, Q. Ashournejad, A.J.E.p. Barkhordari, Characteristics and health effects of formaldehyde and acetaldehyde in an urban area in Iran, 242 (2018) 938–951. F. Golkhorshidi, A. Sorooshian, A.J. Jafari, A.N. Baghani, M. Kermani, R.R. Kalantary, Q. Ashournejad, M. Delikhoon, On the nature and health impacts of BTEX in a populated middle eastern city: Tehran, Iran, Atmospheric Pollution Research 10 (3) (2019) 921–930. J.A. Hoskins, Health effects due to indoor air pollution, Survival and Sustainability, Springer, 2010, pp. 665–676. W.H. Organization, WHO Guidelines for Indoor Air Quality: Selected Pollutants, (2010). M.T. Smith, Advances in understanding benzene health effects and susceptibility, Annu. Rev. Public Health 31 (2010) 133–148. A.J. Jafari, S. Faridi, F. Momeniha, Temporal variations of atmospheric benzene and its health effects in Tehran megacity (2010−2013), Environ. Sci. Pollut. Res. (2019) 1–10. Z.T. Fan, X. Zhu, K.H. Jung, P. Ohman-Strickland, C.P. Weisel, P.J. Lioy, Exposures to volatile organic compounds (VOCs) and associated health risks of socio-economically disadvantaged population in a “hot spot” in Camden, New Jersey, Atmos. Environ. 57 (2012) 72–79. S. Hazrati, R. Rostami, M. Fazlzadeh, F. Pourfarzi, Benzene, toluene, ethylbenzene and xylene concentrations in atmospheric ambient air of gasoline and CNG refueling stations, Air Quality, Atmosphere & Health 9 (2016) 403–409. Y. Huang, S.S.H. Ho, K.F. Ho, S.C. Lee, J.Z. Yu, P.K. Louie, Characteristics and health impacts of VOCs and carbonyls associated with residential cooking activities in Hong Kong, J. Hazard. Mater. 186 (2011) 344–351. O. Stathopoulou, V. Assimakopoulos, H. Flocas, C. Helmis, An experimental study of air quality inside large athletic halls, Build. Environ. 43 (2008) 834–848. A. Carlisle, N. Sharp, Exercise and outdoor ambient air pollution, Br. J. Sports Med. 35 (2001) 214–222. K. Slezakova, C. Peixoto, M. Oliveira, C. Delerue-Matos, M. do Carmo Pereira, S. Morais, Indoor particulate pollution in fitness centres with emphasis on ultrafine particles, Environ. Pollut. 233 (2018) 180–193. A. Hydrocarbons, Method 1501, NIOSH Manual of Analytical Methods (NMAM), Foure, Available from http://www.cdc.gov/niosh/docs/2003-154/pdfs/1501.pdf, (2015) , Accessed date: 2 May 2019. M. Rezazadeh Azari, Z. Naghavi Konjin, F. Zayeri, S. Salehpour, M. Seyedi, Occupational exposure of petroleum depot workers to BTEX compounds, The international journal of occupational and environmental medicine (2011) 3. NIOSH, NIOSH Manual of Analytical Methods (NMAM), Fourth edition, Hydrocarbons, Aromatic, Centers for Disease Control and Prevention, 1600 Clifton Rd. Atlanta, GA 30329–4027, USA, 2003. A. Shrivastava, V.B. Gupta, Methods for the determination of limit of detection and limit of quantitation of the analytical methods, Chronicles of Young Scientists 2 (2011) 21. A.N. Baghani, R. Rostami, H. Arfaeinia, S. Hazrati, M. Fazlzadeh, M. Delikhoon, BTEX in indoor air of beauty salons: risk assessment, levels and factors influencing their concentrations, Ecotoxicology environmental safety 159 (2018) 102–108. USEPA, Integrated Risk Information System (IRIS) (Online Database of Toxicity

[40] [42] [43] [45] [46] [47] [48] [49] [50] [51] [52] [53] [54]

[55]

[56]

[57]

[58] [60]

6

Values), United States Environmental Protection Agency, Washington, DC, 2018 Available at http://www.epa.gov/iris. U.S.E.P.A. (USEPA), Integrated Risk Information System (IRIS), USEPA, Environmental Criteria and Assessment Office Cincinnati, Ohio, 2004. K.M. Thompson, D.E. Burmaster, E.A. Crouch, 3, Monte Carlo techniques for quantitative uncertainty analysis in public health risk assessments, Risk Anal. 12 (1992) 53–63. F.O. Hoffman, J.S. Hammonds, Propagation of uncertainty in risk assessments: the need to distinguish between uncertainty due to lack of knowledge and uncertainty due to variability, Risk Anal. 14 (1994) 707–712. ACGIH, TLV/BEI Guidelines, American Conference of Governmental Industrial Hygienists 1330 Kemper Meadow Drive, Cincinnati, Ohio 45240, (2007). MHMEI, E.O.H. Center (Ed.), Occupational exposure limits, Ministry of Health and Medical Education, Tehran, 2012. HSE, EH40/2005 Workplace Exposure Limits, Second edition ed., Health and Safety Executive, London, 2011. Clean Air Standard, Iran Environmetal Protection Organization, Tehran, Iran, 2012 (IEPO). HKSAR, E.P. Department (Ed.), A Guide on Indoor Air Quality Certification Scheme for Offices and Public Places, Air Quality Management Group. Fanling Environmental Resource Centre, Hong Kong, 2003. ANSES, Indoor Air Quality Guidelines (IAQGs), French Agency for Food, Environmental and Occupational Health & Safety 94701, Maisons-Alfort Cedex France, 2008. WHO, WHO Guidelines for Indoor Air Quality: Selected Pollutants, WHO, 2010. E.M. Martins, S.L. Quiterio, S.M. Corrêa, J.D.N. Fortes, M. Monteiro, B. Prestes, BTEX inside a spinning classroom, Cadernos Saúde Coletiva 22 (2014) 218–220. C. Ramos, J. Reis, T. Almeida, F. Alves, H. Wolterbeek, S. Almeida, Estimating the inhaled dose of pollutants during indoor physical activity, Sci. Total Environ. 527 (2015) 111–118. A. Katsoyiannis, E.E. Anda, A. Cincinelli, T. Martellini, P. Leva, A. Goetsch, T.M. Sandanger, S. Huber, Indoor air characterization of various microenvironments in the Arctic, The case of TromsØ, Norway, Environmental research 134 (2014) 1–7. M. Hadei, P.K. Hopke, M. Rafiee, N. Rastkari, M. Yarahmadi, M. Kermani, A. Shahsavani, Indoor and outdoor concentrations of BTEX and formaldehyde in Tehran, Iran: effects of building characteristics and health risk assessment, Environ. Sci. Pollut. Res. 25 (2018) 27423–27437. M. Miri, M.R.A. Shendi, H.R. Ghaffari, H.E. Aval, E. Ahmadi, E. Taban, A. Gholizadeh, M.Y. Aval, A. Mohammadi, A. Azari, Investigation of outdoor BTEX: concentration, variations, sources, spatial distribution, and risk assessment, Chemosphere 163 (2016) 601–609. A. Esplugues, F. Ballester, M. Estarlich, S. Llop, V. Fuentes-Leonarte, E. Mantilla, C. Iñiguez, Indoor and outdoor air concentrations of BTEX and determinants in a cohort of one-year old children in Valencia, Spain, Sci. Total Environ. 409 (2010) 63–69. C. Zhou, Y. Zhan, S. Chen, M. Xia, C. Ronda, M. Sun, H. Chen, X. Shen, Combined effects of temperature and humidity on indoor VOCs pollution: intercity comparison, Build. Environ. 121 (2017) 26–34. Y. Hajizadeh, M. Mokhtari, M. Faraji, A. Mohammadi, S. Nemati, R. Ghanbari, A. Abdolahnejad, R.F. Fard, A. Nikoonahad, N. Jafari, Trends of BTEX in the central urban area of Iran: a preliminary study of photochemical ozone pollution and health risk assessment, Atmospheric Pollution Research 9 (2018) 220–229.