Figure 1
Search strategy for articles on occupational exposure to BTEX and styrene across major literature databases (slight differences in search strings are owed to different functionality of these systems)
| Web of Science | (TS=(Benzene OR Toluene OR Ethylbenzene OR Xylenes OR Styrene OR Volatile Organic compound) AND TS=(Occupational exposure OR Industrial exposure OR Workplace exposure OR Chemical exposure) AND TS=(Threshold limit value OR Occupational exposure limit OR Recommended exposure level OR Permissible exposure limit) AND TS= (West Asia OR Middle east OR Iran OR Iraq OR Kuwait OR Syria OR Jordan OR Bahrain OR Lebanon OR Oman OR Qatar OR Saudi Arabia OR Afghanistan, Armenia OR Azerbaijan OR Yemen OR Israel OR Turkey OR Palestine) AND LANGUAGE: (English) Indexes=SCI-EXPANDED, SSCI, AND Time span=1980-2021 |
| Scopus | TITLE-ABS-KEY (Benzene OR Toluene OR Ethylbenzene OR Xylenes OR Styrene) AND TITLE-ABS-KEY (Occupational exposure OR Industrial exposure OR Workplace exposure OR Chemical exposure) AND TITLE-ABS-KEY (Threshold limit value OR Occupational exposure limit OR Recommended exposure level OR Permissible exposure limit) AND TITLE-ABS-KEY (West Asia OR Middle East OR Iran OR Afghanistan, Armenia OR Azerbaijan OR Yemen OR Israel OR Turkey OR Arab countries, Gulf Cooperation Council countries) AND PUBYEAR ≥ 1980 |
| PubMed | (Benzene [Title/Abstract] OR Toluene [Title/Abstract] OR Ethylbenzene [Title/Abstract] OR Xylenes [Title/Abstract] OR Styrene [Title/Abstract] OR Volatile Organic compound [Title/Abstract]) AND (Occupational exposure [Title/Abstract] OR Industrial exposure [Title/Abstract] OR Workplace exposure [Title/Abstract] OR Chemical exposure [Title/Abstract]) AND (Threshold limit value [Title/Abstract] OR Occupational exposure limit [Title/Abstract] OR Recommended exposure level [Title/Abstract] OR Permissible exposure limit [Title/Abstract]) AND (West Asia [All Fields] OR Middle East [All Fields] OR Iran [All Fields] OR Iraq [All Fields] OR Kuwait [All Fields] OR Syria [All Fields] OR Jordan [All Fields] OR Bahrain [All Fields] OR Lebanon [All Fields] OR Oman [All Fields] OR Qatar [All Fields] OR Saudi Arabia [All Fields] OR [All Fields] Afghanistan [All Fields], Armenia [All Fields] OR Azerbaijan [All Fields] OR Yemen [All Fields] OR Israel [All Fields] OR Turkey [All Fields] OR Palestine [All Fields]) Filters: from 1980/1/1 - 2020/6/30 |
| Cochrane Library | (Benzene [Title Abstract Keywords] OR Toluene [Title Abstract Keywords] OR Ethylbenzene [Title Abstract Keywords] OR Xylenes [Title Abstract Keywords] OR Styrene [Title Abstract Keywords] OR Volatile Organic compound [Title/Abstract]) AND (Occupational exposure [Title Abstract Keywords] OR Industrial exposure [Title Abstract Keywords] OR Workplace exposure [Title Abstract Keywords] OR Chemical exposure [Title Abstract Keywords]) AND (Threshold limit value [Title Abstract Keywords] OR Occupational exposure limit [Title Abstract Keywords] OR Recommended exposure level [Title Abstract Keywords] OR Permissible exposure limit [Title Abstract Keywords]) AND (West Asia [Title Abstract Keywords] OR Middle East [Title Abstract Keywords] OR Iran [Title Abstract Keywords] OR Afghanistan [Title Abstract Keywords], Armenia [Title Abstract Keywords] OR Azerbaijan [Title Abstract Keywords] OR Yemen [Title Abstract Keywords] OR Israel [Title Abstract Keywords] OR Turkey [Title Abstract Keywords] OR Arab countries [Title Abstract Keywords], Gulf Cooperation Council countries [Title Abstract Keywords]) Filters: from 1980/1/1 - 2020/6/30 |
| CINAHL (EBSCO) | (Benzene [Title/Abstract] OR Toluene [Title/Abstract] OR Ethylbenzene [Title/Abstract] OR Xylenes [Title/Abstract] OR Styrene [Title/Abstract] OR Volatile Organic compound [Title/Abstract]) AND (Occupational exposure [Title/Abstract] OR Industrial exposure [Title/Abstract] OR Workplace exposure [Title/Abstract] OR Chemical exposure [Title/Abstract]) AND (Threshold limit value [Title/Abstract] OR Occupational exposure limit [Title/Abstract] OR Recommended exposure level [Title/Abstract] OR Permissible exposure limit [Title/Abstract]) AND (West Asia [All Fields] OR Middle East [All Fields] OR Iran [All Fields] OR Iraq [All Fields] OR Kuwait [All Fields] OR Syria [All Fields] OR Jordan [All Fields] OR Bahrain [All Fields] OR Lebanon [All Fields] OR Oman [All Fields] OR Qatar [All Fields] OR Saudi Arabia [All Fields] OR [All Fields] Afghanistan [All Fields], Armenia [All Fields] OR Azerbaijan [All Fields] OR Yemen [All Fields] OR Israel [All Fields] OR Turkey [All Fields] OR Palestine [All Fields]) Filters: from 1980/1/1 - 2020/6/30 |
| Embase | TITLE-ABS-KEY (Benzene OR Toluene OR Ethylbenzene OR Xylenes OR Styrene OR Volatile Organic compound) AND TITLE-ABS-KEY (Occupational exposure OR Industrial exposure OR Workplace exposure OR Chemical exposure) AND TITLE-ABS-KEY (Threshold limit value OR TLV OR Occupational exposure limit OR OEL OR Recommended exposure level OR REL OR Permissible exposure limit OR PEL) AND TITLE-ABS-KEY (West Asia OR Middle East OR Iran OR Iraq OR Kuwait OR Syria OR Jordan OR Bahrain OR Lebanon OR Oman OR Qatar OR Saudi Arabia OR Afghanistan, Armenia OR AND Azerbaijan OR Yemen OR Israel OR Turkey OR Palestine) PUB YEAR ≥ 1980 |
| Science direct from inception | TITLE-ABS-KEY (Benzene OR Toluene OR Ethylbenzene OR Xylenes OR Styrene OR Volatile Organic compound) AND TITLE-ABS-KEY (Occupational exposure OR Industrial exposure OR Workplace exposure OR Chemical exposure) AND TITLE-ABS-KEY (Threshold limit value OR TLV OR Occupational exposure limit OR OEL OR Recommended exposure level OR REL OR Permissible exposure limit OR PEL) AND TITLE-ABS-KEY (West Asia OR Middle East OR Iran OR Iraq OR Kuwait OR Syria OR Jordan OR Bahrain OR Lebanon OR Oman OR Qatar OR Saudi Arabia OR Afghanistan, Armenia OR Azerbaijan OR Yemen OR Israel OR Turkey OR Palestine) AND PUB YEAR ≥ 1980 |
Occupational exposure to BTEX and styrene reported for oil-related and solvent-related professions in West Asian countries (mean ± SD, where available)
| Country | National OELs | Industry | Benzene (ppm) | Toluene (ppm) | Ethylbenzene (ppm) | Xylenes (ppm) | Styrene (ppm) |
|---|---|---|---|---|---|---|---|
| Qatar | No | Oil-related | 0.39 | 7.02 | 0.75 | 0.32 | - |
| Solvent-related | 0.004 | 0.012 | 0.0046 | 0.016 | - | ||
| Kuwait | No | Oil-related | 0.23 | 0.144 | 0.085 | 0.16 | - |
| Solvent-related | 0.003±0.038 | 0.03±0.05 | 0.0063±0.03 | 0.162±0.09 | - | ||
| Iran | Yes | Oil-related | 1.165±0.69*,# | 5.87±8.18 | 2.28±8.93 | 12.104±17.7 | 3.588±4.52 |
| Solvent-related | 0.785±0.49*,# | 4.53±4.01 | 4.34±5.11 | 10.56±12.28 | 9.585±3.70 | ||
| Turkey | Yes | Oil-related | 1.33*,# | 0.051 | 0.015 | 0.041 | 0.0057 |
| (except for styrene) | Solvent-related | - | - | - | - | - | |
| Saudi | No | Oil-related | 11.7* | 4.09 | - | 3.97 | - |
| Arabia | Solvent-related | 0.0067 | 0.253 | 0.022 | 0.73 | - | |
| Israel | No | Oil-related | 0.41 | - | - | - | - |
| Solvent-related | - | - | - | - | - |
Summary of occupational exposure to BTEX and styrene in West Asian countries from data gathered from 49 published articles between 1999 and 2021 (mean ± SD)
| References | Publication type | Country | Type of sampling | Industry or workplace | Number of workers (exposed vs unexposed) | Concentration (ppm) Mean ± SD | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| Benzene | Toluene | Ethylbenzene | Xylene | Styrene | ||||||
| (Alabdulhadi et al., 2019) (24) | Cross-sectional | Kuwait | Static | Printing industry | - | 0.0028±0.076 | 0.062±0.101 | 0.118±0.071 | 0.311±0.174 | - |
| (Alfoldy et al., 2019) (25) | Cross-sectional | Qatar | Static | Traffic Petrochemical police, | - | 0.038±0.025 | 0.07±0.05 | 0.007±0.009 | 0.009±0.007 | - |
| (Al-Harbi et al., 2020) (7) | Cross-sectional | Kuwait | Static | Gasoline station | - | 0.23±0.062 | 0.144±0.07 | 0.085±0.07 | 0.16±0.12 | - |
| (Azari et al., 2012) (26) | Cross-sectional | Iran | Personal | Shoe factory | 12 (12:0) | 1.33±0.11*,# | 14.24±1.77 | - | - | - |
| (Baghani et al., 2018) (27) | Cross-sectional | Iran | Static | Beauty salon | - | 0.01±0.009 | 0.0045±0.0041 | 0.0143±0.007 | 0.0031 ±0.002 | - |
| (Bagham et al., 2019) (28) | Cross-sectional | Iran | Static | Gas station & CNG | - | 0.145±0.045 | 0.231±0.053 | 0.113±0.031 | 0.209±0.016 | - |
| (Bahrami et al., 2007) (29) | Cross-sectional | Iran | Personal | Petrol station | 145 (80:65) | 1.41±0.80*,# | - | - | - | - |
| (Bakhtian et al., 2018) (30) | Cross-sectional | Iran | Static | Taxi driver | - | 0.088±0.008 | 0.088±0.011 | 0.073±0.009 | 0.126±0.015 | - |
| (BakoIlu et al., 2004) (31) | Cross-sectional | Turkey | Static | Incinerator Waste | - | 1.33±0.08*,# | 0.051±0.003 | 0.015±0.03 | 0.041 ±0.08 | 0.0057 |
| (Dehgham et al., 2020) (32) | Cohort | Iran | Personal | Steel factory | 372 (372:0) | 2.17±0.11*,# | 4.08±3.25 | 0.32±1.39 | 1.38± 1.35 | - |
| (El-Hashemy and Ali, 2018) (33) | Cross-sectional | Arabia Saudi | Static | Printing copy centre and | - | 0.0067±0.002 | 0.253±0.032 | 0.022±0.005 | 0.73±0.005 | - |
| (Farshad et al., 2014) (34) | Cross-sectional | Iran | Static | Waste hospital disposal in | - | 0.57±0.1*,# | 1.23±1.1 | 1.18± 1.2 | 0.58±0.6 | - |
| (Golbabaei et al., 2018) (35) | Cross-sectional | Iran | Personal | Automobile Industry | 40 (36:4) | 0.96±0.05*,# | 0.28±0.08 | 2±0.2 | 3.02±0.08 | - |
| (Golkhorshidi et al., 2019) (36) | Cross-sectional | Iran | Static | Bus terminal driver: | - | 0.108±0.001 | 0.235±0.002 | 0.188±0.001 | 0.304±0.06 | - |
| (Hadei et al., 2018) (37) | Case-control | Iran | Static | Beauty salon | - | 0.0034±0.002 | 0.0026±0.0018 | 0.0054±0.004 | 0.0043±0.006 | - |
| (Harati et al., 2018) (38) | Case-control | Iran | Personal | Automobile Industry | 80 (40:40) | 0.775±0.12*,# | 1.2±2.08 | 45.8±8.5 | 42.5±23.9 | - |
| (Harati et al., 2020) (39) | Cross-sectional | Iran | Personal | Petrochemical industry | 50 (50:0) | 2.12±0.95*,# | 9.84±2.53 | - | 11.87±4.44 | - |
| (Heibati et al., 2018) (4) | Cross-sectional | Iran | Personal | transfer Petroleum station | 50 (50:0) | 2.7±2.91*,# | 4.07±3.65 | 0.535±0.412 | 0.752±0.812 | - |
| (Hormozi et al., 2019) (9) | Case-control | Iran | Personal | Printing industry | 84 (44:40) | - | 37.64±24.09*,# | - | 105±20.05*,# | - |
| (Hosseini et al., 2015) (40) | Cross-sectional | Iran | Personal | Tyre Factory | 100 (100:0) | 1.88±1.37*,# | 3.2±2.79 | - | - | - |
| (Jalai et al., 2017) (10) | Cross-sectional | Iran | Personal | industry Chemical & police officer | 260 (185:75) | 1.56±0.34*,# | - | - | - | |
| (Javadi et al., 2017) (41) | Cross-sectional | Iran | Personal | Petrol station | 24 (24:0) | 0.56±0.102*,# | 0.242±0.033 | 0.223±0.041 | 0.109±0.025 | - |
| (Karbasi et al., 2020) (42) | Cross-sectional | Iran | Personal | Oil pit worker | 40 (40:0) | 0.82±0.38*,# | - | - | - | - |
| (Maghsodi Moghadam et al., 2013) (43) | Cross-sectional | Iran | Personal | Petrochemical industry | 204 (204:0) | 2.0±8.3*,# | 0.27±0.50 | 0.16±0.59 | 0.8±2.7 | - |
| (Mohamadyan et al., 2019) (44) | Cross-sectional | Iran | Personal | Plastic industry | 53 (53:0) | - | - | - | - | 19.56±9.03 |
| (Mohammadyan and Baharfar, 2015) (45) | Cross-sectional | Iran | Personal | Pesticide production factory | 100 (100:0) | - | 4.7±5.5 | - | ||
| (Mohammadyan et al., 2019) (46) | Cross-sectional | Iran | Personal | Electronic industry | 59 (59:0) | - | - | - | - | 18.68±5.68 |
| (Moradi et al., 2019) (47) | Case-control | Iran | Personal | Beauty salon | 72 (36:36) | 0.015±0.019 | 0.31±0.36 | 0.017±0.021 | 0.055±0.051 | - |
| (Moradpour et al., 2017) (48) | Cross-sectional | Iran | Personal | Petrochemical industry | 358 (358:0) | 1.08±1.46*,# | 9.19±1.68 | 11.56±2.94 | 8.88±2.46 | 8.45±8.29 |
| (Moshiran et al., 2021) (49) | Cross-sectional | Iran | Personal | Petrochemical industry | 50 (50:0) | - | - | - | - | 0.455±0.392 |
| (Moslem et al., 2020) (50) | Cross-sectional | Iran | Static | Surgery room | - | 0.003±0.0005 | 0.002±0.0004 | 0.004±0.0006 | 0.001±0.0003 | - |
| (Nabizadeh et al., 2020) (51) | Cross-sectional | Iran | Static | Paper recycling | - | 0.27±0.01 | 0.28±0.01 | 0.151±0.02 | 1.7±0.007 | - |
| (Nassiri and Golbabai, 1999) (52) | Cross-sectional | Iran | Personal | Paint industry | 54 (54:0) | - | 11.2±7.3 | 20.2±4.1 | - | |
| (Nazarparvar-Noshadi et al., 2021) (11) | Cross-sectional | Iran | Personal | Tyre factory | 38 (38:0) | 2.306±2.63*,# | 8.65±7.7 | 0.07±0.09 | 0.10±0.14 | 0.07±0.08 |
| (Neghab et al., 2015) (12) | Cross-sectional | Iran | Personal | Petrol station | 60 (60:0) | 0.25±0.083 | 0.39±0.071 | - | 0.69±0.36 | - |
| (Omidi et al., 2019) (53) | Cross-sectional | Iran | Personal | slaughterhouse Poultry | 20 (20:0) | 1.34±0.75*,# | 3.65±1.12 | 15.4±0.68 | - | - |
| (Partovi et al., 2018) (54) | Cross-sectional | Israel | Personal | Petrol station | 258 (258:0) | 0.41±0.18*,# | - | - | - | - |
| (Rahimpoor et al., 2014) (1) | Cross-sectional | Iran | Personal | Petrochemical industry | 104 (104:0) | 1.19±0.63*,# | 1.3±4.74 | - | 3.2±7.94 | - |
| (Rahimpour et al., 2018) (55) | Cross-sectional | Iran | Personal | Petrochemical and petroleum depot industry | 84 (84:0) | 0.657±0.791*,# | 12.42±5.95 | - | 32.24±22.1 | - |
| (Ramadan, 2010) (56) | Cross-sectional | Kuwait | Static | Police officer | - | 0.004±0.001 | 0.01±0.008 | 0.0026±0.003 | 0.0138±0.008 | - |
| (Rashnuodi et al., 2021) (57) | Cross-sectional | Iran | Personal | Petrochemical industry | 30 (30:0) | 1.28±2.10*,# | 2.62±4.50 | 4.45±7.35 | 2.41 ±1.07 | - |
| (Rezazadeh Azari et al., 2012) (58) | Case-control | Iran | Personal | Petroleum industry depot | 78 (46:32) | 1.63±3.92*,# | 2.72±19.33 | 0.46±1.61 | 3.53±10.84 | - |
| (Rostami et al., 2021) (59) | Cross-sectional | Iran | Personal | Printing copy centre and | 136 (136:0) | 0.029±0.019 | 0.039±0.026 | 0.007±0.0038 | 0.006±0.003 | - |
| (Salama et al., 2020) (60) | Cross-sectional | Saudi Arabia | Static | Petrol station | - | 11.7±3.1* | 4.09±1.09 | - | 3.97±2.25 | - |
| (Salehpour et al., 2019) (61) | Cross-sectional | Iran | Personal | Petrochemical industry | 80 (40:40) | 1.03±1.40*,# | 5.6±13.66 | - | 8.19±22.20 | 3.48±10.75 |
| (Sarkhosh et al., 2012) (62) | Cross-sectional | Iran | Static | Printing copy centre and | - | 0.0257±0.029 | 0.0713±0.0328 | 0.0083±0.056 | 0.0063±0.024 | 0.0316±0.0352 |
| (Shanh et al., 2017) (63) | Cross-sectional | Iran | Personal | Petrochemical industry | 169 (169:0) | 1.25±2.28*,# | 1.21±4.17 | 2.975±6.125 | 3.6±4.32 | 1.97±3.01 |
| (Yaghmaien et al., 2019) (64) | Cross-sectional | Iran | Personal | Landfill plant | - | 0.009±0.005 | 0.011±0.006 | 0.014±0.009 | 0.024±0.014 | - |
| (Zoleikha et al., 2017) (65) | Cross-sectional | Iran | Personal | Petrol station | 15 (15:0) | 1.28±0.447*,# | 0.337±0.71 | 0.124±0.13 | 0.092±0.012 | - |
Comparison of existing OELs and DNELs of BTEX and styrene by institutions and countries
| Institution or country | Benzene | Toluene | Ethylbenzene | Xylene (isomers) | Styrene | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| mg/m3 | ppm | mg/m3 | ppm | mg/m3 | ppm | mg/m3 | ppm | mg/m3 | ppm | |
| ACGIH, USA | 1.6 | 0.5 | 75.37 | 20 | 86.84 | 20 | 434.19 | 100 | 85.19 | 20 |
| OSHA, USA | 3.19 | 1 | 376.85 | 100 | 434.22 | 100 | 434.19 | 100 | 212.99 | 50 |
| NIOSH, USA | 0.32 | 0.1 | 753.7 | 200 | 434.22 | 100 | 434.19 | 100 | 425.97 | 100 |
| Australia | 3.19 | 1 | 188.43 | 50 | 434.22 | 100 | 347.35 | 80 | (monomer) 212.99 | (monomer) 50 |
| Brazil | - | - | 293.94 | 78 | 338.69 | 78 | 338.67 | 78 | - | - |
| Canada | 1.6 | 0.5 | 75.37 | 20 | 86.84 | 20 | 434.19 | 100 | (monomer) 149.09 | (monomer) 35 |
| Japan | 3.19 | 1 | 188.43 | 50 | 86.84 | 20 | 217.1 | 50 | 85.19 | 20 |
| South Korea | 3.19 | 1 | ||||||||
| MAK, Germany | - | - | 188.43 | 50 | 86.84 | 20 | 217.1 | 50 | 85.19 | 20 |
| AGS, Germany | 1.92 | 0.6 | - | - | - | - | - | - | - | - |
| Netherlands | (0.19*) 0.7 | (0.06*) 0.22 | 150.74 | 40 | 214.07 | 49.3 | 217.1 | 50 | ||
| Poland | 1.6 | 0.5 | 99.87 | 26.5 | 198.87 | 45.8 | 99.86 | 23 | 49.84 | 11.7 |
| United Kingdom | 3.19 | 1 | 188.43 | 50 | 434.22 | 100 | 217.1 | 50 | 425.97 | 100 |
| European Union | 0.32 | 0.1 | 188.43 | 50 | 434.22 | 100 | 217.1 | 50 | - | - |
| REACH RAC | 0.16 | 0.05 | - | - | - | - | - | - | - | - |
| REACH DNELs** | 0.8 | 0.25 | 192 | 50 | 77 | 100 | 221 | 50 | 85 | 23.5 |
| Iran | 1.6 | 0.5 | 75.37 | 20 | 86.84 | 20 | 434.19 | 100 | 85.19 | 20 |
| Turkey | 0.32 | 0.1 | 188.43 | 50 | 434.22 | 100 | 217.1 | 50 | - | - |