The smoke of five charcoal grilled meat-restaurants in Amman city were chosen to do this study. The restaurants were given the symbols [S, Z, G, B and J]. This study focused basically on S restaurant that many experiments (7 experiments) were done there under different conditions. A comparison was made between the restaurant S with the other restaurants [Z, G, B and J]. The results of the all restaurants samples for the 17 PCDD/Fs compounds are shown in Table S1 and in Figure 1. 2,3,7,8-TCDD was found in the concentration range from 0.0008 µg/m3 (G) to 0.0179 µg/m3 (S). 2,3,7,8-TCDF was found in the concentration range from 0.0129 µg/m3 (S) to 0.0167µg/m3 (B).1,2,3,7,8-PnCDD was found in the concentration range from 0.0066 µg/m3 (J) to 0.0722 µg/m3 (S).1,2,3,7,8-PnCDF was found in the concentration range from 0.0041 µg/m3 (B) to 0.0054 µg/m3 (S).2,3,4,7,8-PnCDF was found in the concentration range from 0.0012 µg/m3 (B) to 0.0293 µg/m3 (S).1,2,3,7,8,9-HxCDD was found in the concentration range from 0.0086 µg/m3(B) to 0.0424 µg/m3 (S).1,2,3,4,7,8-HxCDF was found in the concentration range from 0.0004 µg/m3 (Z) to 0.0007 µg/m3 (S). 1,2,3,6,7,8-HxCDFwas found in the concentration range from 0.0008 µg/m3 (Z) to 0.013 µg/m3 (S).1,2,3,7,8,9-HxCDF was found in the concentration range from 0.0003 µg/m3 (B) to 0.0847 µg/m3 (S).2,3,4,6,7,8-HxCDF was found in the concentration range from 0.0004 µg/m3 (G) to 0.0101 µg/m3 (S). 1,2,3,4,6,7,8-HpCDD was found in the concentration range from 0.0007 µg/m3 (Z) to 0.0272 µg/m3 (S). 1,2,3,4,6,7,8-HpCDF was found in the concentration range from 0.0009 µg/m3 (G) to 0.0129 µg/m3 (S).1,2,3,4,7,8,9-HpCDF was found in the concentration range from 0.0002 µg/m3 (G) to 0.0824 µg/m3 (S). OCDD was found in the concentration range from 0.0042 µg/m3 (J) to 0.0817 µg/m3 (S).OCDF was found in the concentration range from 0.0038 µg/m3 (G) to 0.0143 µg/m3 (S).1,2,3,6,7,8-HxCDD was found only in (S restaurant) with the concentration 0.0041 µg/m3. 1,2,3,4,7,8-HxCDD was not detected in any samples of the studied restaurants.
The results of the studied seven samples of S restaurant were compared with those of the other restaurants for the 17 PCDD/Fs compounds. The most detected compounds were 1,2,3,4,7,8,9-HpCDF (TEF= 0.01), OCDD (TEF= 0.0001), 1,2,3,7,8-PnCDD (TEF= 0.5), and 1,2,3,7,8,9-HxCDF (TEF= 0.1) and they also were the highest concentrations of PCDD/Fs compounds in µg/m3. While the lowest concentrations of PCDD/Fs compounds were 1,2,3,6,7,8-HxCDD (TEF= 0.1) ,1,2,3,4,7,8-HxCDF (TEF= 0.1) , and 1,2,3,7,8-PnCDF (TEF= 0.05) as shown in Figure 2.
The average total PCDD/Fs concentrations were in the range 0.0220 µg/m3 ( J restaurant) to 0.5112 µg/m3 (S restaurant) and the toxicity equivalency quantity values were found in the range from 0.5439 ng TEQ/m3 (Z restaurant) to 87.031 ng TEQ/m3 (S restaurant) as shown in Table S1 and Figure 1. The order of the restaurants according to the average total concentrations of PCDD/Fs in ng TEQ/m3 was: S > J > B > G > Z, as shown in Figure 3.
The total emissions of PCDD/Fs in g TEQ/year for the five restaurants were determined depending on the stack emissions for each restaurant and the average total concentrations in µg TEQ/m3.year as shown in Table S2 and Figure 4.
Charcoal grilled meat-restaurants generate PCDD/Fs compounds. The concentrations of these pollutants and compounds strongly dependent on many factors and conditions mentioned previously. From these factors that were determined and studied, the results were discussed. The variations in results between samples of the five studied restaurants are caused by many possible factors. One of these studied factors is sampling time, (morning or evening). As we mentioned before we focused on S restaurant. For this restaurant the samples S2, S4, S6, and S7 those taken in the evening were the highest concentrations except for S4. The reason is simple, because the food consumption is more in the evening than in the morning, and thus the increase in the amount of charcoal used. Eventually the increase of chimneys emissions means more production of PCDD/Fs pollutants, and this considered as a major source of urban outdoor air pollution. In addition, S restaurant was the highest restaurants in food consumption, therefore amount of charcoal used was higher than the other studied restaurants, which means that restaurant’s food and charcoal consumption is another factor that explains the difference between restaurant emissions. Also, one of the important factors that play the main role in the difference between the studied restaurants was the type and quantity of oil used. Finally, the meat type such as local or Romanian is also an important factor due to the amount of fat that the meat contained.
Comparison was made between the results of this study and previous study (Lin et al. 2011). Lin studied the levels of seventeen (PCDD/Fs) in the stacks of three fast food restaurants in Taiwan. Table S3 shows a comparison between the results of restaurant S in this study and the results of (Lin et al., 2011) study for PCCD/Fs. Table S5 shows a comparison between the average concentrations in (ng/m3) and in (ng TEQ/m3) in S restaurant with the values of 73.0229 and 12.4240 respectively, which are much higher than those of (Lin et al.,) study (0.0908 and 0.0085 respectively). This may have resulted from the highest concentrations of 2,3,7,8-TCDD , 1,2,3,7,8-PnCDD , and 2,3,4,7,8-PnCDF in our study, which are the most toxic congeners among the 17 PCDD/Fs . This could be due to different cooking styles used. The most detected and measured PCDD/Fs compounds in S restaurant were 1,2,3,4,7,8,9-HpCDF (TEF = 0.01), OCDD (TEF= 0.001), 1,2,3,7,8-PnCDD (TEF = 0.5) , and 1,2,3,7,8,9-HxCDF(TEF= 0.1). While in Lin et al. (2011) study ,the most detected and measured PCDD/Fs compounds were 1,2,3,4,6,7,8-HpCDF (TEF=0.01), OCDF(TEF= 0.001), OCDD(TEF= 0.001), and 2,3,7,8-TCDF(TEF= 0.1).The average concentration of the high TEF values PCDD/Fs compounds 2,3,7,8-TCDD , 1,2,3,7,8-PnCDD , and 2,3,4,7,8-PnCDF (ng/m3) in S restaurant were 8.95, 14.44, 9.65, respectively. But, in Lin et al. (2011) study were 0.00054, 0.00125, and 0.00709, respectively. In addition, the cooking oils and fuels were different between the two studies. In this study charcoal was used as a fuel, while in Lin et al. (2011) study vegetable oil , butter, or corn oil were used. Also the cooking style and method was different. In this study, S restaurant used grilling style while in the Lin et al. (2011) study deep frying and stewing methods were used. The mean stack outlet velocity in the Lin et al. (2011) study was 4.12 m/s, while in S restaurant was 19.5 m/s. Also the mean of stack diameters in S restaurant was more than that in the Lin et al. (2011) study.