# Table 4 Average metal concentrations (ppb) of four tobacco samples for each metal in four different compartments of the waterpipe setup

Metal concentration in ppb (fraction of total in sample)
Metal Original sample Ash residue Water vessel Smoke Of which >0.045 μm
U 845.58 (1.00) 42.37 (0.05) 3.27 (0.004) 799.946 (0.95) 71.25
Cr 22656.66 (1.00) 4677.02 (0.21) 262.99 (0.012) 17716.645 (0.78) 781.51
Fe 212694.44 (1.00) 62577.98 (0.29) 2187.05 (0.010) 147929.416 (0.70) 1261517
Mg 1169370.72 (1.00) 404081.91 (0.35) 37931.91 (0.032) 727356.904 (0.62) 40906.88
Mn 21170.84 (1.00) 10903.92 (0.52) 35.48 (0.002) 10231.429 (0.48) 701.89
Mo 532.72 (1.00) 214.10 (0.40) 8.60 (0.016) 310.026 (0.58) 22.98
Pb 1329.66 (1.00) 449.00 (0.34) 37.47 (0.028) 843.188 (0.63) 294.56
Ni 10154.03 (1.00) 2216.33 (0.22) 78.52 (0.008) 7859.176 (0.77) 1159.21
V 578.94 (1.00) 170.58 (0.29) 25.23 (0.044) 383.127 (0.66) 29.50
Cu 6694.65 (1.00) 2179.41 (0.33) 46.84 (0.007) 4468.404 (0.67) 735.82
Bi 21.17 (1.00) 5.71 (0.27) 0.42 (0.020) 15.043 (0.71) 4.96
1. The fraction of metal in each compartment is calculated by dividing the average value of each metal from all samples in that compartment by the average value of that metal in the original sample. The readings are subject to an RSD of 5.25%.