Congener WHO-TEF DL [ng kg-1DM] Concentration WHO-TEQ Concentration [ng kg-1DM] [ng WHO-TEQ kg-1DM] A B1 B2 B3 A B1 B2 B3 2,3,7,8-TCDD 1 0.1 <DL <DL <DL <DL 0.050 0.050 0.050 0.050 1,2,3,7,8-PCDD 1 0.5 <DL 0.60 <DL <DL 0.250 0.600 0.250 0.250 1,2,3,4,7,8-HxCDD 0.1 0.5 <DL <DL 0.60 <DL 0.025 0.025 0.060 0.025 1,2,3,6,7,8-HxCDD 0.1 0.5 2.60 1.10 4.00 <DL 0.260 0.110 0.400 0.025 1,2,3,7,8,9-HxCDD 0.1 0.5 <DL <DL 1.20 1.70 0.025 0.025 0.120 0.170 1,2,3,4,6,7,8-HpCDD 0.01 0.5 57.00 31.00 46.00 48.00 0.570 0.310 0.460 0.480 OCDD 0.0001 0.5 466.00 323.00 355.00 412.00 0.047 0.032 0.036 0.041 2,3,7,8-TCDF 0.1 0.5 4.10 1.60 2.40 3.30 0.410 0.160 0.240 0.330 1,2,3,7,8-PCDF 0.05 0.5 0.80 0.60 0.60 0.90 0.040 0.030 0.030 0.045 2,3,4,7,8-PCDF 0.5 0.5 <DL 0.50 1.70 1.70 0.125 0.250 0.850 0.850 1,2,3,4,7,8-HxCDF 0.1 0.5 <DL 0.70 1.40 1.60 0.025 0.070 0.140 0.160 1,2,3,6,7,8-HxCDF 0.1 0.5 0.80 1.70 0.90 1.00 0.080 0.170 0.090 0.100 2,3,4,6,7,8-HxCDF 0.1 0.5 0.60 1.60 2.00 <DL 0.060 0.160 0.200 0.025 1,2,3,7,8,9-HxCDF 0.1 0.5 <DL <DL <DL <DL 0.025 0.025 0.025 0.025 1,2,3,4,6,7,8-HpCDF 0.01 0.5 17.90 16.70 6.20 16.40 0.179 0.167 0.062 0.164 1,2,3,4,7,8,9-HpCDF 0.01 0.5 <DL 0.50 0.60 <DL 0.003 0.005 0.006 0.003 OCDF 0.0001 0.5 44.00 49.00 59.00 52.00 0.004 0.005 0.006 0.005 Total - - 595.60 429.40 482.15 540.15 2.178 2.194 3.024 2.748

Table 1: PCDD/F concentrations and respective WHO-TEQ concentrations in the sludge samples for the WWTP taken as reference for the population exposed to POP contamination (A) and for the background WWTPs (B1, B2 and B3); concentrations below the DL are assumed equal to half the DL itself for the calculation of the total concentrations.