Abstract
We established an estimation equation for dioxin TEQ (based on the WHO-2006 TEF system) by using the concentrations of indicative congeners. In the equation, total TEQ was evaluated by the sum of the products of each concentration of five indicative congeners (2,3,4,7,8-pentachlorodibenzofuran, 3,3′,4,4′,5-pentachlorobiphenyl (#126), 2,3,3′,4,4′-pentachlorobiphenyl (#105), 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin and 1,2,3,7,8-pentachlorodibenzo-p-dioxin) and the corresponding coefficient (0.866, 0.112, 1.11X10-4, 0.0313 and 1.29, respectively). To evaluate the effectiveness of the equation, analytical data of various environmental samples (ambient air, soil, and river sediment) were applied. As a result, the estimated total TEQ was in good agreement with the actual total TEQ which calculated from 29 TEF congener concentrations: the ratio of the estimated and actual total TEQ was 0.98 with the standard deviation at 0.09. This suggests the equation can assess the validity of dioxin-analytical result by comparing the total TEQ which calculated from 29 TEF congener concentrations with the estimated total TEQ. The equation can be useful for checking the quality of analytical results. We proposed an acceptable range of the ratio of the estimated total TEQ to the 29 TEF congener concentrations based one was 0.76-1.21.
