Ca. 8000 kg, or 16 ... 21 kg in WHO TEQ (tetrachlorodibenzodioxin equivalent) unit, of two dioxin-like chemicals, octachlorodibenzofuran (OCDF), and heptachlorodibenzofuran (HpCDF), were released from a wood preservative chemical manufacturing plant into the Kymijoki River in Southern Finland between years 1940 and 1984. The released chemicals have accumulated in the bottom sediments of the river and the Gulf of Finland, and they have bioaccumulated strongly in the fatty fish in the Baltic Sea. Consumption of Baltic fish has been the main pathway of the released chemicals, the longer half life HpCDF in particular, into human body burdens. In humans, HpCDF is stored in fatty tissues.
We used the measurements of human fat in four population samples, one representing the general population of Finland (aged 15...85 years), another one representing the subpopulation living along the contaminated river, the third representing lactating mothers (sampled in 1987, 93, and 96 onwards) and the fourth consisting of coastal fishermen. Body burdens were assessed from the fat HpCDF data by computing the total body fat mass from the computed body mass index (BMI) and body weight for each sampled individual.
Analyses of the data revealed that (i) HpCDF accumulated in men by an order of magnitude from the age of 15 to 80 years, but it did not accumulate in women, probably due to HpCDF lost in breast feeding, (ii) in lactating women the HpCDF levels were reduced by an order of magnitude from 1987 to 1996, due to environmental decay of HpCDF after the end of the release, (iii) HpCDF body burden distributions for the population of the Kymijoki basin was not elevated in comparison to the rest of the population, highlighting the low contribution of local food and river water to the diet, (iv) HpCDF body burdens of the coastal fishermen were an order of magnitude higher than among the general population, pointing out the significance of the fish diet for the exposure. Acknowledgement: Project has been funded by the European Chemical Industry Council (CEFIC) LRI contract B3.3-KTLE-0511.