ALKYL POLYCHLOROBIBENZYLS AND PLANAR AROMATIC CHLOROCOMPOUNDS IN PULP-MILL PRODUCTS, EFFLUENTS, SLUDGES AND EXPOSED BIOTA

Aromatic chlorocompounds which interfere in GC/MS analysis of dioxins were studied in samples from three different pulp mills and in fish and mussels exposed to pulp mill effluents. The major interfering compounds were chlorinated alkyl bibenzyls (R-PCBBs; R = C5-alkyl; P = 1-4). In pulp mill samples, levels of C5-PCBBs (10-120 ng/l in effluents, 5-33 ng/g in dried sludges) were orders of magnitude higher than the levels of toxic PCDDs and PCDFs. C5-PCBBs bioaccumulated slightly to the recipient fish (0-2 pg/g in fresh muscles) and to incubated mussels (3-26 ng/g in lipid). In mussels, significant levels (19-73 ng/g in lipid) of other than pulp mill originated toxic hepta- and octa-CDFs were found. Polychloronapthalenes and toxic coplanar polychlorobiphenyls occurred at low levels in all samples and appeared to be from other sources than pulp mills except 3,3',4,4'-tetrachlorobiphenyl, which was more abundant in sulfite mill samples.