Tissue Distribution, Maternal Transfer, and Age-Related Accumulation of Dechloranes in Chinese Sturgeon

While dechloranes have been detected in environmental media and wildlife, limited information was available on their tissue distribution in wildlife. <i>Syn</i>-dechlorane plus (<i>syn</i>-DP), <i>anti</i>-DP, <i>syn</i>-undecachloropentacyclooctadecadiene (<i>syn</i>-Cl₁₁DP), <i>anti</i>-Cl₁₁DP, dechlorane 602, dechlorane 603 and mirex were measured in 13 organs of 17 female Chinese sturgeon (<i>Acipenser sinensis</i>). Dechloranes were detected in all tissues and the highest concentrations of total dechloranes were detected in heart (87 pg/g ww, 4.5–645 pg/g ww), followed by adipose (61 pg/g ww, 14–531 pg/g ww) and eggs (57 pg/g ww, 13–261 pg/g ww). The tissue distribution of DP was mainly determined by lipid partition, while Dec 602 and Dec 603 preferred to accumulate in the intestine and stomach. The values of <i>f</i>_anti (the concentration of anti-DP relative to the sum concentration of DP) in maternal tissues (0.72 ± 0.03 in muscle) were significantly higher than those found in eggs (0.65 ± 0.04) (<i>p</i> < 0.001), while <i>f</i>_{anti‑Cl11DP} (the concentration of anti-Cl₁₁DP relative to the sum concentration of Cl₁₁DP) in maternal tissues (0.59 ± 0.10 in muscle) was significantly lower than that in eggs (0.75 ± 0.13) (<i>p</i> < 0.05). High maternal transfer efficiencies of dechloranes were observed in eggs, which accounted for 49% of the total body burden, and the ratios of concentrations in eggs to maternal tissues (EMR) for mirex, Dec 602, Dec 603, <i>syn</i>-Cl₁₁DP, <i>anti</i>-Cl₁₁DP, <i>syn</i>-DP, and <i>anti</i>-DP were 18, 8.8, 5.2, 2.6, 5.2, 5.5 and 3.7, respectively, which are dependent on their <i>K</i>_OW values <i>(r </i>= −0.66, <i>p</i> < 0.01). Negative age-related trends were observed for mirex, Dec 603, <i>syn</i>-Cl₁₁DP and <i>anti</i>-Cl₁₁DP in eggs (<i>R</i>² = 0.28–0.38, <i>p</i> = 0.02–0.05), which were possibly due to their high transfer efficiencies to eggs from maternal body (49%)