Comparison of laboratory-derived biomagnification factors for hexachlorobenzene in common carp conducted under 9 test...

Nine dietary exposure bioaccumulation fish tests with hexachlorobenzene (HCB) were conducted with common carp to explore how differences in test conditions (different test foods and feeding rates) influenced the lipid-corrected, growth-corrected kinetic biomagnification factor (BMF_kgL ) value (BMF_kgL  = BMF_kg  × lipid content of test food/lipid content of test fish). The BMF_kgL values for HCB differed by approximately a factor of 5 among the tests. The average, median, 95% confidence interval, and coefficient of variation of the BMF_kgL values were 0.925, 0.998, 0.578 to 1.27, and 49%, respectively. The BMF_kgL value differed markedly between tests conducted using test food with lipid contents of approximately 5 and 15%. Different feeding rates (2 or 3% of body weight/d) had comparatively little effect on the BMF_kgL of HCB. The present study revealed that the lipid content of test fish was correlated with the growth-corrected kinetic BMF (BMF_kg ) value of HCB but the lipid content of test food was poorly correlated with BMF_kg . This lack of correlation might explain the large variations of the BMF_kgL values observed. The value of the BMF_kg normalized to a fish with a 5% lipid content (defined as the 5% lipid-normalized BMF_kg in the present study) did not differ markedly between tests conducted using test food with different lipid contents (5-15%). It is therefore useful to report the 5% lipid-normalized BMF_kg as well as the BMF_kgL when dietary exposure tests are conducted. Environ Toxicol Chem 2018;37:1032-1039. © 2017 SETAC.