Factors regulating the exposure dynamics of polychlorinated biphenyls in two fish species, Oncorhynchus mykiss and Pimephales notatus.

摘要

The aim of this research was to quantify the relative importance of biological and chemical properties in regulating the exposure dynamics of organic chemicals in aquatic ecosystems. This was achieved by (1) calibrating the bluntnose minnow (P. notatus) as a biomonitor, (2) examining the influence of chemical properties such as hydrophobicity and substitution patterns on chemical elimination rates and (3) examining the kinetics of the more toxic non-ortho PCBs. Elimination rate constants (k$sb2$) for bluntnose minnow ranged from 0.00987 to 0.00116 (ug/kg/day) for compounds with octanol-water partition coefficients varying from 5.69 to 7.80. It was further determined that substitution patterns in PCBs, as well as K$msb{ow}$, were important factors regulating chemical kinetics in rainbow trout. Multivariate analysis of covariance revealed a highly significant interaction between chlorine substitution pattern and time, suggesting that substitution pattern influences elimination kinetics. A significant relationship was also observed between elimination rate constants and octanol-water partition coefficients (log K$msb{ow}$). The non-ortho (coplanar) congeners, IUPAC #81 and #77 had the highest elimination rate constants of 0.0062 and 0.0090 (ug/kg/day) respectively, significantly faster than other tetrachlorobiphenyls present. The k$sb2$ values for rainbow trout (Oncorhynchus mykiss) ranged from 0.0030 to 0.0090 (ug/kg/day) for congeners with log K$msb{ow}$ values varying from 5.85 to 7.42. A closer examination of the kinetics of the toxic coplanar congeners in bluntnose minnow revealed a range in uptake rate constants (k$sb1$) of 8.2, 5.3, and 3.02 (ug/kg/day) for congeners #77, #126, and #169 respectively. Elimination rate constants (k$sb2$) and bioconcentration factors for congeners #77, #126, and #169 were 8.2, 5.3, and 3.02 (ug/kg/day), and 2500, 1220, and 960 respectively.Dept. of Biological Sciences. Paper copy at Leddy Library: Theses u26 Major Papers - Basement, West Bldg. / Call Number: Thesis1995 .C67. Source: Masters Abstracts International, Volume: 34-06, page: 2331. Thesis (M.Sc.)--University of Windsor (Canada), 1995.