All statistical tests were performed with SPSS software (SPSS
17.0 for Windows, SPSS Inc.). Nonparametric Kruskal–Wallis tests
were used to analyze overall differences among the cities in lipid
content and R36PCB concentrations. Nonparametric Mann–
Whitney tests were used to compare interspecies differences for
the lipid proportion and the PCB concentrations. Statistical signifi-
cance was accepted at p < 0.05.