Technical Bulletin No. 0950: Evaluating Trends in Hydrophobic Organic Contaminants in Biological Tissues Using Linear Regression

This technical bulletin describes the basis for and application of several linear regression methods to the analysis of time trends in the concentrations of hydrophobic organic contaminants (HOCs) from existing fish tissue data sets. The methods described are applicable to other tissues and tissue contaminants, and to other environmental matrices. The uses, strengths, and weaknesses of several techniques found in peer-reviewed literature are presented, including ordinary least squares regression, maximum likelihood estimation, and nonparametric regression.