US EPA

2165837 

Journal Article 

TO NORMALIZE OR NOT TO NORMALIZE - FAT IS THE QUESTION 

Hebert, CE; Keenleyside, KA 

1995 

Yes 

Environmental Toxicology and Chemistry
ISSN: 0730-7268
EISSN: 1552-8618 

14 

5 

801-807 

WOS:A1995QV45600009 

Concentrations of lipophilic contaminants in biota are frequently corrected for variation in tissue lipid content. Usually, this correction is accomplished by dividing tissue contaminant concentration by lipid concentration to form lipid-normalized data, This ratio-based approach is satisfactory when contaminant concentration varies in direct proportion to lipid content. However, when such a relationship does not exist, erroneous conclusions may be reached. Recent research has emphasized the potential shortcomings of the use of ratio variables. We demonstrate the importance of considering these shortcomings when lipid-normalizing data. Three examples are presented, and an alternative approach based upon the use of analysis of covariance (ANCOVA) is suggested. 

LIPID NORMALIZATION; CONTAMINANTS; ORGANOCHLORINES; ANCOVA