Use of “Whole Egg Residues” in Pesticide/Eggshell Studies

Abstract

HAZELTINE¹ questions the well established belief that DDE probably causes eggshell thinning in brown pelicans chiefly by finding four points of disagreement with the proposal by Blus et al.² that a concentration-effect relationship seems to exist between DDE in eggs and shell thickness. In their subsequent reply, Blus et al.³ refute Hazeltine's criticisms. There is a further argument against Hazeltine's third criticism of Blus et al.'s conclusions; and the argument has an important bearing on the interpretation of analyses based on “whole egg residues”.