In Part II, chemical bioaccumulation is referred to as a highly undesirable process through which the availability of certain environmental endocrine disruptors (EEDs) could increase substantially. Part II also states that exposure to pollutants is a matter of their availability in the environment, in that contact with these chemicals is essentially an involuntary act. As it shall become evident later on in this and the final chapter, with all things else being equal, a pollutant’s persistence in the environment would greatly increase the potential for its bioaccumulation. Equally unfortunate, this persistence property would provide a greater window of opportunity for exposure to EEDs at the wrong time or in the wrong place.

The objectives of this part, Part III of the lecture, are for students: (1) to learn the terms and definitions used, especially those having direct relevancy to a chemical’s persistence; (2) to recognize the two major aspects of persistence and the science-based criteria for persistence and bioaccumulation determination; (3) to appreciate the cumulative effects that are made more possible due to a chemical’s persistence properties; and (4) to review the methods, the models, and the strategies developed for assessing a chemical’s persistence potential and for the removal or the reduction of such potential.

From the literature data presented in Part III here, it shall further become evident that the majority of the persistent and bioaccumulative chemicals now detected in the environment are pesticides applied or present worldwide. As summarized in Part I, many of these persistent bioaccumulative pesticides have been listed as substances potentially quite capable of disrupting the endocrine system in humans and wildlife.