ABSTRACT

Ecosystems are open systems, and it is therefore inevitable that sooner or later all the chemicals we are using today will nd their way into the environment. Consequently, this raises the question: What harmful effects can the chemicals used in pharmaceuticals cause in nature, and what harm can their accumulation impose on humans, either indirectly or directly? The modern industrialized society uses about 100,000 chemicals, many of which have been detected in nature in concentrations that may cause harm. More than 3000 compounds out of a total of 100,000 are pharmaceutical compounds. They are in principle not different from other organic compounds with respect to the potential harm they pose to nature and human beings, but because of their medical value, it is necessary to strike a balance between their positive and negative effects. These compounds are used as pharmaceutical components because they have a biological effect, and therefore it should not be surprising that several pharmaceuticals become harmful and have an adverse effect on nature and humans at certain concentrations. An obvious question in this context would be, “Is it sensible and feasible to assess potential adverse effects in ecosystems and their organisms?” Because

CONTENTS

15.1 Introduction ................................................................................................ 415 15.2 Environmental Risk Assessment ............................................................. 416 15.3 Characteristics and Structure of Ecotoxicological Models, in

Comparison with Other Models Applied in Ecological and Environmental Management ................................................................... 424

15.4 Overview of Pharmaceutical Models......................................................427 15.5 An Illustrative Example of a Pharmaceutical Model ............................ 431

15.5.1 The Equations ................................................................................. 432 References ............................................................................................................. 437

of constant release in most cases, a chronic-rather than an acute-effect will probably be observed.