Module 3: Toxicology - Section 2: General Principles of Toxicology

TOX2.1: Introduction

INTRODUCTION:

Toxicology has been defined as "the study of the adverse effects of chemicals on living organisms, and the assessment of the probability of their occurrence". The field has evolved to include adverse effects to humans and the environment. There are several sub-disciplines in toxicology and these include environmental, industrial, forensic and regulatory toxicology among others.

Toxicokinetics and Toxicodynamics:

Toxicokinetics is the study of the movement of toxic substance within the body. This refers to the absorption, distribution, metabolism and excretion of xenobiotics and the interpersonal variability thereof. It also encompasses the relationship between the dose that enters the body and the level of the toxic substance in any biological sample.

Toxicodynamics is the study of the relationship between the dose of the toxic substance that enters the body and the measured response. Toxicokinetics takes into consideration differences in susceptibility among individuals. The factors to consider in these processes are those of (1) bioavailability, (2) absorption, (3) distribution, (4) metabolism and (5) excretion and how they may be affected by genomic or environmental factors or combinations thereof.

REFERENCES:

General list of references for Modules 3,4 & 5.

Postgraduate Diploma in Occupational Health (DOH) - Modules 3: Occupational Medicine & Toxicology (Basic) by Profs Mohamed Jeebhay and Rodney Ehrlich, Health Sciences UCT is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.5 South Africa License. Major contributors: Mohamed Jeebhay, Rodney Ehrlich, Jonny Myers, Leslie London, Sophie Kisting, Rajen Naidoo, Saloshni Naidoo. Source available from here. For any updates to the material, or more permissions beyond the scope of this license, please email healthoer@uct.ac.za or visit www.healthedu.uct.ac.za. Last updated Jan 2007.
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