ABSTRACT

EVOLUTIONARY PERSPECTIVE Michel Fournier,1,4 Pauline Brousseau,2 Helen Tryphonas,3 and Daniel

Université du Quebec a Montreal Montreal, Quebec

2 Department of Biological Sciences Concordia University

Montreal, Quebec 3 Toxicolology Research Division

Bureau of Chemical Safety Food Directorate, Health Protection Branch, Health Canada

Ottawa, Ontario 4 Department of Fisheries and Oceans

Institut Maurice-Lamontagne Mont-Joli, Quebec

Introduction

The immune system, developed during evolution through interactions between hosts and infectious agents, uses its effector mechanisms against all potentially pathogenic agents: viruses and other microorganisms, parasites and neoplasic cells (Roitt et al., 1993). Without this system, which defines and determines the “self” and the “nonself,” animal life would likely not exist or, at least, not exist as we know it. The considerable importance of the immune system justifies the work devoted to immunotoxic phenomena and their consideration in evaluating the risk of chemical substances.