Since the first edition of this book five years ago, testingmustbeseriouslyexaminedbyresponsibletoxicologists. The sophistication of new computer systemsthefieldoftoxicologyhascontinuedtogrowunabated. Thisyoungersiblingofthemoreestablishedsciencesis is allowing studies in such areas as structure–activity relationships. Indeed, computers in general are aidingcrossingmoreandmoredisciplinaryboundarieswhile graduallyrefiningitsscientificbasis.Muchfundamen- experiments in direct measurement and analysis, as well as data capture, manipulation, and retrieval.talresearchisstillnecessary.Theexcitementoftoxicology is based, in large measure, on the difficulty of Areas of toxicology that this book has not stressed aremanagementofhazardouswastes,aspectsofpollu-ma