The aim of the editors of this volume is to use basic and ap- plied studies in the field of mutagenesis to approach a problem of especial concern. The problem is that of the usage of toxic chemi- cals, particularly agricultural chemicals, in ever-increasing quan- tities in those parts of the world that feed the most people. Agri- cultural chemicals that are in use in Pakistan are emphasized here. These are the same chemicals that are in use throughout the develop- ing world, although the quantities of the different types that are used may vary from country to country, and from region to...