Proceedings of a symposium held in Hyderabad, India, 4-7 November 1996. The aim of the symposium was to provide an international forum for discussion of the applications of nuclear analytical techniques and related isotopic tracer methods, particularly in the area of analytical quality assurance, including validation of analytical methods and development of new analytical reference materials. As these methodologies contribute substantially to the harmonization of data, they are playing an important role in the application of newly emerging techniques such as quality management and quality assurance standards (e.g. ISO-25 and ISO-9000) in environmental analytical laboratories. The symposium programme covered a wide variety of applications of nuclear (and related) analytical techniques (mainly neutron activation analysis, energy dispersive X ray fluorescence, particle induced X ray emission and inductively coupled plasma-mass spectrometry) as used in the study of air particulates, solid waste products, sediments, food, water, human tissues, biomonitors and other kinds of environmental samples.