After a brief historical survey of the role of neutron activation analysis (NAA) in environmental analysis there follows a section on the main types of NAA and their application to environmental problems and a table of ideal sensitivities is given. The rest of the article deals with NAA as it is applied to the main divisions of the environment. Each of these sections includes a short summary of the sampling requirements suitable for NAA. Section 3 deals with its application to biological samples and includes a brief discussion on standard reference materials (SRMs) in NAA. Applications to various types of biological material are discussed, ending with a survey of biomonitoring using NAA. The next section (the longest) is the analysis of water by NAA. This is mainly based on the preconcentration and postirradiation procedures currently used for the major types of water (seawater, surface water and underground water). A table of element concentrations in seawater and surface water illustrates the low limits of detection required to determine many trace elements by instrumental neutron activation analysis (INAA). Applications are discussed in the main body of the text. There then follows a section on the use of NAA in air particulate analysis for trace elements. The importance of PM10s (particles with aerodynamic diameter less than 10 µm) to human health and the reasons for concentrating on the analysis of these particles by NAA is discussed. Having discussed the main areas of NAA used there follows an application section. Large‐scale biomonitoring procedures are outlined, particularly those involving plant materials. The final section on major environmental divisions covers the use of NAA in analysis of soils and sediments together with the analysis of coal. This latter topic also includes on‐line analysis of coal using isotope sources. Finally, there is a discussion of speciation and the function of NAA in environmental speciation, particularly atmospheric and aqueous speciation analysis.
