Examination of some heavy metal pollution in roadside plants using X-ray spectroscopy

Abstract

PhD thesis of mgr Punsiri Dam-o is dedicated to studies of the heavy metal pollution in samples of biological origin using the X-ray spectroscopy technique. The thesis contains the 156 pages, is preceded by a table of contents, list of figures and tables. It consists of eight chapters, two appendices, a bibliography containing almost 70 items, acknowledgments and a short CV on last two pages. In the first introductory chapter mgr Punsiri Dam-o describes the origin of the project which is an essential part of her work and its importance from the physical and socio-educational points of view. In the next chapter she discusses the sources of heavy metals pollutants characteristic to the human activity analysed in this work. In the third chapter she shows the current state of research in this field and results obtained by other authors experiments and results characteristic of specific plants to justify the selection of species made in the work. In the third chapter there is described the method of collecting and preparation of samples and the measuring technique using the X-ray fluorescence spectrometer with the particular method of analysis obtained spectra involving high school students participating in the project. Next chapter is dedicated to the problem of obtaining non-professional forces to project activities. There is described the structure of the webpage of the "nuclear e-cology" project, its functioning and problems associated with such a kind of scientific activity. The fifth chapter presents the physical results obtained and their general overview, and the sixth summarizes them in five short and specific statements. The results are divided into two classes: the first is the analysis of the total contents of heavy metals in the vicinity of the roads and there is shown the significant achievement of this work consisting of the discovery of the significant dependence of the pollution levels with time elapsed from a particular road construction; and the second is the examination of the rate of decrease of the pollutant contamination with the distance from the road. The measured abundances confirm some of the measurements known from the literature. It is worth noting that for the first time in this context, there is measured the diminishing the content of bromine in roadside plants. The results increased the world database and give rise to the application of the developed methodology for the future studies, so that is described in the seventh chapter. In the appendices mgr Punsiri Dam-o describes in detail actions of the students involved in the "nuclear e-cology" project, the created project website, the informatics system that supports the project, the Facebook page of the project and the results obtained by all groups of students on their specific research sites.