Chanthawan Thabngern. The study of characteristics of dust samples in Mae Moh communities by neutron activation analysis . Master's Degree(Radiological Science). Mahidol University. : Mahidol University, 2003.
The study of characteristics of dust samples in Mae Moh communities by neutron activation analysis
Abstract:
In this research, the composition, the concentration of the elements and the comparison
of the concentration of the elements in air particulate samples taken from Mae Moh area were
determined by using the neutron activation analysis (NAA) technique. Fifteen samples from
the Mae Moh area were collected by a Mini Vol portable air sampler. Four samples were
collected from the sources of dust such as the fly ash dumping area, coal mine area, along the
road in Mae Moh and the Limestone mill. Eleven samples were collected from the Mae Moh
area about 30-120 kilometers from the coal mine pit.
The sample and the standard reference material SRM 1633b and SRM 1648 from NIST
were irradiated under identical geometry with thermal neutrons from TRR-1/M1 research
reactor at the Office of Atoms for Peace prior to the gamma-ray measurement. Seventeen
elements, Mn, Na, Cl, Mg, V, Ca, Fe, Au, Sb, Sc, Sm, As, Br, Zn, La, Ce and Cs were found.
After the repetitive analyses of SRM 1633b and SRM1648 standard reference materials, the
precision and the accuracy were found to be within the acceptable limit of 10%. Seven
elements were determined quantitatively in ng/m3 of the samples. The values were found in
the ranges of 0.14-2.38 ng/m3, 8.26-51.81 ng/m3, 7.13-13.22 ng/m3, 0.89-38.28 ng/m3, 143.75-
926.25 ng/m3, 12.62-24.25 ng/m3 and 5.54-6.29 μg/m3 for Sm, As, Sc, Mn, Na, V and Ca,
respectively. The comparative method was used to analyze the other ten elements which
cannot be directly quantified by determining the ratio of the references’ peak areas such as the
peak area of fly ash dumping area, coal mine area or Ban Thasi with the other areas. Sm, As,
Sc, Mn, Na, V and Ca were found in the fly ash dumping area. The element As was found in
Ban Sob Moh and Ban Huai King. Mn was high in Ban Mai and Ban Sob Moh. The
concentration of As, Mn, Na,V and Ca were found within the Threshold Limit Values (TLVs)
published by the American Conference of Govermental Industrial Hygienists and the
Permissible Exposure Limits (PELs) by the Occupational Safety and Health Administration
(OSHA).