Highly enriched concentrations of several heavy metals have been found in municipal solid waste incinerator (MSWI) ash. In an effort to identify possible sources of these metals in MSWI ash, a variety of disposable household plastic products was examined for heavy metal content. Using both thermal and epithermal neutron activation analysis (NAA) along with Compton suppression techniques, concentrations of several trace and heavy metals including Ag, As, Au, Ba, Br, Cd, Cr, Cu, Fe, Mn, Ni, Sb, Se, Sn, Sr, V, W and Zn were determined. Results indicate a wide range of concentrations for these elements, with large variations in plastics of similar color and intended use. As limits dealing with heavy metal content of consumer products are lowered, NAA techniques will provide a useful method for verification of product compliance.
Technological process of welding is significant source of pollution of working environment with heavy metals. Evaluation of chemical quality of working environment was made by means of radionuclide X-ray fluorescent analysis and activation analysis with fast neutrons. Welding aerosols were sampled by filtration method on Synpor 4 membrane ultra-filters. For selected types of welding filter metals, determination of heavy metals in aerosols was performed.
Neutron activation analysis has been used to analyze sediment cores from the Rock River and two branches of Kent Creek, one of its tributaries, to determine the concentrations of thirteen heavy metals (Ti, Cu, V, Mn, As, Sb, Se, Cr, Ni, Sc, Fe, Zn, and Co) and two rare earths (Sm and La). The downstream sites of both the Rock River and the two branches of Kent Creek have elevated concentrations of several heavy metals including arsenic, antimony, and zinc. In addition, hundreds of parts per million of copper have been found in samples from the downstream site of the North Fork of Kent Creek. Toxicity tests of the sediment also indicate that the downstream sites are detrimental to lifeforms. Analysis of the data from the two branches of Kent Creek clearly indicate that heavy metal concentrations increase as the distance from the center of industrial activity (Rockford) decreases.
Twenty trace elements and heavy metals of Dalat lake sediment were analyzed by neutron-activation analysis at the ASTRAREACTOR. The elaborated method was also controlled by analyzing the reference material for lake sediment SL-1 of IAEA. It showed a good agreement with the certified values for most of the elements. The relative errors ranged from 1% to 25%.
Authors:A. Garg, V. Ramakrishna, Vivek Singh, and M. Olaniya
Solid wastes and sewage sludges in metropolitan cities are potential health hazards due to toxic heavy metal pollutants. Sewage sludges from six Indian cities viz., Ahmedabad, Bikaner, Bombay, Calcutta, Jaipur, Kanpur and solid wastes from six different disposal sites of the capital city of Delhi have been analyzed for 26 elements (As, Au, Ba, Br, Co, Cr, Cs, Cu, Eu, Fe, Hg, Hf, K, La, Mg, Mn, Mo, Na, P, Rb, Sb, Sc, Se, Sr, Th and Zn) by employing instrumental neutron activation analysis (INAA). Sewage sludges from Bombay after different treatments (settled, digested, aerobic, anaerobic) along with several environmental SRMs were also analyzed. An attempt has been made to attribute the pollutant sources to the degree of urbanisation and industrialization of the city. Role of treatment processes in the removal/retention of heavy metals is discussed.
A fully instrumental method for the neutron activation analysis of heavy metals in sewage sludges has been developed, based
on short-lived isotopes, and restricting the total experiment time to 1 hour per sample. The irradiation scheme consists of
a cyclic and conventional part, the period of the cyclic irradiation being optimised for the determination of lead, using207mPb (T=0.8 s). Gamma ray spectra from Ge(Li) detectors are stored on magnetic tape and analysed using the SAMPO programme.
An IDENTIFY subroutine enables absolute determinations to be made eliminating the need for standards. Sensitivities and detection
limits for 21 heavy metals have been determined and the results for several sludges are presented.
Contamination of ground level air at Lublin town was studied by measurements of radioactive isotope and heavy metal contents in Parmeliaceae lichens exposed during six months on the area of the town. The concentration of the elements studied was compared with these ones measured in unexposed (blank) samples of lichens. The highest increase of radioactivity was noticed for 232Th, 226Ra and 40K. The contamination by 137Cs does not increased markedly, ranging from 2 to 107 Bq/kg of the dry lichen sample. Nearly half of the exposed samples do not reveal any increase of cesium radioactivity. Heavy metal concentrations in analyzed lichens were low. From the results obtained, one may conclude that concentration of these metals in ground air level does not reach appreciable values.