E. Rizzio

Determination of trace elements and evaluation of their enrichment factors in Himalayan lichens.

Within the framework of the Ev-K2-CNR research program of the Italian National Research Council a specific task project has been initiated for the identification of trace elements in lichens in remote high altitude areas. This is to evaluate the possibility of using lichens as biomonitors of trace elements of atmospheric pollution. In this preliminary study, more than 20 elements have been determined in some species of lichens collected at different altitudes (from 1300 to 5000 m) in the region of the Sagarmatha National Park (Nepal). Samples of superficial soils were also collected and analyzed to calculate the trace element enrichment factors (EF) using scandium as a normalizing element. Most of the trace elements were determined by instrumental neutron activation analysis (INAA), while lead and cadmium measurements were carried out with electrothermal atomic absorption spectroscopy (ET-AAS). The EF values as well as the elemental concentrations are reported and discussed.

COMPARATIVE STUDIES ON THE CONCENTRATIONS OF SOME ELEMENTS IN THE URBAN AIR PARTICULATE MATTER IN LODZ CITY OF POLAND AND IN MILAN, ITALY

Urban air particulate matter (APM) was collected at two sampling sites in the city of Lodz, Poland in March, May and July 2001. The concentrations of several trace elements (TEs) as well as heavy metals were determined by neutron activation analysis (NAA). It was found that for many elements, the contribution of the blank values arising from the filtering material is very high, especially for glass fiber filters. The results obtained for Lodz were compared to those obtained for Milan, Italy. The data of Lodz are, in general, lower than those found in Milan downtown in the winter season. The influence of three coal-fired power plants located within the city of Lodz on the concentration of trace elements in APM was also considered.

Trace elements determination in lichens and in the airborne particulate matter for the evaluation of the atmospheric pollution in a region of northern Italy

Lichens as biomonitors and neutron activation analysis as analytical technique have been employed to study the distribution of trace elements (TE) in a mountain region of north Italy (Biella) characterized by settlements of wool industry. Samples of airborne particulate matter collected onto filters, different species of lichens and samples of soils have been analyzed for the calculation of the enrichment factors (EFs) of more than 25 TE. By comparison of the corresponding EFs, the most suitable lichen species (Parmelia caperata) was selected as specific TE biomonitor of the area investigated. Samples of this lichen were collected and analyzed for the evaluation of the TE distribution in four different locations. The results obtained from the analysis of the lichens gave information about the predominant direction of pollutants transportation, while those related to the concentrations found in the air particulate allowed the evaluation of the degree of the local TE atmospheric pollution.

Some analytical problems encountered for trace elements determination in the airborne particulate matter of urban and rural areas

The determination of trace elements (TE) in airborne particulate matter collected onto filters requires an accurate evaluation of the entire analytical procedure. Since many elements have to be determined at a few milligrams of air dust at nanogram levels, possible sources of error can arise from uncontrolled parameters such as blank of the filters, sample homogeneity, pre-analytical treatment, primary and comparator standards. These potential critical points are presented here and discussed on the basis of the experience developed in our laboratory in previous studies where several TE monitoring campaigns have been performed for air particulate matter collected in urban as well as in rural residential areas of north Italy. Instrumental neutron activation analysis (INAA) and electrothermal atomic absorption spectroscopy (ET-AAS) have been used for the investigation of more than 30 trace elements.

The use of neutron activation analysis for particle size fractionation and chemical characterization of trace elements in urban air particulate matter

The concentration of more than 25 trace elements have been determined in total air particulate matter and in the size segregated fractions from the urban area of Pavia (North Italy). The PM10 fraction was also collected and analyzed. A study of the solubility in water and in physiological solution of the trace elements contained in the PM10 was also carried out. The resulting solutions were further submitted to column chromatography using Chelex 100 to perform a preliminary chemical characterization. INAA was used as the main analytical technique. ET-AAS was used for all Pb and Cd measurements and, in some cases, for the analysis of V, Mn, Cu and Ni.

Content of trace elements in the respirable fractions of the air particulate of urban and rural areas monitored by neutron activation analysis

The concentrations (ng/m3) of more than 30 trace elements have been determined in the total air particulate matter and in the sizesegregated fractions collected in urban, industrialized, and rural residential areas in northern Italy by means of a multistage inertial impactor with the PM10 inlet. All measurements have been carried out by instrumental neutron activation analysis, except for Pb and Cd, which have been determined by electrothermal atomic absorption spectroscopy. Analytical quality assurance procedures have been developed with special regard to blanks, reagents, and sampling. Total concentrations and the granulometric distribution found in the different locations are reported and compared.

The determination of iron and other metals by INAA in Cortex, Cerebellum and Putamen of human brain and in their neuromelanins

Neuromelanin (NM) is an ubiquitary intraneuronal pigment in human brain and its abundance is probably related to neuronal vulnerability, especially in Parkinson Disease. In this and other neurodegenerative diseases an association was shown with endogenous accumulation and environmental exposure to metals. Melanins are strong metal chelators, therefore it is important to measure their content in brain regions and in their NMs. In this work the concentration of 18 elements was measured in each brain region and in the corresponding NM by instrumental neutron activation analysis.

Gallium distribution in several human brain areas

Gallium is an element of increasing biological interest: It is involved in problems related to environmental pollution (Ga compounds are used in electronics industry) and to clinical treatments (Ga radionuclides are employed to detect neoplastic lesions). Moreover, since its chemical behavior is similar to that of aluminum, gallium could play a role in the health effects attributed to this element.Data on naturally occurring Ga levels in human samples from healthy subjects are scanty; regarding the brain, the only reliable values available in the literature were published by Hamilton in 1972/73. In this work, the gallium distribution in several human brain areas, evaluated by radiochemical neutron activation analysis (RNAA), was found to be dishomogeneous. The element concentration determined in dry samples was, in any case, lower than the ppb level.