Mercury (Hg) and methyl mercury (MeHg) concentrations in fish from the coastal lagoon of Orbetello, central Italy.

Total mercury (Hg tot) and methyl mercury (MeHg) were quantified in several specimens of Dicentrarchus labrax and Sparus aurata from the east basin of the Orbetello lagoon, central Italy. The size of each specimen was recorded to estimate body burdens (BBs); =Hg tot and MeHg were measured in fillets of both species. Hg tot and MeHg in S. aurata ranged between 0.355-1.58 and 0.341-1.53 µg/g wet weight (ww), respectively; in D. labrax, their ranges were 0.284-2.54 and 0.214-2.35 µg/g ww. Approximately 90% of the concentrations measured exceeded Hg tot regulatory maximum level of 0.5 µg/g ww; however, exceedance rate was different in the two species studied. No correlations between specimen size and Hg tot or MeHg BBs were detected in this study.

The two PM(2.5) (fine) and PM(2.5-10) (coarse) fractions: evidence of different biological activity.

Recent studies have shown that an increased concentration of environmental particulate matter (PM(10)) is related to many respiratory diseases. One major issue is whether the toxicity of the particles resides in some particular fraction as defined by chemical composition and size. The overall purpose of this study was to compare the in vitro toxicity of coarse (PM(2.5-10)) and fine (PM(2.5)) particulate matter, collected in an urban area of Rome, in relation to their physicochemical composition as assessed by analytic electron microscopy and atomic absorption spectroscopy. In particular, our aim was to evaluate the importance of particle physicochemical components in the induced toxicity. The in vitro toxicity assays used included human red blood cell hemolysis, cell viability, and nitric oxide (NO) release in the RAW 264.7 macrophage cell line. The hemolytic potential has been widely used as an in vitro toxicity screen and as a useful indicator of oxidative damage to biomembranes. We found that human erythrocytes underwent dose-dependent hemolysis when they were incubated with varying concentrations of fine and coarse particles. The hemolytic potential was greater for the fine particles than for the coarse particles in equal mass concentration. However, when data were expressed in terms of PM surface per volume unit of suspension, the two fractions did not show any significant hemolytic differences. This result suggested that the oxidative stress induced by PM on the cell membranes could be due mainly to the interaction between the particle surfaces and the cell membranes. RAW 264.7 macrophage cells challenged with particles showed decreased viability and an increased release of NO, a key inflammatory mediator, and both effects were not dose dependent in the tested concentration range. The fine particles were the most effective and the differences between the two size fractions in inducing these biological effects remained unchanged when the basis of comparison was changed from weight to surface measures. It seemed therefore that these differences relied on the different physicochemical nature of the particles. The main chemical difference between the two fractions resided in a greater abundance of C-rich particles with S traces in the fine fraction. Therefore, we cautiously suggest a role for these particles in the induction of toxicity.

[Concentrations of PM10 and PM2.5 particulate material in the atmosphere of Rome]. / Misure di materiale particellare PM10 e PM2.5 nell'atmosfera di Roma.

Starting from 1993, various monitoring campaigns were carried out in Rome to determine PM10 and PM2.5. Their results are presented here cumulatively, with the aim of obtaining preliminary information on relationships among these size fractions, in various seasonal periods and in two sites with different characteristics (a road site and an urban background site in a public park). Particles were collected on filter and gravimetrically determined. Both PM10 and PM2.5 concentrations show temporal fluctuations with higher values during winter months. Background concentrations are lower than those contemporaneously measured at the road site only to a limited extent (10-17%). The contribution of PM2.5 to PM10 during the winter semester is higher than during the summer one (67 vs. 52%), with no substantial intersite differences.

Heavy metals: sources and environmental presence.

The Istituto Superiore di Sanità has for many years been involved in the problem of environmental pollution caused by heavy metals. A brief review of the sources of this pollution is first presented which also includes the presence in nature of some heavy metals which are among the most dangerous. Data gathered by the authors is then presented from sampling of the emissions of urban solid waste (USW) incinerators and from environmental monitoring programs in different areas in Italy according to four categories: urban, industrial, rural and mixed.

Determination of heavy metals in samples of urban solid wastes by means of the ICP atomic spectrometry technique.

The concentration of elements of environmental significance in the leachate from landfills of urban solid wastes was determined by means of Inductively-Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The suitability of extraction tests which simulate the leaching process were undertaken. Both highly toxic elements (As, Cd, Co, Cr, Pb and V) and elements present at major concentrations (Al, B, Cu, Fe, Mn, Ni and Zn) were quantified at different levels within and under the landfill. Results showed that the extraction test recommended by EPA is acceptable in order to simulate natural leaching compared with the amounts of the elements which are brought into solution after digestion with nitric acid. Furthermore, significant correlations were found in the landfill composition at different levels for element pairs such as Al-Mn, Co-Cr, Co-Cu, Co-Fe, Co-Mn, Co-Zn, Cr-Fe, Cr-Mn, Cu-Fe, Cu-Zn, Fe-Mn, Fe-Zn, Mn-Zn and Pb-Zn.

[Cadmium as an air pollutant]. / Cadmio come inquinante dell'aria.

Daily concentrations of airborne cadmium has been determined for a year in three italian urban areas presenting different characteristics. Results obtained are in the following ranges: Rome, 0,0017--0,0194 micrograms/m3; Venice, 0,0012--0,2234 micrograms/m3 and Marghera, 0,0037--0,704 micrograms/m3. Some data for urban inciniretors emissions are also presented. Origin, effects and legislation concerning airborne cadmium are briefly discussed.

[Determination of atmospheric lead]. / Determinazione del piombo atmosferico.

The AA. discuss the analytical determination of airborne lead, pointing out the importance of a good standardization of the sampling conditions to obtain comparable data. Results of an experimental study on several sampling techniques for lead in air particulates are reported. The investigated factors were: location of samplers, time and rate of sampling and type of filter used. The study includes the comparison of low and high volume sampling techniques, as well as the distribution of blank and deposited lead values on the surface of the glass fiber filter used in the high volume sampling technique.