Is PM(10) mass measurement a reliable index for air quality assessment? An environmental study in a geographical area of north-eastern Italy

The aim of this study was to measure the concentration of some metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Ti) in PM(10) samples collected in one urban and one industrial site and to assess that PM(10) total mass measurement may be not sufficient as air quality index due to its complex composition. Metals were determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and differential pulsed anodic stripping voltammetry (DPASV). The measured concentrations were used to calculate the content of metals in the PM(10) total mass, and to estimate the enrichment factors and the correlations between PM(10), metal concentrations and meteorological data for the two sites. The mean PM10 concentration during the sampling period in the urban site exceeded the annual European Union (EU) standard (40 microg/m(3)) and, for some sampling days, the daily EU standard (50 microg/m(3)) was also exceeded. In opposite, both EU standards were never exceeded in the industrial site. The overall metal content was nearly double in the industrial site compared to the urban one, and the mean Ni concentration exceeded the EU annual limit value (10 ng/m(3)). The metals with the highest enrichment factor were Cd, Cu, Ni and Pb for both sites, suggesting a dominant anthropogenic source for these metals. Metal concentrations were very low and typical of rural background during Christmas holidays, when factories were closed. PM(10) total mass measurement is not a sufficient air quality index since the metal content of PM(10) is not related to its total mass, especially in sites with industrial activities. This measurement should be associated with the analysis of toxic metals.

Penetration of benzene, toluene and xylenes contained in gasolines through human abdominal skin in vitro

Few studies are available in literature on the risk for humans from skin exposure to gasolines. This work is focused on the in vitro skin penetration of benzene (carcinogenic substance), toluene and xylenes. We examined three commercial gasolines using the Franz diffusion cells and human abdominal full thickness skin. Gasoline composition was determined using a multi-dimensional gas chromatographic (MDGC) technique. Aromatic compounds into the receptor fluid, consisting of saline solution were quantitated by a gas chromatography technique equipped with a flame ionization detector (GC-FID) and coupled with a headspace-solid phase micro extraction system (HS-SPME). Among the three substances, benzene showed the highest average apparent permeability coefficient (K(p)=43.8x10(-5)cmh(-1)) compared to toluene (K(p)=6.48x10(-5)cmh(-1)) and xylenes (K(p)=0.84x10(-5)cmh(-1)). This value could be explained by the lower boiling point and higher water solubility of benzene. Lag times were about 1h for benzene and 2h for toluene and xylenes. Averaged total recoveries in the receptor fluid were 0.43% of dose for benzene, 0.06% for toluene and 0.008% for xylenes. A statistical significative difference (Student's t-test, P<0.05) between the fluxes calculated for the three gasolines are noted only for xylene and for toluene between gasolines #1 (richer in aromatic compounds) and #3. The obtained apparent permeability coefficient are useful for determining the permeability of these aromatics components from gasolines of a different composition. Hands exposure risk, calculated using RfD and RfC as defined by US EPA, is critical for benzene. The risk of skin permeation of gasoline, and, in particular, of benzene, should be better evaluated for those workers who have a large potential for exposure. Adequate personal protective equipment should be used in the high exposure jobs, mainly for hands and forearms.

Levels of cadmium and zinc in hepatopancreas of reared Mytilus galloprovincialis from the Gulf of Trieste (Italy)

Cadmium and zinc concentrations were determined in hepatopancreatic tissues of Mytilus galloprovincialis, reared in three non-contaminated hatcheries of the Gulf of Trieste (Northern Adriatic Sea). Mussels were collected in 13 sampling exits with monthly frequency for verifying possible seasonal variations. Freeze dried hepatopancreatic tissues were dissolved by nitric acid procedure using a microwave system; analysis of Zn and Cd followed by AAS technique. Metal concentrations were below the critical values for mollusc soft tissues, but xenobiotic cadmium had values requiring monitoring attention. Cadmium and zinc showed moderate variations along the months, with a slight winter maximum followed by a summer pre-spawning minimum, matching the seasonal trends of temperature/salinity. The estuarine site appears to have the best quality of the examined area in terms of metal contents. The results can constitute a guideline for the water quality in the Northern Adriatic Sea, and permit comparisons with the quality of other areas of the Mediterranean Sea.

Case study of groundwater pollution in a critical area of the Southern-Friuli exposed to agricultural and landfill pressures

Groundwater of the Southern-Friuli displays high levels of agricultural pollutants, such as nitrates and triazinic herbicides not only in the surficial layers, but also in the deeper ones, below 150 m. Some wells of the district of Gonars was monitored. The examined waters, used for irrigation but also for drinkable use, are exposed to environmental risk due to both agricultural practices and presence of many waste disposal sites. Heavy metals, nitrates and triazinic herbicides were measured in samples taken at four wells in three periods having different rain conditions. We found that groundwater quality is affected mainly by agricultural practices: nitrates and triazines are present at levels very near as well as superior to the maximum concentration allowable by Italian law. These agricultural contaminants have similar levels at all sampled sites: no difference was detected between dry periods and rain ones. Heavy metal contents are negligible in all cases; this fact suggests that ion-exchange, sorbing and complexing properties of the soils hinder the way of the metal leachates towards underlying groundwater. Zinc constitutes an exception; it is found at levels near or superior to the maximum allowable concentration (CMA), and the highest contents are observed in rain periods; different sites display different zinc levels, suggesting that this metal could have various point sources. Nitrates fertilisers were found in all sites at similar levels, very near to CMA (50 mg/L). Triazines are specific herbicides for corn growing, highly diffused here: their use in recent years is forbidden by Italian law, but the presence in groundwater of parent triazines and metabolites is a persistent problem of this area. The Italian law indicates a CMA of 0.10 microgram/L for the sum of atrazine and desethylatrazine, but we found that desethylatrazine by itself exceeds largely CMA in all sites.

Metal contents in tench otoliths: relationships to the aquatic environment

A monitoring of the quality of waters was attempted determining metal accumulation in target organs as otoliths of freshwater fish. Tenchs of age ranging between 2 and 10 years were sampled in three different canals receiving wastewater from industrial, agricultural and urban activities. Metal contents were determined in both lapilli and asterisci otoliths, using inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Analytical data are reported for minor metals and for some trace metals. Al, Fe and Zn have contents depending on the environment where the fish has lived, while Na, K, Ca and Sr contents are insensitive to the different aquatic habitat. Considering the two types of otolith separately, lapilli display a different affinity for trace metals (Al, Fe and Zn), while in asterisci this affinity is matched only for zinc. The high affinity of zinc for both types of otoliths suggests using this metal for discriminating the fresh waters by checking its accumulation in otoliths, as well as correlating this accumulation with age of the fish: a negative power curve equation is proposed. Since highest concentrations are found in individuals of 2-3 yr., it is advisable to use this fish for such environmental studies.

Detecting and characterising sources of persistent organic pollutants (PAHs and PCBs) in surface sediments of an industrialized area (harbour of Trieste, northern Adriatic Sea)

A sediment sampling based on a two-dimensional mapping was performed in the harbour of Trieste (northern Adriatic Sea), considering 28 sites exposed to pollutant inputs from harbour and industrial activities. Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were determined in surface sediments, because these very persistent pollutants seem to be responsible for the depletion of benthic populations observed in this area. The correlation matrix indicates that PAHs and PCBs are non-correlated, and probably have different sources. Both cluster analysis performed on the sampling sites and graphical drawing of the PAH sediment contents make it possible to locate along the shoreline a band of more polluted sediments, clustered around a site facing a steelmaking factory, to be considered as the main source point for PAHs. The evaluation of phenanthrene to anthracene (P/AN) and fluoranthene to pyrene (FL/PY) ratios permits the assessment of the pyrolytic, industrial origin of these PAHs, rejecting a second possible source of hydrocarbons (i.e., an oil-pipeline terminal, situated near the steelmaking factory). Graphical drawing of the total PCB iso-concentrations reveals a different source-point for this other category of very persistent pollutants.

Skin absorption in vitro of glycol ethers

OBJECTIVES

The increased use of glycol ethers (GEs) for water-based paints and cleaning products, combined with a lack of information about many of these products, particularly with regard to the effects of percutaneous exposure, led us to evaluate the skin absorption rates of a group of glycol ethers in vitro.

METHODS

Skin permeation was calculated using the Franz cell method with human skin. A physiological solution was used as the receiving phase. The amount of solvent passing through the skin was analysed with a gas chromatographic technique employing flame ionization detection. A permeation profile was obtained and steady state, lag time and permeation constant flux was calculated for each of the following solvents: ethylene glycol monoethyl ether (EGMEE), propylene glycol mono-methyl ether (PGMME); propylene glycol mono-methyl ether acetate (PGMMEac); 2-propylene glycol 1-butyl ether (2PG1BE), ethylene glycol dimethyl ether (EGDME), ethylene glycol diethyl ether (EGDEE) and diethylene glycol dimethyl ether (DEGDME). All solvents were tested in their pure form and with 70% acetone.

RESULTS

For all solvents tested the lag time was less than 2 h, and for the majority of them was about 60 min. Flux at steady state ranged between 0.017 +/- 0.005 and 3.435 +/- 1.897 mg/cm(2)/h and permeation rate was from 0.0192 to 1.02 x 10(-3) cm/h. The presence of acetone in the solution caused a reduction in lag time and an increase in permeation rate, higher for EGMEE, lower for EGDEE, indicating the enhancing effect of this mixture of solvents.

CONCLUSIONS

Our results confirm the high percutaneous absorption of the GEs tested. The Franz method might be helpful for obtaining a grading of skin notation for hydrophilic substances: in the case of glycol ethers, it can give us precise information about permeation risk, particularly important in the evaluation of exposure. In the case of solvents with high dermal absorption, the air concentration is no longer a sufficient measure of the total exposure to workers, and therefore merely respecting threshold limit values (TLVs) in the air is not necessarily enough to protect them.

Survey of environmental complex systems: pattern recognition of physicochemical data describing coastal water quality in the Gulf of Trieste

A data set reporting temperature, salinity, dissolved oxygen, nitrogen as ammonia, nitrite and nitrate, silicate, chlorophyll a and phaeopigment values, determined in seawaters sampled during two years with a monthly frequency in 16 stations in the Gulf of Trieste, and at different depths of the water column, has been studied. In order to find synthetic descriptors useful for following the spatial and temporal variations of biogeochemical phenomena occurring in the considered ecosystem, the data set has been factorized using principal component analysis. A graphical display of scores, by means of boxplots and biplots, helped in the interpretation of the data set. The first factor conditioning the system is related to the input of freshwater from the estuary of the Isonzo River and to the stratification of the seawater (thermohaline discontinuity), while the second and third components describe interactions between biological activity, nutrients and physicochemical parameters; typical spring and autumn phytoplankton blooms were identified, in addition to an exceptional winter bloom conditioned by anomalous meteorological/climatic conditions. The fourth principal component explains the reducing activity of seawaters, which often increases when the decomposition of organic matter is relevant. The simple linear model proposed, and the related graphs, are shown to be useful tools for monitoring the main features of such a complex dynamic environmental system. The outlined approach to the considered complex data structure presents in a cognitive easy way (graphical outputs) the significant variations of the data, and allows for a detailed interpretation of the results of the monitoring campaign. Temporal and spatial effects are outlined, as well as those related to the depth in the water column.

Heavy metals and nutrients in coastal, surface seawaters (Gulf of Trieste, Northern Adriatic Sea): an environmental study by factor analysis

Trace metals and nutrients were monitored voltammetrically and spectrophotometrically during a one-year period (1992/93) in the filtered fraction of coastal surface seawaters sampled with a monthly frequency at 6 different sites in the Gulf of Trieste (Northern Adriatic Sea), to evaluate the degree of pollution in an area receiving industrial, agricultural and urban wastes. The sites devoted to hatcheries of edible mussels are of particular interest. A multivariate statistical analysis of the collected concentration data by the principal component method allows to identify the sources and typology of pollution, and to discriminate between the quality of waters at the different sampling sites. The coastal waters in the Gulf of Trieste seem to be comparable to, or better than, waters of analogous areas in the Mediterranean Sea.

Multivariate data analysis of sea waters and mussels in relation to pollution sources of trace elements

The total concentration of Cu, Zn and Pb in surface sea waters from the Bay of Muggia (Gulf of Trieste, Northern Adriatic Sea) was determined by anodic stripping voltammetry. The association of these trace elements in relation to the known sources of pollution was discussed. The content of eight trace elements (Mn, Co, Ni, Cu, Zn, Cd, Hg, Pb) in the soft part of mussels (Mytilus galloprovincialis Lamarck) is also considered. The wild molluscs were sampled in the harbour of Trieste, in the proximity of an important city sewer. Principal component analysis was used to analyse the correlation matrix obtained from an 8 x 43 data matrix after a logarithmic transformation of the concentration variables. Eight variables were reduced to four principal components, which explained 80% of the total variance. The orthogonally rotated factor matrix shows that Co, Ni, Cd, and Pb are associated with the first principal component, Cu and Zn to the second, Hg to the third and Mn to the fourth principal component. The results of this multivariate data analysis are compared with those already obtained from two sampling sites in the Bay of Muggia and the origin of some trace metals in the soft part of mussels from the Gulf of Trieste is discussed.