Lead isotopic fingerprint in human scalp hair: The case study of Iglesias mining district (Sardinia, Italy).

The Sulcis-Iglesiente district (SW Sardinia, Italy) has been, until recently, one of the most important Italian polymetallic mining areas for the extraction of lead. Epidemiological studies conducted over several decades have indicated this site at high risk of environmental crisis with possible adverse effects on the public health. In the present paper we discuss Pb isotope signatures in human scalp hair and road dust collected from the Sulcis-Iglesiente area in order to trace the exposure of populations to potential Pb sources. A total of 23 determinations (20 on hair samples and 3 on road dust samples) of lead isotope ratios (206Pb/207Pb and 208Pb/206Pb) were carried out. The obtained results were integrate with literature data regarding the total content of Pb in hair samples from the same study area. Hair from children living in Sant'Antioco exhibited lead isotope ratios in the ranges 1.152-1.165 for 206Pb/207Pb and 2.101-2.108 for 208Pb/206Pb, while hair samples from Iglesias resulted less radiogenic: 206Pb/207Pb~1.147-1.154 and 208Pb/206Pb~2.106-2.118. These values pointed to a multi-source mixing between the less radiogenic sources, corresponding to the Pb ore deposits, and the more radiogenic sources identified in local background.

Perturbation vectors to evaluate air quality using lichens and bromeliads: a Brazilian case study.

Samples of one lichen species, Parmotrema crinitum, and one bromeliad species, Tillandsia usneoides, were collected in the state of Rio de Janeiro, Brazil, at four sites differently affected by anthropogenic pollution. The concentrations of aluminum, cadmium, copper, iron, lanthanum, lead, sulfur, titanium, zinc, and zirconium were determined by inductively coupled plasma-atomic emission spectroscopy. The environmental diagnosis was established by examining compositional changes via perturbation vectors, an underused family of methods designed to circumvent the problem of closure in any compositional dataset. The perturbation vectors between the reference site and the other three sites were similar for both species, although body concentration levels were different. At each site, perturbation vectors between lichens and bromeliads were approximately the same, whatever the local pollution level. It should thus be possible to combine these organisms, though physiologically different, for air quality surveys, after making all results comparable with appropriate correction. The use of perturbation vectors seems particularly suitable for assessing pollution level by biomonitoring, and for many frequently met situations in environmental geochemistry, where elemental ratios are more relevant than absolute concentrations.

Impact of trace metals from past mining on the aquatic ecosystem: a multi-proxy approach in the Morvan (France).

This study seeks to determine to what extent trace metals resulting from past mining activities are transferred to the aquatic ecosystem, and whether such trace metals still exert deleterious effects on biota. Concentrations of Cd, Cu, Pb and Zn were measured in streambed sediments, transplanted bryophytes and wild brown trout. This study was conducted at two scales: (i) the entire Morvan Regional Nature Park and (ii) three small watersheds selected for their degree of contamination, based on the presence or absence of past mining sites. The overall quality of streambed sediments was assessed using Sediment Quality Indices (SQIs). According to these standard guidelines, more than 96% of the sediments sampled should not represent a threat to biota. Nonetheless, in watersheds where past mining occurred, SQIs are significantly lower. Transplanted bryophytes at these sites consistently present higher trace metal concentrations. For wild brown trout, the scaled mass and liver indices appear to be negatively correlated with liver Pb concentrations, but there are no obvious relationships between past mining and liver metal concentrations or the developmental instability of specimens. Although the impact of past mining and metallurgical works is apparently not as strong as that usually observed in modern mining sites, it is still traceable. For this reason, past mining sites should be monitored, particularly in protected areas erroneously thought to be free of anthropogenic contamination.

Metals and metalloids in hair samples of children living near the abandoned mine sites of Sulcis-Inglesiente (Sardinia, Italy).

The Sulcis-Iglesiente district (SW Sardinia, Italy) is one of the oldest and most important polymetallic mining areas in Italy. Large outcrops of sulfide and oxide ores, as well as the products of the long-lasting mining activity, are present throughout the district releasing significant quantities of metals and metalloids into the surrounding environment. Here are reported concentrations of 21 elements determined in scalp hair samples from children (aged 11-13 years) living in different geochemical environments of southwestern Sardinia: Iglesias, hosting several abandoned mines, and the island of Sant׳Antioco, not affected by significant base metal mineralization events. Trace element determinations were performed by ICP-MS. Statistically significant differences (p<0.01) in elemental concentration levels between the two study sites were found. Hair of children from Iglesias exhibited higher concentration values for Ag, Ba, Cd, Cr, Ni, Pb, Rb, Sb, U, V, and Zn. Rubidium, V and U resulted more abundant at Sant׳Antioco. Hair samples from Iglesias showed gender-related differences for a larger number of elements (Ag, Ba, Cd, Co, Cu, Ni, Sr, U and Zn) than at Sant׳Antioco, where only U was significantly different. The above elemental concentrations in females were always higher than in male donors. Robust Principal Component Analysis operated on log-transformed elemental concentrations showed components indicative of a) sulfides ore minerals (PC1) reflecting the influence of the diffuse mineralization covering the entire study area, b) the presence of some bioavailable As sources (PC2) as As-rich pyrite and Fe-containing sphalerite and c) other sources of metals overlapping the diffuse mineralizations, as carbonate rocks and coal deposits (PC3). The results provided evidence of a potential risk of adverse effects on the health of the exposed population, with children living at Iglesias being greatly exposed to several metals and metalloids originated in mining tailings, enriched soils, waters and food.

Impact of historical mining assessed in soils by kinetic extraction and lead isotopic ratios.

The aim of this study is to estimate the long-term behaviour of trace metals, in two soils differently impacted by past mining. Topsoils from two 1 km(2) zones in the forested Morvan massif (France) were sampled to assess the spatial distribution of Cd, Cu, Pb and Zn. The first zone had been contaminated by historical mining. As expected, it exhibits higher trace-metal levels and greater spatial heterogeneity than the second non-contaminated zone, supposed to represent the local background. One soil profile from each zone was investigated in detail to estimate metal behaviour, and hence, bioavailability. Kinetic extractions were performed using EDTA on three samples: the A horizon from both soil profiles and the B horizon from the contaminated soil. For all three samples, kinetic extractions can be modelled by two first-order reactions. Similar kinetic behaviour was observed for all metals, but more metal was extracted from the contaminated A horizon than from the B horizon. More surprising is the general predominance of the residual fraction over the "labile" and "less labile" pools. Past anthropogenic inputs may have percolated over time through the soil profiles because of acidic pH conditions. Stable organo-metallic complexes may also have been formed over time, reducing metal availability. These processes are not mutually exclusive. After kinetic extraction, the lead isotopic compositions of the samples exhibited different signatures, related to contamination history and intrinsic soil parameters. However, no variation in lead signature was observed during the extraction experiment, demonstrating that the "labile" and "less labile" lead pools do not differ in terms of origin. Even if trace metals resulting from past mining and metallurgy persist in soils long after these activities have ceased, kinetic extractions suggest that metals, at least for these particular forest soils, do not represent a threat for biota.

Wild brown trout affected by historical mining in the Cévennes National Park, France.

In the protected area of the Cévennes National Park (Southern France), 114 wild brown trout (Salmo trutta fario) were captured at six locations affected to different extents by historical mining and metallurgy dating from the Iron Age to Modern Times. Cadmium and lead in trout livers and muscles reflect high sediment contamination, although an age-related effect was also detected for hepatic metal concentrations. Lead isotope signatures confirm exposure to drainage from mining and metallurgical waste. Developmental instability, assessed by fluctuating asymmetry, is significantly correlated with cadmium and lead concentrations in trout tissues, suggesting that local contamination may have affected fish development. Nowadays, the area is among the least industrialized in France. However, our results show that 60% of the specimens at one site exceed EU maximum allowed cadmium or lead concentration in foodstuffs. The mining heritage should not be neglected when establishing strategies for long-term environmental management.

Dissolution and solubility of trace metals from natural and anthropogenic aerosol particulate matter.

An open flow reactor is used to simulate the dissolution process of mineral aerosol particles in atmospheric water droplets. Data on dissolution kinetic and solubility are provided for the major trace metals from two kinds of matrix: alumino-silicated and carbonaceous sample. The results emphasise that the metals contained in the carbonaceous aerosols are easier dissolved than in the alumino-silicated particles. The released concentrations are not related to the total metal composition or the origin of particles, but are directly associated with the type of liaisons whereby the metals are bound in the solid matrix. Thus, the metals coming from carbonaceous particles are adsorbed impurities or salts and hence are very soluble and with a dissolution hardly dependent on pH, whereas the metals dissolved from alumino-silicated particles are less soluble, notably the ones constitutive of the matrix network (Fe, Mn), and with a dissolution highly influenced by pH. Consequently, in the regions with an anthropogenic influence, the dissolved concentrations of metals found in the atmospheric waters are mainly governed by the elemental carbon content. Moreover, it appears that the dissolution kinetic of metals is not constant as a function of time. The dissolution rates are very rapid in the first 20 min of leaching and then they are stabilised to lower values in comparison to initial rates. By consequence, the total dissolved metal content is provided after the first 20 min of the droplet lifetime. For this reason, the effects of trace metals on the atmospheric aqueous chemistry and as atmospheric wet input to the marine biota are maximal for "aged" droplets.

History and environmental impact of mining activity in Celtic Aeduan territory recorded in a peat bog (Morvan, France).

The present study aims to document historical mining and smelting activities by means of geochemical and pollen analyses performed in a peat bog core collected around the Bibracte oppidum (Morvan, France), the largest settlement of the great Aeduan Celtic tribe (ca. 180 B.C. to 25 A.D.). The anthropogenic Pb profile indicates local mining operations starting from the Late Bronze Age, ca. cal. 1300 B.C. Lead inputs peaked at the height of Aeduan civilization and then decreased after the Roman conquest of Gaul, when the site was abandoned. Other phases of mining are recognized from the 11th century to modern times. They have all led to modifications in plant cover, probably related in part to forest clearances necessary to supply energy for mining and smelting. Zn, Sb, Cd, and Cu distributions may result from diffusional and biological processes or from the influence of groundwater and underlying mineral soil, precluding their interpretation for historical reconstruction. The abundance of mineral resources, in addition to the strategic location, might explain why early settlers founded the city of Bibracte at that particular place. About 20% of the anthropogenic lead record was accumulated before our era and about 50% before the 18th century, which constitutes a troublesome heritage. Any attempts to develop control strategies in accumulating environments should take into account past human activities in order to not overestimate the impact of contemporary pollution.

Iron analysis in atmospheric water samples by atomic absorption spectroscopy (AAS) in water-methanol.

To distinguish between Fe(II) and Fe(III) species in atmospheric water samples, we have adapted an analytical procedure based on the formation of a specific complex between Fe(II) and ferrozine (FZ) on a chromatographic column. After elution of Fe(III), the Fe(II) complex is recovered with water-methanol (4:1). The possibility of trace iron measurements in this complex medium by graphite-furnace atomic-absorption spectrometry has been investigated. A simplex optimization routine was required to complete the development of the analytical method.

Figures of merit of pneumatic and ultrasonic sample introduction systems in inductively coupled plasma-multichannel-based emission spectrometry in an ultra-clean environment.

Conventional figures of merit such as limits of detection, signal to background ratio or repeatability, are used to determine the performance of pneumatic and ultrasonic sample introduction systems in an ultra-clean environment with an axially viewed inductively coupled plasma-atomic emission spectrometry and multichannel detection. We observed that the ultrasonic nebuliser offered a large improvement of signal intensity (10-133 greater) compared to a cyclone chamber coupled with a pneumatic Meinhard nebuliser. This improvement is associated with an average increase of signal to background ratio by a factor 86 and an average decrease of detection limits by a factor 6. The improvement factors generally depend on the element and for the same element on spectral lines. Typically, the observed values of detection limits in this work are lower than those published and obtained in non-ultra-clean conditions. The results emphasize that the environmental conditions of cleaning and analysis are essential to avoid and control cross contamination of the samples and hence to obtain low detection limits.

[Sensitivity of the parietal cell to the effect of pentagastrin in men living at high altitude]. / Sensibilidad de la célula parietal a la acción de la pentagastrina en el hombre de altura.

This study evaluates the response of the gastric mucosa to pentagastrin in a group (HAG) of 17 andean subjects compared to a similar group of 17 subjects at sea level (LAG). Both groups had normal fundic, body and antrum mucosa as demonstrated by endoscopic and histological means. Each group underwent two assays, the first one with a dose of 6 micrograms/kg and 72 hours later, the second administration with 3 micrograms/kg. In the HAG the acid response expressed as concentration and output was significantly greater with 6 micrograms/kg that with 3 micrograms/kg. In the LAG the difference was not statistically significant. The ANOVA analysis showed, for both determinations, free and total acidity, a different response pattern between the HAG and LAG for both doses. The response of both groups to the 3 micrograms/kg reveals a lesser sensitivity to pentagastrin of the parietal cell in HAG.

[Achlorhydria, blood gastrin and normal gastric mucosa in high-altitude subjects]. / Aclorhidria, gastrinemia y mucosa gástrica normal en sujetos de altura.

According to current concepts, it is not feasible to associate achlorhydria with normal gastric mucosa. We have found in a group of high altitude dwellers, that it is possible to associate achlorhydria with normal gastric mucosa verified by endoscopic and histological studies. In this case, basal achlorhydria is associated with resistance to histamine stimulation and with high values of gastrinemia. The possibility of reduced parietal cell mass or the absence of gastrin and histamine receptors and of G-cell hyperfunction or hyperplasia, is discussed.

Immediate skin test reactivity to common aeroallergens in patients with respiratory allergies: a comparative analysis of allergen-induced skin reactions and their histamine controls.

The results of the immediate skin test response to a panel of 16 common aeroallergens performed in a group of 659 consecutive patients with symptoms suggestive of a respiratory allergy were analyzed. A group of 108 healthy individuals served as control subjects. Ninety-four percent of the patients and 87% of the control subjects had at least one allergen-induced reaction (wheal greater than or equal to 2 by 2 mm). The prevalence of positive skin reactions to each aeroallergen was equally high in both groups. However, if a skin reaction is considered as positive only when an allergen-induced wheal is equal or larger compared to the 50% of the wheal obtained with the histamine control in that individual, 70% of the patients had positive skin reactions and only 38% of the control subjects were positive (p less than 0.05). Similarly, the prevalence rates to five aeroallergens (pollen, Fusarium, Mucor, Pullularia, and Curvularia) in the patient group were reduced to those levels observed with the control group, suggesting they are clinically less important. The age and not the sex influenced both the prevalence rates (p less than 0.001) and the mean size (p less than 0.01) of allergen and histamine-induced skin reactions. Lower prevalence rates and mean size values were observed in the youngest group (0 to 9 years). Moreover, there was an inverse relationship between lower skin reactivity with more younger subjects in our patient population. These results indicate that patients and healthy individuals have similar mechanisms for skin reactivity.(ABSTRACT TRUNCATED AT 250 WORDS)