Cd, Pb and Zn oral bioaccessibility of urban soils contaminated in the past by atmospheric emissions from two lead and zinc smelters.

Ingestion of dust or soil particles could pose a potential health risk due to long-term metal trace element (MTE) exposure. Twenty-seven urban topsoil samples (kitchen garden and lawn) were collected and analyzed for Cd, Pb and Zn using the unified Bioaccessibility Research Group of Europe (BARGE) method (UBM) test to estimate the human bioaccessibility of these elements. The quantities of Cd, Pb and Zn extracted from soils indicated, on average, 68, 62 and 47% bioaccessibility, respectively, in the gastric phase and 31, 32 and 23% bioaccessibility, respectively, in the gastro-intestinal phase. Significant positive correlations were observed between concentrations extracted with UBM and total MTE contents. Stepwise multiple regression analysis showed that human bioaccessibility was also affected by some physico-chemical soil parameters (i.e. total nitrogen, carbonates, clay contents and pH). The unified test presents some valuable data for risk assessment. Indeed, the incorporation of oral bioaccessible concentrations into risk estimations could give more realistic information for health risk assessment.

Contamination of woody habitat soils around a former lead smelter in the North of France.

The contamination of the topsoil of 262 woody habitats around a former lead smelter in the North of France was assessed. In this urbanized and industrialized area, these kinds of habitats comprise of hedges, groves, small woods, anthropogenic creations and one large forest. Except for the latter, which is 3 km away, these woody habitat soils often present a high anthropization degree (a significant amount of pebbles and stones related to human activities) with a high metal contamination. In the studied woody habitat topsoils, Cd, Pb and Zn concentrations largely exceeded those of agricultural topsoils located in the same environmental context. Therefore, atmospheric emissions from the smelter are not the only cause of the high contamination of the woody habitat soils. This last one is related to the nature and the contamination level of deposit in relation with human activities (rubbles, slag, soils, etc). With regard to the results obtained with chemical extractions, the mobility of Cd, Pb and Zn in these soils is also greater than in agricultural soils. In the forest, pollutant solubility is increased by soil acidic pH. The variability of the physico-chemical parameters and the high metal contamination of the topsoils are the main characteristics of the woody habitats located around the former smelter. Although never taken into account during risk assessment, the disturbance of these environmental components could have important biogeochemical impacts (nutrients and metal cycles). Moreover, any modification of the soils' use could potentially cause mobilization and transfer of the pollutants to the biosphere. Six years after the closure of the smelter, and as social and economic pressures considerably increase in this area, the study of these peculiar ecosystems is necessary to understand and predict the bioavailability, transfer, bioaccumulation and effects of pollutants in food chains.

Assessment of a remediation technique using the replacement of contaminated soils in kitchen gardens nearby a former lead smelter in Northern France.

Vegetables cultivated in kitchen gardens that are strongly contaminated by heavy metals (Pb, Cd) may represent to consumers a means of exposure to these metals. This exposure is more problematic for those families that include a large quantity of home-grown vegetables in their diet. Researchers have shown that the majority of vegetables produced in kitchen gardens in the vicinity of the Metaleurop Nord smelter (Northern France) do not conform to European regulations. This study was carried out in three of these kitchen gardens. The concentrations of Cd and Pb in the topsoils were up to 24 and 3300 mg kg(-1) respectively. The method consisted of delineating a surface area of about 50 to 100 m(2) for each garden, then removing the contaminated soil and replacing it with a clean one. Seven species of vegetables were cultivated from 2003 to 2005 in the original contaminated soils and the remediated ones. The data showed a clear improvement of the quality of the vegetables cultivated in remediated soils, although 17% of them were still over the European legislative limits for foodstuffs. This suggested that there was a foliar contamination due to contaminated dust fallout coming from the closed smelter site and the adjacent polluted soils. In addition, the measurement of the Cd and Pb concentrations in the dust fallout showed that the substantial rise in metal concentrations in the remediated soil was not only due to atmospheric fallout. These results raise questions about possible technical, economic and sociological problems associated with this kind of remediation.

Behavior of Trifolium repens and Lolium perenne growing in a heavy metal contaminated field: Plant metal concentration and phytotoxicity.

The use of a vegetation cover for the management of heavy metal contaminated soils needs prior investigations on the plant species the best sustainable. In this work, behaviors of Trifolium repens and Lolium perenne, growing in a metal-polluted field located near a closed lead smelter, were investigated through Cd, Pb and Zn-plant metal concentrations and their phytotoxicity. In these plant species, metals were preferentially accumulated in roots than in shoots, as follow: Cd>Zn>Pb. Plant exposure to such metals induced oxidative stress in the considered organs as revealed by the variations in malondialdehyde levels and superoxide dismutase activities. These oxidative changes were closely related to metal levels, plant species and organs. Accordingly, L. perenne seemed to be more affected by metal-induced oxidative stress than T. repens. Taken together, these findings allow us to conclude that both the plant species could be suitable for the phytomanagement of metal-polluted soils.

Myocardial infarction: is bepridil, a new calcium antagonist, able to improve the course of the acute phase?

Several calcium antagonists are useful in the treatment of ischemic heart disease. This open randomized study was designed to determine the effects of bepridil, a new long-acting calcium antagonist with antiarrhythmic properties, on the course of acute myocardial infarction (AMI). Two hundred patients with AMI of less than 48 hours duration (average 10.9 hours) were randomly assigned to two treatment groups: The first one was treated with bepridil (BEP, n = 100), and the second one was considered as a control group, using isosorbide dinitrate at a low dosage (ISDN, n = 100). BEP was administered intravenously for 48 hours at a dosage of 4 mg/kg/day; at the same time, an oral dose of 200 mg t.i.d. was started and continued for 21 days. In the control group, ISDN was given orally at the low dosage of 5 mg every 4 hours for 21 days. An uneventful course was seen in 28 BEP patients versus 15 in the control group (p less than 0.05). Mortality and recurrence of angina were lower in the BEP group than in the control group, but the difference is not significant. On the other hand, moderate and severe hemodynamic complications did not occur in 80 BEP patients versus 65 in the control group (p less than 0.05). Ventricular arrhythmias occurred in 36 BEP patients versus 50 in the control group (p less than 0.05). Antiarrhythmic therapy was required in 14 BEP patients versus 61 in the control group (p less than 0.001). These results show that bepridil seems capable of improving the hemodynamics and arrhythmologic course of AMI.

[Left ventricular function of the coronary patient: relation between ventricular kinetic disorders and alterations of myocardial contractility]. / La fonction ventricularire gauche du coronarien: Relations entre les troubles de la cinétique ventriculaire et les altérations de la contractilité myocardique

The left ventricular kinaetics of 29 coronary patients (pure angina and with sequela of myocardial infarction) was studies by biplane angiocardiography. Their contractility was assessed by measurement of the Vmax and VECmax indices derived from the relationship between contractile elements shortening speed-overall wall tension, in isovolumetric phase. An excellent relationship links the hypokinaetic area with decrease of the ejection fraction (SV/LSV): when the hypokinaetic area exceeded 20% of the overall endocardial surface, the ejection fraction deveased below 0.40, and signs of cardiac failure were manifest. Pure anginal patients at rest kept normal kinaetics, late diastolic volume, ejection fraction and myocardial mass. A myocardial hypertrophy develops in the areas adjacent to the fibrous scar. In some cases (group I) it compensates for the ventricular dysfunction; in other cases, it is not sufficient to compensate for the ejection fraction reduction. One must then admit the presence of diminished contractility in the areas adjacent to the fibrous scar, as is suggested by the increase of the late diastolic pressure, the decrease of the externel work of the left ventricle and of the contractility indices. Analysis of both the natural and post-operative courses in these patients shows that Vmax the ejection fraction and the hypokinaetic areas afford excellent criteria for prognosis and operability.