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Niveaux d' ozone et endommagement foliaire sur quelques essences mediterraneennes.
2001
Dalstein L. | Teton S. | Cottereau C. | Vas N.
En France, dans les Alpes-Maritimes, une recherche est menee pour connaitre l' impact eventuel de l' ozone sur l' endommagement foliaire repere ces dernieres annees sur peuplements de pins d' Alep, sylvestre et cembro. L' etude s' effectue dans le cadre d' un contrat franco-italien Interreg 2 et d' un programme Primequal. Cet article donne tout d' abord, les resultats pour l' ete 1999, interessant les niveaux de concentration d' ozone mesures depuis le littoral azureen jusqu' au massif du Mercantour au moyen d' analyseurs physico-chimiques et de capteurs passifs. La dose d' AOT 40 et la somme cumulee des concentrations horaires sont indiquees pour les periodes de mesure estivales. Les capteurs passifs se situent notamment parmi des placettes de suivi d' arbres. Afin d' apprehender l' impact de la pollution par l' ozone sur ces ecosystemes forestiers, des notations d' endommagement foliaire sont effectuees. Des correspondances sont recherchees entre les niveaux moyens d' ozone et les degres d' atteinte des trois principales essences suivies (pins d' Alep, sylvestre et cembro). Il semble y avoir une correlation entre augmentation des concentrations d' ozone et endommagement foliaire au moins en ce qui concerne les pins cembro.
Show more [+] Less [-]Trace Element Emissions from some Cement Plants in Turkey
2001
Kalafatoğlu, Ersan | Örs, Nuran | Sain Özdemir, Sibel | Munlafalioğlu, Ismet
The cement industry has been one of the major sources of air pollution in the past and the Turkish Air Quality Protection Regulation has issued limits also to trace elementemissions to minimise the polluting effects of this industrialsector. In the present study, dust samples were obtained isokinetically from 18 main stacks of 10 cement plants locatedin different geographical areas of Turkey. The samples were analysed for trace elements Hg, Cd, Cr, Pb, Ni, Se, Te, TI, V, Sb, Ba, Zn, Co, Sr, Cu, Bi, Mo, Be, and As. The results are presented both as concentration in the dust samples as well as emissions per unit production, and concentration inthe stack gas. The trace element emissions of the main stacksagree to great extent with the values given in the literature. On the other hand, the trace element emissions of the plants considered are well below the limits set in the Turkish Air Quality Protection Regulation.
Show more [+] Less [-]Atmospheric Bronze and Copper Corrosion as an Environmental Indicator. A Study Based on Chemical and Sulphur Isotope Data
2001
Nord, A. G. | Tronner, K. | Boyce, A. J.
Corrosion products have been takenfrom 130 copper or bronze outdoor objects all overEurope. Their chemical composition and crystalsymmetry have been determined by means of scanning electron microscopy (SEM/EDS) and X-ray powderdiffraction. Data on location, sampling, objectcharacteristics, general environment and air pollutionlevel; type, colour and chemical composition of thecorrosion layers have been obtained and evaluated by multivariate statistical analysis. The resultsverify that the highest air pollution levels are usually associated with the occurrence of thick,black or dark grey corrosion layers on copper orbronze objects, preferentially containing soot, ironoxide hydroxides, and antlerite,Cu₃(SO₄)(OH)₄. Pale green corrosionusually contains brochantite,Cu₄(SO₄)(OH)₆, and is rather associatedwith less polluted areas. Atacamite, a copper hydroxide chloride with the chemical formula Cu₂Cl(OH)₃, is preferentially observed in coastal regions.In addition, sulphur isotope analyses have beenperformed on eleven corrosion samples from citycenters. The δ³⁴S values are typically inthe region from +4 to +6‰ relative to the sulphurisotope standard CDT (Canyon Diablo Troilite) with amean value of 4.7±1.2 (1σ), therebyindicating that the sulphur in the corrosion layers,in the form of brochantite or antlerite, mainlyoriginates from a similar source despite geographicvariation, most likely sulphur contained in air pollutants.
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