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Šio darbo tikslas – pasyviosios lichenoindikacijos metodu įvertinti oro kokybę pasirinktame Vilniaus miesto transekte. Buvo ištirta 20 Vilniaus miesto transekto barelių, kurių plotas 1 km2. Epifitinių kerpių bendrijos buvo tiriamos ant 156 apskaitos medžių, stengiantis išlaikyti kuo tikslesnį vyraujančių medžių rūšių santykį, kaip ir 2001 metais atlikto tyrimo metu. Kiekviename kvadrate buvo tiriama iki 10 medžių. 2010 m. aptiktas toks pat (31) kerpių rūšių skaičius, kaip ir 2001 m., tačiau jis skyrėsi rūšių sudėtimi; sumažėjo jautresnių oro taršai kerpių. Epifitinių kerpių rūšių skaičius transekto kvadratuose reikšmingai skiriasi priklausomai nuo substrato savybių - ant skurdžia mineralinėmis medžiagomis pasižyminčia žieve medžių aptikta mažiau rūšių, nei ant turtinga mineralinėmis medžiagomis žieve pasižyminčių medžių rūšių. Atlikta analizė parodė ryšį tarp kerpių rūšių skaičiaus ir rajono. Nustatyta epifitinių kerpių rūšių skaičiaus sąsaja tarp atskiro atmosferinės taršos agento - SO2 koncentracijos. Taip pat nustatyta kad dominuoja nitrofilinės rūšys. Mažiausia PI reikšmė nustatyta Antakalnyje. Didžiausia PI reikšmė nustatyta miesto centre. Įvertinus visų 20 transekto kvadratuose esančią užteršimo būklę pasyviosios lichenoindikacijos metodu paaiškėjo, kad: silpnesnio užterštumo zona nebuvo nustatyta nei vienam kvadratui; didžioji tirtų kvadratų dalis priskiriama stipresnio užterštumo zonai, o likusieji miesto periferinėje zonoje esantys kvadratai priskiriami vidutinio... [toliau žr. visą tekstą] / The aim of this study was to evaluate air quality of Vilnius city chosen area, by using passive lichenoindication method. 20 (1 km2 area each) squares were investigated. Epyphytic lichens communities were studied on the 156 trees, trying to hold on the same trees species that were in the 2001 made research. In the each square it was studied about 10 trees. In 2010 m. was discovered the same lichens species number (31) as in 2001, but the species set was different by species composition: lichens species, that are sensitive to the air pollution was found less than in the 2001. Epyphytic lichens species number is different on the poor and rich in mineral substance trees: on the poor bark – less lichens species were found and on the rich one – more species were found. The analysis showed that there is a link between lichens species number and Vilnius districs. Also a link between lichens species number and SO2 koncentration was discovered, nitrofylic species also are dominant in the squares. The least PI meaning was identified in Antakalnis. The biggest PI value was in the Vilnius city center. Using lichenoindication methog it was determined that: weak pollution zone wasn‘t identified in Vilnius area squars, the most of the squares were on stronger pollution zone and the rest (in the edges of the city) squares are belong to average pollution zone.

A number of continuous and retrospective passive monitoring techniques have been employed in this study to carry out a comprehensive assessment of heavy metal dispersion and deposition from a secondary lead smelting complex. The principal period of monitoring was designed to coincide with contemporaneous changes in the operation of the complex involving, the incorporation of new smelting and refining centres. The initial phase of the sampling programme began with a preliminary multi-element survey to establish the degree of communality between different metals in smelter emissions and their interrelationships with background factors. Heavy metal deposition was monitored at bimonthly intervals over a two year period at 40 bulk precipitation sites located within an area of 250 km[sup]-2. In a complementary survey suspended moss-bags were collected at bimonthly intervals from 60 sites over a period of one year. Bimonthly levels of Pb deposition at these sites ranged from 7.0 to 1148 g ha[sup]-1 in bulk precipitation and 31 to 1792 mg kg[sup]-1 in moss-bags. The longer term pollution effects resulting from smelter emissions were assessed by determining retrospective heavy metal accumulations in saxicolous lichens and coniferous woodland soil profiles. The results of these surveys have been subjected to a range of interactive computer application packages including statistical analysis, computer mapping and plotting techniques. In the largest of these exercises, a series of 68 two-dimensional and 3-dimensional computer map projections are used to model patterns of heavy metal dispersion and deposition from the smelting complex. The surface profiles produced in these map projections reveal distinctive patterns of severe fugative pollution close to their source region and highly consistent linear stack emission trends largely moderated by the effects of local topographic relief. Local topographic expression is considered to be the most important single determinant influencing the atmospheric dispersion and deposition of heavy metal emissions. The development of locally induced wind patterns appear to largely suppress the vertical dispersion of emissions, leading to higher incident levels of heavy metal pollution within the local system of valleys. Relatively low levels of metal pollution were encountered away from these areas of low elevation during the early monitoring phase, but were later supplanted by more acute pollution effects, up to 500% greater at some outlying sites. On balance, only a marginal increase in pollution is indicated over consecutive yearly monitoring periods.

The main objective of this research was to understand the fate of naphthalene and n-alkylnaphthalenes during diesel combustion, and an evaluation of their sources in diesel exhaust emissions. This was achieved by the use of a procedure which employed a [14C]radiolabelled PAH technique and a diesel enriched fuel technique (DEFT). The combustion of diesel fuel spiked with [14C]naphthalene has shown unequivocally that 0.5% of the naphthalene contained in diesel fuel survives combustion under the engine conditions studied (2500 rpm and 50 Nm). The survived naphthalene represented 22.8% of the total recovered naphthalene, the other 77.2% was presumably pyrosynthetic in nature. The sources of the pyrosynthesised naphthalene in the emissions was investigated at 2500 rpm and 50 Nm. The previously unreported input of n-methylnaphthalenes to the pyrosynthesised naphthalene was demonstrated by combusting fuel spiked with [14C]2-methylnaphthalene. Radiolabelled 2- methylnaphthalene (0.53% of the original [14C]2-methylnaphthalene) which had survived combustion, and radiolabelled naphthalene (0.02% of the original [14C]2-methylnaphthalene), were recovered in the exhaust extracts. This showed unequivocally that 2-methylnaphthalene was converted to naphthalene in the combustion chamber. The first enrichment experiments (DEFT), in which 1- and 2-methylnaphthalene were added separately to fuel prior to combustion confirmed that demethylation of both species produced naphthalene in small yields (1.9% and 6.1% respectively). The contribution of n-alkylnaphthalenes with the alkyl group greater than methyl in length, to pyrosynthesised naphthalene contained in exhaust emissions was investigated using fuel spiked with non-radiolabelled alkyl-PAH. The major product of combustion of these compounds was 2- vinylnaphthalene, with a 0.08% conversion for 2-butylnaphthalene and a 0.01% conversion for 2- ethylnaphthalene. No dealkylated products were detected in the exhaust emissions. A mechanism for the formation of 2-vinylnaphthalene was proposed. The effect of engine speed and load on the recovery of naphthalene and the contribution of pyrosynthesised and survived naphthalene to recovered naphthalene were established using [14C]naphthalene. At all speeds and loads investigated the pyrosynthesised fraction of recovered naphthalene was shown to be dominant.