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This research project examines the application of mineral magnetic techniques to the characterisation of particulates and their sources in the urban highway environment and in stormwater runoff. A review of previous investigations into sources, levels and pathways of metals through the urban highway environment is presented. The principles upon which the mineral magnetic techniques are based and those parameters employed in this study are described. Previous environmental applications are reviewed. A representative sampling scheme was established in a small well-defined sub-catchment. Copper, Fe, Pb and Zn concentrations in highway associated sediments increased with proximity to the road centre and seasonal maxima occurred in summer. Heavy metal loadings were dominated by the sediment loadings. Strong linear relationships between the metals, Cu, Fe, Pb and Zn, and magnetic mineral concentration related parameters, X and IRM3oomT, were observed. Mineral magnetic characterisation achieved complete discrimination between highway associated sediments and roof sediments allowing the derivation of equations defining the sediment groupings. Variations in metal-magnetic properties of sediments with particle size ,were investigated. Primary source materials and particulates were analysed. Metallic and magnetic mineral parameters indicated that atmospheric and vehicle derived· particulates were probably the dominant origins of source particulates. The variation of particulate associated heavy metals in stormwater runoff at the sub-catchment is discussed. Mineral magnetic parameters characterised the majority of stormwater particulates with the roof sediment grouping. The implications of these investigations is discussed. The study was expanded to encompass the parent c~tchment. The characterisation of source sediments from land use and road types other than that· represented by the sub-catchment was carried out. Stormwater particulates collected at the main catchment'· outfall were found to be generally characterised with soil and roof sediment groupings. The further application and use of mineral magnetic parameters in similar research is discussed.

Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-06-28T19:13:21Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO_MARLYETE_ MESTRADO_CCB.pdf: 1359439 bytes, checksum: c77312ff5d07a6b83188d66e242b0ba7 (MD5) / Made available in DSpace on 2016-06-28T19:13:21Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO_MARLYETE_ MESTRADO_CCB.pdf: 1359439 bytes, checksum: c77312ff5d07a6b83188d66e242b0ba7 (MD5) Previous issue date: 2015-02-25 / CNPQ / Acetilcolinesterase (AChE; 3.1.1.7) é uma enzima do grupo das serino-esterases que atua na hidrólise do neurotransmissor acetilcolina garantindo a intermitência dos impulsos nervosos responsáveis pela comunicação neuronal. A inibição deste mecanismo ocorre devido aos efeitos da exposição a pesticidas organofosforados e carbamatos, bem como a íons metálicos. A atividade da acetilcolinesterase de várias espécies de peixes tem sido utilizada como biomarcador em programas de monitoramento de recursos hídricos por ser um método diagnóstico informativo e efetivo, além de economicamente viável, visto que esta enzima está localizada e disponível de forma abundante num tecido descartado do peixe, o cérebro. Este trabalho objetivou caracterizar parcialmente parâmetros cinéticos e físico-químicos da acetilcolinesterase cerebral de Parachromis managuensis e investigar o efeito in vitro de pesticidas e íons metálicos sobre sua atividade. O pH ótimo e a temperatura ótima foram determinados ensaiando a atividade do extrato em pH de 4,0 a 9,0 e temperaturas de 25 a 80°C. A termoestabilidade foi determinada submetendo o extrato as mesmas temperaturas durante 30 min e, após o equilíbrio, foi mensurada a atividade remanescente. Parâmetros cinéticos; velocidade máxima (Vmax) e constante de Michaelis - Menten (Km) foram calculados em concentrações crescentes (0,8 a 20,8 mM) dos substratos iodeto de acetil e butirilcolina. O extrato foi incubado durante 60 min com um pesticidas organoforforado (diclorvós) e dois carbamatos (carbaril e carbofuran) e foi exposto durante 40 min a 10 íons (Al3+, Ba2+, Cd2+, Cu2+, Hg2+, Mg2+, Mn2+, Pb2+, Fe2+ e Zn2+) em cinco concentrações de 0,001 a 10 mM. A atividade enzimática foi analisada após exposição aos inibidores seletivos BW284c51, Iso-OMPA, neostigmina e eserina nas mesmas concentrações. Estes inibidores confirmaram AChE e BChE como responsáveis pela atividade analisada. O pH ótimo e a tempertura ótima encontrados para a AChE foram 8,0 e 35°C respectivamente. A AChE reteve 70% da atividade após incubação a 40°C por 30 min. Os parâmetros cinéticos, Vmax e Km foram respectivamente 0,520 ± 08,98 mU/mg e 0,587 ± 0,95 mM para AChE; e 0,267 ± 5,2 mU/mg e 4,06 ± 0,82 mM para BChE. Todos os pesticidas usados mostraram efeito inibitório na atividade da AChE. Os valores da concentração inibitória média dos pesticidas (IC50) foram: 1,68 μM (diclorvós), 4,35 μM (carbaril) e 0,28 μM (carbofuran). A maioria dos íons em 1 mM não mostraram efeito significativo (p = 0.05), enquanto Zn2+, Cd2+, Cu2+, Hg2+, inibiram a atividade da enzima em 17%, 25%, 53% e 100% respectivamente. AChE de P. managuensis mostrou potencial como biomarcador para todos os pesticidas usados, principalmente para o carbamato carbofuran, além do íon mercúrio (Hg2+). Sendo, portanto, considerada uma ferramenta útil no monitoramento ambiental. / Acetylcholinesterase (AChE; 3.1.1.7) is an enzyme from the group of serine esterases acting in the hydrolysis of the neurotransmitter acetylcholine ensuring the burst of nerve impulses responsible for neuronal communication. The mechanism of this inhibition is due to the effects of exposure to organophosphorus and carbamate pesticides, as well as metal ions. The acetylcholinesterase activity of several species of fish has been used as a biomarker for monitoring water resources programs to be a method informative diagnosis and effective, and economically viable, since this enzyme is localized and available in abundance in a discarded tissue fish, the brain. This study aimed to partially characterize physicochemical and kinetic parameters of the brain acetylcholinesterase from Parachromis managuensis and investigate the in vitro effects of pesticides and metal ions on its activity analyzing its potential role as biomarker. Optimal pH and temperature were estimated exposing the enzyme extracts to a pH variation between 4.0 and 9.0 and a temperatures ranging from 25 to 80°C. The thermostability was determined submitting the extracts to the temperatures decribed above during 30 min and assaying the residual activity. Kinetic parameters such as maximum velocity (Vmax) and Michaelis-Menten constant (Km) were calculated using increasing concentrations (from 0.8 to 20.8 mM) of the substrates acetyl and butyrylcholine iodide. The extract was incubated during 60 min with one organophosphate (dichlorvos) and two carbamate (carbaryl and carbofuran) pesticides and was exposed for 40 min to 10 ions (Al3+, Ba2+, Cd2+, Cu2+, Hg2+, Mg2+, Mn2+, Pb2+, Fe2+ and Zn2+) in five concentrations from 0.001 to 10 mM. The enzymatic activity was analyzed after exposure to the selective inhibitors BW284c51, Iso-OMPA, neostigmine and eserine in the same concnetrations. These inhibitors confirmed AChE and BChE as responsible for the analyzed activity. Optimal pH and temperature found were 8.0 and 35°C, respectively. AChE retained 70% of its activity after incubation with 40°C for 30 min. The kinetic parameters Vmax and Km were, respectively, 520 ± 8.98 mU/mg and 0.587 ± 0.95 mM for AChE; and 267 ± 5.2 mU/mg and 4.06 ± 0.82 mM for BChE. All the used pesticides showed inhibitory effect on ChE acitivities. The mean inhibitory concentration (IC50) values were: 1.68 μM (dichlorvos); 4.35 μM (carbaryl) and 0.28 μM (carbofuran). Most of the analyzed ions did not show significant effect at 1 mM (p = 0.05), whereas Zn2+, Cd2+, Cu2+ and Hg2+ inhibited the enzyme activity in 17%, 25%, 53% and 100%, respectively at the same concentration. P. managuensis AChE showed potential as biomarker for all the pesticides under study, mainly for the carbamate carbofuran as well as for the mercury ion (Hg2+) and being, therefore, considered a promising tool for environmental monitoring