Orientador: Lucia Regina Durrant, Matthew James Grossman / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-22T02:43:16Z (GMT). No. of bitstreams: 1 Santos_LigiaGibinidos_M.pdf: 3848321 bytes, checksum: 46f91a01a783f6fd7d5153ba73c6e8a0 (MD5) Previous issue date: 2013 / Resumo: Dentre os contaminantes ambientais mais abundantes, destacam-se os Hidrocarbonetos aromáticos policíclicos (HAPs), que apresentam elevado potencial tóxico, sendo imprescindível sua remoção do ambiente. O objetivo deste trabalho foi analisar, em microcosmos, a biodegradação de HAPs por um consórcio bacteriano e identificar fatores que influenciam nesta degradação e na análise dos dados. A degradação dos HAPs no solo sem histórico de contaminação foi muito semelhante em todos os microcosmos, apresentando uma porcentagem de aproximadamente 85%. Para analisar a toxicidade do solo antes e depois da biorremediação, realizou-se um testes de germinação de sementes de Lactuca sativa (alface). O teste mostrou baixa toxicidade do solo após 80 dias da contaminação, com ou sem a adição do consórcio. Durante estudos de remediação biológica, é necessário utilizar um marcador interno para minimizar a dispersão e extração irregulares dos contaminantes. Neste estudo foi utilizado o hexaclorobenzeno, que mostrou excelente, uma vez que não sofreu nenhum tipo de degradação. Análises moleculares mostram que a adição de HAPs alterou significativamente a comunidade microbiana, favorecendo os membros degradadores de tais poluentes. O consórcio adicionado inibiu o crescimento de alguns micro-organismos autóctones. Além disso, não houveram evidências de que os micro-organismos degradadores de HAPs adicionados persistiram, sugerindo que eles podem não competir eficientemente com a população microbiana autóctone. Não houve efeito claramente identificado do hexaclorobenzeno sobre o crescimento de micro-organismos, com exceção de um aumento no número de organismos pertencentes da classe Alphaproteobacteria / Abstract: Polycyclic aromatic hydrocarbons (PAHs) stand out as among the most abundant and toxic of environmental contaminants, and their removal from contaminated sites is indispensable for a healthy environment. The objective of this study was to analyze, in soil microcosms, the biodegradation of PAHs by a bacterial PAH degrading consortium and identify factors that influence this degradation and data analysis. Degradation of PAHs in soil with no history of contamination was very similar in microcosms with or without bioaugmentation, with the extent of PAH removal of about 85% in all cases. The germination of Lactuca sativa (lettuce) in soils taken from the microcosms was used to examine the toxicity of the soil before and after bioremediation. The test showed a low toxicity of the soil 80 days after PAH contamination, with or without the addition of the consortium. During studies of biological remediation it is necessary to use an internal non-biodegradable marker to minimize the effect of uneven dispersion and irregular extraction of pollutants. This study used hexachlorobenzene as the nonbiodegradable marker and it proved to be an excellent marker as it did not suffer any significant degradation in the soil microcosms. Molecular analyzes showed that the addition of PAHs significantly altered the microbial community by encouraging the growth of PAH degraders. In addition, the added microbial consortium was found to inhibit the growth of some of the indigenous microorganisms. Furthermore, there was no evidence that the added PAH degraders persisted, suggesting that they might not compete effectively with the native microbial population. There was little effect of hexachlorobenzene on the microbial community or on the removal of the PAH contaminants, with the exception of an increase in the number of organisms belonging to the class Alphaproteobacteria / Mestrado / Ciência de Alimentos / Mestra em Ciência de Alimentos

The Arctic represents a huge area with poor infrastructure contributing to limited possibilities to establish monitoring and research programs. From the investigations that have been performed we know that the arctic environment is affected by anthropogenic emissions from lower latitudes, but knowledge about underlying transport processes, the arctic pollution extent and the rates of changes are limited. This is of particular concern since we are facing climate changes that will not only influence the pole-ward transport of pollutants, but also change conditions for the already accumulated pollutants in the arctic environment. In this thesis lake sediments and soil samples are used to study sub-arctic and arctic time trends and loads of PCBs, PBDE, pesticides, mercury and lead. The study sites are the area around Kangerlussuaq, located in western Greenland, and the Swedish mountains. The temporal trends for PCBs (69 congeners), PBDE (#47) and two pesticides (chlordane and hexachlorobenzene) are studied in seven surface lake sediment cores from Greenland. The concentrations of these persistent organic pollutants are one to two orders of magnitude lower compared to lake sediments from lower latitudes, but with temporal trends following emission and usage trends at lower altitudes, i.e., decreasing trends for PCBs, increasing for PBDE and no specific trends for the pesticides. A delayed deposition of the low-chlorinated PCBs compared to the high-chlorinated PCBs may support the hypothesis of ‘cold condensation’ and ‘global fractionation’ i.e., volatile compounds are fractionated during the pole-ward transport. For lead the concentration in three Greenland lake sediments is about 10 times lower than in sediments from industrial regions, but the past 200 years’ temporal trends follow emission trends in industrial regions. The mercury concentration and enrichment following the Industrial Revolution in the mid 19th century are in three lake sediments from Greenland and in twelve lake sediments from the Swedish mountains comparable with those in sediments from industrial regions; a result of the long atmospheric residence-time for mercury, making it a global pollution. Recently decreased mercury emissions in North America and Europe give declining concentrations in the sediment surfaces, especially in lakes located in the Swedish mountains. In Greenland deeper sediment cores, spanning the last 8000 years, there are substantial fluctuations in mercury concentration and stable lead isotopes (206Pb/207Pb). These fluctuations are the result of variations in deposition to the lake of aeolian material, driven by past variations in arctic climate. In surface soil the mercury concentrations and inventories from the Swedish mountains are 1.5-2 times higher than in soils from Greenland, but for both regions the concentrations are below the critical concentration set up by UN-ECE to protect the terrestrial ecosystem. No indications for mercury enrichment in colder areas, as suggested by the hypothesis of ‘cold condensation’, or in coastal areas, as suggested by the hypothesis of ‘mercury depletion events’, were observed. The highly minerogenic surface soils in sub-arctic and arctic regions have reduced capacity to store mercury, compared to boreal soils.

L'hexaclorobenzè (HCB) és un compost organoclorat àmpliament distribuït per tot el planeta, altament lipofílic que s'acumula als sistemes biològics. Els nounats s'exposen a aquests compostos organoclorats (OCs) a través de la placenta i de la lactància materna. Tot i que l'HCB és un dels OCs més comuns, la seva transferència a través de la placenta de la mare al fetus durant la gestació i a través de l'alletament matern està poc documentada. El coneixement sobre els seus possibles efectes sobre la salut infantil és també bastant limitat. A Flix, un poble de la Ribera d'Ebre, es van detectar nivells molt elevats d'HCB a l'atmosfera degut a la seva proximitat a una empresa electroquímica. Els objectius del present treball són els d'avaluar l'exposició a OCs a través de la placenta i de la lactància materna i els seus efectes sobre la salut infantil durant el primer any de vida en el conjunt de nounats d'aquesta població. / Hexachlorobenzene (HCB) is an organochlorine compound widely spread in the environment, highly lipophyilic which accumulates in all biological systems. Newborns are exposed to organochlorine compounds (OCs) through placenta and via breastfeeding. Although HCB is one of the most common OCs, its transference from the mother to the child through placenta and via breastfeeding is poorly documented. The knowledgement of the possible adverse effects on infant's health is also limited. In Flix, a small village in the Ribera d'Ebre area, high levels of HCB were detected in the atmosphere of the village due to the vicinity of an electrochemical factory. The objectives of the present study are to evaluate OCS exposition through placenta and breastfeeding and its effects on infant's health during the first year of life.

Persistent organic pollutants (POPs) are hydrophobic substances that readily sorb to organic matter in particles and colloids instead of being freely dissolved in the water phase. This sorption affects the bio­availability and environmental transport of the POPs. The major part of this thesis concerns the role of sediments as secondary sources of POPs. As the primary emissions decrease, contaminated sediments where POPs have accumulated can become the main source of contamination. If the contaminated sediment by time becomes covered with cleaner layers, the POPs are buried and no longer in contact with the aquatic environment. Experiments in this thesis showed, however, that new invading species can alter the sediment-water dynamics as a result of their bioturbation, i.e. mixing of sediment particles and pore-water. Marenzelleria spp., invading species in the Baltic Sea that burrow deeper than native species, were found to increase the remobilization of buried contaminants. The sediment-to-water flux was inversely related to the burial depth (2-10 cm) of the POP congeners (polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers) and also inversely related to the hydrophobicity of the congener. The flux was therefore most pronounced for less hydrophobic contaminants, which was linked to the bioirrigating behaviour of these species. Marenzelleria spp. also accumulated the buried POPs and increased concentrations in surface sedi­ment. Contaminants previously considered buried at a ’safe’ depth can thus be remobilized as a result of the invasion of Marenzelleria spp. in the Baltic Sea. One method to decrease the remobilization of contaminants from sediments is ’capping’, i.e. a layer of clean material is placed as a cap on the sediment. By amending the cap with active materials, which sequester the POPs and decrease their availability, thinner layers can be used (’active capping’ or ’thin-layer capping’). Results from an experiment with thin-layer capping using different active materials (activated carbon (AC) and kraft lignin) showed that both the sediment-to-water flux and the bioaccumulation by benthic species of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), hexachlorobenzene (HCB) and octachlorostyrene (OCS) decreased with increased thick­ness of the cap layer (0.5-5 cm). Amendments with active materials further increased the cap efficiency. AC was more efficient than kraft lignin, and a 3 cm cap with 3.3% AC reduced the flux and bioaccumulation with ~90%. The reduction of the sediment-to-water flux was inversely related to the hydrophobicity of the POP, and reductions in the flux had similar magnitudes as reductions in the concentration in deep-burrowing polychaetes, demonstrating the importance of bioturbation for sediment-to-water transport. In a one-year study on the levels of PCDD/Fs, PCBs, and HCB in a coastal area of the Baltic Sea, the correlations between the POP levels and the levels of particles and organic carbon in the water were found to differ for POPs of different structure and hydrophobicity. The levels of PCDD/Fs decreased to one third in May, which could be related to the increased sedimentation, i.e. water-to-sediment transport, during spring bloom.

Using a comparative spatial and temporal analysis on sediment cores from 8 lakes in the Mackenzie River Delta uplands region, NT, Canada, this study assessed how persistent organic pollutant (POP) deposition to lake sediments was affected by: (1) the presence of retrogressive thaw slumps on lake shores; and (2) changes occurring with increased autochthonous primary productivity. POPs examined included polychlorinated biphenyls (PCBs), penta- and hexachlorobenzenes (CBzs), and dichlorodiphenyltrichloroethane and metabolites (DDTs). Surface sediments of slump-affected lakes contained higher total organic carbon (TOC)-normalized POP concentrations than nearby reference lakes unaffected by thaw slumps. Inorganic sedimentation rates were positively related to contaminant concentrations, suggesting that the influx of siliciclastic material reducing organic carbon in slump-affected lake water indirectly results in higher concentrations of POPs on sedimentary organic matter. This explanation was corroborated by an inverse relationship between sedimentary POP concentrations and TOC content of the lake water. Deposition proxies of autochthonous carbon were not significantly correlated to POP fluxes of surface sediments, and historical profile fluctuations did not coincide with variation in POP deposition. Thus this study does not support the contention that algal-derived organic carbon increases the delivery of organic pollutants to sediments (the algal-scavenging hypothesis), as previously proposed for mercury. Higher POP concentrations observed in surface sediments of slump-affected lakes are best explained by simple solvent switching processes of hydrophobic contaminants onto a lower pool of available organic carbon when compared to neighbouring lakes unaffected by thaw slump development.

Using a comparative spatial and temporal analysis on sediment cores from 8 lakes in the Mackenzie River Delta uplands region, NT, Canada, this study assessed how persistent organic pollutant (POP) deposition to lake sediments was affected by: (1) the presence of retrogressive thaw slumps on lake shores; and (2) changes occurring with increased autochthonous primary productivity. POPs examined included polychlorinated biphenyls (PCBs), penta- and hexachlorobenzenes (CBzs), and dichlorodiphenyltrichloroethane and metabolites (DDTs). Surface sediments of slump-affected lakes contained higher total organic carbon (TOC)-normalized POP concentrations than nearby reference lakes unaffected by thaw slumps. Inorganic sedimentation rates were positively related to contaminant concentrations, suggesting that the influx of siliciclastic material reducing organic carbon in slump-affected lake water indirectly results in higher concentrations of POPs on sedimentary organic matter. This explanation was corroborated by an inverse relationship between sedimentary POP concentrations and TOC content of the lake water. Deposition proxies of autochthonous carbon were not significantly correlated to POP fluxes of surface sediments, and historical profile fluctuations did not coincide with variation in POP deposition. Thus this study does not support the contention that algal-derived organic carbon increases the delivery of organic pollutants to sediments (the algal-scavenging hypothesis), as previously proposed for mercury. Higher POP concentrations observed in surface sediments of slump-affected lakes are best explained by simple solvent switching processes of hydrophobic contaminants onto a lower pool of available organic carbon when compared to neighbouring lakes unaffected by thaw slump development.