Degradation of streams in urban-rural fringe regions occurs through complex interactions between hydrological, physical, chemical and biological mechanisms of the stream environment and surrounding landscape. Biological monitoring using macroinvertebrates may capture the complex and cumulative influences of land activity on the stream environment. The Salmon River catchment in the township of Langley, British Columbia, Canada straddles urban and rural environments in the Lower Fraser Valley. To date the Salmon River catchment has been subject to several environmental surveys. Following these earlier investigations, this study quantified relationships between the stream environment and changing land activity, across multiple scales, from 1975 to 2005, using macroinvertebrates as environmental integrators. Current and historical water, sediment, and macroinvertebrate information along with land use and land-cover evaluations were used to quantify relationships between the macroinvertebrate community and land activity in the catchment. Spatial and seasonal results for specific conductivity (a total dissolved ion indicator) and NO������-N and PO����� (nutrient indicators) traced groundwater and overland inputs to the stream environment. Nitrate guideline exceedances occurred at groundwater-influenced sites. Elevated sediment trace metal concentrations and Zn guideline exceedances occurred mid-reach in the catchment. Peak total macroinvertebrate and sensitive taxa abundance occurred mid-reach in the catchment in 2005, while richness and proportional sensitive abundance peaks were seen at groundwater-influenced sites. The dominance of tolerant to moderately pollution tolerant taxa occurred throughout. Despite historical water quality concerns at groundwater-influenced sites, greater shifts in community composition occurred in headwaters regions. Patterns of land use and land cover changed in sensitive areas (i.e. above aquifer and in the headwaters). A greater number of correlations between land activity and macroinvertebrate measures occurred at streams sites with 100 m buffers. The abundance of sensitive taxa positively correlated with the amount of agricultural land use, while rarefaction declined. Several Macroinvertebrate functional feeding groups correlated positively to forest cover, while sensitive taxa abundance and Zn concentrations declined. Results suggest continued water quality and sediment trace metal concerns, while macroinvertebrate results point to nutrient enrichment and greater historical variability in headwaters regions. Agricultural activity appears to have a stronger influence on aspects of the stream environment despite the presence of urban-rural land activity.

Abstract This study investigated the distributions of polyclic aromatic hydrocarbons (PAHs) in the sediment cores collected from continental shelf of Gaoping submarine canyon. The sediment cores were analyzed for PAHs to reconstruct historical contamination record of these compounds and to find out the possible sources, trends and fluxes. The average concentrations of £U50 and £U16 PAHs ranged from 568 to 816 ng/g and from 169 to 256 ng/g, respectively. Except for sediment cores L10 and L26, the high molecular weight PAHs (4-6 ring PAHs) were found dominant in 1960s-2006, while the low molecular weight PAHs (2-3 ring PAHs) were found dominant before 1960s. Results from diagnostic ratios and hierarchical cluster analysis (HCA) both suggested that sources of PAHs in the cores of southern continental shelf were primarily from petrogenic, while those in the cores of northern continental shelf were from pyrogenic and petroleum combustion. There is a significant increasing of total PAH concentrations between 1930-1950, suggesting that might be an evident during the World War II. Due to increase of importing fossil fuel and the growth of heavy industrials in Gaoping area, the total concentrations of PAHs showed an increasing trend again since 1950s in the core from continental shelf of Gaoping submarine canyon. In addition, during 1990-2006, the total concentrations of PAHs showed a decreasing trend might result from the environmental protection laws. It is noteworthy that in L28 and L29 sediment cores, the increase of total PAH concentrations recorded during 1990-2006 may be due to the dumping of the sludge from dredged Kaohsiung harbor sediments. Comparing with the sediment quality guidelines (SQG), the PAH concentrations in the northern continental shelf sediment samples were higher than the Threshold Effect Level (TEL) value, suggesting there might be an adverse biological effects caused by PAHs. Keywords¡GPolycyclic aromatic hydrocarbons (PAHs), Kaohsiung harbor, Sediment quality guidelines (SQG)

The main purpose of this research was to analyze the distribution and accumulation of metals in sediment cores of Gao-ping Canyon nearby areas. Enrichment factor (EF) and Sediment Quality Guidelines (SQGs) were also used to assess the pollution history, sources and extent of heavy metal pollution. The results revealed that copper and cadmium metal concentrations have not been contaminated significantly; while zinc and lead concentrations reached moderate degree of pollution, which exceeded guidelines of Low-SLG in Ontario and ERL in NOAA. The concentration of lead was higher than most found in Taiwan. Although chromium was found mild polluted, but attention should still be paid as those concentrations exceeded the values of Low-SLG¡BSevere-SLG and ERL. Comparing results from cores in Southern and Northern shelves of Gao-ping Canyon, the trend of heavy metal concentrations in Northern shelf rose gradually but had an apparent downward trend in surface mixed layer; while distinct variation with time was observed in Southern shelf.

Orientador: Marcelo Luiz Martins Pompêo / Resumo: Objetivou-se avaliar a heterogeneidade espacial do reservatório Broa a partir das variáveis limnológicas, metais em água e sedimento e comunidade fitoplanctônica. As coletas foram realizadas no período seco em nove pontos amostrais distribuídos ao longo do eixo longitudinal do reservatório. Determinou-se in situ, laboratório e/ou microscopia: coordenadas GPS, profundidade, temperatura superficial, oxigênio dissolvido, condutividade elétrica, pH, transparência, nutrientes inorgânicos, clorofila-a, metais em água e sedimento, matéria orgânica, nutrientes em sedimento, riqueza, densidade, biomassa e grupos funcionais do fitoplâncton, a partir de microscópio óptico binocular e invertido, e método de câmaras de sedimentação. As seguintes análises estatísticas foram aplicadas: Análise de Componentes Principais (ACP), Análise de Correspondência Canônica (ACC), ANOVA, análise de correlação, assim como os índices de Uniformidade (Evenness E2), Fator de Enriquecimento (FE), Carga Poluidora (PLI) e Risco Ecológico (RI). As variáveis OD, NT, Clor-a, densidade de cianobactérias e concentração de Cu estiveram em desacordo com a Resolução CONAMA 357/05, com classificação da qualidade da água como “Ruim” pelo Evenness E2, sendo que as baixas concentrações dos elementos conservativos e metais em sedimento favoreceram respostas positivas aos índices FE, PLI e RI. Foi identificada tendência de eutrofia, com destaque das cianobactérias na estrutura da comunidade em relação à densidade, biomassa ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of the study was to evaluate the spatial heterogeneity of the Broa reservoir from the limnological variables, metals in water and sediment and phytoplankton community. The samples were collected during the dry period at nine sampling points distributed along the longitudinal axis of the reservoir. The following variables were determined in situ, laboratory and/or microscopy: GPS coordinates, depth, surface temperature, dissolved oxygen, conductivity, pH, transparency, inorganic nutrients, chlorophyll a, metals in water and sediment, organic matter, sediment nutrients, richness, density, biomass and phytoplankton functional groups, using binocular and inverted optical microscope, and sedimentation chamber method. The statistical analyzes were Principal Components Analysis (PCA), Canonical Correspondence Analysis (CCA), ANOVA, correlation analysis, as well the Uniformity Index (Evenness E2), Enrichment Factor (EF), Pollutant Concentration (PLI) and Ecological Risk (ER). The DO, TN, Chlor-a, cyanobacteria density and Cu concentrations variables were in disagreement with CONAMA Resolution 357/05, with water quality classified as "Bad" by Evenness E2. For the concentrations of the conservative elements and metals in sediment the classification of pollutant was "absent/very low" by the EF, PLI and ER indexes. Eutrophic tendency was identified, with emphasis on cyanobacteria in the community structure in relation to density, biomass and descriptive species from functional gr... (Complete abstract click electronic access below) / Mestre

Os efluentes de fábricas de celulose são conhecidos por apresentarem uma ampla gama de compostos químicos naturais e antropogênicos, que possuem potencial inibidor e estimulador à biota. Muitos destes podem se agregar ao sedimento e causar efeitos agudos ou crônicos aos organismos. Diversos estudos têm sido realizados para se avaliar a qualidade ambiental do corpo receptor adjacente às fábricas de celulose, entretanto a maioria destes são avaliados de forma isolada, o que dificulta a identificação das áreas realmente afetadas pelo efluente. A abordagem TQS (Tríade de Qualidade dos Sedimentos) integra análises químicas do sedimento, testes de toxicidade e ecologia do bentos. O objetivo do presente trabalho foi avaliar a qualidade dos sedimentos no entorno do emissário de uma fábrica de celulose, através da abordagem TQS. Foram feitas 4 amostragens, em julho e dezembro de 2001 e 2002. O sedimento foi coletado em 9 estações de amostragem, sendo 6 ao redor do emissário da fábrica e 3 afastadas do mesmo (referência). Foram realizadas análises químicas (metais pesados, ácidos graxos, beta sitosterol, EOX, PCBs, N, C, etc.) do sedimento, testes de toxicidade da água intersticial (MICROTOX® e ouriço Echinometra lucunter) e sedimento (anfípodo Tiburonella viscana) e análise da estrutura da comunidade do zoobentos. A análise integrada dos dados da tríade mostrou uma baixa influência do efluente da fábrica na estação de coleta mais próxima do emissário (5) e em duas estações ao sul do mesmo (3 e 7A). A Estação 5 apresentou evidências químicas e toxicológicas de degradação, enquanto que as Estações 3 e 7A apresentaram evidências químicas. / Effluents from pulp mills are known to contain a large number of chemicals that have inhibitory and stimulatory effects on aquatic biota. Many contaminants may adsorb to sediment and cause acute or chronic effects to sediment-dwelling organisms. Several studies have been conducted to evaluate the environmental quality of the receiving body adjacent to a pulp mill (Brazil) outfall. However, most of them were conducted separately, making it difficult to identify the real affected area. The SQT (Sediment Quality Triad) approach integrates chemical analyses of the sediment, toxicity tests and benthic ecology. The purpose of the present study was to evaluate the sediment quality around the outfall of a pulp mill by use of the SQT approach. Samples were collected seasonally over two years, in July and December of 2001 and 2002. The sediment was collected at nine sampling stations, six of them around the outfall and three reference stations located far from the outfall. Several chemical analyses were made (heavy metals, fatty acids, beta sitosterol, EOX, PCBs, N, C) in the sediment, toxicity tests were done with pore water (MICROTOX® and the sea urchin Echinometra lucunter early life stage tests) and sediment (amphipod Tiburonella viscana), and analyses of the structure of the zoobenthic community were performed. The integrated analysis of the SQT data showed some influence, although low, of the effluent on the sampling station closest to the outfall (station 5) and on two stations to the south of the outfall (stations 3 and 7A). Station 5 exhibited evidence of toxicological effects, and stations 5, 3 and 7A exhibited slightly elevated concentrations of chemicals relative to the reference stations.

The Australian and New Zealand Environment and Conservation Council (ANZECC) and the Agriculture and Resource Management Council of Australia and New Zealand (ARMCANZ) have announced that the 1997 review of the Australian Water Quality Guidelines will include for the first time, consideration of sediment quality guidelines. For this reason, it is timely to review the methods for establishing such guidelines, and the manner in which they could be used in managing the quality of sediments in Australian rivers, lakes and drainage systems. In this thesis, the problem of the development of sediment quality guidelines is introduced and basic questions relating to the development of such guidelines are addressed. The importance of sediment monitoring and sediment quality assessment in aquatic ecosystem management is demonstrated, and the role of sediment quality guidelines in the process of sediment quality assessment is discussed. The arguments considered in this thesis are illustrated by specific reference to the setting and use of sediment quality guidelines for heavy metal contamination. A number of physico-chemical factors (grain size distribution, pH, redox potential, alkalinity and hardness, salinity, organic matter) can affect the bioavailability and toxicity of contaminants in sediments, and these factors may vary spatially and temporally within and between sediment deposits. Changes in physico-chemical conditions as a result of natural or anthropogenic processes may lead to major changes in bioavailability of sediment contaminants. The variability of these physico-chemical factors has ramifications for the way in which sediment quality guidelines are derived and used. Factors affecting the way in which toxicity is measured (test species chosen, toxicological end-point measured, duration of test relative to life-cycle), and toxicity data is interpreted, are also important to the development of useful sediment quality guidelines. All of these factors must be taken into account in deriving sediment quality guidelines for Australian conditions. The large number of factors affecting the sensitivity and efficiency of sediment quality guidelines means that a simple set of numerical guidelines, as has been used in the past, is not appropriate. A multi-step assessment procedure will be required. Methods of setting sediment quality guidelines that have been used by authorities in overseas jurisdictions were reviewed. Advantages and disadvantages of the various methods were compared. None of the methods used overseas has been shown to be applicable to Australian conditions. In the absence of a suitable method for deriving Australian sediment quality guidelines in the short term, the adoption of the Canadian Interim Sediment Quality Guidelines as interim sediment quality guidelines for Australia is recommended. Sediment quality guidelines need to be viewed in the context of the overall environmental management process, of which they form an integral part. The policy background to environmental management in Australia, and the management frameworks that have been put in place to implement the policy, are outlined. The AS/NZS/ISO 14000 series of standards for environmental management systems provides a framework which is consistent with the principles and objectives of environmental management in Australia. It therefore provides an appropriate framework within which to develop and use sediment quality guidelines. Within the broad AS/NZS/ISO 14000 policy, a framework for the development and use of sediment quality guidelines is proposed, which will provide a technically and legally defensible basis for the management of aquatic sediments in Australia, in the short term and long term. The proposed framework involves the setting of Interim Sediment Quality Guidelines for Australia, based on the best scientific knowledge currently available. The framework recognises that the factors affecting the bioavailability and toxicity of sediment contaminants are complex, and that the current level of knowledge of sediment processes is incomplete. Therefore, a conservative approach to setting guidelines is taken, and a highly sensitive guideline based on that used in Canada, is proposed. The framework further recognises that this approach will lead to over protection of the environment in some cases, so a "Decision Tree" approach is taken. The "decision tree" allows the consideration of more complex interactions than can be incorporated into simple numeric guidelines, while attempting to simplify the assessment process. In keeping with the ISO 14000 series of standards for environmental management, the framework also explicitly includes steps designed to ensure that monitoring data are regularly collated, and analysed, and where necessary, guidelines are able to be updated in light of new knowledge gleaned from the review process. The proposed framework is appropriate to, and supportive of, the principles of environmental management as set out in Australian Government policy documents, inter governmental and international agreements, and legislation. It provides a basis for the on-going collection of data suited to increasing our understanding of the factors influencing the behaviour of contaminants in sediments, and thereby lead to continual improvement in sediment quality guidelines for use in Australian conditions.

The river water quality management strategy involves a series of complex inter-disciplinary decisions based on speculated responses of water and sediment quality to changing controls. In the aquatic system a rapid removal of the heavy metals from the water to sediments may occur by settling particles while some of these pollutants can be mobilized by getting accumulated into the biota from the sediments sink. Thus, sediment plays a major role in the determining pollution pattern of aquatic systems. It acts as both carriers and sinks for contaminants, reflecting the history of pollution, and providing a record of catchment inputs into aquatic ecosystems. The Yan Shuei Gang River watershed is one the river watersheds in Kaohsiung City, Taiwan. It is 5-km long, drains a catchment of more than 1,200 ha. Part of the river water is from the domestic drainage areas located in the upper catchment. In Linhai Industrial Parks, there are more than 493 registered industrial factories that discharge their wastewater into the Yan Shuei Gang River. Thus, recent water and sediments quality analysis indicates that the Yan Shuei Gang River is heavily polluted. The major objectives of this study were to (1) perform water quality and sediments sampling and analyses, (2) perform water quality simulation and demonstrates the model application to the Yan Shuei Gang River, (3) assess the water and sediments quality, (4) provide foci for immediate remediation efforts, (5) provide benchmark levels to test outcomes of future remediation efforts, (6) design a novel extraction technique that utilizes a mildly elevated pressure in consecutive cycles with a chelating agent for the sediment slurry. Water quality investigation results show that the biochemical oxygen demand (BOD), ammonia-nitrogen (NH3-N), and suspended solid (SS) average concentrations in water samples of the Salt-water River varied from 10.2 to 194, 8.51 to 18.3, and 7.9 to 19.5 mg/L, respectively. The results of the chemical analysis of the Salt-water River surface sediments showed that the sediments present highly elevated Cd, Cr, Ni, Cu, Pb, Zn and Fe concentrations. Investigation results reveal that sediment samples contained significant amount of iron (up to 3.6%), Cr (up to 66.5 mg/kg), Pb (up to 36.5 mg/kg), Ni (up to 43 mg/kg), and Al (up to 1.8%). All heavy metal concentrations were higher than the world average, sediments average and sediment quality guidelines (SQGs). Although all metals showed varied concentrations, the approaches of factor analysis, normalized enrichment factor (EF), and the geo-accumulation index (Igeo) proposed in this paper were effectively used to differentiate the natural and anthropogenic sources of the metals. Both the EF and Igeo indicated similar anthropogenic contamination degree of the metals. The potential acute toxicity in sediment of Yan Shuei Gang River was observed to be mainly due to Cu contamination. Cu was the major toxicity contributor accounting for 32-46% of the total toxicity in Salt-water River, followed by Zn. The Water Quality Analysis Simulation Program (WASP) model developed by US Environmental Protection Agency (EPA) was selected as a water quality planning tool to perform the water quality evaluation. Modeling results show that the current daily pollutant inputs were much higher than the calculated carrying capacity for nutrients and BOD of the Yan Shuei Gang River. Based on the results from this study, the following remedial strategies have been proposed to minimize the impacts of industry and domestic source pollution on the water quality of Salt-water River: (1) increase the flow by transporting 1 m3/s unpolluted surface water from other sources to dilute the polluted river water, (2) construction of the intercepting systems to effective intercept and transport the untreated wastewater to the wastewater treatment systems. The sediments batch extracted by 150 psi pressure cycles has the most Cu removed rater (70%), much higher than without treatment (55%) or with 90 psi pressure cycles treatment (65%). Pressure-assisted extraction achieves in 60 min the amounts of Cu equal to or exceeding those achieved in 240 min without pressure cycles under the same concentration conditions. This research indicates that the advantages of pressure cycle system are increased process speed, more thorough extraction, and reduced use of the chelating agent. The heightened treatment is explained by sediments aggregate fracturing upon pressure cycles that exposes the contaminants as well as by the chelating agents. The technique is expected to accelerate extraction treatment of a wide range of heavy metal contaminants, and it may provide treatment to dredged and stored contaminated sediments. Experience obtained from this study will be helpful in designing the sediment and river management strategies for other similar river watersheds.

The distribution of butyltin compounds (BTs) in the sediments and seawater, at the river outfalls, fishing ports, shipyards, and industrial zone docks of Kaohsiung Harbor, Taiwan were investigated. Twenty sediment and seawater samples were collected from various locations in the Harbor in 2006, and analyzed for monobutyltin (MBT), dibutyltin (DBT), and tributyltin (TBT). Results showed that the concentration of total BTs varied from 1.5 to 151 ng/g in sediment samples, with TBT being the major component of the sediment samples. This suggests that sediments could be the most possible sink of TBT brought by the sorption mechanism. The concentrations of BTs ranged from 9.7 to 270 ng/L in seawater samples, whereas DBT and MBT, the degradation byproducts of TBT, were mainly the most abundant BT compounds of the seawater samples. This indicates that the abiotic or biotic degradation potential of TBT was significant. Spatially, the highest concentrations of BTs were observed in both water and sediment samples collected from the shipyard and fishing port areas. This indicates that the shipping related activities (e.g., navigation, ship repair, and ship building), would contribute most of BTs in the environment. Results show that the concentrations of degradation products (DBT and MBT) were related closely to temperature, salinity, dissolved oxygen (DO), and chlorophyll-a of the seawater. This implies that seasonal changes of the water parameters controlled the degradation of TBT in seawater. The observed levels of BT compounds in both seawater and sediments were much higher than those required to induce toxic effects on marine organisms suggesting that appropriate TBT control strategies should be taken in Kaohsiung Harbor. Sediment samples were collected from the river outfalls, fishing ports, shipyards, and industrial zone docks of Kaohsiung Harbor, Taiwan to evaluate the distribution of polycyclic aromatic hydrocarbons (PAHs) in sediments. Collected sediment samples from 12 locations were analyzed for 17 different PAHs, organic content, and grain size. The results show that the total PAH concentrations varied from 472 to 16,201 ng/g dry wt, with a mean concentration of 5,764 ng/g dry wt The highest PAH concentrations were from the industrial zone docks situated in south Kaohsiung Harbor, ranging from 8,788 to 16,201 ng/g dry wt Among those sediment samples, the 5-, 6-ring PAHs were predominant PAH congeners in sediments, ranging from 42 to 71%. However, the dominant PAH congeners were 2-, 3-ring PAHs (37 to 42%) collected from steel industrial zone docks. This indicates that the sources for the PAH contamination at steel industrial zone docks were different from the other zones in Kaohsiung Harbor. According to the diagnostic ratios, the possible source of PAHs in the industrial zone dock could be coal combustion while in the other zones it could be petroleum combustion. The total PAH levels were expressed as the total toxic equivalent (TEQcarc). The total TEQcarc varied from 55 to 1,964 ng TEQ/g dry wt. Higher total TEQcarc values were found at industrial zone docks (from 1,404 to 1,964 ng TEQ/g dry wt). As compared with the US Sediment Quality Guidelines (SQGs), the observed levels of PAHs at industrial zone docks exceeded the effects range low (ERL), and could thus cause acute biological damage. However, the lower levels of PAHs at the other zones would not exert adverse biological effects. Results would be helpful in developing strategies for sediment remediation in Kaohsiung Harbor.

This research investigated the accumulation of metals (Cu, Zn, Cr, Pb, Cd and Fe) in sediment of Gao-ping River and Gao-ping submarine canyon. Both Sediment Quality Guidelines (SQGs) by National Oceanic and Atmospheric Administration (NOAA) and Soil Quality Guidelines by Taiwan Environmental Protection Agency (EPA) were used to assess the extent of risk of these metals to the local ecological system. The results found no significant correlation between concentration of metals and volatile solid as well as particle size. It is noted that significant contaminations in zinc and lead were observed in sediments from both Gao-ping River and the starting point of Gao-ping submarine canyon, which concentrations exceeded the guidelines of Effect Range-Medium (ERM) by NOAA. Very likely, this is resulted from the metal and electroplating factories in the catchment area of Gao-ping River. It also provides evidence of the role of Gao-ping submarine canyon in accumulation of terrestrial and anthropogenic pollutants.

Made available in DSpace on 2016-08-19T12:56:43Z (GMT). No. of bitstreams: 1 dissertacao Adriana.pdf: 1061561 bytes, checksum: fdd7fb29d8af4d9ba71f59fcbab46042 (MD5) Previous issue date: 2013-11-01 / Although they are found at trace levels in the environment, the metals Cd, Ni, Cr, Zn, Cu and Pb have received numerous studies due to the toxic potential. Some of them have no known biological function such as Pb and Hg. However, these metals, at certain concentrations, offer risk for aquatic organisms. This risk, Beyond to the total concentration of them, is associated with their mobility in environmental matrices. To assess the risk of trace metals in sediments from mangrove Tibiri River, located on the Maranhão island, This study used the guide values developed by environmental agencies based on the total concentration of these elements. The results showed that the levels were below the metal TEL (Threshold effect level) and ERL (Effect low range), ranges associated with occasional adverse biological effects for aquatic life. The concentrations of trace metals found in sediments are the same order of magnitude of the background prescribed by the National Oceanic and Atmospheric Administration (NOAA). The order of mobility (considering the sum of the first three most mobile fractions) was: Ni (24%)> Zn (20.6%)> Cu (14.5%)> Pb (1.9%)> Cd = Cr (not detected). The low mobility values contribute to minimizing the environmental risk of trace metals. / Embora sejam encontrados em níveis de traço no meio ambiente, os metais Cd, Ni, Cr, Zn, Cu e Pb têm recebido inúmeros estudos em função de seu potencial tóxico. Alguns deles não possuem função biológica conhecida como é o caso do Pb e Hg. Porém, todos estes metais, em determinadas concentrações, oferecem risco aos organismos. Este risco, além da concentração total dos mesmos, está associado à mobilidade deles nas matrizes ambientais. Para se avaliar o risco dos metais traço nos sedimentos de manguezal do Rio Tibiri, localizado na Ilha do maranhão, este estudo dispôs de valores guias desenvolvidos por agências ambientais, baseados na concentração total destes elementos. Os resultados demonstraram que os níveis de metal estavam abaixo do TEL (Threshold effect level) e do ERL (Effect range low), faixas associadas a efeitos biológicos adversos ocasionais para a vida aquática. As concentrações de metais traço encontrados nos sedimentos estão na mesma ordem de grandeza dos valores basais prescritos pela National Oceanic and Atmospheric Administration (NOAA). A ordem de mobilidade (considerando a soma das três primeiras frações mais móveis) foi a seguinte: Ni (24%) > Zn (20,6%)> Cu (14,5%)> Pb (1,9%) > Cd = Cr (não detectado). Os baixos valores de mobilidade contribuem para minimização do risco ambiental dos metais traço.