Abstract: Aim: The Aura River, located in the second-largest Brazilian Amazon city, has been experiencing the effects of human activities from riverine communities and the Aura landfill for many years. In this study, we assess the occurrence, sources, and distribution of selected sterol markers in surface sediments of Aura River in order to evaluate the organic matter inputs in this water body. Methods: Gas chromatography-tandem mass spectrometry (GC/MS/MS) was used to identify and quantify sterol compounds. Pearson correlation, principal component analysis (PCA) and sterol ratios were used to assess sewage pollution. Results: The sterol markers identified, the related diagnostic ratios, and statistical analysis showed that Aura River sediments presented two primary sterol sources: anthropogenic (domestic sewage and inputs from Aura landfill) and biogenic sources (terrestrial higher plants). Station 1 (the closest site to the Aura landfill) presented the highest level of coprostanol (219.8 ng g-1). This maximum level of coprostanol and the sterol ratios indicate moderate human fecal contamination in the upper reach of the Aura River. Coprostanol levels were similar to the lower to midrange concentrations reported for surficial river sediments around the world. Conclusions: This study demonstrated that domestic sewage pollution from riverine communities and organic matter inputs from Aura landfill might be assumed as potential threats to environmental and human health.
Keywords: surface sediments; organic matter; domestic riverine sewage; ecological and human health risk; amazonic aquatic systems.
Resumo: Objetivo: O rio Aura, no nordeste da Amazonia brasileira, vem sofrendo influencia antropica de comunidades ribeirinhas e do aterro sanitario Aura ha muitos anos. Neste trabalho, avaliamos a ocorrencia, fontes e distribuicao de seis marcadores de esterois em sedimentos superficiais do Rio Aura para avaliar aportes organicos neste corpo d'agua. Metodos: A cromatografia gasosaacoplada a espectrometria de massas (GC/MS) foi empregada para determinar os esterois. A analise de correlacao de Pearson, analise de componentes principals (PCA) e razoes de esterois foram utilizadas para avaliar a poluicao por esgoto. Resultados: Os analitos de interesse identificados e as razoes diagnosticas indicaram que os sedimentos do rio estudado apresentam compostos organicos provenientes de fontes tanto antropogenicas (esgotos domesticos e MO do aterro sanitario) quanto biogenicas autoctones (plantas superiores terrestres). A Analise de Componentes Principals (PCA) corrobora com esse resultado e possibilitou o agrupamento dos pontos de amostragem segundo essas fontes. A estacao 1 (ponto mais proximo do aterro Aura) apresentou o maior nivel de contaminacao observado e o coprostanol foi detectado em maior concentiacao 219,8 ng g-1 nesse local, o que indica contaminacao fecal Humana moderada. Conclusoes: Este trabalho demonstrou que a poluicao por esgoto domestico e insum os de MO do aterro do Aura podem ser ameacas potenciais ao ecossistema e a saude Humana da regiao estudada.
Palavras-chave: sedimentos superficiais; materia organica; esgoto domestico em rios; risco ecologico e para a saude Humana; sistemas aquaticos amazonicos.
1. Introduction
Amazonia is the worlds largest tropical forest, containing 15 to 20% of the world s freshwater supply (Melo et al., 2019). It is estimated that approximately 12-14% of global surface water drains through the twelve hydrographic regions in Brazilian territory. Although the importance of this region, there has been an increased deterioration of water quality due to the input of high amounts of pollutants related to the increase of human activities (Edokpayi et al., 2017; Duarte & Vai, 2020) which includes the discharge of untreated domestic sewage, irregular landfills, and open dumps (Bacha et al., 2021; Melo et al., 2019; Siqueira et al., 2016). In addition, contaminants leached from landfills are subject to infiltration into groundwater (Amano et al., 2021). The organic pollution of surface waters affects the supply of clean water and threatens the ecological services provided by water bodies, especially near urban centers where there is poor management of multiple impacts (Hadlich et al., 2018; Hader et al., 2020).
Sterols are some of the most used chemical markers in studies that include sewage and biogenic organic matter inputs because of their specificity with the human fecal material, resistance to microbial degradation, and relative ease to track and quantify (Frena et al., 2016b; Cabral et al., 2020; Souza et al., 2020). Furthermore, sterols have been used to identify fecal pollution from landfill leachate (Zhang et al., 2008). These compounds have hydrophobic properties and are easily adsorbed to particles, allowing them to accumulate in sediments (Wen et al., 2020). Sterol markers provide much more consistent evidence of the source and the severity of sewage pollution compared to traditional methods that use microorganisms (e.g., Escherichia coli) (Cabral et al., 2019; Thornes et al., 2019; Wen et al., 2020). Particularly in tropical locations and low-density residential areas, microbiological indicators of household sewage, mainly fecal indicator bacteria of the coliform group, are thought to be non-specific and easily influenced by environmental conditions (Melo et al., 2023)
Coprostanol is a sterol synthesized in the digestive tracts of humans and higher vertebrates through the hydrogenation of cholesterol. This sterol is the most abundant in human feces, accounting for 60% of the total sterols (Leeming et al., 1996; Murtaugh & Bunch 1967). Thus, it has been used to trace anthropogenic fecal inputs in aquatic ecosystems (e.g., Araujo et al., 2021; de Oliveira et al., 2022). Investigations of sewage contamination in sediments comparing fecal sterols and coliform counts showed that coprostanol may be considered the best indicator of fecal contamination (Costa & Carreira 2005). Other studies in which pathogens, such as E. coli, have been destroyed by chlorination or heat have used coprostanol to indicate fecal contamination in the environment (e.g., Reeves & Patton 2005; Reichwaldt et al., 2017). However, sterol markers diagnostic ratios have been proposed to improve the reliability of the pollution assessment caused by domestic sewage, allowing confirmation of fecal pollution and distinguishing between human and animal sources (e.g., Bujagic et al., 2016; He et al., 2018).
Cholesterol and cholestanol support research on anthropogenic organic matter input patterns in sediments (Bull et al., 2002; Martins et al., 2014). Cholesterol is the main zoosterol. However, it can be attributed to other organisms, including algae, diatom, macrophytes, and a wide variety of phytoplankton (Volkman 1986; Sojinu et al., 2012, He et al., 2018;). Moreover, cholesterol can also enter into riverine ecosystems through sewage runoff and agricultural inputs (Thornes et al., 2019). Cholestanol, the epimer of cholesterol, is found in situ as a cholesterol bacterial reduction product and can be considered as a sewage sterol (Grimalt et al., 1990; Frena et al., 2016). It can also be produced by marine and terrestrial plants, zooplankton, and phytoplankton (Volkman 2005, 2006). Plant sterols such as campesterol, P-sitosterol, and stigmasterol are used to estimate plant-derived OM input to aquatic systems (Volkman 2005; Bataglion et al., 2016).
The Aura River is relevant for Belem city (the second-largest city in Brazilian Amazon) because it directly influences the catchment springs of water to urban supply (Siqueira & Aprile 2013). There are two main sources of anthropogenic organic matter (OM) affecting the Aura River basin. First, this river drains the surroundings of the Aura landfill, actually deactivated but which did not treat correctly the garbage disposed on it for many decades. Consequently, this water body has constantly received organic anthropogenic contamination from soil runoff (Siqueira et al., 2016). And finally, the study river is under constant contamination as a consequence of the inadequate sewage system in the local riverside community (de Oliveira et al., 2013; Siqueira & Aprile 2013). To date, some research has been carried out in the Aura river basin. In 2013, Siqueira & Aprile assessed the environmental risks due to contamination by metals. More recently, Carneiro et al. (2016) evaluated the spatial variation and sources of polycyclic aromatic hydrocarbons (PAH) in the surface sediments of this river. The results of these studies showed that the studied area is contaminated by metals (Al and Fe) and PAH, mainly close to the Aura landfill. However, no research has been found that surveyed sewage pollution in this aquatic system so an approach based on sterols biomarkers is of special interest.
In this context, this study aimed to determine sterol markers concentrations in surficial sediments along the Aura River, to evaluate: (i) organic contamination levels related to sewage input, and (ii) sterols distribution and sources to monitor the domestic effluents input and the influence of the Aura sanitary landfill into the river. This research contributes to the literature concerning organic pollution in Amazonian aquatic bodies. In addition, the data can support the implementation of pollution control programs and sustainable decision-making in the region.
2. Materials and Methods
2.1. Study area
The Aura River basin is located southeast of Belem city, Para, Northern Brazil. This river is the third-largest in extension inside Belem Metropolitan Region (BMR) (Siqueira et al., 2016). The river mouth is 200 m from the water collection site of Companhia de Saneamento do Para (COSANPA) on the Guama River. The water captured is conducted to Bolonha and Agua Preta lakes and supplies 75% of the BMR (Siqueira et al., 2016). A landfill, created in 1990 and closed in 2015, is located approximately 1400 m north of the study river; it operated uncontrolled and irregularly for about 24 years (Carneiro et al., 2016). According to previous studies, the water quality from Aura River is negatively impacted by organic and inorganic pollutants such as heavy metals and PAHs from runoff of the landfill soil (Siqueira & Aprile 2013; Siqueira et al., 2016; Carneiro et al., 2016).
Sampling was carried out in March/2020 along the Aura River, and a total of 9 surficial sediment samples (depth 0-10 cm) were collected (Figure 1) using a handheld Van Veen grab. Sediment samples were placed into pre-cleaned aluminum recipients and stored under refrigeration during transportation to the laboratory. Before initial chemical treatments, all sediment samples were freeze-dried, pulverized in a mortar, and stored at 4°C before further analysis.
2.2. Chemicals and reagents
Cholesterol (cholest-5-en-3P-ol), Coprostanol (5P-cholestan-3P-ol), Stigmastanol (5ctcholestan22E-en-3P-ol), Cholestanol (5ct-cholestan-3P-ol), P-sitosterol (24-ethylcholest5-en-3P-ol), androstanol (5ct-androstan-3P-ol) and 5ct-cholestane (internal standard) were obtained from Sigma-Aldrich (St. Louis, USA). Stigmasterol (24-ethylcholest5, 22E-dien-3P-ol and BSTFA (bis(trimethylsilyl) trifluoroacetamide)/TMCS (trimethylchlorosilane) (99:1) from Spectrum (Gardena, CA). Stock solutions containing individual sterols were prepared in HPLC-grade dichloromethane (DCM). Working standard solutions were prepared from these solutions and diluted with 95% hexane before analysis. HPLC-grade 95% w-hexane, methanol, and DCM were purchased fromTedia (RJ, Brazil).
2.3. Sterols analytical procedures
Sterols extraction and analysis methods applied in this study were described by Frena et al. (2016b). An amount of 5 g of freeze-dried sediment from each sampling site was extracted in an ultrasonic bath (model UltraCleaner 1400; Callmex, Sao Paulo, Brazil). Sediment samples were immersed in a mixture of 10 mL of DCM and 5 mL of methanol (2:1, v/v) for 30 min (three times) at a 40 kHz frequency. Extracts were reduced to 2 mL by rotoevaporation and posteriorly evaporated to dryness under a nitrogen stream (99.996% purity). Sterols in the extracts were derivatized into the form of trimethylsilyl ethers using 50 pL of BSTFA with 1% TMCS, this process was carried out for 60 min at 60°C. The extracts obtained after derivatization were reconstituted in 1 mL of w-hexane. The internal standard 5ct-cholestane (500 ng mL1) was added after extraction and dilution. Finally, an aliquot of 10 pL of the reconstituted and the derivatized extract was injected into the GC-MS/MS in splitless mode (1 min), at 280°C, for sterols markers identification and quantification.
The analysis was conducted on a Shimadzu GC-MS-MS QP2010 system (Kyoto, Japan), the extracts carried by helium (99.995% purity) at a 1 mL min'1 flow rate, and a Zebron ZB 5-MS capillary column (30 m, 0.25 mm i.d., 0.25 pm thickness film) supplied by J.W Scientific (Santa Clara, CA, USA) was used under the following conditions: 100°C (held for 3 min), increasing at 25°C mim1 to 280°C (held for 2 min), then rising at 1°C mim1 to 300 °C (held for 1 min). The mass spectrometer ion source was operated in electron impact (El) mode at 70 eV, GC-MS interface temperature was set at 300°C, and the ion source at 280°C. Analysis was performed in selective ion monitoring (SIM) mode. Data were obtained by GC Solution software (Shimadzu, Kyoto, Japan).
Calibration curves for each sterol were obtained from standard solutions of coprostanol, cholesterol, stigmastanol, cholestanol, stigmasterol, and P-sitosterol at different concentration levels. The evaluated sterols were identified based on mass spectra and retention times obtained for standards and quantified based on response factors of standards relative to 5ct-cholestane (internal standard). Procedural blanks were performed, and no peaks interfered with the analyses of the target compounds. An amount of 50 uL of the surrogate (androstanol 500 ng mL'1 solution) was added to samples before extraction to evaluate method recovery, which ranged from 76 to 99%, an acceptable rate considering environmental samples (Ribani et al., 2004). Each analyte's limit of quantification (LOQ) was defined as the first point of the analytical curve (10 ng mL'1) divided by the sediment mass and the limit of detection (LOD) as three times lower than the LOQ.
2.4. Sterols origin
The diagnostic ratios of sterols origin (Table 1) were used to distinguish between human and animal fecal origins and assess the degree of pollution caused by residential sewage (He et al., 2018).
2.5. Bulk parameters
For grain size analyses, 4 g of dried sediment were treated with H,O, 10%, then centrifuged, and finally washed with distilled water to eliminate the organic matter (OM). The grain size was analyzed with a laser granulometer (SALD 2101 Shimadzu) (Suguio, 1973). The OM content in samples was determined by calcinating 5 g of dried sediment at 500°C for 4 h (Ranney, 1969).
2.6. Statistical analysis
Statistical and multivariate statistical analyses, such as Pearson correlation and principal component analysis (PCA), respectively, are generally used to assess sewage pollution in aquatic systems (Martins et al., 2008; Frena et al., 2016; Cabral et al., 2019). Statistical analysis was performed using Rstudio Statistical Software (Foundation for Statistical Computing, Vienna, Austria), version 2021.09.0. It was applied principal component analysis (PCA) to identify relations among the sterol markers and bulk parameters (grain size and OM) and to distinguish sampling stations according to sterols sources. Pearson correlation was determined to better understand the relationship between the sterols and bulk parameters.
3. Results
The concentrations of sterols determined in nine samples of the superficial sediments are presented in (Table 2). The total sterols concentrations (Ssterols) ranged from 364.9 ng g-1 at site 7 up to 1319.6 ng g-1 at site 4, with a mean of45.68 ng g-1. Coprostanol was identified in six of the nine samples, ranging from the below quantification limit at stations 6-9 up to 219.8 ng g-1 at site 1. This sterol represented 5.2% of the Ssterols in the study area and was found to be highest at site 1, which is located closest to the Aura landfill. The predominant sterol in all examined samples along the Aura River basin was P-sitosterol.
In order to evaluate the sewage contamination sources in the Aura River sediments, various diagnostic ratios were considered (Table 1). The values for (Rl) (coprostanol/(coprostanol + cholestanol) ranged from 0.2 to 0.7, while the ratio coprostanol/cholesterol (R2) ranged from 3.9 to 0.4 across the nine sites. Another ratio assessing fecal contamination in sediments of rivers is the coprostanol/(cholestanol + cholesterol) ratio (R3). In the present study, all samples yielded values above 0.06 for this ratio. In addition, R4 was used to evaluate the level of diagenetic transformation in the sediments. In this study, values for R4 ranged from 0.4 up to 2.3.
Statistical and multivariate statistical analyses, such as Pearson correlation and principal component analysis (PCA), respectively, are generally used to assess sewage pollution in aquatic systems (Martins et al., 2008; Frenaet al., 2016; Cabral et al., 2019). The first component (PCI) and the second component (PC2) explained 45.9 and 23.7% of the total variance, respectively. Stigmasterol, cholesterol, cholestanol, and coprostanol were the significant variables for PCI, while the dominant sterols for PC2 were stigmastanol and P-sitosterol. PC 1 showed a positive correlation among the sterols (except P-sitosterol) and allowed to associate the studied stations in two groups according to the contamination sources.
Pearson's correlation analysis (r; p < 0.05) involving sterols compounds, %OM, and %MUD revealed a high positive correlation between two groups of sterols (Figure 2). The first group, (coprostanol and cholesterol) showed a low positive correlation coefficient (0.23). The second group of sterols, comprising cholestanol, cholesterol, and stigmasterol, demonstrated high positive correlation coefficients (>0.9). Furthermore, P-sitosterol demonstrated a positive correlation with coprostanol.
4. Disscussion
Coprostanol is the most abundant sterol found in human feces and constitutes a biomarker of human fecal contamination (Leeming et al., 1998; Bull et al., 2002). The threshold coprostanol values proposed by de Melo et al. (2019) of 10 ngg'1 for uncontaminated sediments, 100 ng g'1 for contaminated sediments, and 500 ng g'1 for severely polluted sediments were employed in this study. The coprostanol values found in the Aura River suggest a similar range of fecal material input to other aquatic systems in Brazil and worldwide (Table 3). Coprostanol levels were comparable to those in Tokyo Bay, Japan (243 ng g'1) (Chalaux et al., 1995), Ubatuba Bay, Brazil (max. 270 ng g'1) (Muniz et al., 2006), and slightly higher than sediments of the inner shelf adjacent to Sergipe River (184.1 ng g'1) (Carreira et al., 2015) and those from Taruma-Acu Stream in the Brazilian Amazon (142 ng g'1) (Melo et al., 2019). The analysis of the sterol composition of the samples collected along the Aura River showed that the predominant sterol present was P-sitosterol. This finding suggests that a major source of organic matter in the Aura River basin is terrestrial vegetation, such as trees and plants.
Data determined for Station 1 indicated input of long-term discharge from the Aura landfill, which ceased activity in 2015, and may be the main source of coprostanol to the river. Coprostanol was not detected at Stations 6-9, suggesting that domestic sewage likely does not affect these sites. The absence of coprostanol at these sites implies that the hydrodynamics of the Aura River are effective for contaminant dispersion. A similar distribution pattern was observed for polycyclic aromatic hydrocarbons (PAHs) in the Aura River sediments by Rodrigues et al. (2018). Moreover, the study area is characterized by intense precipitation and fluvial-dominated hydrodynamics, which have effects on the depuration and dilution of sewage effluents.
The prevalence and high levels of P-sitosterol in all the samples suggest a significant input of terrigenous material to the studied area. However, the presence of P-sitosterol may also be attributed to domestic sewage discharges due to its typical presence in vegetable oils used for cooking (Froehner et al., 2009; Frena et al., 2016b). Other sterols that were prevalent along the Aura River basin included stigmastanol (at sites 1-3 and 5-6) and stigmasterol (at sites 1-4), which are indicative of herbivore feces and vascular plants metabolism, respectively (Frena et al., 2016b). High levels of phytosterols and sewage sterols at station 1 may also be related to eutrophication processes that favor the production of cholesterol, cholestanol, and phytosterols in addition to sewage markers (Melo et al., 2019).
Accordingto Grimalt et al. (1990), the diagnostic ratio coprostanol/(coprostanol + cholestanol) R1 with values higher than 0.7 suggests sewage pollution, and values lower than 0.3 indicate the absence of sewage contamination. Station 1 exhibits moderate sewage pollution, as indicated by the relatively high levels of coprostanol (> 100 ng g'1) and values close to 0.7 for R1 (Frena et al., 2016b). In contrast, the other studied sites had R1 values lower than 0.30, indicating a low influence of sewage. The coprostanol/cholesterol ratio R2 can be used to distinguish between biogenic and anthropogenic organic matter inputs. Values of R2 greater than 0.5 indicate sewage contamination, while values less than 0.5 are attributed to biogenic sources (Grimalt et al., 1990; Takada et al., 1994; Leeming et al., 1996,). This ratio showed that station 1 is the most affected by sewage pollution. The cross-plot representations of R1 and R2 versus coprostanol concentrations showed that station 1 is affected by sewage pollution, while the other sites are influenced by biogenic organic matter inputs. The cross plots of coprostanol levels versus coprostanol/ (coprostanol+cholestanol) and coprostanol/ cholestanol (shown in Figure 3) also indicate that only station 1 is contaminated by sewage.
Moreover, the ratio coprostanol/(cholestanol + cholesterol) (R3) has been used to indicate fecal contamination in sediments of rivers (Writer et al., 1995; Dsikowitzky et al., 2017). In the present study, R3 values above suggest that the presence of coprostanol in these points may be related to human fecal origin. The cholestanol/cholesterol (R4) ratio has been used to evaluate contamination by sludge (Froehner et al., 2009; Machado et al., 2014; Thornes et al., 2019). Values close to and above 0.5 for R4 were detected in all stations, indicating high rates of biohydrogenation processes (Nishimura & Koyama 1976; Souza et al., 2020). These high rates may be related to an increase in terrestrial organic matter input, nutrients, and bacteria, which can affect primary productivity and redox conditions at the water/sediment interface (Ali & Mudge, 2005; Machado et al., 2014).
According to PCA (Figure 4), stations grouped in red exhibit both anthropogenic and biogenic sources, as indicated by coprostanol levels greater than 24.9 ng g-1. Stations grouped in blue are associated only with biogenic sources. This maybe because plant sterols such as stigmasterol are derived from both municipal sewage and terrestrial sources (Bujagic et al., 2016; Melo et al., 2019; Wen et al., 2020).
The correlation between coprostanol and stigmasterol evidenced through Pearsons correlation analysis may be attributed to the presence of plant sterols, such as stigmasterol, which could be derived from both municipal sewage and terrestrial sources (Bujagic et al., 2016; Melo et al., 2019; Wen et al., 2020). Previous studies have also reported a strong correlation between fecal and plant sterols (Yao et al., 2013; Melo et al., 2019; Wen et al., 2020). High positive correlation among cholestanol, cholesterol, and stigmasterol, could be due to the fact that the river in question is influenced by both anthropogenic and biogenic sources of OM. Pearson correlation confirms the observations made through PCA, as it also shows that the surficial sediments of the Aura River are influenced by both anthropogenic and higher plants inputs.
The coprostanol and cholesterol positive correlation coefficient of 0.23 indicates the presence of human fecal contamination in the Aura River because cholesterol, besides being found in zooplankton, a wide variety of phytoplankton, and several forms of marine animals, is also a byproduct of higher animals' feces, such as humans (Martins et al., 2007; Bataglion et al., 2016; Frena et al., 2016b). This finding is further corroborated by Pearson correlation, which also highlights the coexistence of anthropogenic and biogenic sources in the surface sediments of the Aura River.
The results of this study suggest that sterols composition and levels in the sediments of Aura River are mainly influenced by organic matter inputs from anthropogenic and higher plant sources. This is evidenced by the positive correlation between P-sitosterol and coprostanol, which is considered a fecal sterol. Moreover, sedimentological characteristics did not appear to influence sterols composition or levels, except for coprostanol.
5. Conclusions
For the first time, fecal pollution was determined in surficial sediments from Aura River using sterol biomarkers, diagnostic ratios, and statistical analysis. Sterol ratios and coprostanol levels permitted the identification of anthropogenic OM from the Aura Landfill and domestic sewage relied by riverine communities. Statistical analysis (PCA) corroborates this result. In addition, PCA allowed grouping the studied sites according to the main source of organic matter (anthropogenic and higher plants inputs). Although the Aura landfill is currently out of service, there is evidence of organic contamination reaching the Aura River. The absence of efficient sewage treatment for the riverine communities and the metropolitan region of Belem (PA) represents an ecological threat to Aura River. Hence, this study provides a basis for future management of the studied area and its surroundings which is an important source of water supply.
Acknowledgements
The authors thank the Programa de Pos-Graduacao em Geologia e Geoquimica of the Universidade Federal do Para, a Coordenacao de Aperfcicoamento de Pessoal de Nivel Superior (CAPES) for the MSc grant for J. Agudelo Morales, and the Laboratdrio de Analise de Compostos Organicos Poluentes from Universidade Federal de Sergipe.
Data availability
The authors have stored all the necessary databases for anyone who might be interested in making a query.
Cite as: Morales, J.H.A. et al. Sedimentary sterol levels to track river contamination by sewage in one of the largest Amazonian cities (Belem - Para), northern Brazil. Acta Limnologica Brasiliensia, 2023, vol. 35, e21.
Received: 13 April 2023
Accepted: 11 July 2023
Associate Editor: Andre Andrian Padial.
References
Ali, M., & Mudge, S., 2005. Lipid geochemistry in a sediment core from Conwy Estuary, North Wales. Sains Malays. 34(2), 23-33.
Amano, K.O.A., Danso-Boateng, E., Adorn, E., Kwame Nkansah, D., Amoamah, E.S., & AppiahDanquah, E., 2021. Effect of waste landfill site on surface and ground water drinking quality. Water Environ. J. 35(2), 715-729. http://dx.doi. org/10. Ill 1/wej. 12664.
Araujo, M.R, Hamacher, C., Farias, C. de O., & Soares, M.L.G., 2021. Fecal sterols as sewage contamination indicators in Brazilian mangroves. Mar. Pollut. Bull. 165, 112149. PMid:33610111. http://dx.doi. org/10.1016/j .marpolbul.2021.112149.
Bacha, D.C.S., Santos, S., Mendes, R.A., Rocha, C.C.S., Correa, J.A., Cruz, J.C.R., Abrunhosa, F.A., & Oliva, P.A.C., 2021. Evaluation of the contamination of the soil and water of an open dump in the Amazon Region, Brazil. Environ. Earth Sci. 80(3), 113. http://dx.doi.org/10.1007/sl2665-021-09401-3.
Bataglion, G.A., Koolen, H.H.F., Weber, R.R., & Eberlin, M.N., 2016. Quantification of sterol and triterpenol biomarkers in sediments of the Cananeia-Iguape estuarine-lagoonal system (Brazil) by UHPLC-MS/MS. Int. J. Anal. Chem. 2016, 8361375. PMid:27087811.
Bujagic, I., Grujic, S., Jaukovic, Z., & Lausevic, M., 2016. Sterol ratios as a tool for sewage pollution assessment of river sediments in Serbia. Environ. Pollut. 213, 76-83. PMid:26874877. http://dx.doi. org/10.1016/j.envpol.2015.12.036.
Bull, I.D., Lockheart, M.J., Elhmmali, M.M., Roberts, D.J., & Evershed, R.P., 2002. The origin of faeces by means of biomarker detection. Environ. Int. 27(8), 647-654. PMid:11934114. http://dx.doi. org/10.1016/50160-4120(01)00124-6.
Cabral, A.C., Dauner, A.L.L., Xavier, F.C.B., Garcia, M.R.D., Wilhelm, M.M., dos Santos, V.C.G., Netto, S.A., & Martins, C.C., 2020. Tracking the sources of allochthonous organic matter along a subtropical fluvial-estuarine gradient using molecular proxies in view of land uses. Chemosphere 251, 126435. PMid:32169703. http://dx.doi.org/10.1016/ j .chemosphere.2020.126435.
Cabral, A.C., Wilhelm, M.M., Figueira, R.C.L., & Martins, C.C., 2019. Tracking the historical sewage input in South American subtropical estuarine systems based on faecal sterols and bulk organic matter stable isotopes (8 13 C and 8 15 N. Sci. Total Environ. 655, 855-864. PMid:30481712. http:// dx.doi.org/10.1016/j.scitotenv.2018.11.150.
Carneiro, C., Santos, D., Da, L., Soares, S., Augusto, J., & Correa, M., 2016. Occurrence and sources of priority polycyclic aromatic hydrocarbons in sediment samples along the Aura River (Northern Brazil. Geochim. Bras. 30(301), 26-32.
Carreira, R.S., Albergaria-Barbosa, A.C.R., Arguelho, M.L.P.M., & Garcia, C.A.B., 2015. Evidence of sewage input to inner shelf sediments in the NE coast of Brazil obtained by molecular markers distribution. Mar. Pollut. Bull. 90(1-2), 312-316. PMid:25467184. http://dx.doi.Org/10.1016/j.marpolbul.2014.l 1.011.
Carreira, R.S., Ribeiro, R, Silva, C.E.M., & Farias, C.O., 2009. Hydrocarbons and sterols as indicators of source and fate of organic matter in sediments from Sepetiba Bay, Rio de Janeiro. Quim. Nova 32(7), 1805-1811. http://dx.doi.org/10.1590/S0100-40422009000700023.
Chalaux, N., Takada, H., & Bayona, J.M., 1995. Molecular markers in Tokyo bay sediments: sources and distribution. Mar. Environ. Res. 40(1), 77-92. http://dx.doi.org/10.1016/0141-1136(95)90001-8.
Costa, R.L., & Carreira, R.S., 2005. A comparison between faecal sterols and coliform counts in the investigation of sewage contamination in sediments. Braz. J. Oceanogr. 53(4)
Dsikowitzky, L., Schafer, L., Dwiyitno, Ariyani, F., Irianto, H.E., & Schwarzbauer, J., 2017. Evidence of massive river pollution in the tropical megacity Jakarta as indicated by faecal steroid occurrence and the seasonal flushing out into the coastal ecosystem. Environ. Chem. Lett. 15(4), 703-708. http://dx.doi. org/10.1007/s 10311-017-0641-3.
Duarte, R.M., & Vai, A.L., 2020. Water-related problem with special reference to global climate change in Brazil. In: Singh, R, Milishna, Y., Tian, K., Gusain, D., & Bassin, J.R, eds. Water conservation and wastewater treatment in BRICS Nations: technologies, challenges, strategies and policies. Amsterdam: Elsevier, 3-21. http://dx.doi.org/! 0.1016/B978-0-12-818339-7.00001-1.
Edokpayi, J.N., Odiyo, J.O., & Durowoju, O.S., 2017. Impact of wastewater on surface water quality in developing countries: a case study of South Africa. Water Qual. 10(66561), 10-57. http://dx.doi. org/10.5772/66561.
Fattore, E., Benfenati, E., Marelli, R., Cools, E., & Fanelli, R., 1996. Sterols in sediment samples from Venice Lagoon, Italy. Chemosphere. 33(12), 2383-2393. http://dx.doi.org/10.1016/S00456535(96)00340-2.
Frena, M., Bataglion, G.A., Tonietto, A.E., Eberlin, M.N., Alexandre, M.R., & Madureira, L.A.S., 2016. Assessment of anthropogenic contamination with sterol markers in surface sediments of a tropical estuary (Itajai-Aqu), Brazil. Sci. Total Environ. 544, 432-438. PMid:26657388. http://dx.doi. org/10.1016/j .scitotenv.2015.11.137.
Frena, M., Santos, A.P.S., Santos, E., Silva, R.P., Souza, M.R.R., Madureira, L.A.S., & Alexandre, M.R., 2016b. Distribution and sources of sterol biomarkers in sediments collected from a tropical estuary in Northeast Brazil. Environ. Sci. Pollut. Res. Int. 23(22), 23291-23299. PMid:27696200. http://dx.doi.org/10.1007/sl 1356-016-7744-4.
Frena, M., Santos, A.P.S., Souza, M.R.R., Carvalho, S.S., Madureira, L.A.S., & Alexandre, M.R., 2019. Sterol biomarkers and fecal coliforms in a tropical estuary: seasonal distribution and sources. Mar. Pollut. Bull. 139, 111-116. PMid:30686407. http://dx.doi. org/ 10.1016/j.marpolbul.2018.12.007.
Froehner, S., Martins, R.F., & Errera, M.R., 2009. Assessment of fecal sterols in Barigui River sediments in Curitiba, Brazil. Environ. Monit. Assess. 157(1-4), 591-600. PMid:18841487. http://dx.doi. org/10.1007/sl0661-008-0559-0.
Garcia Junior, M.D.N., Damascene, M.T.S., Vilela, D.S., & Souto, R.N.P., 2022. The Brazilian Legal Amazon Odonatofauna: a perspective of diversity and knowledge gaps. EntomoBrasilis 15, e977. http://dx.doi.org/10.12741/ebrasilis.vl5.e977.
Grimalt, J.O., Fernandez, P., Bayona, J.M., & Albaiges, J., 1990. Assessment of fecal sterols and ketones as indicators of urban sewage inputs to coastal waters. Environ. Sci.Technol. 24(3), 357-363. http://dx.doi. org/10.1021/es00073a011.
Hader, D., Banaszak, A.T., Villafahe, V.E., Narvarte, M.A., Gonzalez, R.A., & Helbling, E.W, 2020. Anthropogenic pollution of aquatic ecosystems: emerging problems with global implications. Sci. Total Environ. 713, 136586. PMid:31955090. http://dx.doi.Org/10.1016/j.scitotenv.2020.136586.
Hadlich, H.L., Venturini, N., Martins, C.C., Hatje, V, Tinelli, P, Gomes, L.E.O., & Bernardino, A.E, 2018. Multiple biogeochemical indicators of environmental quality in tropical estuaries reveal contrasting conservation opportunities. Ecol. Indic. 95, 21-31. http://dx.doi.Org/10.1016/j.ecolind.2018.07.027.
He, D., Zhang, K., Tang, J., Cui, X., & Sun, Y., 2018. Using fecal sterols to assess dynamics of sewage input in sediments along a human-impacted river-estuary system in eastern China. Sci. Total Environ. 636, 787-797. PMid:29727845. http://dx.doi. org/10.1016/j.scitotenv.2018.04.314.
Institute Brasileiro de Geografia e Estatistica - IBGE, 2020. Legal Amazon. Retrieved in 2022, May 25, from https://www.ibge.gov.br/en/geosciences/ environmental-informat ion/vegetation/17927legalamazon.html?=&t=acesso-ao-produto
Leeming, R., Ball, A., Ashbolt, N., & Nichols, R, 1996. Using faecal sterols from humans and animals to distinguish faecal pollution in receiving waters. Water Res. 30(12), 2893-2900. http://dx.doi.org/10.1016/ 50043-1354(96)00011-5.
Leeming, R., Bate, N., Hewlett, R., & Nichols, P., 1998. Discriminating faecal pollution: a case study of stormwater entering Port Phillip Bay, Australia. Water Sci. Technol. 38(10), 15-22. http://dx.doi. org/10.2166/wst. 1998.0369.
Machado, K.S., Froehner, S., Sanez, J., Figueira, R.C.L., & Ferreira, P.A.L., 2014. Assessment of historical fecal contamination in Curitiba, Brazil, in the last 400 years using fecal sterols. Sci. Total Environ. 493, 1065-1072. PMid:25016471. http://dx.doi. org/10.1016/j.scitotenv.2014.06.104.
Martins, C.C., Cabral, A.C., Barbosa-Cintra, S.C.T., Dauner, A.L.L., & Souza, F.M., 2014. An integrated evaluation of molecular marker indices and linear alkylbenzenes (LABs) to measure sewage input in a subtropical estuary (Babitonga Bay, Brazil. Environ. Pollut. 188, 71-80. PMid:24556228. http://dx.doi. org/10.1016/j.envpol.2014.01.022.
Martins, C.D.C., Fillmann, G., & Montone, R.C., 2007. Natural and anthropogenic sterols inputs in surface sediments of Patos Lagoon, Brazil. J. Braz. Chem. Soc. 18(1), 106-115. http://dx.doi.org/10.1590/ S0103-50532007000100012.
Martins, C.D.C., Gomes, F.B.A., Ferreira, J.A., & Montone, R.C., 2008. Marcadores organicos de contaminacao por esgotos sanitarios em sedimentos superficiais da Baia de Santos, Sao Paulo. Quim. Nova31(5), 1008-1014. http://dx.doi.org/10.1590/ S0100-40422008000500012.
Melo, M.G., Anjos, C.O., Nunes, A.P., Farias, M.A.S., Vai, A.L., Chaar, J.S., & Bataglion, G.A., 2023. Correlation between caffeine and coprostanol in contrasting Amazonian water bodies. Chemosphere 326, 138365. PMid:36906004. http://dx.doi. org/10.1016/j.chemosphere.2023.138365.
Melo, M.G., Silva, B.A., Costa, G.S., Silva Neto, J.C.A., Soares, P.K., Vai, A.L., Chaar, J.S., Koolen, H.H.E, & Bataglion, G.A., 2019. Sewage contamination ofAmazon streams crossing Manaus (Brazil) by sterol biomarkers. Environ. Pollut. 244, 818-826. PMid:30390455. http://dx.doi.Org/10.1016/j.envpol.2018.10.055.
Muniz, P, Pires-Vanin, A.M.S., Martins, C.C., Montone, R.C., & Bicego, M.C., 2006. Trace metals and organic compounds in the benthic environment of a subtropical embayment (Ubatuba Bay, Brazil. Mar. Pollut. Bull. 52(9), 1098-1105. PMid: 16824551. http://dx.doi.Org/10.1016/j.marpolbul.2006.05.014.
Murtaugh, J.J., & Bunch, R., 1967. Sterols as a measure of fecal pollution. J. Water Pollut. Control Fed. 39(3), 404-409. PMid:6021836.
Nishimura, M., & Koyama, T., 1976. Stenols and stanols in lake sediments and diatoms. Chem. Geol. 17(C), 229-239. http://dx.doi.org/10.1016/00092541(76)90037-1.
Oliveira, A.F.B., Gomes, B.R.S., Franca, R.S., Moraes, A.S., Bataglion, G.A., & Santos, J.M., 2022. Assessment of urban contamination by sewage in sediments from Ipojuca river in Caruaru City, Pernambuco, Brazil. J. Braz. Chem. Soc. 33(2), 163-172. http://dx.doi.org/10.21577/01035053.20210133.
Oliveira, R.S., Kiyatake, D.M., Harada, M.L., & Ribeiro, K.T., 2013. Sanitary quality of the public groundwater supply for the municipality of Belem in Northern Brazil. Cad. Saude Colet. 21(4), 377-383. http://dx.doi.org/10.1590/S1414462X2013000400004.
Ranney, R.W, 1969. Organic carbon-organic matter conversion equation for Pennsylvania surface soils. Soil Sci. Soc. Am 33(5), 809-811. http://dx.doi. org/10.2136/sssajl969.03615995003300050049x.
Reeves, A.D., & Patton, D., 2005. Faecal sterols as indicators of sewage contamination in estuarine sediments of theTay Estuary, Scotland: an extended baseline survey. Hydrol. Earth Syst. Sci. 9(1-2), 81-94. http://dx.doi.org/10.5194/hess-9-81-2005.
Reichwaldt, E.S., Ho, W.Y., Zhou, W, & Ghadouani, A., 2017. Sterols indicate water quality and wastewater treatment efficiency. Water Res. 108, 401-411. PMid:27839832. http://dx.d0i.0rg/l0.1016/j. watres.2016.11.029.
Ribani, M., Bottoli, C.B.G., Collins, C.H., Jardim, I.C.S.E, & Melo, L.F.C., 2004. Validacao em metodos cromatograficos e eletroforeticos. Quim Nova. 27(5), 771-780. http://dx.doi.org/10.1590/ S0100-40422004000500017.
Rodrigues, C.C. dos S., Santos, E., Ramos, B.S., Damascene, EC., & Correa, J.A.M., 2018. PAH baselines for Amazonic surficial sediments: a case of study in Guajara Bay and Guama River (Northern Brazil). Bull. Environ. Contam. Toxicol. 100(6), 786791. PMid:29721595. http://dx.doi.org/10.1007/ s00128-018-2343-3.
Siqueira, G., Aprile, E, Darwich, A., Santos, V, & Menezes, B., 2016. Environmental diagnostic ofthe Aura River Basin (Para, Brazil): water pollution by uncontrolled landfill waste. Arch. Curr. Res. Int. 5(2), 1-13. http://dx.doi.org/10.9734/ACRI/2016/28249.
Siqueira, G.W, & Aprile, E, 2013. Avaliacao de risco ambiental por contaminaqao metalica e material organico em sedimentos da bacia do Rio Aura, Regiao Metropolitana de Belem-PA. Acta Amazon. 43(1), 51-62. http://dx.doi.org/10.1590/S004459672013000100007.
Sojinu, S.O., Sonibare, O.O., Ekundayo, O., & Zeng, E.Y., 2012. Assessing anthropogenic contamination in surface sediments of Niger Delta, Nigeria with fecal sterols and n-alkanes as indicators. Sci. Total Environ. 441, 89-96. PMid:23 137973. http://dx.doi.org/10.1016/j. scitotenv.2012.09.015.
Souza, M.R.R., Santos, E., Suzarte, J.S., Carmo, L.O., Soares, L.S., Santos, L.G.G.V., Vilela Junior, A.R., Krause, L.C., Frena, M., Damascene, EC., Huang, Y., & Alexandre, M.R., 2020. The impact of anthropogenic activity at the tropical Sergipe-Poxim estuarine system, Northeast Brazil: fecal indicators. Mar. Pollut. Bull. 154, 111067. PMid:32319900. http://dx.doi.org/10.1016/j. marpolbul.2020.111067.
Suguio, T., 1973. Introduqao a sedimentologia. Sao Paulo: EDUSP
Takada, H., Farrington, J.W., Bothner, M.H., Johnson, C.G., & Tripp, B.W., 1994. Transport of sludgederived organic pollutants to deep-sea sediments at deep water dump site 106. Environ. Sci. Technol. 28(6), 1062-1072. PMid:22176231. http://dx.doi. org/10.1021/es00055a015.
Thornes, M.W., Vaezzadeh, V., Zakaria, M.P., & Bong, C.W., 2019. Use of sterols and linear alkylbenzenes as molecular markers of sewage pollution in Southeast Asia. Environ. Sci. Pollut. Res. Int. 26(31), 31555-31580. PMid:31440968. http://dx.d0i.0rg/l0.1007/ si 1356-019-05936-y.
Volkman, J.K. 2006. Lipid Markers for Marine Organic Matter. In J.K. Volkman, ed. Marine organic matter: biomarkers, isotopes and DNA. New York: Springer, 27-70. http://dx.doi. org/10.1007/698_2_002.
Volkman, J.K., 1986. A review of sterol markers for marine and terrigenous organic matter. Org. Geochem. 9(2), 83-99. http://dx.doi.org/10.1016/01466380(86)90089-6.
Volkman, J.K., 2005. Sterols and other triterpenoids: source specificity and evolution of biosynthetic pathways. Org. Geochem. 36(2), 139-159. http://dx.doi.Org/10.1016/j.orggeochem.2004.06.013.
Wen, X., Bai, Y., Zhang, S., Ding, A., Zheng, L., & Li, J., 2020. Distributions and sources of sedimentary sterols as well as their indications of sewage contamination in the Guanting Reservoir, Beijing. J. Chem. 2020, 1-11. http://dx.doi. org/10.1155/2020/3050687.
Writer, J.H., Leenheer, J.A., Barber, L.B., Amy, G.L., & Chapra, S.C., 1995. Sewage contamination in the upper Mississippi River as measured by the fecal sterol, Coprostanol. Water Res. 29(6), 1427-1436. http://dx.d0i.0rg/l 0.1016/0043- 1354(94)00304-P.
Yao, X., Lu, J., Liu, Z., Ran, D., & Huang, Y., 2013. Distribution of sterols and the sources of pollution in surface sediments of Ulungur lake, Xinjiang. Water Sci. Technol. 67(10), 2342-2349. PMid:23676408. http://dx.doi.org/10.2166/wst.2013.107.
Zhang, C., Wang, Y., & Qi, S., 2008. Identification and significance of sterols in MSW landfill leachate. J. Chromatogr. B Analyt. Technol. Biomed. Life Sci. 874(1-2), 1-6. PMid:18818129. http://dx.doi. org/10.1016/j.jchromb.2008.08.014.
You have requested "on-the-fly" machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Show full disclaimer
Neither ProQuest nor its licensors make any representations or warranties with respect to the translations. The translations are automatically generated "AS IS" and "AS AVAILABLE" and are not retained in our systems. PROQUEST AND ITS LICENSORS SPECIFICALLY DISCLAIM ANY AND ALL EXPRESS OR IMPLIED WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES FOR AVAILABILITY, ACCURACY, TIMELINESS, COMPLETENESS, NON-INFRINGMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Your use of the translations is subject to all use restrictions contained in your Electronic Products License Agreement and by using the translation functionality you agree to forgo any and all claims against ProQuest or its licensors for your use of the translation functionality and any output derived there from. Hide full disclaimer
© 2023. This work is published under https://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.
Abstract
Objetivo: O rio Aura, no nordeste da Amazonia brasileira, vem sofrendo influencia antropica de comunidades ribeirinhas e do aterro sanitario Aura ha muitos anos. Neste trabalho, avaliamos a ocorrencia, fontes e distribuicao de seis marcadores de esterois em sedimentos superficiais do Rio Aura para avaliar aportes organicos neste corpo d'agua. Metodos: A cromatografia gasosaacoplada a espectrometria de massas (GC/MS) foi empregada para determinar os esterois. A analise de correlacao de Pearson, analise de componentes principals (PCA) e razoes de esterois foram utilizadas para avaliar a poluicao por esgoto. Resultados: Os analitos de interesse identificados e as razoes diagnosticas indicaram que os sedimentos do rio estudado apresentam compostos organicos provenientes de fontes tanto antropogenicas (esgotos domesticos e MO do aterro sanitario) quanto biogenicas autoctones (plantas superiores terrestres). A Analise de Componentes Principals (PCA) corrobora com esse resultado e possibilitou o agrupamento dos pontos de amostragem segundo essas fontes. A estacao 1 (ponto mais proximo do aterro Aura) apresentou o maior nivel de contaminacao observado e o coprostanol foi detectado em maior concentiacao 219,8 ng g-1 nesse local, o que indica contaminacao fecal Humana moderada. Conclusoes: Este trabalho demonstrou que a poluicao por esgoto domestico e insum os de MO do aterro do Aura podem ser ameacas potenciais ao ecossistema e a saude Humana da regiao estudada.