Occurrence of marine plastic litter and plasticizers from touristic beaches of Arauco Gulf in Central Chile.

Marine plastic litter (MPL) was collected from beaches (n = 3) of the Arauco Gulf in central Chile in spring 2021 and summer 2022. MPL was analyzed for physical and chemical characteristics, and plasticizers were also screened using FTIR-ATR. Three hundred seventeen plastic items with an accumulated weight of 226.8 g were found. MPL densities ranged from 0.4 to 17.1 items m-2. Significant differences (p < 0.05) between seasons were observed for Arauco and Maule beaches, being ∼ten times higher in summer compared to spring. Solid pieces were the predominant shape, macroplastics were the most abundant (>2.5 cm), and white and blue colors were dominant. Polypropylene (52 %) and polyethylene (31 %) were the predominant polymers. Plasticizers (n = 3) were detected in the MPL in the study area (dioctyl phthalate, polybutene, and alpha-methylstyrene) for the first time. This study contributes new information related to MPL in coastal areas of central Chile and their chemical composition.

Plastic debris, persistent organic pollutants and their toxicity impacts in coastal areas in Central Chile.

The chemical components of plastic wastes have made their disposal a major economic, social, and environmental problem worldwide. This study evaluated the acute toxicity and genotoxicity of marine plastic debris on the beaches of Concepción Bay, Central Chile, taken during three periods (spring, summer, and winter). An integrated approach was used, including chemical and toxicological data, using the Microtox® test with Vibrio fischeri and SOS chromotest with Escherichia coli and concentrations of polychlorinated biphenyls (PCBs), Organochlorine Pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs). The results presented here exclusively include the novel data obtained from the winter campaign, revealing high concentrations of PBDEs (238 ± 521 ng g-1). In addition, the genotoxicity and acute toxicity tests were sensitive for most of the samples studied. This investigation is the first attempt to analyse the toxicity of plastic debris in coastal areas along the Chilean coast.

Revealing the environmental pollution of two estuaries through histopathological biomarkers in five fishes from different trophic guilds of northeastern Brazil.

Estuaries in Brazil are mostly anthropically affected due to the discharge of industrial and domestic effluents. In two of them, the Santa Cruz Channel Estuary (ITAP) and Sirinhaém River Estuary (SIR), historically affected by mercury pollution and sugarcane industry in Northeast Brazil, we assessed environmental pollution using liver and gill histopathological biomarkers in fish from different trophic levels. Liver samples exhibited serious damages such as hepatic steatosis, necrosis, and infiltration. The gills showed moderate to severe changes, such as lifting of epithelial cells, lamellar aneurysm, and rupture of lamellar epithelium. Most of the changes in the liver and gills were reported for species Centropomus undecimalis and the Gobionellus stomatus, which were considered as good sentinels of pollution. The combination of biomarker methodologies was efficient in diagnosing the serious damage to the species, reinforcing the need for monitoring the health of the ecosystems evaluated.

Multiple anthropogenic influences in the Pará River (Amazonia, Brazil): A spatial-temporal ecotoxicological monitoring in abiotic and biotic compartments.

The mineral wealth of the Amazon region is prone to intense exploration with consequent metals mobilization in ecosystems. Besides that, a number of other anthropogenic activities contribute to the imbalance of this important environment. The Pará River is an important water body in the Amazon basin and is under multiple anthropogenic influences, including disorderly urbanization, port activities and processing of minerals such as bauxite and kaolin. In this study, metals concentrations (Al, Cr, Pb, Ba, Ni, and Mn) in water, sediment and organisms (the fish Cheirocerus goeldii and the shrimp Macrobrachium amazonicum) and biochemical biomarkers (total antioxidant capacity, ACAP and lipid peroxidation, LPO) were analyzed along five points in the Para River with different distances to a center of anthropogenic activity, in three seasonal periods (rainy, transition and dry). Metals concentrations were similar among sites in each seasonal period but Aluminium (Al) presented the highest concentrations among all analyzed metals both in sediment and water considering all sampling points and all seasonal periods. In the dissolved fraction, Al had values above those established by the local environmental agency, especially during the rainy season. In the biotic compartment, both fish and shrimps showed higher concentrations of metals (Al and Ba) in the rainy season compared to the other seasons. Shrimp was more responsive to metal accumulation than fish, showing an adaptive response of biomarkers. Fish showed an increase of LPO in gills for individuals from the point of greater anthropogenic interference during the rainy season, but no differences in metal accumulation. We conclude that there is a seasonal pattern of metals concentration in different environmental compartments. Metal concentration in organisms and biomarkers responses, showed the effect of anthropogenic influences, which was not evident in results from chemical analyses alone, due to the intensive hydrodynamics in the region.

Investigating spatial-temporal contamination for two environments of the Amazon estuary: A multivariate approach.

An assessment of environmental quality in Amazonian estuaries utilizing histological and immunohistochemical biomarkers concomitantly with analyses of trace metals in the tissues of Sciades herzbergii, also considering physical chemical analyzes of the water. 352 animals were captured from two sites and during two periods (dry and rainy). Site 1: São Marcos Bay - heavy anthropic influence and Site 2: Caeté estuary-preserved estuary. In the laboratory, the fish were weighed (g) and measured (cm). Fragments of gills and liver were analyzed using histology and immunohistochemistry (Caspase 3). The specimens from Site 1 presented a low-value condition factor, with the highest concentrations of Al, Cd, and Hg appearing in the muscle, and most severe damages to gills and liver. In contrast, individuals from Site 2 presented a high-value condition factor and showed low metal concentrations in the muscle with only slight tissue lesions. Furthermore, our results demonstrated that seasonal changes affect metal modulation and pathologies in fish at Site 1. The sentinel species chosen in this study is considered a strong bioindicator of pollution and the combination of different biomarkers was efficient in providing a clear view of the signs of exposure to pollutants, and the risks posed to fish health by the presence of metals in the environment, especially in Site 1.

Slow and steady hurts the crab: Effects of chronic and acute microplastic exposures on a filter feeder crab.

Microplastics are a widespread environmental contaminant. Although detrimental effects on aquatic organisms are well documented, little is known about the long-term effects of microplastic exposure to filter-feeding organisms at ecologically realistic levels. This study investigates the effects of environmentally relevant concentrations of polyethylene micro beads ranging in size from 3 to 30 µm, on the physiology and energetics of a coastal filter-feeding crab Petrolisthes laevigatus. We evaluated the impact of microplastics by exposing P. laevigatus to two different concentrations and exposure times: i) a chronic exposure for five months at 250 particles L-1, and ii) an acute exposure for 48 h at 20,800 particles L-1, ~80 times higher than the chronic exposure. The results showed that only chronic exposures elicited negative effects on the coastal crab in both, metabolic and physiological parameters. Our findings demonstrate a strong correlation between the ingestion rate and weight loss, even at low concentrations, the crabs exhibited severe nutritional damage as a result of long-term microplastic exposure. By contrast, acute exposure revealed no significant effects to the crabs, a possible explanation for this being short-term compensatory responses. These results suggest that environmentally relevant concentrations of microplastics are harmful to marine organisms, and they should be evaluated during realistic temporal scales, as their effects strongly dependent on the exposure time. Our results also suggest that the effects of microplastics have been likely underestimated to date, due to the dominance of short-term exposures (acute) reported in the current literature.

The legacy of artisanal gold mining and its impact on fish health from Tapajós Amazonian region: A multi-biomarker approach.

Tapajós Region, is an area with intense historical artisanal and small-scale gold mining. Therefore, the core objective of this study was to evaluate the environmental status of different rivers located in this region, using biomarker endpoints in Serrasalmus rhombeus as a tool. Fish and sediment were collected from two rivers, Tropas and Crepori, affluent of Tapajós River, located inside a Federal Protection Area and in a Reference site. Mercury concentration in sediment and fish were traced, and biomarkers in gills and liver were analyzed. Results showed a clear difference between these two rivers compared to the Reference site. Fish tissues presented biomarker responses according to the site of collection. Catalase (CAT) activity was statistically higher in fish gills from Crepori, confirming the capacity of mercury interference with redox equilibrium. High levels of lipid peroxidation were also noted to contribute greatly in incidence of morphological changes in the liver and gills, suggesting that mercury bioaccumulation during continuous exposure promote biological responses in a cumulative manner, from molecules to tissues. This study also indicates adaptation in fish defense mechanisms given the conditions in the Tropas River, as well as a variation in biomarker responses to that of the Crepori river. In summary, Tapajós affluents presented high mercury levels in fish tissues leading to biomarker responses, demonstrating a hazardous signal of a long history of mercury pollution.

Evaluation of metal contamination effects in piranhas through biomonitoring and multi biomarkers approach.

The present field study aimed to assess the water quality of the Itacaiúnas River, located at the eastern part of the Brazilian Amazon, using water's physicochemical parameters, ecological risk assessment in sediments, biomarkers and metal bioaccumulation in piranhas at two points: upstream (P1) and downstream (P2), and the type of season (Dry and Rainy). We revealed a significant difference between the points and the seasons. Concerning, the concentration of metals (Cd, Cu, Zn, Cr, and Hg) in sediment and water, we reported significant concentrations of Cd and Cu especially on P2 at dry season. The fish gills collected in P2 showed various types of damages (moderate and severe), furthermore, the Degree of Tissue Change (DTC) reported a significant difference between points, highlighting the dreadful condition in animals' health originated from this point. In terms of the biotransformation enzyme, the GST activity was higher in fishes from P2 in both seasons. The obtained results showed clear signs of stress in fish from the downstream point. Linear correlation analysis exhibited that the biomarkers' response could be linked to the detected metals bioaccumulation. This field investigation provides baseline data on pollution status in this region and the results showed that although the overall potential ecological risks of the metals were considered low at our sampling sites including cadmium, however, Cd posed a noteworthy monomial potential ecological risk factor. Strong evidence of correlation was obtained between Cd in the environment with the gills' damage in fishes from P2. The results also indicated that S. rhombeus could be useful for biomonitoring species for assessing metal contamination.

Differential modulation of ammonia excretion, Rhesus glycoproteins and ion-regulation in common carp (Cyprinus carpio) following individual and combined exposure to waterborne copper and ammonia.

The main objective of this study was to understand the mode of interaction between waterborne copper (Cu) and high environmental ammonia (HEA) exposure on freshwater fish, and how they influence the toxicity of each other when present together. For this purpose, individual and combined effects of Cu and HEA were examined on selected physiological and ion-regulatory processes and changes at transcript level in the common carp (Cyprinus carpio). Juvenile carp were exposed to 2.6µM Cu (25% of the 96h LC50value) and to 0.65mM ammonia (25% of the 96h LC50value) singly and as a mixture for 12h, 24h, 48h, 84h and 180h. Responses such as ammonia (Jamm) and urea (Jurea) excretion rate, plasma ammonia and urea, plasma ions (Na(+), Cl(-) and K(+)), muscle water content (MWC) as well as branchial Na(+)/K(+)-ATPase (NKA) and H(+)-ATPase activity, and branchial mRNA expression of NKA, H(+)-ATPase, Na(+)/H(+) exchanger (NHE-3) and Rhesus (Rh) glycoproteins were investigated under experimental conditions. Results show that Jamm was inhibited during Cu exposure, while HEA exposed fish were able to increase excretion efficiently. In the combined exposure, Jamm remained at the control levels indicating that Cu and HEA abolished each other's effect. Expression of Rhcg (Rhcg-a and Rhcg-b) mRNA was upregulated during HEA, thereby facilitated ammonia efflux out of gills. On the contrary, Rhcg-a transcript level declined following Cu exposure which might account for Cu induced Jamm inhibition. Likewise, Rhcg-a was also down-regulated in Cu-HEA co-exposed fish whilst a temporary increment was noted for Rhch-b. Fish exposed to HEA displayed pronounced up-regulation in NKA expression and activity and stable plasma ion levels. In both the Cu exposure alone and combined Cu-HEA exposure, ion-osmo homeostasis was adversely affected, exemplified by the significant reduction in plasma [Na(+)] and [Cl(-)], and elevated plasma [K(+)], along with an elevation in MWC. These changes were accompanied by a decline in NKA activity. Gill H(+)-ATPase mRNA levels and activities were not affected by either Cu or HEA or both. Likewise, NHE-3 expression remained unaltered but tended to be numerically higher during HEA exposure. Overall, these data suggest that at equitoxic concentrations (25% of 96h LC50), the individual effect of Cu is more harmful while HEA induces quicker adaptive responses. Our findings also denote a competitive mode of interaction, exemplified by the inhibition of HEA -mediated adaptive responses in the presence of Cu.

Quantificação da produção de lodo de estações de tratamento de água de ciclo completo: uma análise crítica / Quantification of complete cycle water treatment plant sludge production: a critical assessment

RESUMO Grande parte do lodo gerado em estações de tratamento de água (ETAs) no Brasil ainda é disposta em rios ou em aterros sanitários. Contudo, principalmente em grandes centros urbanos, legislações ambientais restritivas e custos logísticos crescentes têm levantado interesse em usos benéficos para esse resíduo. Para uma avaliação dos possíveis usos, além do conhecimento das características qualitativas do lodo, operadores e projetistas de ETAs devem ser capazes de prever, com algum grau de confiabilidade, sua massa e volume. Os objetivos deste trabalho são: comparar o desempenho de dois dos principais métodos quantitativos de estimativa de produção de lodo - o método de fórmulas empíricas e o de balanço de massa; investigar a prática disseminada de se estimar a concentração de sólidos em suspensão totais na água bruta por meio de modelos de regressão linear com a turbidez como variável independente e delinear condições para a aplicação dessa correlação.

ABSTRACT Most of the water treatment plant (WTP) residuals generated in Brazil are still discharged into water bodies, or disposed in landfills. However, especially in large urban areas, ever-stringent environmental legislation and rising logistical costs have put focus into beneficial uses for those residuals. To evaluate the possible beneficial uses, beyond the knowledge of qualitative characteristics of the residuals, operators and designers should be able to predict, with some degree of certainty, its mass and volume. The objectives of this work are: to compare the performance of two of the main quantitative estimation methods for residuals production - the empirical formulas and the mass balance; to investigate the widespread practice of estimating the concentration of total suspended solids using turbidity as a surrogate; and to identify the conditions under which such procedure is acceptable.

Environmental quality of an estuary in Amazon delta using immunohistochemical and morphological analyses of gill as biomarkers / Qualidade ambiental de um estuário no delta amazônico utilizando análises imunohistoquímicas e morfológicas de brânquias como biomarcadores

In this study, histological, ultrastructural, and immunohistochemical observations of the gill tissue of two fish species (Plagioscion squamosissimus and Lithodoras dorsalis) were used as biomarkers to assess the ecological conditions of an estuary in the Amazon delta, by relating the health status of the fishes to environmental quality. The gill tissue was analyzed both qualitatively and semi-quantitatively. Marked differences in the type and severity of lesions were verified between species and among study sites. A variety of severe damages were confirmed histologically in specimens from the two impacted areas (B and C), including aneurysms, epithelial lifting, and intense hyperplasia. Electron microscopy and immunohistochemical analyses also revealed injuries in the gill tissue of specimens from these two areas. While, on area A only few specimens showed mild changes in gill tissues and rare marking of apoptosis. These results confirm the urgent need for the more effective control of the discharge of pollutants into the estuary as well as more effective urban planning, given the close proximity of a major industrial complex to residential areas.

Neste estudo foram utilizados biomarcadores histológicos, ultraestruturais e imunohistoquímicos em tecidos brânquiais de duas espécies de peixes, Plagioscion squamosissimus e Lithodoras dorsalis, para avaliar a situação ecológica em um estuário amazônico relacionando a saúde do peixe com a qualidade ambiental. O tecido branquial foi analisado qualitativamente e semiquantitativamente. Foram verificadas diferenças entre as espécies selecionadas e as áreas de estudo, no que se refere ao tipo e severidade das lesões no tecido branquial. Foi detectada uma variedade de alterações histopatológicas severas somente nos peixes capturados nas áreas B e C, tais como: Aneurisma, elevação epitelial e intensa hiperplasia. As análises de microscopia eletrônica e de imunohistoquímica confirmaram danos mais prejudiciais nas brânquias apenas nestas áreas de estudo. Enquanto que na área A poucos peixes apresentaram alterações leves nos tecidos e pouca marcação de apoptose. Estes resultados confirmam a necessidade de um efetivo controle dos dejetos de poluentes assim como um planejamento urbano eficaz nesta região, uma vez que esta área possui um complexo industrial importante próximo à área urbana.

Fish histopathology and catalase activity as biomarkers of the environmental quality of the industrial district on the Amazon estuary, Brazil / Histopatologia e atividade catalase em peixes como biomarcadores da qualidade ambiental no distrito industrial, estuário Amazônico, Brasil

The environment quality of an industrial district on the river Pará, Amazon estuary, Brazil, based on the assessment of histological alterations and on the determination of catalase activity of the hepatic tissue of two fish species, Plagioscion squamossissimus and Lithodoras dorsalis, is provided. Histopathological changes were evaluated semi-quantitatively and qualitatively. Mean Assessment Values (MAV) and Histological Alteration Index (HAI) of organ lesions were calculated for each zone under analysis, with different impact levels: Zone 1 (industrial district, with high contamination risk); Zone 2 (medium risk) and Zone 3 (minimum risk). Strong positive catalase activity and histopathological changes were reported in Zone 1. None of the specimens of either species captured in Zones 1 and 2 was healthy, whereas more than 60% of the specimens from Zone 3 presented healthy hepatic tissue. The principal alterations observed in the tissue of the two species included an increase in the number of Melanomacrophagous centers, fatty degeneration, inflammation, congestion, hepatitis and focal necrosis. The carnivorous P. squamosissimus presented higher levels of alteration than the herbivorous L. dorsalis. Results showed that local anthropogenic impacts were affecting the health of the two fish species under analysis.

Com o presente estudo foi avaliada a qualidade ambiental em um distrito industrial no rio Pará, estuário Amazônico, Brasil, baseado nas alterações histológicas e na determinação da atividade da catalase no fígado para duas espécies de peixes: Plagioscion squamossissimus e Lithodoras dorsalis. As mudanças histopatológicas foram avaliadas semiquantitativamente e qualitativamente. Os Valores Médios de Avaliação (MAV) e o índice de alteração histológica (IAH) das lesões nos órgãos foram calculados para cada zona com diferentes níveis de impacto: Zona 1 (distrito industrial, com risco alto de contaminação); Zona 2 (risco médio) e Zona 3 (risco mínimo). Na Zona 1 foi observada, para as duas espécies, forte atividade catalase positiva e algum tipo de alteração histopatológica. Não foram observados indivíduos saudáveis nas Zonas 1 e 2. Na zona 3, mais de 60% dos espécimes estudados apresentaram tecido hepático saudável. As principais alterações observadas no tecido hepático para as duas espécies foram: aumento dos centros melanocacrófagos, degeneração gordurosa, inflamação, congestão, hepatite e necrose focal. A espécie carnívora P. squamosissimus apresentou níveis mais elevados de alteração que o herbívoro L. dorsalis. Estes resultados mostram que as alterações da qualidade ambiental no entorno do distrito industrial está afetando a saúde destas espécies de peixes.

Branchial histopathological study of Brachyplatystoma rousseauxii ( Castelnau, 1855 ) in the Guajará bay, Belém, Pará State, Brazil / Estudo histopatológico da brânquia de Brachyplatystoma rousseauxii na baía do Guajará, Belém, Estado do Pará, Brasil

This work analyzes the morphological alterations in Brachyplatystoma rousseauxii gills and evaluates whether this species can be considered an environmental monitoring biomarker of Guajará Bay. Sampling was carried out in four areas around Belém, Brazil, in four annual periods: dry/wet season, wet season, wet/dry season and dry season. Water pH, temperature and suspended material were evaluated. A total of 36 specimens were collected. The second right gill arch of each animal was removed and immediately fixed and processed for histopathology analysis with light microscopy. The physicochemical analysis of the water during the study period showed slight acidity, temperature and material in suspension within normal levels. Histopathological analysis of the gills from 14 individuals from area I presented no alterations, and only 2 individuals from this area presented some significant type of alteration. In contrast, all individuals captured in areas II, III, and IV presented at least one of the following alterations: aneurism-like alterations, epithelial elevation, infiltration, cell proliferation and cell hypertrophy. Based on the gill histopathological analysis, this organ is considered a good biomarker and the native species B. rousseauxii could be used as a bioindicator for environmental monitoring.

O objetivo deste trabalho foi analisar as alterações morfológicas branquiais em Brachyplatystoma rousseauxii e verificar se esta espécie pode ser considerada como indicador biológico para o monitoramento ambiental da baía do Guajará. As coletas aconteceram em quatro áreas ao redor da cidade de Belém: I (controle), II, III e IV (forte influência antrópica), nos quatro períodos anuais: estação seco/chuvoso, estação chuvoso, estação chuvoso/seco e estação seco. Nesses períodos foram medidos pH, temperatura e material em suspensão. Foram capturados 36 exemplares. O segundo arco branquial direito de cada animal foi retirado, imediatamente fixado e processado para análise histopatológica. A análise físico-química da água revelou pH levemente ácido, a temperatura e o material em suspensão se encontravam nos parâmetros de normalidade. As análises histopatológicas das brânquias de 14 animais da área I não apresentaram alterações branquiais e somente dois revelaram algum tipo de alteração. Todos os indivíduos capturados nas áreas II, III e IV apresentaram pelo menos uma das seguintes alterações: aneurisma, elevação epitelial, infiltração, proliferação celular, fusão lamelar e hipertrofia celular. De acordo com as análises histopatológicas branquiais, este órgão é considerado como um bom biomarcador e a espécie nativa B. rousseauxii pode ser utilizada como bioindicador no monitoramento ambiental.