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Marajó Island, an environmental protection area for sustainable use in the Brazilian Amazon, was the first region in Brazil to apply the pesticide DDT, a persistent organic pollutant (POP), to control malaria outbreaks. This study investigated background levels of various POPs, including o,p'- and p,p'-DDT and their primary metabolites (o,p'- and p,p'-DDE, o,p'- and p,p'-DDD), as well as hexachlorocyclohexane (α-, β-, γ-, δ-HCH), using estuarine surface sediments and sediment cores from areas influenced by urbanization and agriculture. All samples were collected during the dry season (September 2014). Surface sediments exhibited ΣDDT concentrations up to 2.71 ng g⁻ 1 , with isomeric ratios indicating past DDT application and contributions from dicofol. Sediment profiles revealed alternating aerobic and anaerobic degradation processes of DDT. Other organochlorinated contaminants were not detected. The presence of γ-HCH as the main isomer (0.24 to 0.90 ng g⁻ 1 ) in surface samples suggests recent lindane application as a wood preservative or cattle parasite treatment. A dated sediment core revealed historical contamination of early DDT tests in the Amazon during the mid-1940s. Increasing ΣDDT concentrations (up to 12.3 ng g⁻ 1 ) were identified in the 1970s, coinciding with the intensification of DDT use for public health campaigns, which lasted until 2009 and reached the highest ΣDDT flux. Legal restrictions on the use and commercialization of POPs, along with natural degrading processes, likely led to decreased accumulation and limited ecological risks. Furthermore, the low concentrations of POPs suggested biodegradation and dispersion from northeast to southeast., Competing Interests: Declarations. Ethical approval: This study was authorized by the Chico Mendes Institute for Biodiversity (ICMBio/SISBIO 49140–1). Consent to participate: The authors consent to participate in this study. Consent for publication: The authors consent to publish the study. Competing interest: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Most patients hospitalized for heart failure (HF) present with signs of congestion. Prognostic significance of clinical congestion may vary depending on left ventricular ejection fraction (LVEF). This study aims to investigate the prognostic impact of congestion across different LVEF categories., Methods and Results: Composite congestion scores (CCSs; 0-9) derived from the severity of edema, jugular venous pressure, and orthopnea, were analyzed on admission and at discharge in 3787 patients hospitalized for HF (LVEF ≥ 40%: n = 2347, LVEF < 40%: n = 1440). The median admission CCS was 4 in both LVEF strata (P = .64). Adjusted hazard ratios (HRs; 95% confidence interval [CI]) of the moderate (CCS 4-6) and severe congestion [7-9] groups relative to the mild congestion [0-3] group on admission for a composite of all-cause death or HF rehospitalization were 1.20 (1.04-1.39, P = .01) and 1.54 (1.27-1.86, P < .001) in the LVEF ≥ 40% stratum, and 1.20 (1.01-1.44, P = .04) and 0.82 (0.61-1.07, P = .14) in the LVEF < 40% stratum, respectively (P interaction < .001). A total of 16% of the patients with LVEF ≥40% and 14% with LVEF <40% had residual congestion (CCS ≥ 1) at discharge, which was associated with a respective adjusted HR of 1.40 (1.18-1.65, P < .001) and 1.25 (0.98-1.58, P = .07) for postdischarge death or HF rehospitalization (P interaction  = 0.63)., Conclusion: The severity of clinical congestion on admission was associated with adverse clinical outcomes in patients with LVEF ≥ 40%, but not in those with LVEF < 40%. These findings warrant further studies to better understand the detailed profile of congestion across the LVEF spectrum., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Mercury (Hg) is a toxic globally spread pollutant that has been found at increasing concentrations in the South Atlantic Ocean. The present work provides the first insight into the total mercury (HgT, unfiltered waters) content in the water of the Brazilian Exclusive Economic Zone (BEEZ), within a 24°S to 20°S. Water samples were collected from surface to 3400 m depth along transects, and analyzed with atomic fluorescence. The mean HgT concentration for the Tropical Water mass (TW) was 6.3 ± 1.4 pM (n = 16), for the South Atlantic Central Water (SACW), 5.9 ± 0.7 pM (n = 8), for the Antarctic Intermediate Water (AAIW), 5.0 ± 0.6 pM (n = 2), for the Upper Circumpolar Deep Water (UCDW), 6.5 pM (n = 1), and for the North Atlantic Deep Water (NADW), 5.7 ± 0.9 pM (n = 12). HgT concentrations were highest throughout the BEEZ in comparison with other parts of the Atlantic Ocean, farther from the coast., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The sources and depositional history of OCPs (organochlorine pesticides), PCBs (polychlorinated biphenyls) and PAHs (polycyclic aromatic hydrocarbons) over the last 100years were determined in two sediment cores collected in the Amazon region. It was possible to distinguish two depositional periods along the cores. The first period occurred before extensive anthropogenic effects were registered in the sediments. During this time interval, the concentrations of all OCPs and PCBs were below the detection limits (DL), and the PAH concentrations were low and essentially constant (58.19-124.28ngg -1 ). The second period starts in the mid-1960s and reflects the increased human influence in the area. The concentrations of OCPs, PCBs, and PAHs increased towards the top of the cores, varying between

-1 ,

-1 and 331 to 2341ngg -1 , respectively. In general, OCP results showed trends corresponding to the production, usage and prohibition periods of POPs in Brazil. Compounds related to wood treatment, such HCHs and chlordanes, were predominant among the OCPs, which may be associated with many sawmills located in this region. The increase in PAH concentration after the 1960s is mainly due to forest fires, caused by the implementation of large-scale cattle ranches, which burned forests to create pastures. The background PAH concentrations before the 1960s are probably related to natural diagenetic processes., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Copper, Cd and Zn can be found at elevated concentrations in contaminated estuarine and coastal waters and have potential toxic effects on phytoplankton species. In this study, the effects of these metals on the intracellular production of the polypeptides phytochelatin and glutathione by the marine diatom Phaeodactylum tricornutum were examined in laboratory cultures. Single additions of Cu and Cd (0.4 microM Cu2 and 0.45 microM Cd2+) to the culture medium induced the production of short-chained phytochelatins ((gamma-Glu-Cys)n-Gly where n = 2-5), whereas a single addition of Zn (2.2 microM Zn2+) did not stimulate phytochelatin production. Combination of Zn with Cu resulted in a similar phytochelatin production compared with a single Cu addition. The simultaneous exposure to Zn and Cd led to an antagonistic effect on phytochelatin production, which was probably caused by metal competition for cellular binding sites. Glutathione concentrations were affected only upon exposure to Cd (85% increase) or the combination of Cd with Zn (65% decrease), relative to the control experiment. Ratios of phytochelatins to glutathione indicated a pronounced metal stress in response to exposures to Cu or Cd combined with Zn. This study indicates that variabilities in phytochelatin and glutathione production in the field can be explained in part by metal competition for cellular binding sites.