18 research outputs found
Distribution of lipid compounds in sediments from Conceição Lagoon, Santa Catarina Island, Brazil
Lipid compounds from five sediment-water interface samples and a sediment core with 75 cm depth were used to assess sources of organic matter in Conceição Lagoon, located on Santa Catarina Island. The results which were based on the molar C:N:P ratios, relative abundance of sterols (dominated by the C27 sterols), n-alkanols (0.2-1.2 µg g-1), n-alkanes (0.4-5.0 µg g-1) and the Carbon Preference Index (CPI), indicated that the organic matter is predominantly of terrestrial origin (C/N > 10 and CPI > 2). Total phosphorus (TP, average 5.20 µmol g-1) and organic carbon (TOC, average 2.90 mmol g-1) contents were well correlated with the silt and clay fractions at all locations. In the sediment core, chronologically dated with the radionuclide 210Pb, the depth interval from 55 to 75 cm was dominated by the sand fraction (> 50%). However, parameters such as TOC, TP and n-alkane contents increased considerably at this depth suggesting a change in organic matter input sources
Distribution and sources of aliphatic and polycyclic aromatic hydrocarbons in surface sediments of Itajaí-Açu estuarine system in Brazil
The Itajaí-Açu estuarine system, located in southern Brazil, has great economic importance due to the presence of two ports (Itajaí and Navegantes). This system is affected by industrial and dredging activities, which can cause the remobilization of pollutants accumulated over time in the sediment. In this context, hydrocarbons were assessed in twelve surface sediment samples. n-Alkane and polycyclic aromatic hydrocarbons (PAH) concentrations were determined by gas chromatography and their sources assessed. Total concentrations ranged between 0.50 ± 0.04 and 69.70 ± 3.90 μg g-1 dry weight (d.w.) for n-alkanes and from 63.9 ± 12.1 to 1459.0 ± 43.5 ng g-1 d.w. for PAH. Most of the sediment samples presented carbon preference index (CPI) values close to unity, indicating that the area is submitted to petroleum-related sources, mainly close to Itajaí harbor, where an intense unresolved complex mixture (UCM) was observed. The presence at all stations of αβ-hopane biomarkers also indicated petrogenic input. Based on selected PAH ratios, the sedimentary PAH composition reflects a mixture of both petrogenic and pyrolytic sources. A comparison of the PAH concentrations found in this study with those listed in the sediment quality guidelines (SQGs) indicated that adverse biological effects on the biota are rarely expected.The Itajaí-Açu estuarine system, located in southern Brazil, has great economic importance due to the presence of two ports (Itajaí and Navegantes). This system is affected by industrial and dredging activities, which can cause the remobilization of pollu28460361
Source correlation of biomarkers in a mangrove ecosystem on Santa Catarina Island in southern Brazil
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
Lipids as indicators of paleoclimatic changes, II: terrestrial biomarkers
Variations in the abundance of specific lipid biomarker compounds derived from terrestrial sources are shown to be closely related to past climatic changes. Despite biodegradation processes, which take place mostly at the water column and sediment water interface, these compounds are found well preserved in oceanic sediments. Here, their relative distribution is employed as a tool to assess changes in terrestrial fluxes to the seabed accompanying climatic variations during glacial and interglacial intervals. These changes in biomarker distribution were estimated in two sediment cores taken ttom the eastern North Atlantic, covering the past 210,000 years. Comparisons with other paleoclimate proxies showed good agreement and suggest that some specific groups of biomarkers are important indicators of changes in terrestrial inputs to the sea.<br>A variação na abundância de alguns biomarcadores lipídicos derivados de aportes terrestres pode estar relacionada com mudanças climáticas no passado. Apesar dos processos de biodegradação que, na grande maioria, ocorrem na coluna aquática e na interface sedimento-água, esses compostos são encontrados bem preservados em sedimentos oceânicos. Nesse trabalho, a distribuição relativa desses compostos é empregada como uma ferramenta para avaliar mudanças no transporte de material terrestre para o mar em paralelo às variações climáticas durante os intervalos glaciais e interglaciais. As mudanças na distribuição dos biomarcadores foram estimadas em dois testemunhos coletados ao leste do Atlântico Norte e que correspondem aos últimos 210 mil anos. Os resultados mostraram uma boa correlação entre a distribuição dos biomarcadores e outros parâmetros paleoclimáticos previamente avaliados nos perfis, sugerindo que alguns grupos específicos de compostos orgânicos são importantes indicadores de aporte terrestre para ornar
Application of Headspace Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry (HS-SPME-GC/MS) on the Evaluation of Degradation Efficiency of Phenolic Compounds and Identification of By-Products from Produced Water
Application of the headspace solid-phase microextraction and gas chromatography-mass spectrometry (HS-SPME-GC/MS) technique as an analytical tool to monitoring the degradation of phenolic compounds and the formation of by-products in produced water by UV photolysis and UV/peroxide is proposed. All of the experimental conditions for the degradation tests were carried out according to the response of the surface modeling methods developed. The direct photolysis and the UV/H2O2 processes were capable to degrade more than 99% of the initial concentrations of total phenolic components of produced water. The main by-product found was 2,6-di-tert-butylbenzoquinone (DBQ). The presence of DBQ and other hydroxy compounds, constituting the major fraction of by-products identified, demonstrates that the degradations are initiated by the oxidation of the aromatic phenolic ring generating quinones, diphenols, benzoic acids and phenones
Photochemical Degradation of Diesel Oil in Water: a Comparative Study of Different Photochemical Oxidation Processes and their Degradation By-Products
This paper provides a comparative study of different photochemical oxidation processes and a detailed characterization of the by-products of diesel oil degradation performed using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOFMS). Diesel degradation was conducted in a photolytic reactor using UV, H2O2, UV/H2O2, O3 or O3/UV. The best conditions for each process were obtained applying multivariate analysis and the experimental results indicated that the O3/UV process was the most feasible for the treatment of wastewater containing diesel fuel, with a degradation percentage of > 90%. Almost complete degradation of the aromatics was achieved. Phenolic compounds were identified as by-products of the diesel samples treated with the UV, H2O2, O3 and O3/UV processes. Besides the phenolic compounds, other by-products identified included carboxylic acids and ethers in the UV/peroxide treatment, ethers in the UV irradiation treatment and ketones in the ozone treatment