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

Apports des biomarqueurs moléculaires à la connaissance du développement des plantes terrestres au cours du Paléozoïque

Le contenu en biomarqueurs aliphatiques et aromatiques de sédiments d’origine terrestre et marine de l’Ordovicien supérieur au Carbonifère inferieur a été comparé aux assemblages de palynomorphes (acritarches, prasinophytes, chitinozoaires, cryptospores, spores trilètes et mégaspores) afin de contribuer à la connaissance de l’évolution des plantes terrestres au cours du Paléozoïque. Cette étude est donc basée sur les biomarqueurs d’origine terrestre et leur attribution à une espèce de plantes. L’enregistrement des biomarqueurs dans les successions clastiques du Silurien moyen – Dévonien inferieur de Tunisie méridionale, dans le basin de Ghadamis (Gondwana) révèle la présence de rétène, cadalène, kaurane, norabiétane, tetrahydroretene, C19 isohexylalkylnaphthalene et simonellite. Les premières bryophytes et les trachéophytes du Paléozoïque (par exemple Cooksonia, lycophytes et zosterophylles) peuvent donc être considérés comme de potentiels précurseurs pour le rétène et ses composés moléculaires associés dans les sédiments du Silurien Moyen au Dévonien Inférieur. En contrepartie, la flore du Carbonifère inferieur formée principalement de lycopodes arborescents, sphenopsides et pteridospermes est proposée comme une possible source pour le phyllocladane, abiétane, ent-béyerane, bisnorsimonellite, totarane diaromatique,sempervirane diaromatique et 2-méthylrétène dans les dépôts de charbon du Carbonifère inférieur (Viséan) de Dunbar (Est Lothian, Ecosse). Parmi les autres biomarqueurs identifiés dans nos échantillons, ionène, alkyldibenzofuranes, pérylène et les hydrocarbures aromatiques polycycliques (HAPs) dérivés de combustion indiquent la contribution de pollens, lichens, champignons et végétation carbonisée, respectivement. La plupart des biomarqueurs identifiés ici ont été généralement associées aux conifères, qui ne se sont développés qu’après le Carbonifère supérieur. Il apparait donc que ces composés sont également caractéristiques des premières plantes terrestres.The aliphatic and aromatic biomarker content from terrestrial and marine sediments of Late Ordovician to Early Carboniferous age have been related to their palynomorph assemblages (e.g. acritarchs, prasinophytes, chitinozoans, cryptospores, trilete spores and megaspores) in order to contribute to the knowledge of land plant evolution during the Palaeozoic. This investigation is therefore focused on the land-derived biomarkers and their attributions to specific kind of plants. The biomarker record of middle Silurian – lower Devonian sediments from southern Tunisia, Ghadamis Basin (Gondwana) reveals the presence of retene, cadalene, kaurane, norabietane, tetrahydroretene, C19 isohexylalkylnaphthalene and simonellite. The early Palaeozoic bryophytes and tracheophytes (e.g. Cooksonia, lycophytes and zosterophylls) may therefore be considered as potential precursors for retene and its related molecular compounds in sediments of Middle Silurian to Early Devonian age. In contrast, the Early Carboniferous flora formed by arborescent lycopods, sphenopsids and pteridosperms have been suggested here as apossible terrestrial source for phyllocladane, abietane, ent-beyerane, bisnorsimonellite, diaromatic totarane, diaromatic sempervirane and 2-methylretene in the Lower Carboniferous (Viséan) coal deposits at Dunbar (East Lothian, Scotland). Among the other biomarkers detected in our samples, ionene, alkyldibenzofurans, perylene and combustion-derived polycyclic aromatic hydrocarbons (PAHs) indicate pollen, lichens, fungi and vegetation fire contributions, respectively. Most of the biomarkers identified here had been so far generally associated to conifers, though conifers only evolved during Late Carboniferous. Thesecompounds therefore are also characteristic of early land plants

A quick analytical approach to estimate both free versus sorbed hydrocarbon contents in liquid-rich source rocks

International audienceFree and sorbed low-to-medium molecular weight thermovaporized hydrocarbons (<C20) are the main organic compounds released at the temperature range corresponding to the Rock-Eval® Shale PlayTMSh0 parameter (100°C–200°C), whereas medium and high molecular weight thermovaporized compounds (< C30) are the predominant components that are thermal released in the temperature range corresponding to the Shale Play Sh1 parameter (200°C–350°C). Now, an analytical methodology is proposed here to predict the quantity of free versus sorbed hydrocarbons still present in any liquid-rich sedimentary rock. The method compares shale play parameters (Sh0 and Sh1) obtained from both whole-rock samples and their corresponding organic matter (OM) concentrates isolated by standard nonoxidizing acid treatments and drying procedures. The hydrocarbon content obtained from whole rock (HCTotal,rock) is mainly considered as the total amount of free liquid hydrocarbons (HCFree) and sorbed liquid hydrocarbons (HCSorbed,OM) still contained in the investigated rock sample. formulaThe hydrocarbon content obtained from OM concentrates, however, only reflects the sorbed liquid hydrocarbons. formulaIn these equations, TOCrock is the total organic carbon of the rock sample; TOCOM corresponds to the TOC content of the OM concentrate sample; Massrock is the initial mass of the rock sample; MassOM is the initial mass of the OM concentrate sample; FIDsignalrockSh0+Sh1 is the flame ionization detection (FID) signal that corresponds to the global surface area under each thermal peak (Sh0 and Sh1) generated by the Rock-Eval FID; FIDsignalOMSh0+Sh1 corresponds to the global surface area under each thermal peak (Sh0 and Sh1) measured by the Rock-Eval FID between 100°C and 350°C after the themovaporization of the OM concentrate sample. Free liquid hydrocarbons are finally calculated as the difference between these last two values (HCFree = HCTotal,rock − HCSorbed,OM). This paper illustrates the application of this methodology on rock samples derived from the Vaca Muerta Formation (Argentina). Along the selected vertical profile, the lower rock interval contains approximately 60% of sorbed liquid hydrocarbons, whereas the upper sample contains more than 90% free liquid hydrocarbons. The parameters FreeHCSh0 and FreeHCSh0+Sh1 could be used to identify potential producible free liquid hydrocarbons intervals in early exploration campaigns

Lacustrine Type I kerogen characterization at different thermal maturity levels : Application to the Late Cretaceous Yacoraite Formation in the Salta Basin - Argentina

International audienceA maturation series from the Late Cretaceous to Danian Yacoraite Formation in the Salta Basin (Argentina) was selected to investigate the evolution of organic matter properties from source rock samples mainly containing lacustrine Type I kerogen. Organic petrography determined the thermal maturity and the spatial distribution of organic matter particles. Rock-Eval analyses and kerogen isolation procedures were then applied to assess the hydrocarbon generation potential of the investigated intervals. Biomarker ratios as well as the molecular composition of organic compounds present in four immature to early-mature rock samples and their corresponding aliphatic and aromatic fractions were investigated to complete the lacustrine organic matter characterization. Based on petrographic results, immature to early-mature Yacoraite samples have a large content of yellow-brownish liptinites (alginites) whereas mature samples are characterized by abundant solid bitumen. Three kerogen samples from the Yacoraite Formation at different thermal maturity levels were also selected for analysis of bulk-kinetic parameters (e.g. activation energy distribution, frequency factor) using programmed open-system pyrolysis. In this way, bulk-kinetic parameters were calculated as a function of the thermal maturity for these three lacustrine kerogen samples. Bulk-kinetic results show both an increasing activation energy and loss of petroleum generation potential as thermal degradation proceeds. The investigated Yacoraite kerogen samples show single activation energy distributions which are typical for a Type I kerogen of lacustrine origin. Finally, it was demonstrated that the organic matter (OM) characteristics from the Yacoraite Formation (Argentina) could be compared to the typical Type I kerogen from the Green River Formation (USA), showing similar OM characteristics, petroleum potential and activation energy distributions. The novelty of the geological and geochemical information brought in this article about Yacaroite system in Argentina provides premises for further investigation

Artificial thermal maturation of source rocks at different thermal maturity levels: Application to the Triassic Montney and Doig formations in the Western Canada Sedimentary Basin

International audienceArtificial thermal maturation of petroleum source rocks is widely performed by either open- or closedsystempyrolysis. These experiments are performed usually on immature source rock or isolated kerogensamples to quantify petroleum generation potential and to calculate kinetic parameters. Here, we characterizea maturation series from the Triassic Montney and Doig formations in the Western CanadaSedimentary Basin (WCSB), in order to investigate the evolution of the source rock properties and theircorresponding kerogen kinetic parameters as a function of the thermal maturity. Organic petrographydetermined the thermal maturity and the spatial distribution of organic matter particles. Rock-EvalShale Play analyses were then applied to assess the presence of both free and sorbed hydrocarbons stillcontained in the sample as well as the hydrocarbon generation potential. Based on vitrinite reflectancevalues, three kerogen samples from the Doig Formation and one kerogen sample from the MontneyFormation at different thermal maturity levels were selected for analysis of bulk kinetic parameters(e.g., activation energy distribution, frequency factor) using programmed open-system pyrolysis.Additionally, we evaluated the type of hydrocarbons and determined the molecular composition oforganic compounds that comprise the first two Rock-Eval peaks (Sh0 and Sh1) obtained during theimproved thermovaporization. TD–GC–MS–FID analyses were carried out on rock samples sequentiallyfrom 100 C to 200 C and then from 200 C to 350 C in order to characterize the composition of hydrocarbonsrepresented by each Rock-Eval Shale Play peak. Free and sorbed low-to-medium molecularweight aliphatic and aromatic hydrocarbons (<C20) are the main hydrocarbon components released inthe temperature range corresponding to the Rock-Eval Shale Play Sh0 parameter. Medium and highmolecularweight hydrocarbons (C10–C30 aromatics and saturates) are predominant components thermallyreleased in the temperature range corresponding to the Rock-Eval Shale Play Sh1 parameter.Results show both an increasing activation energy and loss of petroleum generation potential as thermaldegradation proceeds. The Shale Play method has been developed to better discriminate the generatedfluids (Sh0 + Sh1) from the residual kerogen (Sh2) providing a more accurate Rock-Eval Tmax. Sh0 andSh1 parameters also offer a practical way for an early estimate of oil in place

Aliphatic and aromatic biomarkers from Carboniferous coal deposits at Dunbar (East Lothian, Scotland): Palaeobotanical and palaeoenvironmental significance

International audienceCarboniferous (Viséan) coals from Dunbar, East Lothian, Scotland, contain well-preserved miospore and megaspore assemblages suggesting a lycopod-dominated forest ecosystem with some ferns, sphenopsids and pteridosperms. The low rank of the coals and the well defined microflora permit assessment of the palaeoenvironmental significance of lipid biomarkers during the Early Carboniferous. Rock-Eval, petrographic, and lipid analyses indicate a fully terrestrial depositional environment. Although we also present and discuss a wide diversity of other lipid biomarkers (alkanes, hopanoids, steroids), we focus on the terrestrial-derived biomarkers. Combustion-derived PAHs pyrene, fluoranthene, benzo[a]anthracene, chrysene and triphenylene indicate the occurrence of forest fires in the study areas during Early Carboniferous times. Alkyldibenzofurans are considered to derive from lichen-biomass. Retene, cadalene, simonellite, tetrahydroretene and kaurane are poorly specific and can derive from a variety of early Palaeozoic land plants. Abietane, phyllocladane, ent-beyerane and 4β(H)-eudesmane, as well as bisnorsimonellite, diaromatic totarane, diaromatic sempervirane and 2-methylretene, however, as yet had only been reported from conifers, which do not appear in the fossil record until the Late Carboniferous. Within the lower Carboniferous forest ecosystem, arborescent lycopsids and pteridosperms are proposed as alternative sources for these compounds

Geochemical and petrographic investigation of Triassic and Late Miocene organic-rich intervals from onshore Cyprus, Eastern Mediterranean

International audienceIn order to improve the understanding of potential petroleum systems in the still underexplored Eastern Mediterranean Sea, two field campaigns were performed to investigate potential source rocks onshore Cyprus. Elemental data (total organic (TOC) and inorganic carbon (TIC), total sulfur (TS), Fe, Ni, V), Rock-Eval® pyrolysis, biomarker and microscopic analysis (organic petrography, random vitrinite reflectance (VRr), palynofacies) of the obtained Mesozoic to Cenozoic samples have proven the existence of organic matter (OM) rich deposits within the following two geological formations:(1) The Triassic Vlambouros Formation (Fm.) of the Mamonia Complex comprises frequently occurring, few centimeter thin clay layers interbedded between meter thick sandstone units. The clay layers of this formation are characterized by TOC contents of about 1 wt% representing a Type III kerogen showing hydrogen index (HI) values of 48 mg HC/g TOC on average. VRr values of 0.5 to 0.6% as well as several biomarker ratios indicate low thermal maturity. The formation was deposited at the northern margin of Gondwana and similar strata may be present in the basement of the Levant Basin and the Eratosthenes Seamount. There, thermal maturity would be higher and such rocks might contribute to thermogenic gas systems.(2) In the Miocene Pakhna Fm., OM-bearing intervals are mainly present in the upper part of the formation in outcrops east of the Troodos Mountain, while organic-rich intervals are very scarce to absent in the south and southwest of the island. The eastern outcrops show abundant fine-grained, (marly) mud- to wackestones interbedded with coarser-grained carbonates. The fine-grained intervals have TOC contents of about 4 wt% representing mainly Type II-III kerogen with HI values of 238 mg HC/g TOC on average. The OM is immature as indicated by VRr values between 0.3 and 0.5%. TS/TOC ≥ 2.8 and several biomarker ratios indicate oxygen-depleted, even anoxic conditions during deposition. A negative correlation between the TOC and TIC indicates that such conditions were reached during enhanced primary bioproductivity controlled by local and regional clastic derived nutrient input. Similar conditions may have been present along the southeastern margin of the Eratosthenes Seamount, south of Cyprus. Presence of abundant organic matter and high sedimentation rates during the Miocene were favorable for microbial gas generation in the deeper parts of the basins

Characterization of Potential Source Rock Intervals of Late Mesozoic to Cenozoic Age in the On- and Offshore Area of Cyprus and Their Impact on Petroleum Systems in the Eastern Mediterranean Sea

International audiencePotential organic-rich rocks have been sampled onshore Cyprus and offshore, along the Eratosthenes Sea Mount. Offshore, potential source rock intervals are mainly present in the Upper Eocene and in the Lower Upper Cretaceous. In the onshore area, good source rock properties are reached in Upper Miocene intervals. These samples contain marine oil-prone type II kerogen. TS/TOC as well as several biomarker ratios indicate anoxic depositional conditions for the onshore samples and dysoxic conditions for the offshore ones. Tmax values around 420 °C and VRr values lower or equal 0.5 indicate an immature state of the organic matter. However, in terms of biogenic gas, these immature rocks might contribute to natural gas generation in the area. Furthermore, the Upper Miocene as well as the Upper Eocene sections might continue in the deeper offshore parts, where burial depths are sufficient for thermal maturation. The presence of thermogenic hydrocarbon generation is indicated by the presence of solid bitumen staining in Lower Eocene offshore intervals