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

A Sustainable Alternative for Green Structural Lightweight Concrete: Performance Evaluation

The use of structural lightweight concrete in the construction industry is on the rise in the last few decades mainly because of the higher strength per unit density, as it reduces the total deal load of the structural elements as compared with normal strength concrete. In addition, the environmental concerns of the concrete industry have gained supreme importance in recent times, demanding vital and effectual steps. In this regard, the current study was carried out to formulate an alternative approach for producing a sustainable lightweight structural concrete. The study followed two stages: initially, the selection of optimized manmade plastic aggregates based on trial concrete mixes, and finally, to gauge the physical-, mechanical- and durability related properties of the concretes integrating optimized manmade aggregate series at different replacement fractions. As a result of the first phase: two aggregate series out of eight were selected based on the compressive strength and durability properties of their concretes. In the next stage, all the properties for the optimized aggregate concrete were analyzed in terms of compressive strength. It was noted that the physical, mechanical and chloride penetration resistances have generally displayed a decreasing trend, with an increase in the manmade plastic aggregate replacement fractions as compared with reference lightweight concrete. However, the two aggregates, i.e., 70% DS-30% LLDPE and 50% QF-50% PET at the replacement fractions of 25% and 100%, were found to be the best two contenders that fulfilled the criteria for structural lightweight concrete, i.e., ASTMC330/C330M-14, and were proposed for structural lightweight purposes with low and relatively high strength and chloride resistance-based durability requirements, respectively. In addition, the brittleness ratios and structural efficiency parameters for the concretes of the 70% DS-30% LLDPE and 50% QF-50% PET also supplemented the aforementioned findings. Overall, this study presents a sustainable approach for the effective utilization of plastic waste for producing structural lightweight concrete

LEED Study of Green Lightweight Aggregates in Construction

Decreasing the demand for natural aggregates is doubly justified by the significant contribution of the construction industry to the unsustainable development path of the natural environment, and the projected global increase of the consumption of construction aggregates. Extensive research has been carried out on the physical and mechanical properties of concrete which incorporates plastic as aggregates; yet, no single study has been able to draw on structured research which demonstrates the improved sustainability performance of plastic-based aggregates to support sustainable development in the construction industry for a project seeking Leadership in Energy and Environmental Design (LEED) certification. The goal of this research is to explore the potential benefits that green processed lightweight aggregates (PLA) can provide to a project seeking LEED certification in accordance with the requirements of LEED v4 for Building Design and Construction. The objectives are to: (1) determine which LEED credit requirements can be met through using the studied material; (2) provide a comprehensive analysis of the applicable attainable LEED credits, given the existing technical information of the selected material, and (3) provide guidelines to maximize further credit attainment. To this end, the findings indicated that the use of PLA as a total replacement for coarse aggregates in lightweight concrete applications would contribute to earning directly up to 8 points (out of 110 total points) towards LEED certification. Such significant number allows for the potential increase of the project’s certification by one level. This is the first study of its kind to investigate the improved sustainability performance of recycled plastic aggregates from a LEED point of view. Moreover, the guidelines provided by the research will enable developers to maximize the financial and environmental benefits of their buildings through the reduced lifecycle cost and the enhanced LEED score. This research should encourage project teams to incorporate the knowledge of sustainable practices, and play an active role in sustainable development

A Sustainable Alternative for Green Structural Lightweight Concrete: Performance Evaluation

The use of structural lightweight concrete in the construction industry is on the rise in the last few decades mainly because of the higher strength per unit density, as it reduces the total deal load of the structural elements as compared with normal strength concrete. In addition, the environmental concerns of the concrete industry have gained supreme importance in recent times, demanding vital and effectual steps. In this regard, the current study was carried out to formulate an alternative approach for producing a sustainable lightweight structural concrete. The study followed two stages: initially, the selection of optimized manmade plastic aggregates based on trial concrete mixes, and finally, to gauge the physical-, mechanical- and durability related properties of the concretes integrating optimized manmade aggregate series at different replacement fractions. As a result of the first phase: two aggregate series out of eight were selected based on the compressive strength and durability properties of their concretes. In the next stage, all the properties for the optimized aggregate concrete were analyzed in terms of compressive strength. It was noted that the physical, mechanical and chloride penetration resistances have generally displayed a decreasing trend, with an increase in the manmade plastic aggregate replacement fractions as compared with reference lightweight concrete. However, the two aggregates, i.e., 70% DS-30% LLDPE and 50% QF-50% PET at the replacement fractions of 25% and 100%, were found to be the best two contenders that fulfilled the criteria for structural lightweight concrete, i.e., ASTMC330/C330M-14, and were proposed for structural lightweight purposes with low and relatively high strength and chloride resistance-based durability requirements, respectively. In addition, the brittleness ratios and structural efficiency parameters for the concretes of the 70% DS-30% LLDPE and 50% QF-50% PET also supplemented the aforementioned findings. Overall, this study presents a sustainable approach for the effective utilization of plastic waste for producing structural lightweight concrete

Construction of Green Concrete Incorporating Fabricated Plastic Aggregate from Waste Processing

The recent industrial revolution has improved the quality of human life with technological advancement; adversely, it has also doubled waste generation, including plastic waste, in the last two decades. The concrete industry is under strict scrutiny to deliver tangible sustainable solutions to lessen its carbon footprint; the use of plastic waste in concrete can deliver a potential solution to these global environmental issues. In the current study, the fresh, mechanical and durability properties, including water absorption and chloride ion permeability of green concrete containing a plastic, fabricated aggregate were examined. The compressive and flexural strength gain with time was also examined and compared to reference concrete. All the mechanical parameters including compressive strength, flexural strength, splitting tensile strength and modulus of elasticity were found to decrease with the addition of fabricated plastic aggregates as compared to the reference concrete. The increase in the compressive strength and flexural strength at 100% replacement, with an increase in the curing period from 28 to 90 days, was 13% and 11%, respectively. The flexural deformation of green fabricated plastic aggregate concrete signposted the ductile behavior compared to the reference concrete. The concrete with 100% fabricated plastic aggregates showed an increase of 16.4% and a decrease of 68% in the water absorption and chloride ion permeability in comparison to the reference concrete, respectively. This study presents an effectual method for the utilization of plastic waste with promising results, especially for non-structural applications

Exploring the Effect of Different Waste Fillers in Manufactured Sustainable Plastic Aggregates Matrix on the Structural Lightweight Green Concrete

The infrastructure demands for mega cities, urbanization and environmental concerns are pushing for smart and sustainable solutions. Structural lightweight concrete is gaining popularity in the concrete industry because of its intrinsic properties of resisting the load and being lighter in weight. Therefore, in this study, a green structural lightweight concrete was targeted by fabricating a plastic-based aggregate incorporating different industrial by-products to reduce the carbon tracks along with an alternate lightweight structural material. Thus, the compatibility of the different industrially by-products (dune dust, fly ash, and quarry dust) with plastic to produce a sustainable structural lightweight aggregate was evaluated in this study. The major physical characteristics of manufactured aggregates along with fresh, hardened, and durability properties of concretes were studied. Results revealed that altering the filler type had altered the texture and size of the developed aggregate. The aggregates developed with dune dust showed the largest particle size, bulk specific gravity, and strength while the ones with fly ash had the smallest size and water absorption. The decrease in the strength was found to be 24.7, 43.6, and 29% for dune dust, fly ash, and quarry dust respectively, once the filler percentage was increased from 50 to 70%. Additionally, all the concretes incorporating developed aggregates have evidently demonstrated their likely usage in structural lightweight applications by complying with ASTM C330/C330M-14 for compressive, flexural, and splitting tensile strength values, in addition to the improved durability behavior

A Multilayer Perception for Estimating the Overall Risk of Residential Projects in the Conceptual Stage

The ability to foresee hazards early plays a critical role in estimating the entire cost of a project. Although several studies have established models to predict the total cost of a project at a conceptual stage, there remains a research vacuum in measuring the overall risk at this stage. Using artificial neural networks, this research provides a strategy for estimating the overall risk in residential projects at the conceptual stage. There are eight important components in the suggested paradigm. The model was created using data from 149 projects. In the first hidden layer in the model, there are five neurons, and in the second hidden layer, there are three neurons. The suggested model’s mean absolute error rate was 11.7%. In the conceptual stage of residential projects, the number of floors, the type of interior finishes, and the implementation of risk management processes are the significant aspects that influence the overall risk. The proposed model assists project managers in precisely estimating the project’s overall risk, which leads to a more accurate estimation of the contract’s entire worth at the conceptual stage, allowing the stakeholders to decide whether or not to proceed with the project

Application of Integrated Project Delivery (IPD) in the Middle East: Implementation and Challenges

The Integrated Project Delivery method (IPD) is a contractual framework that features enhanced collaboration, risk and reward sharing under a single contract among the major project parties. This delivery method is gaining popularity in the US and other parts of the world, due to its proven results in efficient risk and cost sharing. Despite that, no significant investigations have been made to address the adaptability of the Middle East construction sector to the IPD delivery system. The objective of this research is to investigate the level of preparedness Middle Eastern markets have for adoption of the IPD delivery system. First, a thorough literature review was carried out to identify common barriers and enablers of applying IPD in construction. Second, a survey was carried out to assess and rank such barriers and enablers as they specifically apply to the Middle East construction sector. Third, through structured interviews with contract experts, strategies and guidelines were devised to be used by Middle East owners, consultants, and contractors who have the intention to implement the IPD delivery method in their projects. Finally, a thorough comparison was made between two major Middle Eastern countries, Egypt and the Kingdom of Saudi Arabia (KSA), in terms of IPD application. The findings reveal that the main barriers to implementing IPD stem from cultural resistance to the new system and lack of knowledge about it. The subsequent strategies outlined by the research are expected to help the construction industry in the Middle East gain more depth of knowledge about the benefits and application of IPD