Economic and agronomic impact assessment of wheat straw based alkyl polyglucoside produced using green chemical approaches

Results from a previous environmental impact assessment highlight the potential for the proposed process, that converts low-value agricultural residue (wheat straw) into a high-value biosurfactant, to result in significant (>75%) GHG savings, relative to the commercial candidate derived from palm kernel and wheat grain. This was achieved via the use of low-energy techniques like supercritical CO2 extraction, low-temperature microwave and in-situ fractionation of platform chemicals. Despite the environmental benefits, process commercialization relies on the economic feasibility of the production. Adopting a ‘cradle-to-gate’ life cycle costing approach, this paper has quantified the economic feasibility and resource efficiency characteristics of producing wheat-straw based APG, via the previously suggested green low-waste generating processes. Here, we undertook economic analysis of a wheat straw-derived APG production pathway, in comparison to palm-kernel and wheat-grain APG. Total processing costs were determined to range between $0.92-$1.87 per kg of wheat straw-APG demonstrating relatively better output service quality and energy efficiency, while conventional APG costs $1.95-$2.87 per kg, highlighting the significant potential of the residue-derived pathway to be scaled to commercial-level. In addition, a semi-quantitative assessment of the demand-based implications of adopting and scaling-up the green process, in the current context and practices of wheat cultivation was also undertaken. Potential agronomic impact that might be result from such scale-up scenarios, focusing on the effect of conventional residue incorporation practiced by farmers was assessed in detail to encourage farmers opt for informed choices and also to encourage both environmentally and economically sustainable systems-thinking

Updated global estimates of respiratory mortality in adults ≥ 30 years of age attributable to long-term ozone exposure

BACKGROUND: Relative risk estimates for long-term ozone (O3) exposure and respiratory mortality from the American Cancer Society Cancer Prevention Study II (ACS CPS-II) cohort have been used to estimate global O3-attributable mortality in adults. Updated relative risk estimates are now available for the same cohort based on an expanded study population with longer follow-up. OBJECTIVES: We estimated the global burden and spatial distribution of respiratory mortality attributable to long-term O3 exposure in adults ≥30 y of age using updated effect estimates from the ACS CPS-II cohort. METHODS: We used GEOS-Chem simulations (2×2.5º grid resolution) to estimate annual O3 exposures, and estimated total respiratory deaths in 2010 that were attributable to long-term annual O3 exposure based on the updated relative risk estimates and minimum risk thresholds set at the minimum or fifth percentile of O3 exposure in the most recent CPS-II analysis. These estimates were compared with attributable mortality based on the earlier CPS-II analysis, using 6-mo average exposures and risk thresholds corresponding to the minimum or fifth percentile of O3 exposure in the earlier study population. RESULTS: We estimated 1.04–1.23 million respiratory deaths in adults attributable to O3 exposures using the updated relative risk estimate and exposure parameters, compared with 0.40–0.55 million respiratory deaths attributable to O3 exposures based on the earlier CPS-II risk estimate and parameters. Increases in estimated attributable mortality were larger in northern India, southeast China, and Pakistan than in Europe, eastern United States, and northeast China. CONCLUSIONS: These findings suggest that the potential magnitude of health benefits of air quality policies targeting O3, health co-benefits of climate mitigation policies, and health implications of climate change-driven changes in O3 concentrations, are larger than previously thought

A roadmap to achieve the global methane pledge

The Global Methane Pledge (GMP), launched in 2021 and signed by 149 countries and the European Union, aims to reduce global anthropogenic methane emissions by 30% in 2030 compared to 2020 levels. However, the GMP does not specify the contribution of countries or methane-emitting sectors (fossil fuel production, agriculture and waste) to achieve this global goal. Nationally determined contributions (NDCs) describe countries’ climate change commitments, and 86% of countries include methane within the scope of these targets. This paper aims to assess whether a roadmap (i.e. a set of mitigation actions) to achieve the GMP can be developed from those methane-targeted mitigation actions included within NDCs. The 476 methane-focussed mitigation actions within the 168 NDCs analysed are targeted in countries and sectors emitting approximately 40% of global methane. These mitigation actions are not specified in NDCs with implementation targets and timelines that are currently collectively sufficient to achieve the GMP goal. However, if all 476 mitigation actions are implemented to their maximum technical mitigation potential, their implementation could reduce global emissions by ∼31%. Therefore, mitigation actions in NDCs could achieve the GMP goal, but only if implemented to their fullest possible extent. There are also multiple opportunities to increase methane mitigation ambition further. Additional commitments to implement technical methane mitigation measures could lead to mitigation in excess of the GMP goal. Behavioural measures, such as dietary shifts and reduction in waste generation could further reduce methane, and are included in few NDCs currently

Global Air Quality and Health Co-benefits of Mitigating Near-Term Climate Change through Methane and Black Carbon Emission Controls

Background: Tropospheric ozone and black carbon (BC), a component of fine particulate matter (PM ≤ 2.5 µm in aerodynamic diameter; PM:2.5), are associated with premature mortality and they disrupt global and regional climate. Objectives: We examined the air quality and health benefits of 14 specific emission control measures targeting BC and methane, an ozone precursor, that were selected because of their potential to reduce the rate of climate change over the next 20–40 years.: Methods: We simulated the impacts of mitigation measures on outdoor concentrations of PM2.5 and ozone using two composition-climate models, and calculated associated changes in premature PM2.5- and ozone-related deaths using epidemiologically derived concentration–response functions. Results: We estimated that, for PM:2.5 and ozone, respectively, fully implementing these measures could reduce global population-weighted average surface concentrations by 23–34% and 7–17% and avoid 0.6–4.4 and 0.04–0.52 million annual premature deaths globally in 2030. More than 80% of the health benefits are estimated to occur in Asia. We estimated that BC mitigation measures would achieve approximately 98% of the deaths that would be avoided if all BC and methane mitigation measures were implemented, due to reduced BC and associated reductions of nonmethane ozone precursor and organic carbon emissions as well as stronger mortality relationships for PM2.5 relative to ozone. Although subject to large uncertainty, these estimates and conclusions are not strongly dependent on assumptions for the concentration–response function. Conclusions: In addition to climate benefits, our findings indicate that the methane and BC emission control measures would have substantial co-benefits for air quality and public health worldwide, potentially reversing trends of increasing air pollution concentrations and mortality in Africa and South, West, and Central Asia. These projected benefits are independent of carbon dioxide mitigation measures. Benefits of BC measures are underestimated because we did not account for benefits from reduced indoor exposures and because outdoor exposure estimates were limited by model spatial resolution.

Invariant natural killer T cells act as an extravascular cytotoxic barrier for joint-invading Lyme Borrelia

SignificanceInvariant natural killer T cells (iNKT) have been found primarily patrolling inside blood vessels in the liver, where they respond to bacterial glycolipids presented by CD1d on liver macrophages. We show joint iNKT cells are localized outside of blood vessels and respond directly to the joint-homing pathogen, Borrelia burgdorferi, which causes Lyme borreliosis using multichannel spinning-disk intravital microscopy. These iNKT cells interacted with B. burgdorferi at the vessel wall and disrupted its dissemination attempts into joints. Successful penetrance of B. burgdorferi out of the vasculature and into the joint tissue was met by a lethal attack by extravascular iNKT cells through a granzyme-dependent pathway. These results suggest a critical extravascular iNKT cell immune surveillance in joints that functions as a cytotoxic barrier

Environmental impact assessment of wheat straw based alkyl polyglucosides produced using novel chemical approaches

This paper evaluates and quantifies the environmental performance of alkyl polyglucosides sourced from wheat straw (WS-APG), a low-cost and low-ecological impact agricultural residue, compared to that of their commercial counterpart, which is sourced from palm kernel oil and wheat grain (PW-APG). Escalating pressure to consider the environmental sustainability of fossil derived surfactant consumption has driven biosurfactants to become the product of choice within the surfactant market, and a class of ‘plant’ based non-ionic surfactants called alkyl polyglucosides (APG) are particularly prevalent. However, the existing food based feedstock of APG such as coconut oil, palm oil, wheat and corn (in addition to being expensive) will potentially undermine the claimed ‘sustainability’ of the APG products (i.e. the ‘food vs. chemical’ issue). Here, we present the “cradle-to-gate” life cycle impact assessment of a suggested alternative, hybridised APG synthesis technique where the Fisher glycosidation method is supplemented by novel, green chemistry based techniques. This evaluation provides a quantitative insight into direct GHG intensity and other ecological impact indicators, including land use, waste generation and energy consumption. Upon evaluation, the wheat straw-derived pathway delivered GHG-emission savings in the range of 84–98%, compared to that of the palm kernel–wheat grain pathway. Waste generated from the production of unit mass of the product amounted to 0.43 kg and 10.73 kg per kg of WS-APG and PW-APG, respectively. In addition to the above mentioned facts, the ‘cradle–gate’ stages of WS-APG production were also found to consume relatively lower amounts of water and fossil-derived energy. In conclusion, of the two APG production pathways, the suggested ‘hybrid’ pathway using an agricultural residue, wheat straw, was found to be sustainable and to demonstrate better environmental performance

Development of the Low Emissions Analysis Platform – Integrated Benefits Calculator (LEAP-IBC) tool to assess air quality and climate co-benefits : Application for Bangladesh

Low- and middle-income countries have the largest health burdens associated with air pollution exposure, and are particularly vulnerable to climate change impacts. Substantial opportunities have been identified to simultaneously improve air quality and mitigate climate change due to overlapping sources of greenhouse gas and air pollutant emissions and because a subset of pollutants, short-lived climate pollutants (SLCPs), directly contribute to both impacts. However, planners in low- and middle-income countries often lack practical tools to quantify the air pollution and climate change impacts of different policies and measures. This paper presents a modelling framework implemented in the Low Emissions Analysis Platform – Integrated Benefits Calculator (LEAP-IBC) tool to develop integrated strategies to improve air quality, human health and mitigate climate change. The framework estimates emissions of greenhouse gases, SLCPs and air pollutants for historical years, and future projections for baseline and mitigation scenarios. These emissions are then used to quantify i) population-weighted annual average ambient PM2.5 concentrations across the target country, ii) household PM2.5 exposure of different population groups living in households cooking using different fuels/technologies and iii) radiative forcing from all emissions. Health impacts (premature mortality) attributable to ambient and household PM2.5 exposure and changes in global average temperature change are then estimated. This framework is applied in Bangladesh to evaluate the air quality and climate change benefits from implementation of Bangladesh's Nationally Determined Contribution (NDC) and National Action Plan to reduce SLCPs. Results show that the measures included to reduce GHGs in Bangladesh's NDC also have substantial benefits for air quality and human health. Full implementation of Bangladesh's NDC, and National SLCP Plan would reduce carbon dioxide, methane, black carbon and primary PM2.5 emissions by 25%, 34%, 46% and 45%, respectively in 2030 compared to a baseline scenario. These emission reductions could reduce population-weighted ambient PM2.5 concentrations in Bangladesh by 18% in 2030, and avoid approximately 12,000 and 100,000 premature deaths attributable to ambient and household PM2.5 exposures, respectively, in 2030. As countries are simultaneously planning to achieve the climate goals in the Paris Agreement, improve air quality to reduce health impacts and achieve the Sustainable Development Goals, the LEAP-IBC tool provides a practical framework by which planners can develop integrated strategies, achieving multiple air quality and climate benefits