Particulate Research Articles

Changing trends in lung cancer disease burden between China and Australia from 1990 to 2019 and its predictions.

Lung cancer (LC) is a leading cause of death and presents a substantial societal burden. This article compares its disease burden and risk factors between China and Australia to support health policymakers for LC prevention and treatment. The data from the 2019 Global Burden of Disease Study were used to analyze disease temporal trends using Joinpoint regression model. The Bayesian age-period-cohort model was used for prediction. The population-attributable fraction (PAF) was used to analyze LC risk factors. In 2019, the age-standardized rates (ASR) of incidence and of mortality of LC in China were 41.71/100 000 and 38.70/100 000, while Australia's rates were 30.45/100 000 and 23.46/100 000. It showed an increasing trend in China but a decreasing trend in Australia. By 2030, the ASR of incidence and mortality are predicted to be 47.21/100 000 and 41.54/100 000 in China, while Australia's rates will reach 30.09/100 000 and 23.3/100 000, respectively. Smoking is the most common risk factor for LC, followed by particulate matter and occupational carcinogenesis. The PAF of smoking dropped in Australia (from 68.38% to 53.75% in females; 77.41% to 58.47% in males) but increased in China (from 19.56% to 26.58% in females; 80.45% to 82.03% in males) from 1990 to 2019. The disease burden of LC in China is rising, whereas in Australia, it is declining. China still faces a heavy LC burden. Risk factor analysis supported for further improving the compliance and enforcement of polices on tobacco control and environmental management to reduce this disease burden.

Construction of Heavy-Duty Diesel Vehicle Atmospheric Pollutant Emission Inventory Based on Onboard Diagnosis Data

Motor vehicles emit a large amount of air pollutants. NOx and particulate matter (PM) account for 53.2% and 74.7%, respectively, of vehicle emissions in China. Using the technical guidelines for compiling road vehicle emission inventories, the emission factors based on the onboard diagnostics (OBD) system of heavy-duty diesel vehicles are obtained. The trajectory of heavy-duty diesel vehicles is corrected using big data interpolation, and the correction coefficients for different vehicle speeds are fitted to calculate the corresponding correction factors. Simultaneously, the Weather Research and Forecasting model is used for the meteorological correction of emissions, a heavy-duty diesel vehicle emission inventory under the community multiscale air quality model is established, and the distribution characteristics of pollution emissions from heavy-duty diesel vehicles in Chengdu are analyzed at the time and space levels. Overall, the pollutant gasses emitted by heavy-duty diesel vehicles in Chengdu are largely concentrated at the city center. In 2023, the total annual emissions of the pollutants NOx, CO, fine PM, and volatile organic compounds from heavy-duty diesel vehicles in Chengdu were 10,590.60, 28,852.90, 686.18, and 657.60 tons, respectively. NOx and CO have the highest proportions among the major pollutants, accounting for 70.7% and 26%, respectively.

The power of personalised feedback: evidence from an indoor air quality experiment

Abstract Indoor air pollution is one of the leading causes of morbidity and mortality worldwide, but its sources and impacts are largely misunderstood by the public. In a randomised controlled trial including 281 households in France, we test two interventions aimed at changing indoor polluting behaviour by raising households’ awareness of health risks associated with indoor air pollution. While both generic and personalised information increased knowledge, only personalised information including social comparison feedback changed behaviour, leading to a reduction of indoor PM2.5 (particulate matter with an aerodynamic diameter ≤2.5 µm) emissions by 20% on average. Heterogeneous treatment effects show that this effect is concentrated on the most polluted households at baseline, for whom the reduction reaches 40%.

Short-term effects of temperature and air pollution on mortality in Norway: a nationwide cohort-based study

BackgroundThis time-stratified case-crossover study examined short-term associations of air temperature with cause-specific mortality (natural-cause, cardiovascular and respiratory) and potential effect modification by daily mean air pollution concentrations and individual characteristics in the Cohort of Norway (CONOR) cohort.MethodsThe CONOR cohort recruited ∼173,000 participants from 1994 to 2003. Participants’ vital status and the cause of death were collected from the Cause of Death Registry of Norway until 2018. Daily mean air temperatures and concentrations of fine particulate matter (PM2.5) and ozone (O3) estimated by spatial-temporal models were assigned to participants’ residences. We applied conditional logistic regression models with the distributed lag non-linear model approach to assess cold and heat effects on cause-specific mortality. The potential effect modification was analyzed by incorporating an interaction term between air temperature and the modifier in the regression model. The cold and heat effects were estimated for different subgroups of participants and at the low (5th percentile), medium (50th percentile), and high (95th percentile) levels of air pollution.ResultsWe observed an increased risk of natural-cause mortality (OR: 1.26 95% CI: 1.09, 1.46) for a decrease in temperature from the minimum mortality temperature (MMT, 17.6°C) to the 1st percentile and an increased risk of cardiovascular mortality (OR: 1.32, 95% CI: 1.04, 1.67) for a decrease from MMT (16.1°C) to the 1st percentile. The cold effect on natural-cause mortality was more pronounced among women, former smokers, those aged below 75 years and people with a history of cardiovascular diseases. The cold effect on natural-cause mortality was stronger at higher levels of air pollution in winter, and the heat effect on cardiovascular mortality were stronger with elevated air pollution levels in summer.ConclusionWe find adverse short-term cold effects on overall mortality in Norway. We further observe significant risk of cold related effects on natural and cardiovascular mortality in the wintertime and increased risk of respiratory mortality due to higher temperatures in the summer. We identified subpopulations who were likely to be more at risk for temperature-related mortality. We also see that increased air pollution impacts temperature related mortality in winter and summer time.

Burning Cow Dung Emits an Inordinate Amount of Air Pollution in India

Dried cow dung, a main source of household cooking fuel for many in rural India, releases more particulate matter across the country than wood and other biofuels.

Short‐term effects of a heavy dairy manure application on soil chemical and biological indicators in an irrigated semiarid cropping system

AbstractIntensive dairy production in southern Idaho is associated with the annual application of manure to croplands. However, a one‐time heavy application of manure could alternatively be used as a means to improve soil fertility and health for years or even decades, circumventing the need for frequent applications. To determine if this practice would negatively affect soil properties in the short term, we analyzed chemical and biological indicators of soil health for 2 years after dairy manure incorporation. Soil indicators measured were pH, electrical conductivity, extractable nitrogen (N) and phosphorus, total carbon (C) and N, enzyme activities, net N mineralization, soil organic C, soil protein, active C, ammonia oxidation potential, and particulate organic matter. Manure (with and without synthetic fertilizer) was found to significantly affect chemical and biological indicators in both topsoil (0–15 cm) and subsoil (15–30 cm), but the responses were greater in the subsoil. This can be attributed to the fact that manure was incorporated to approximately 30 cm via moldboard plow. All indicators responded positively to manure, except pH, which decreased slightly in the subsoil in the first year after application. Principal component analysis of chemical and biological indicators, across all years and depths, showed that the first two components explained 62% and 8.5% of the variance. While soil indicators were not adversely affected by manure, silage corn (Zea mays L.) yields in year 1 were significantly lower in manured plots, though in year 2, barley grain (Hordeum vulgare L.) yields were statistically similar among manure and fertilizer.

Air pollution is associated with increased risk of venous thromboembolism: the Multi-Ethnic Study of Atherosclerosis.

Air pollution exposure may induce procoagulant effects, and chronic exposure may be linked to greater risk of venous thromboembolism (VTE). We tested the hypothesis that air pollution is associated with increased VTE risk in the prospective Multi-Ethnic Study of Atherosclerosis (MESA), which has well-characterized air pollution measures and information on potential confounding factors. We included 6,651 participants recruited in 2000-2002 (baseline age range: 45-84 yrs; 53% female). Air pollution was assessed with a validated spatio-temporal model that incorporates cohort-specific monitoring. Four indices of air pollution updated each fortnight over follow-up were averaged to estimate participant-level chronic exposure: fine particulate matter ≤2.5 micrometers in aerodynamic diameter (PM2.5), oxides of nitrogen (NOx), nitrogen dioxide (NO2), and ozone (O3). Mean±SD PM2.5 was 13.5±3.0 µg/m3, NO2 17.9±8.2 ppb, NOx 36.1±19.6 ppb, and O3 22.2±3.7 ppb. Incident VTE was identified using hospitalization discharge codes through 2018. A total of 248 VTE events accrued over a median follow-up of 16.7 years. After adjustment for baseline demographics, health behaviors and body mass index, the hazard ratio (95% CI) for incident VTE associated per 3.6 µg/m3 higher PM2.5 was 1.39 (1.04-1.86); per 13.3 ppb higher NO2 concentration was 2.74 (1.57-4.77); and per 30 ppb higher NOx was 2.21 (1.42-3.44). O3 was not related. In this prospective community-based cohort with individual-level estimation of chronic air pollution exposure, higher average ambient concentrations of PM2.5, NO2 and NOX were associated with greater risk of developing VTE. Findings add to accumulating evidence of adverse health effects attributed to air pollution exposure.

Design Modification of the Retort Burner for Phytomass in a Small Heat Source

AbstractPhytomass, a renewable energy source, faces the challenge of ash agglomeration due to its low ash fusion temperature. To address this, chemical modification (adding additives) and co-combustion with other fuels are explored. This study focuses on combustion of phytomass with wood biomass and mechanical modifications to the combustion chamber. The goal is to maintain the chamber temperature below the ash fusion point. Modifications included a modulated burner and water cooling. Combustion of phytomass with wood biomass in the ratio of 60/40, 40/60 and 20/80 had a beneficial effect on increasing the heat source output by 5% and reducing SOX emissions from 61 to 21 mg−3 by adding the wood to hay. The modification of the burner resulted in a reduction of particulate matter from the range 110–140 mg m−3 without cooling to the range 90–110 mg m−3 with cooling depending on the phyto/wood ratio and a reduction in the formation of deposits. By cooling the burner, the temperature at the exit from the combustion chamber was reduced from approx. 560 to 460 °C and at the height above the reaction zone of the flame from 500 to 320 °C. The co-combustion and additional cooling were not such effective, two other modifications were suggested for breaking up or sliding the resulting agglomerates from the surface of the retort. The proposed devices could have potential, as the investment in such a device is more cost-effective than the purchase of a special boiler for burning alternative pellets.

Enhanced Sequence-to-Sequence Attention-Based PM2.5 Concentration Forecasting Using Spatiotemporal Data

Severe air pollution problems continue to increase because of accelerated industrialization and urbanization. Specifically, fine particulate matter (PM2.5) causes respiratory and cardiovascular diseases, and according to the World Health Organization (WHO), millions of premature deaths and significant health burdens annually. Therefore, PM2.5 concentration forecasting is essential. This study proposed a method to forecast PM2.5 concentrations one hour after using Sequence-to-Sequence Attention (Seq2Seq-attention). The proposed method selects neighboring stations using minimum redundancy maximum relevance (mRMR) and integrates their data using a convolutional neural network (CNN). The proposed attention score and Seq2Seq are used on the integrated data to forecast PM2.5 concentration after one hour. The performance of the proposed method is validated through two case studies. The first comparison evaluated the performance of the conventional attention score against the proposed attention scores. The second comparison evaluated the forecasting results with and without considering neighboring stations. The first study showed that the proposed attention score improved the performance index (Root Mean Square Error (RMSE): 3.48%p, Mean Absolute Error (MAE): 8.60%p, R2: 0.49%p, relative Root Mean Square Error (rRMSE): 3.64%p, Percent Bias (PBIAS): 59.29%p). The second case study showed that considering neighboring stations’ data can be more effective in forecasting than considering that of a standalone station (RMSE: 5.49%p, MAE: 0.51%p, R2: 0.67%p, rRMSE: 5.44%p, PBIAS: 46.56%p). This confirmed that the proposed method can effectively forecast the PM2.5 concentration after one hour.

Effects of Wildfire Exposure on the Human Immune System

Wildfires have become a significant environmental and public health concern worldwide, particularly due to their increased frequency and intensity driven by climate change. Wildfire smoke, composed of a complex mixture of particulate matter, gases and chemicals, has been linked to numerous health issues, primarily affecting the respiratory and cardiovascular systems. However, emerging evidence suggests that wildfire smoke exposure also has profound effects on the immune system. This review aims to synthesize current knowledge on how wildfire smoke exposure affects the human immune system, including acute and chronic impacts, underlying mechanisms and potential long-term consequences. The review discusses the role of inflammation, oxidative stress and immune cell modulation in response to wildfire smoke, highlighting the need for further research to fully understand these effects.

Improvement of Engine Combustion and Emission Characteristics by Fuel Property Modulation

The sustainability of diesel engines has come to the forefront of research with the growing global interest in reducing greenhouse gas emissions and improving energy efficiency. The aim of this paper is to support the goal of sustainable development by improving the volatile properties of diesel fuel to promote cleaner combustion in engines. In order to study the effect of diesel fuel volatility on spraying, combustion, and emission, the tests were carried out with the help of the constant volume chamber (CVC) test rig and an engine test rig, respectively. CVC test: A high-speed video camera recorded the spray characteristics of different volatile fuels in a constant-volume combustion bomb. The effects of different rail pressures and ambient back pressures on the spray characteristics were investigated. Engine test: The combustion and emission characteristics of different volatile diesel fuels under different load conditions (25%, 50%, 75%) were investigated in a four-stroke direct-injection diesel engine with the engine speed fixed at 2000 rpm. The test results show that as the rail pressure increases and the ambient pressure decreases, the spray characteristics of the fuels tend to increase; for the more volatile fuels, although reducing the spray tip penetration, the spray projected area and spray cone angle increase, which is conducive to improving the homogeneity of the fuel and air mixing in the cylinder. The improvement of fuel volatility can form more and better-quality mixtures within the ignition delay time (ID), resulting in a 1–2% increase in peak cylinder pressure and a 2–4% increase in peak heat release. For different loads, pre-injection heat release is generated to redefine the ID and combustion duration (CD). Improved fuel volatility effectively reduces carbon monoxide (CO) emissions by about 8–10% and hydrocarbon (HC) emissions by about 13–16%, but it increases nitrogen oxide (NOx) emissions by about 8–11%. Analyzing from the perspective of particulate matter (PM), combined with the aromatic content of volatile fuels, it is recommended to use fuels with moderate volatility and aromatic content under low load conditions, and at medium to large loads, the volatility of the fuel has less weight on particulates and more weight on aromatics, so it is desirable to use the fuel with the lowest volatility and lowest aromatic content of the fuel selected.

Monitoring Air Quality in Bhopal: A Comparative Study of Pollutant Levels at Hamidia Road Chowk and T.T. Nagar in 2022

Urban air pollution is a growing environmental and health challenge in developing countries, driven by industrialization, enlargement of vehicular traffic, and population density. This study focuses on two distinct monitoring sites in Bhopal, India: Hamidia Road Chowk, characterized by high traffic density, and T.T. Nagar, a densely populated residential area. Monthly data for 2022 on key pollutants, including particulate matter (PM10 and PM2.5), sulfur dioxide (SO2), nitrogen oxides (NO2), carbon monoxide (CO), ozone (O3), and heavy metals, were analysed to define seasonal variations and conformity with the National Ambient Air Quality Standards (NAAQS). Findings indicate higher pollutant concentrations in the winter and early summer, correlating with atmospheric conditions and enlargement emissions during these periods. Notably, pollutant levels frequently exceeded NAAQS limits, posing significant health risks to urban populations. The results underscore the significance of continuous air property monitoring and the implementation of targeted emission control measures, especially in high-traffic and densely populated areas. This study contributes to the perception of air pollution dynamics in rapidly urbanizing cities and provides a foundation for informed policy-making to improve urban air quality.

Urban aerosol particulate matter promotes cellular senescence through mitochondrial ROS-mediated Akt/Nrf2 downregulation in human retinal pigment epithelial cells

Urban aerosol particulate matter (UPM) is widespread in the environment, and its concentration continues to increase. Several recent studies have reported that UPM results in premature cellular senescence, but few studies have investigated the molecular basis of UPM-induced senescence in retinal pigment epithelial (RPE) cells. In this study, we primarily evaluated UPM-induced premature senescence and the protective function of nuclear factor erythroid 2-related factor 2 (Nrf2) in human RPE ARPE-19 cells. The findings indicated that UPM exposure substantially induced premature cellular senescence in ARPE-19 cells, as observed by increased β-galactosidase activity, expression levels of senescence-associated marker proteins, and senescence-associated phenotypes. Such UPM-induced senescence is associated with mitochondrial oxidative stress-mediated phosphatidylinositol 3’-kinase/Akt/Nrf2 downregulation. Sulforaphane-mediated Nrf2 activation Sulforaphane-mediated upregulation of phosphorylated Nrf2 suppressed the decrease in its target antioxidant gene, NAD(P)H quinone oxidoreductase 1, under UPM, which notably prevented ARPE-19 cells from UPM-induced cellular senescence. By contrast, Nrf2 knockdown exacerbated cellular senescence and promoted oxidative stress. Collectively, our results demonstrate the regulatory role of Nrf2 in UPM-induced senescence of RPE cells and suggest that Nrf2 is a potential molecular target.

Assessing Particulate Matter Deposition and Resuspension by Living Wall Systems in a Wind Tunnel Setup

This study examines the particulate matter (PM) capture capacity of living wall systems (LWSs), focusing on leaf traits that facilitate PM deposition. Six LWS designs, differing in structure and substrate, were tested under constant airflow conditions with and without additional PM. Results showed that planter-based LWSs reduced PM0.1 by 2% and PM2.5 by 4%, while a textile LWS reduced PM0.1 by 23% and PM2.5 by 5%, though geotextile textile increased PM by 11% for both fractions. A moss substrate LWS worsened air quality, raising PM0.1 by 2% and PM2.5 by 5%. Magnetic analysis of leaf-deposited PM (SIRM) revealed species-specific differences (p < 0.001), with SIRM values ranging from 5 ± 1 µA to 260 ± 1 µA and higher PM accumulation in plants with lower specific leaf areas. No differences were observed in SIRM between deposition and resuspension phases, indicating the PM source lacked sufficient magnetisable particles. The findings highlight the potential of LWSs in urban environments for air quality improvement but underscore the importance of selecting suitable LWS structures and plant species.

Influence of climatic conditions on particulate emissions in mixed traffic conditions across various pavement types

Non-exhaust emissions containing particulate matter (PM), as indicated by PM2.5 and PM10, poses significant health, environmental, and climatic risks. This study investigates the impact of temperature and humidity on PM concentrations across different pavement types (asphalt and cement concrete) under mixed traffic conditions. Utilizing a sensor based portable air quality monitor, air quality data were collected over multiple seasons, encompassing winter, pre-monsoon, monsoon, and post-monsoon periods. The results reveal a strong correlation between PM levels and meteorological conditions, with higher temperatures and lower humidity contributing to elevated PM concentrations, particularly during the pre-monsoon season. Conversely, monsoon rains effectively reduce PM levels. The study also highlights the variations in the PM2.5/PM10 ratio between pavement types, with cement concrete showing a consistently higher ratio, indicating a greater prevalence of fine particulates. These findings underscore the necessity of season-specific air quality management strategies, considering the influence of both pavement type and environmental factors on PM emissions.

Association of ambient particulate matter (PM2.5) with reduced sex ratio at birth after the implementation of a rapid transit system in Taipei, Taiwan

ABSTRACT Sex ratio at birth (SRB) is a simple, noninvasive way to monitor the reproductive health of a population. Apparently only a few studies have assessed the relationship between ambient air pollution and SRBs. The studies that investigated this relationship have yielded inconsistent results. Ambient air pollution levels, including particulate matter (PM2.5) levels, have decreased in Taipei city after a mass rapid transit (MRT) system commenced operations in 1996. The aim of this study was to determine whether the changes in levels of PM2.5 after the implementation of the MRT system in Taipei may have influenced the concurrent alterations noted in the SRB. In order to assess this potential association, annual numbers of male and female births were obtained from Taiwan’s Department of Household Registration, Ministry of Interior Affairs from 1992 to 2023. Mean yearly SRBs were calculated for 4 time periods, 1992–1995, 1996–2004, 2005–2015, and 2016–2023. Linear logistic regression was employed to evaluate the variation in officially reported PM2.5 levels during those periods and alterations in the ratios. The ratios for time periods 1 to 4 were 52.61%, 52.22%, 51.78%, and 51.67%, respectively. Compared to Period 1 (pre-MRT), the odds ratios for Periods 2, 3, and 4 were 0.98 (0.97–0.99), 0.97 (0.96–0.98), and 0.96 (0.95–0.98), respectively. The trend toward the decreased SRB was found to be gradual but significant.

A sustainable Response Surface Methodology and Analytic Hierarchy Process - Weighted Aggregated Sum Product Assessment model to Evaluate Performance and Emissions Characteristics of Diesel engine using Clove Oil Biodiesel Blend

Abstract Replacing diesel with biodiesel generally results in a decrease in exhaust emissions like carbon monoxide, hydrocarbon, particulate matter, and carbon dioxide. However, nitrogen oxide emissions show increasing trends. On the other hand, a decrease in nitrogen oxide emissions has been found using various additives with diesel and biodiesel blends. In this work the experimentations are carried out on diesel, B30 (70% v/v diesel+30% v/v biodiesel), and the B30CL1000 (70% v/v diesel+30% v/v biodiesel+1000 ppm clove oil) to evaluate the performance and emissions of diesel engine. The Response Surface Methodology based approach has been applied to evaluate the effect of different engine operating parameters on engine performance and emission while fueled with the B30CL1000 fuel blend. Further, the Analytic Hierarchy Process - Weighted Aggregated Sum Product Assessment method has been applied to identify the optimal setting of the parameters and rank the optimal engine operating range for the B30CL1000 blend. From results, elicited that the accumulation of 1000 ppm of antioxidant (clove oil) additives in the B30 blend resulted in a reduction in the brake-specific fuel consumption by up to 11.5% at higher loads. Brake thermal efficiency increased by 16.3% at low load conditions for the B30CL1000 blend. After that the B30CL1000 blend showed a 2% drop in carbon monoxide emission at higher loads and the decreased nitrogen oxide emission for the B30CL1000 blend has been also reported as 12% at low loads and 2% at higher loads which follows a similar trend as exhaust gas temperature. The 5th experimental run having CR (17), EGR (0%) and Load (12kg) has been ranked as 1.

Associations of smoke-free policies in multi-unit housing with smoking behavior and second-hand smoke exposure: A systematic review.

Although considerable progress has been made regarding the implementation of smoke-free policies (SFPs), many people continue to be exposed to second-hand smoke (SHS) in the home environment. The aim of this study was to conduct a systematic review on the association of SFPs in multi-unit housing (MUH) with smoking behavior and SHS exposure. In August 2022, we searched five online databases: PubMed, Embase, Web of Science, PsycINFO and CENTRAL. Keywords included terms for SFPs, MUH, smoking behavior and exposure to SHS. We searched for studies that focused on regular combustible cigarettes. Due to the high heterogeneity in methodology and outcomes of the included studies, a meta-analysis was not performed. Our search yielded 4750 articles. All of them were screened (24 based on full-text), and 17 met the inclusion criteria. All studies were published between 2001 and 2022. Most studies were conducted in the United States (n = 16) and used a cross-sectional design (n = 7) or a longitudinal design (n = 7). Seven studies evaluated smoking behavior. Five of them reported that SFPs in MUH were statistically significantly associated with decreases in either current smoking, smoking quantity, smoking frequency or smoking cessation. Fourteen studies evaluated exposure to SHS. Ten reported that SFPs in MUH were statistically significantly associated with decreases in self-reported exposure to SHS, airborne nicotine levels and particulate matter levels. Smoke-free policies in multi-unit housing appear to be associated with reduced smoking behavior and second-hand smoke exposure. Successful implementation depends on accessible cessation support and effective enforcement.

Characterizing regional oceanography and bottom environmental conditions at two contrasting sponge grounds on the northern Labrador Shelf

Abstract. Deep-sea sponge grounds are distributed globally and are considered hotspots of biological diversity and biogeochemical cycling. To date, little is known about the environmental conditions that allow high sponge biomass to develop in the deep sea. Here, we characterize oceanographic conditions at two contrasting sites off the northern Labrador Shelf with respective high and low sponge biomass. Data were collected by year-long benthic lander deployments equipped with current meters, a turbidity and chlorophyll-a measuring device, and a sediment trap. Additionally, regional oceanography was described by analysing vertical conductivity–temperature–depth (CTD) casts, Argo float profiles, and surface buoy drifter data for the northern Labrador Shelf from 2005 to 2022. The stable isotopic composition of benthic fauna was determined to investigate food web structure at the sponge grounds. Our results revealed strong (0.26±0.14 m s−1; mean ± SD) semidiurnal tidal currents at the high-sponge-biomass site but 2-fold weaker currents (0.14±0.08 m s−1; mean ± SD) at the low-sponge-biomass site. Tidal analysis suggests that kinetic energy is dissipated from barotropic tide to baroclinic tide/turbulence at the high-sponge-biomass site, which could enhance food availability for benthic organisms. Bottom nutrient concentrations were elevated at the high-sponge-biomass site, which would benefit growth in deep-sea sponges. Organic matter flux to the seafloor was increased at the high-sponge-biomass site and consisted of fresher material. Finally, both sponge grounds demonstrated tight benthic–pelagic coupling prior to the onset of stratification. Stable isotope signatures indicated that soft corals (Primnoa resedaeformis) fed on suspended particulate organic matter, while massive sponges (Geodia spp.) likely utilized additional food sources. Our results imply that benthic fauna at the high-sponge-biomass site benefit from strong tidal currents, which increase the food supply, and favourable regional ocean currents, which increase the nutrient concentration in bottom waters.

Cost-effective control of air pollution in South Asia: Modeling and policy applications

Abstract Air pollution poses a critical environmental challenge to sustainability, environmental health and public well-being in the South Asia Region (SAR). This study identifies hotspots of fine particulate matter (PM2.5) across SAR, analyzing both concentration levels and exposure. Moreover, it aims at a comprehensive understanding of the various sources of air pollution in these critical areas and a systematic evaluation of the costs and benefits of relevant policy actions, utilizing the GAINS modeling framework. A wide variety of sources contribute to PM2.5 levels in ambient air, and effective air quality management requires a balance of measures across these sources. Current environmental policies, while effective in decoupling emissions from economic growth in SAR, are insufficient to achieve significant reductions in ambient PM2.5 concentrations. However, considerable scope exists for further measures beyond current policies that could help to bring the WHO Interim Targets (IT-1) for PM2.5 closer. Finally, it is shown that cost-optimal strategies for air quality management can achieve significant cost savings compared to conventional approaches; however, they require collaboration between states, regions and countries in South Asia.