Agricultural Waste Burning Research Articles

Air pollutants and primary liver cancer mortality: a cohort study in crop-burning activities and forest fires area.

Northern Thailand experiences high levels of air pollution in the dry season due to agricultural waste burning and forest fires. Some air pollutants can enter the bloodstream, and the liver has the role of detoxifying these along with other harmful substances. In this study, we assessed the effects of long-term exposure to air pollutants on liver cancer mortality in this area. A cohort of 10,859 primary liver cancer patients diagnosed between 2003 and 2018 and followed up to the end of 2020 were included in the study. Extended time-varying covariates of the annually averaged pollutant concentrations updated each year were utilized. The associations between air pollutants and mortality risk were examined by using a Cox proportional hazard model. Metastatic cancer stage had the highest adjusted hazard ratio (aHR) of 3.57 (95% confidence interval (CI):3.23-3.95). Being male (aHR = 1.10; 95% CI: 1.04-1.15), over 60 years old (aHR = 1.16; 95% CI: 1.11-1.21), having a history of smoking (aHR = 1.16; 95%CI: 1.11-1.22), and being exposed to a time-updated local concentration of PM2.5 of 40 μg/m3 (aHR = 1.10; 95% CI: 1.05-1.15) increased the mortality risk. We found that air pollution is one of several detrimental factors on the mortality risk of liver cancer.

Source attribution of carbon monoxide over Northern India during crop residue burning period over Punjab

National Capital Territory of Delhi and its satellite cities suffer from poor air quality during the post-monsoon months of October–November. In this study, a novel attempt is made to estimate the contribution of different emission sources (industrial, residential, power generation, transportation, biomass burning, photochemical production, lateral transport, etc.) towards the criteria air pollutant carbon monoxide (CO) concentration over North India. Multiple simulations of the WRF-Chem model with a tagged tracer approach with different inputs (6 anthropogenic emission inventories and 3 biomass burning emission inventories) were used. The model performance was evaluated against the MOPITT retrieved CO surface concentration. Analysis of model simulated CO over North India suggests that anthropogenic emissions contribute around 32–49% to surface CO concentration while crop residue burning contributes 27–44% of which 80% originates from Punjab. For Delhi, the contribution from anthropogenic sources is dominant (53–77%) of which 10–28% is from the domestic sector and 14–55% is from the transport sector. Agricultural waste burning contributes about 15–30% to Delhi's surface CO concentration (of which 75% originates from Punjab). Crop residue burning emission is a chief source of CO over Punjab with a contribution of about 56–76%. The results suggest that industrial, transport, and domestic sector activities are more responsible for increased CO levels over New Delhi and surrounding regions than crop residue burning over Punjab. Furthermore, critical meteorological parameters like 10 m wind speed, boundary layer height, 2 m temperature, total precipitation, and relative humidity were evaluated against CO concentration to understand their impact on CO distribution. Results conclude that deteriorating air quality over the North Indian region is caused by a combination of prevailing meteorological factors (such as slow winds, shallow mixing layer, and cold temperatures) and man-made emissions.

Eco-friendly, lightweight, and high-strength sandwich corrugated particleboard from tea oil camellia (Camellia oleifera Abel.) shells

This study investigates the potential of developing corrugated panels from tea oil camellia shell (TOCS), an abundant agricultural waste in the southern provinces of China, with an annual production of approximately 4 million tons, using experimental and computational methods. Hence, various corrugated geometries were designed using AutoCAD software, and finite element analysis (FEA) was conducted using Ansys Mechanical software to optimize the panel geometry based on TOCS engineering data. Bending performance simulations revealed that a trapezoidal geometry with a 3 mm edge radius exhibited superior bending performance. Therefore, this geometry was selected to fabricate corrugated panels of different densities to assess the impact of density variation. Mechanical characterization included evaluation of bending stiffness, maximum moment, total deflection, compression strength, ultimate strength, dowel bearing strength, and face screw resistance of the panels was performed. Furthermore, specific energy absorption and failure mechanisms of mechanical tests were analyzed. The results indicate that TOCS-based sandwich panels, characterized by their lightweight and sustainable nature, not only meet, or exceed the criteria specified in APA PS 2–10 for use as structural materials but also mitigate the environmental hazards associated with landfill disposal or burning of agricultural waste.

Global health costs of ambient PM2·5 from combustion sources: a modelling study supporting air pollution control strategies

Climate actions targeting combustion sources can generate large ancillary health benefits via associated air-quality improvements. Therefore, understanding the health costs associated with ambient fine particulate matter (PM2·5) from combustion sources can guide policy design for both air pollution and climate mitigation efforts. In this modelling study, we estimated the health costs attributable to ambient PM2·5 from six major combustion sources across 204 countries using updated concentration-response models and an age-adjusted valuation method. We defined major combustion sources as the sum of total coal, liquid fuel and natural gas, solid biofuel, agricultural waste burning, other fires, and 50% of the anthropogenic fugitive, combustion, and industrial dust source. Global long-term exposure to ambient PM2·5 from combustion sources imposed US$1·1 (95% uncertainty interval 0·8-1·5) trillion in health costs in 2019, accounting for 56% of the total health costs from all PM2·5 sources. Comparing source contributions to PM2·5 concentrations and health costs, we observed a higher share of health costs from combustion sources compared to their contribution to population-weighted PM2·5 concentration across 134 countries, accounting for more than 87% of the global population. This disparity was primarily attributed to the non-linear relationship between PM2·5 concentration and its associated health costs. Globally, phasing out fossil fuels can generate 23% higher relative health benefits compared to their share of PM2·5 reductions. Specifically, the share of health costs for total coal was 36% higher than the source's contributions to corresponding PM2·5 concentrations and the share of health costs for liquid fuel and natural gas was 12% higher. Other than fossil fuels, South Asia was expected to show 16% greater relative health benefits than the percentage reduction in PM2·5 from the abatement of solid biofuel emissions. In most countries, targeting combustion sources might offer greater health benefits than non-combustion sources. This finding provides additional rationale for climate actions aimed at phasing out combustion sources, especially those related to fossil fuels and solid biofuel. Mitigation efforts designed according to source-specific health costs can more effectively avoid health costs than strategies that depend solely on the source contributions to overall PM2·5 concentration. The Health Effects Institute, the National Natural Science Foundation of China, and NASA.

Origins of the seasonal variability of PM2.5 sources in a rural site in Northern France

Air quality in rural areas results from the crossing of aged air masses transported from urban areas with local emissions dominated by agriculture and vegetation. The result is a complex mixture of primary and secondary atmospheric species, coming from varied sources and geographical areas. We implemented a methodology for deconvoluting and determining the geographical origins of the main aerosol sources impacting a typical rural area of northern France. A one-year field campaign was conducted in a rural site located between Paris and Brussels from March 2018 to February 2019. Hourly-based observations of inorganic and organic precursor gases and PM2.5 speciation were collected using on-line instrumentation. The annual PM2.5 concentrations of 12.2 ± 9.23 μg m−3 were explained by four sources extracted through positive matrix factorization analyses: combustion (40.2%), NO3-rich (26.8%), SO4-rich (18%) and mixed aged marine (15%). The combustion and SIA-rich sources drive 85 % of the yearly PM2.5 mass and variability. The combustion factor was most prominent during winter (53.3% of PM2.5 mass) due to high contributions from local and regional transport of biomass burning pollutants (winter OC/EC = 6.0; OC-to-OM factor = 2.05). In summer, it was most likely driven by secondary organic aerosol production and agricultural waste burning events (summer OC/EC = 8.6; OC-to-OM factor = 1.85). Comparing with other regional sites, we observed a strong regional background of carbonaceous particles regardless of the site typology. The SIA fraction is dominated by the NO3-rich source compared to the SO4-rich source. In spring, NO3-rich particles dominate PM2.5 (36.9%) due to intense agricultural activity. The temporal variability is driven by transport processes from the Benelux area in a North-to-South gradient of decreasing concentrations. A minor proportion of the NH4NO3 observed seems to be due to the local effects of morning dew and photochemical oxidation of NO2 in the afternoon. HNO3 appears to be the limiting factor for local NH4NO3 formation. PM2.5 toxicity in rural areas with low population densities should be not only addressed based on mass concentration, but also considering the chemical composition of particles as people from rural environments are exposed to high contributions from biomass burning sources and secondary inorganic aerosols triggered by the NH3 excess.

Peaks, sources, and immediate health impacts of PM2.5 and PM1 exposure in Indonesia and Taiwan with microsensors.

Microsensors have been used for the high-resolution particulate matter (PM) monitoring. This study applies PM and health microsensors with the objective of assessing the peak exposure, sources, and immediate health impacts of PM2.5 and PM1 in two Asian countries. Exposure assessment and health evaluation were carried out for 50 subjects in 2018 and 2019 in Bandung, Indonesia and for 55 subjects in 2019 and 2020 in Kaohsiung, Taiwan. Calibrated AS-LUNG sets and medical-certified RootiRx® sensors were used to assess PM and heart-rate variability (HRV), respectively. Overall, the 5-min mean exposure of PM2.5 and PM1 was 30.4 ± 20.0 and 27.0 ± 15.7 µg/m3 in Indonesia and 14.9 ± 11.2 and 13.9 ± 9.8 µg/m3 in Taiwan, respectively. The maximum 5-min peak PM2.5 and PM1 exposures were 473.6 and 154.0 µg/m3 in Indonesia and 467.4 and 217.7 µg/m3 in Taiwan, respectively. Community factories and mosquito coil burning are the two most important exposure sources, resulting in, on average, 4.73 and 5.82 µg/m3 higher PM2.5 exposure increments for Indonesian subjects and 10.1 and 9.82 µg/m3 higher PM2.5 exposure for Taiwanese subjects compared to non-exposure periods, respectively. Moreover, agricultural waste burning and incense burning were another two important exposure sources, but only in Taiwan. Furthermore, 5-min PM2.5 and PM1 exposure had statistically significantly immediate impacts on the HRV indices and heart rates of all subjects in Taiwan and the scooter subjects in Indonesia with generalized additive mixed models. The HRV change for a 10 µg/m3 increase in PM2.5 and PM1 ranged from -0.9% to -2.5% except for ratio of low-high frequency, with greater impacts associated with PM1 than PM2.5 in both countries. This work highlights the ability of microsensors to capture high peaks of PM2.5 and PM1, to identify exposure sources through the integration of activity records, and to assess immediate changes in heart rate variability for a panel of approximately 50 subjects in Indonesia and Taiwan. This study stands out as one of the few to demonstrate the immediate health impacts of peak PM, complementing to the short-term (days or weeks) or long-term effects (months or longer) assessed in most epidemiological studies. The technology/methodology employed offer great potential for researchers in the resource-limited countries with high PM2.5 and PM1 levels.

Processing of hemp and cannabis residue into non-adhesive chipboards and wall panels

As woods are dwindling and agriculture waste burning causes severe air pollution and releases greenhouse gases, processing Hemp and lignocellulosic surplus materials into chipboards and other construction elements may substitute timber and reduce environmental pollution. The presented environmental-friendly technology can potentially process hemp and recycle residual materials into industrial woodchip boards and structural elements without the use of hazardous expensive resins. By applying cold plasma pre-treatment followed by the pressing stage acceptable wood chip standard physical properties are achieved. The irradiation dosage is probably optimal since once exceeding the dosage applied, wood disintegration starts; the process improvement may be related to the pressing configuration. Since the pressing temperature and duration are probably higher than required, the element that may still be aligned is the pressing pressure. Moreover, the positive correlation between sample strength and pressing pressure did not reach a steady state value even when pressing the sample to the maximum possible pressure allowed in the existing equipment (5.5 tons). It is suggested that a significant strength improvement will be attained by increasing the pressing pressure and decreasing the pressing temperature. It is assumed that 20 tons/m2 pressing pressure will be sufficient to attain the desired properties.

Review on Bio- Bricks

This paper reviews the utilization of Agricultural waste for making Bio Bricks and other construction materials to reduce burning and disposal problems of Agricultural waste due to increasing Air Pollution and make economic and environment efficient construction material. Agricultural waste burning is a significant source of pollution in India, especially after the harvesting season. Bio-bricks was developed as an alternative and sustainable building material that is made up of agricultural waste. And at the same time will also lead to the reduction of air pollution and create new jobs at the grassroots level. The use of Agricultural waste in construction materials is one of new way to deal with disposal and burning of Agricultural waste. India is home to some of the most polluted cities of the world in terms of its air quality. Data shows that around 20 out of the 30 most polluted cities of the world are in India. So the study provides green building material through Agricultural waste for sustainable development of Bio Bricks. Some additional work in this project can be done which will help environment with decreasing Air pollution by reducing of Agricultural waste. Bio-bricks can be developed as a carbon- negative, sustainable and economically viable material for construction. With the right kind of product development and incentives, it can diversify into numerous products satisfying the needs of an ecologically sensitive future

Combined use of principal component analysis/multiple linear regression analysis and artificial neural network to assess the impact of meteorological parameters on fluctuation of selected PM2.5-bound elements.

Based on the data of the State of Global Air (2020), air quality deterioration in Thailand has caused ~32,000 premature deaths, while the World Health Organization evaluated that air pollutants can decrease the life expectancy in the country by two years. PM2.5 was collected at three air quality observatory sites in Chiang-Mai, Bangkok, and Phuket, Thailand, from July 2020 to June 2021. The concentrations of 25 elements (Na, Mg, Al, Si, S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Br, Sr, Ba, and Pb) were quantitatively characterised using energy-dispersive X-ray fluorescence spectrometry. Potential adverse health impacts of some element exposures from inhaling PM2.5 were estimated by employing the hazard quotient and excess lifetime cancer risk. Higher cancer risks were detected in PM2.5 samples collected at the sampling site in Bangkok, indicating that vehicle exhaust adversely impacts human health. Principal component analysis suggests that traffic emissions, crustal inputs coupled with maritime aerosols, and construction dust were the three main potential sources of PM2.5. Artificial neural networks underlined agricultural waste burning and relative humidity as two major factors controlling the air quality of Thailand.

Community Perspectives on Barriers and Facilitators to Haap Reduction; Situating Practices in Context

BACKGROUND: Sub-Saharan Africa (SSA) bears the greatest burden of adverse health outcomes linked to Household and Ambient Air Pollution (HAAP) with mortality rate of 187.1 per 100,000. Previous HAAP studies in SSA have focused on top-down supply based research on effectiveness of improved cook-stoves (ICS), their uptake, sustainability and safety among others. Little demand led HAAP research driven by community and bottom-up perspectives of the targeted poor communities has been done.. We conducted a qualitative study aimed at understanding community perspectives on barriers and facilitators to uptake of HAAP reduction strategies in a rural village in southern Malawi. METHODS: Our study was baseline of a larger project that used acommunity-led-mixed-methods participatory settings approach’ to determine if a suite of interventions would reduce HAAP in a Malawian rural setting. Our data collection approaches included focus group discussions (FGDs), and photo-voice with consenting community members.. Data on community practices contributing to household and ambient pollution facilitators and barriers were isolated. FGDs were recorded, transcribed verbatim in the local language and translated into English using standard procedures. Transcripts and notes were analyzed thematically aided by Dedoose qualitative data analysis software (version 9.0.54). RESULTS: A majority of study participants were aware of health and environmental risks associated with behaviours and practices such as usage of the traditional three-stone-fire for cooking and open burning of household and agricultural waste. However, limited access to improved cook stoves due to availability, and affordability were cited as key barriers to adoption and uptake.. On the other hand, study participants mentioned perceived health benefits from using HAAP reduction technologies, their efficiency when cooking or lighting, portability and durability among others as facilitators of adoption and uptake. CONCLUSION: Studies and interventions aimed to empower, change or modify HAAP related health risk in poor communities of SSA such as Nsungwi village in Malawi are integral for equity in development and for targeted gains in global health. The current study presents hope that if grassroots communities are empowered, involved and given the opportunity to decide, map out and guide their developmental options; development change is possible.. The study also demonstrates that if communities are allowed to own projects there is room for sustainability of efforts.

Regional sources of NH3, SO2 and CO in the Third Pole

The Third Pole (TP) is a high mountain region in the world, and is well-known for its pristine environment, but recent development activities in the region have degraded its air quality. Here, we investigate the spatial and temporal changes of the air pollutants ammonia (NH₃), sulphur dioxide (SO₂) and carbon monoxide (CO) in TP, and reveal their sources using satellite measurements and emission inventory. We observe a clear seasonal cycle of NH3 in TP, with high values in summer and low values in winter. The intense agriculture activities in the southern TP are the cause of high NH₃ (6–8 × 1016 molec./cm2) there. Similarly, CO shows a distinct seasonal cycle with high values in spring in the southeast TP due to biomass burning. In addition, the eastern boundary of TP in the Sichuan and Qinghai provinces also show high values of CO (about 1.5 × 1018 mol/cm2), primarily owing to the industrial activities. There is no seasonal cycle found for SO₂ distribution in TP, but relatively high values (8–10 mg/m2) are observed in its eastern boundary. The high-altitude pristine regions of inner TP are also getting polluted because of increased human activities in and around TP, as we estimate positive trends in CO (0.5–1.5 × 1016 mol/cm2/yr) there. In addition, positive trends are also found in NH₃ (0.025 × 1016 molec./cm2/yr) during 2008–2020 in most regions of TP and SO₂ (about 0.25–0.75 mg/m2/yr) in the Sichuan and Qinghai region during 2000–2020. As revealed by the emission inventory, there are high anthropogenic emissions of NH3, SO2 and CO within TP. There are emissions of pollutants from energy sectors, oil and refinery, agriculture waste burning and manure management within TP. These anthropogenic activities accelerate the ongoing development in TP, but severely erode its environment.

Quantifying effects of long-range transport of NO2 over Delhi using back trajectories and satellite data

Abstract. Exposure to air pollution is a leading public health risk factor in India, especially over densely populated Delhi and the surrounding Indo-Gangetic Plain. During the post-monsoon seasons, the prevailing north-westerly winds are known to influence aerosol pollution events in Delhi by advecting pollutants from agricultural fires as well as from local sources. Here we investigate the year-round impact of meteorology on gaseous nitrogen oxides (NOx=NO+NO2). We use bottom-up NOx emission inventories (anthropogenic and fire) and high-resolution satellite measurement based tropospheric column NO2 (TCNO2) data, from S5P aboard TROPOMI, alongside a back-trajectory model (ROTRAJ) to investigate the balance of local and external sources influencing air pollution changes in Delhi, with a focus on different emissions sectors. Our analysis shows that accumulated emissions (i.e. integrated along the trajectory path, allowing for chemical loss) are highest under westerly, north-westerly and northerly flow during pre-monsoon (February–May) and post-monsoon (October–February) seasons. According to this analysis, during the pre-monsoon season, the highest accumulated satellite TCNO2 trajectories come from the east and north-west of Delhi. TCNO2 is elevated within Delhi and the Indo-Gangetic Plain (IGP) to the east of city. The accumulated NOx emission trajectories indicate that the transport and industry sectors together account for more than 80 % of the total accumulated emissions, which are dominated by local sources (>70 %) under easterly winds and north-westerly winds. The high accumulated emissions estimated during the pre-monsoon season under north-westerly wind directions are likely to be driven by high NOx emissions locally and in nearby regions (since NOx lifetime is reduced and the boundary layer is relatively deeper in this season). During the post-monsoon season the highest accumulated satellite TCNO2 trajectories are advected from Punjab and Haryana, where satellite TCNO2 is elevated, indicating the potential for the long-range transport of agricultural burning emissions to Delhi. However, accumulated NOx emissions indicate local (70 %) emissions from the transport sector are the largest contributor to the total accumulated emissions. High local emissions, coupled with a relatively long NOx atmospheric lifetime and shallow boundary layer, aid the build-up of emissions locally and along the trajectory path. This indicates the possibility that fire emissions datasets may not capture emissions from agricultural waste burning in the north-west sufficiently to accurately quantify their influence on Delhi air quality (AQ). Analysis of daily ground-based NO2 observations indicates that high-pollution episodes (>90th percentile) occur predominantly in the post-monsoon season, and more than 75 % of high-pollution events are primarily caused by local sources. But there is also a considerable influence from non-local (30 %) emissions from the transport sector during the post-monsoon season. Overall, we find that in the post-monsoon season, there is substantial accumulation of high local NOx emissions from the transport sector (70 % of total emissions, 70 % local), alongside the import of NOx pollution into Delhi (30 % non-local). This work indicates that both high local NOx emissions from the transport sector and the advection of highly polluted air originating from outside Delhi are of concern for the population. As a result, air quality mitigation strategies need to be adopted not only in Delhi but in the surrounding regions to successfully control this issue. In addition, our analysis suggests that the largest benefits to Delhi NOx air quality would be seen with targeted reductions in emissions from the transport and agricultural waste burning sectors, particularly during the post-monsoon season.

Modeling study of PM2.5 pollution episode of early spring 2019 in Hokkaido, Japan caused by biomass burning in Northeast China

Biomass burning (BB), in particular agricultural waste burning (Agri-BB), occurs at random locations, scales, and times. These factors make it challenging to detect Agri-BB accurately through satellite observations. Thus, the BB emission inventories using satellite observation data have uncertainties for their emission estimation approach and cause poor model performance for air pollutants including PM2.5. We utilized the two BB emission inventories, GFEDv4.1s and FINNv2.5 with the CMAQ model to simulate the PM2.5 heavy pollution episode in Hokkaido 2019. To estimate Agri-BB contributions, we conducted three simulation cases for each BB emission inventory: with and without Agri-BB emission, and the boosted Agri-BB emission cases. The baseline simulation failed to capture the temporal and spatial variation patterns of PM2.5. Meanwhile, the boosted Agri-BB case could show favorable performance for PM2.5 concentrations. These results indicated that the two BB emission inventories underestimated Agri-BB emissions. In the two boosted Agri-BB cases, the PM2.5 contributions from Agri-BB accounted for more than 50% during the episode. Moreover, high PM2.5 emissions were found in Northeast China and its surrounding regions similar to the two boosted Agri-BB cases. Consequently, the results revealed that Agri-BB emissions during the episode were significantly derived from the agricultural areas in Northeast China.

Levels of Polycyclic Aromatic Hydrocarbons (PAHs) in Sediments from Dadin Kowa Dam, Gombe State, Nigeria

The large class of organic compounds known as polycyclic aromatic hydrocarbons (PAHs) contains two or more fused aromatic (benzene) rings. The burning of agricultural waste and incomplete combustion or pyrolysis of organic material (i.e., emissions from cars, home heating, or cooking) are the two main anthropogenic sources of emissions. Humans may encounter PAHs through inhalation, dermal exposure, or eating food that has been contaminated. According to epidemiological studies, PAHs are linked to poorer lung function, worsening asthma, cancer, higher rates of obstructive lung diseases, and cardiovascular diseases. This raised questions and called for investigation and awareness of the risks posed by these pollutants. Herein, sediment was collected from Dadin Kowa Dam, Gombe State, Nigeria, during the dry and rainy seasons for assessing the levels of polycyclic aromatic hydrocarbon (PAH) residues. The collected samples were extracted, cleaned up, and analyzed for the presence of PAHs using GC-MS equipped with a flame ionization detector. The result shows that concentrations of all the PAHs studied in the sediment samples during the dry season ranged from 6.40E-01 to 1.09E +00 mg/kg, while during the rainy season they ranged from 4.60E+01 to 5.42E +01 mg/kg. The rainy season showed the highest total concentration of all the PAHs studied when compared to the dry season. The result from the diagnostic ratio showed the ratios of Ant/(Ant + Phe) ranged from 0.40-0.52; 0.33-0.58 Fla/(Fla + Pyr); and 0.08-0.5 BaA/(BaA + Chr). Generally, the findings of this work proved that pyrogenic inputs contributed to PAH contamination in the sediment from the study area. The result from the mean effect medium quotient (m-ERM-q) in the sediment samples ranged from 4.52E-05 to 1.41E+01 for both seasons, with a mean value of 5.13E-02.

Eco-efficient cementitious composites using waste cellulose fibers: Effects on autogenous shrinkage, strength and energy absorption capacity

Waste cellulose fibers (WCF) constitute a large portion of biomass which are often burned during removal processing. As a sustainable approach to reduce the negative environmental impacts of the agricultural waste burning, substituting WCF for synthetic and other fibers that are routinely used to reinforce the concrete matrix presents a major opportunity. In this study, the WCF used show groundbreaking potential for mitigating the autogenous shrinkage of high strength cementitious mixes, due to the high water-retention capacity of the fibers, 947%, which perform as internal curing agents and alleviate the internally induced stresses. The reinforcing efficiency of the WCF led to outstanding improvements in the flexural strength and energy absorption capacity of the WCF reinforced mortars, especially at early ages. Based on the findings, WCF are an attractive option as an eco-component in concrete that offers completely new prospects for the construction industry in efficiently mitigating the potential of autogenous shrinkage.

Very high particulate pollution over northwest India captured by a high-density in situ sensor network

Exposure to particulate matter less than 2.5 µm in diameter (PM2.5) is a cause of concern in cities and major emission regions of northern India. An intensive field campaign involving the states of Punjab, Haryana and Delhi national capital region (NCR) was conducted in 2022 using 29 Compact and Useful PM2.5 Instrument with Gas sensors (CUPI-Gs). Continuous observations show that the PM2.5 in the region increased gradually from < 60 µg m−3 in 6–10 October to up to 500 µg m−3 on 5–9 November, which subsequently decreased to about 100 µg m−3 in 20–30 November. Two distinct plumes of PM2.5 over 500 µg m−3 are tracked from crop residue burning in Punjab to Delhi NCR on 2–3 November and 10–11 November with delays of 1 and 3 days, respectively. Experimental campaign demonstrates the advantages of source region observations to link agricultural waste burning and air pollution at local to regional scales.

Spatial heterogeneity in global atmospheric CO during the COVID–19 lockdown: Implications for global and regional air quality policies

The COVID–19 lockdown (LD) provided a unique opportunity to examine the changes in regional and global air quality. Changes in the atmospheric carbon monoxide (CO) during LD warrant a thorough analysis as CO is a major air pollutant that affects human health, ecosystem and climate. Our analysis reveals a decrease of 5–10% in the CO column during LD (April–May 2020) compared to the pre-lockdown (PreLD, March 2020) periods in regions with high anthropogenic activity, such as East China (EC), Indo-Gangetic Plain (IGP), North America, parts of Europe and Russia. However, this reduction did not occur in the regions of frequent and intense wildfires and agricultural waste burning (AWB). We find high heterogeneity in the CO column distributions, from regional to city scales during the LD period. To determine the sources of CO emissions during LD, we examined the ratios of nitrogen dioxide (NO2), sulfur dioxide (SO2) to CO for major cities in the world. This facilitated the identification of contributions from different sources; including vehicles, industries and biomass burning during LD. The comparison between CO levels during the LD and PreLD periods indicates a notable reduction in the global tropospheric CO, but no significant change in the stratosphere. It is found that CO emissions decreased during LD in the hotspot regions, but rebounded after the LD restrictions were lifted. This study, therefore, highlights the importance of policy decisions and their implementations in the global and regional scales to improve the air quality, and thus to protect public health and environment.

Adoption of cleaner technologies and reduction in fire events in the hotspots lead to global decline in carbon monoxide

Carbon Monoxide (CO) is not a greenhouse gas (GHG), but has the capacity to change atmospheric chemistry of other GHGs such as methane and ozone, and therefore indirectly affects Earth's radiative forcing of the GHGs and surface temperature. Here, we use the CO mixing ratio at 850 hPa from the Tropospheric Emission Spectrometer (TES) reanalysis and the Measurement of Pollution in the Troposphere (MOPITT) satellite measurements for the period 2005–2019 to examine the spatio-temporal changes in CO across the latitudes. We find a substantial decrease in global CO, about −0.21 ± 0.09 ppb/yr (−0.23 ± 0.12%/yr) with the TES data and about −0.36 ± 0.07 ppb/yr (−0.45 ± 0.08%/yr) with the MOPITT satellite measurements during the study period. The highest CO decreasing trend is observed in Eastern China (−2.7 ± 0.37 ppb/yr) followed by Myanmar (−2.142 ± 0.59 ppb/yr) and South America (−1.08 ± 0.82 ppb/yr). This negative trend in CO is primarily due to the decrease in biomass burning and stringent environmental regulations in the respective regions and countries. The sources including road transport, which account for about 33.6% of CO emissions, followed by industries (18.3%) and agricultural waste burning (8.8%), might also be responsible for the reduction in CO due to the adaptation of improved emission control technology and regulations in the past decades from 2005 to 2019. Therefore, the study provides new insights on the current trends of global CO distribution and reasons for recent reduction in global CO emissions, which would be useful for future decision-making process to control air pollution.

Shift in Peaks of PAH‐Associated Health Risks From East Asia to South Asia and Africa in the Future

AbstractLung cancer risk from exposure to ambient polycyclic aromatic hydrocarbons (PAHs) is expected to change significantly by 2050 compared to 2008 due to changes in climate and emissions. Integrating a global atmospheric chemistry model, a lung cancer risk model, and plausible future emissions trajectories of PAHs, we assess how global PAHs and their associated lung cancer risk will likely change in the future. Benzo(a)pyrene (BaP) is used as an indicator of cancer risk from PAH mixtures. From 2008 to 2050, the population‐weighted global average BaP concentrations under all RCPs consistently exceeded the WHO‐recommended limits, primarily attributed to residential biofuel use. Peaks in PAH‐associated incremental lifetime cancer risk shift from East Asia (4 × 10−5) in 2008 to South Asia (mostly India, 2–4 × 10−5) and Africa (1–2 × 10−5) by 2050. In the developing regions of Africa and South Asia, PAH‐associated lung cancer risk increased by 30–64% from 2008 to 2050, due to increasing residential energy demand in households for cooking, heating, and lighting, the continued use of traditional biomass use, increases in agricultural waste burning, and forest fires, accompanied by rapid population growth in these regions. Due to more stringent air quality policies in developed countries, their PAH lung cancer risk substantially decreased by ∼80% from 2008 to 2050. Climate change is likely to have minor effects on PAH lung cancer risk compared to the impact of emissions. Future policies, therefore, need to consider efficient combustion technologies that reduce air pollutant emissions, including incomplete combustion products such as PAH.

Assessment of entrainment of key PAHs emanating from major combustion sources into the ambient air

Increasing health problems owing to air pollution is the major cause of concern in the present time, especially in regions with exceptionally high particulate matter (PM) namely Indo-Gangetic Plains (IGP). In the ambient PM, polycyclic aromatic hydrocarbons (PAHs) have been reported to be carcinogenic in nature and its dominant sources are diesel emissions, coal combustion, agricultural waste burning, wood, and cow-dung cake burning. The chemical characteristics of particulate-bound PAHs from all the mentioned sources, their intercomparison, and entrainment into the atmosphere have been assessed in this study. High-molecular weight (HMW) PAHs fraction is highest in emissions from coal combustion (∼95%), followed by agricultural waste burning (83%), wood burning (83%) and cow-dung cake (77%) combustion. Among all the PAH compounds, benzo (b,j) fluoranthene (B[bj]F) was found to be predominant (highest in wood combustion ∼20.3%) in all source samples except exhaust from diesel and bio-diesel engine installed with diesel oxidation catalyst (DOC). Dominant PAH compounds contributing to the carcinogenic potential (CP) are benzo (a) pyrene (B[a]P), dibenzo (a,h) anthracene (D[ah]A), benzo (b,j) fluoranthene (B[bj]F), benzo (a) anthracene (B[a]A) and indeno (1,2,3-c,d) pyrene (IP). Wood combustion (CP = 1.4 ± 0.8) emission is observed to be the most carcinogenic followed by coal combustion (0.8 ± 0.2), diesel exhaust emission (0.4 ± 0.3), cow-dung cake burning (0.2), and agricultural waste burning (0.2 ± 0.1). Further, the range of various diagnostic ratios for each of the source samples has been reported that can be utilized in future studies for more comprehensive source apportionment.