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Air Quality, Atmosphere & Health
Journal Prestige (SJR): 0.862  Citation Impact (citeScore): 3 Number of Followers: 9  Hybrid journal (It can contain Open Access articles)ISSN (Print) 1873-9326 - ISSN (Online) 1873-9318 Published by Springer-Verlag  [2468 journals]
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- Spatial variation, multi-meteorological factors and potential source
analysis of air pollutants in Chengdu megacity of Chengdu-Chongqing
economic circle-
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Abstract: Affected by unique topography, meteorological factors and high emission sources, it is crucial to have an in-depth understanding of the air pollution characteristics of Chengdu megacity. This research investigated the spatial evolution features of the six criteria pollutants in Chengdu from 2014 to 2020. The relationship between air pollutants and multi-meteorological factors also will be systematically elucidated. Together with the backward trajectory model, the potential source areas of PM2.5 and O3 were further simulated. The results revealed that there is spatial heterogeneity in the distribution of air pollution in Chengdu. Besides, the concentrations of PM2.5, PM10, SO2, NO2 and CO are only positively correlated with pressure. While, O3 only shows a negative correlation with relative humidity and pressure. Furthermore, regional transport is also one of the important contributing sources of PM2.5 and O3. This study can accurately grasp the status of regional air pollution, and provide accurate and feasible solutions for the collaborative reduction of air pollution in the Cheng-Yu area. Furthermore, it provides data references for exploring efficient air pollution control measures in complex terrain, and also accumulates some experience for the megacities of similar situations in the world. Graphical
PubDate: 2024-08-24
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- A critical review of NO2 and AOD in major Asian cities: challenges,
mitigation approaches and way forwards-
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Abstract: Abstract Atmospheric aerosols and nitrogen dioxide (NO2) are a global concern, especially in major Asian cities, because of their multiple impacts on climate, health, ecology, and the environment. Although many studies have been conducted individually, studies on the coupling of NO2 and Aerosol optical depth (AOD) in major Asian cities are still scarce. This study aims to critically evaluate the challenges of AOD and NO2 in Asia through a detailed discussion of the sources and mitigation solutions. The impact and intensity of these two pollutants are severe in countries such as India, China, Bangladesh, India, and Japan. China is the region with the highest AOD in the world. Increases in NO2 and AOD have been observed in the megacities of South Asia (e.g., Lahore, Dhaka, Mumbai, and Kolkata). East Asia (China, South Korea, and Japan) is a significant source of aerosols and their precursors, a complex mixture of coarse and small particles. Diesel vehicles are a significant contributor to NO2 emissions in many Asian cities. High population density, rapid urbanization, increasing energy demand, multiple sources, and the complex chemistry of pollutants pose a significant challenge for AOD and NO2 pollution. This study highlights pollution scenarios, emerging issues, and sources of AOD and NO2 in general that have not been thoroughly studied in earlier research on major Asian cities. To summarize, our study identifies these research gaps and proposes solutions to them which are eco-friendly technology, legislation, policy development, and awareness-raising.
PubDate: 2024-08-22
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- Mycological contamination of cabin filters as a potential source of air
pollution inside passenger vehicles-
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Abstract: Abstract Microbiological pollutants of cabin filters may affect the air quality inside vehicles. The main aim of the study was to evaluate cabin filters in terms of their effectiveness in retaining mycological contaminants. The research material consisted of 100 cabin filters obtained during periodic replacement of filters in passenger cars. Mycological contamination of filters was examined using microbiological, biochemical, immunoenzymatic and molecular methods. The average concentration of fungi in cabin filters was 7.2 × 107 CFU/m2, and Cladosporium, Alternaria, Penicillium, and Aspergillus genera were most often isolated. For Aspergillus species, the highest concentration reached 3.3 × 107 CFU/m2, with dominance of A. fumigatus. Among the Aspergillus strains tested, the presence of the aflO gene related to aflatoxin biosynthesis and the polyketide synthase gene related to ochratoxin A biosynthesis was detected. The presence of total aflatoxin (B1, B2, G1, G2) and aflatoxin B1 was detected at levels of 5.37 µg/kg and 1.71 µg/kg for standard filters and 2.43 µg/kg and 0.65 µg/kg for carbon filters. The level of ochratoxin A contamination was 0.96 µg/kg and 0.55 µg/kg for standard and carbon filters, respectively. Aspergillus species showed high enzymatic activity of acid phosphatase, β-glucosidase, naphthol phosphohydrolase and N-acetyl-β-glucosamidase. Based on the test results regarding the concentration of mycotoxins and the effectiveness of capturing fungal conidia, it was found that carbon filters are more effective than standard filters. Recommendations for filter manufacturers and car service policies should include the use of cabin filters with a layer of activated carbon, and their regular replacement after a year of use.
PubDate: 2024-08-21
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- Study on the method of reconstructing the vertical plane distribution of
SO2 using IDOAS-
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Abstract: Abstract This paper presents a method that combines Imaging Differential Optical Absorption Spectroscopy (IDOAS) with Computed Tomography (CT) technique to reconstruct the spatial distribution of SO2 in the vertical plane. A cubic quartz glass container with a side length of 450 mm was used, and SO2 gas was injected into the container from a steel cylinder. Two IDOASs were used to collect spectral data on the vertical plane. The Differential Optical Absorption Spectroscopy (DOAS) algorithm was employed to retrieve the slant column densities (SCDs). The gas distribution in the gas container was estimated with the help of linear fitting. It was found that the experimental SCDs were in good agreement with the theoretical analysis. Based on the sparse gradient of the gas distribution in the gas container and the non-negative of the gas concentration, a CT algorithm called ABOCS-TVM with total variational (TV) regularization was introduced. Numerical simulations show that if the gas in the container is uniform, the algorithm works well even under the influence of perturbations, and the artifacts in the reconstructed images are suppressed. The experiment showed that the algorithm is able to accurately locate the SO2 gas and provide an approximate distribution. In particular, the reconstructed peak molecular number density is approximately 11% higher than the theoretical value. Research has demonstrated the feasibility of utilizing IDOAS-based CT reconstruction technology to reconstruct the spatial distribution of SO2 in a vertical plane. This technology allows precise localization of the spatial position of SO2 and quantitative analysis of its distribution.
PubDate: 2024-08-17
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- Analysis for suspension time of airborne particles due to Diwali fireworks
in an urban atmosphere Lucknow-
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Abstract: Abstract The study analyzed the additional load and suspension time of particle pollutants emerging from Diwali firecracker combustion between two different urban landscape sites in Lucknow, India. PM# (1, 2.5, and 10) and PSD (range: 0.2 μm to 20 μm), and chemical speciation of 15-elements and 6-ions of PM2.5 were assessed for Diwali and non-Diwali-days. In the commercial site, pre-Diwali-days to Diwali-day and pre-Diwali-days to post-Diwali-days added an extra load of PM# in the atmosphere by 3 to 5 times and 1.5 to 2 times respectively. Whereas, in the residential site, 2 to 3 times and 1 to 1.5 times increased PM# was observed. Variations in PM# suspension time due to Diwali fireworks were found as ~10 days at residential site and ~6 days at commercial site due to dissimilarities in the local source mix. Further, unimodal and bimodal PSD distributions and nearness observed between PSDs in two of the study sites revealed the influence of relative sources during Diwali and non-Diwali-days. Chemical markers of Diwali fireworks were identified as abundant in PM2.5 during Diwali and post-Diwali-days, but less in pre-Diwali-days. A strong correlation between markers of Diwali fireworks and their occurrence with PCA groups further confirmed the suspension period of PM# even during post-Diwali-days.
PubDate: 2024-08-17
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- Ambient air pollution exposure and years of life lost due to suicide:
synergistic effect with high temperature-
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Abstract: Abstract Suicide is a major cause of death globally, with recent research highlighting environmental factors. However, studies often focus on individual impacts of air pollutants and temperature, neglecting their synergistic effects. This study assessed the impact of air pollutant exposure combined with temperatures on suicide, using years of life lost (YLLs) as a measure of premature mortality. A generalized additive model examined short-term links between air pollutants including particles < 2.5 μm (PM2.5) and < 10 μm (PM10), ozone (O3), sulfur dioxide (SO2), nitrogen dioxide (NO2), and carbon monoxide (CO) exposures and YLLs due to suicide in Seoul, South Korea, between 2002 and 2019, considering lag effects within 7 days. Synergistic effects of air pollutants and temperature were evaluated using a dummy variable, stratifying temperature levels into low and high (> 90th percentile). During the study period, there were 43,642 suicides, with an average daily YLLs of 193 years. Among the pollutants, NO2 and O3 showed significant associations with YLLs due to suicide. An interquartile range increase of 17.8 ppb for NO2 and 22.1 ppb for O3 was associated with increases in YLLs due to suicide by 4.08 and 5.72 years, respectively. All air pollutants and high temperatures were found to have significant synergistic effects on YLLs due to suicide (PM10 [11.83 years; Pinteract = 0.01]; PM2.5 [10.74 years; Pinteract = 0.01]; NO2 [14.52 years; Pinteract = 0.01]; SO2 [8.72 years; Pinteract = 0.04]; O3 [10.02 years; Pinteract = 0.08]; and CO [11.42 years; Pinteract = 0.03]). The results support creating suicide prevention policies to reduce premature deaths.
PubDate: 2024-08-17
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- Impact of future cold and heat on mortality by two exposure measurements
under different scenarios: Impact of global warming in the west of Iran-
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Abstract: Abstract Satellite-based data has been currently considered as an important exposure in projection studies of climate change impact on mortality. We projected all-cause mortality attributable to heat and cold by 2099 under adaptation, population change and climate scenarios using the data, in addition to ground-based exposure. Air temperature was estimated using Land Surface Temperature (LST) in a city-specific regression model. The predicted temperature was corrected for the bias using Bland–Altman approach and observed data in each city. The bias-corrected and observed predictors were then used in a two-stage time series regression to estimate baseline city-specific and pooled associations across five cities. Combination of the dose–response association and projected temperature by RCPs and GCMs along mortality data were used in the projection analysis. The temperature was estimated to increase by 6 °C in all of the regions under the worst scenario. Based on station data and under all scenarios, the Attributable Fraction (AF) and number of deaths due to cold were higher than heat in all decades in future. Also, the uncertainty in the heat effect was low if there is no adaptation to heat especially during 2020–2050 (e.g., AF for the worst scenario of RCPs and population variant was 0.07 (Empirical CI: 0.01, 0.12)). However, both exposures showed an increasing impact (Attributable Fraction (AF) and number of deaths) of heat and decreasing impact of cold in future. Compared to station-based data, the uncertainty in heat impact using the predicted data was lower under all scenarios in all decades. Along the observed data measured by weather stations the satellite-based exposure should be addressed in the studies of the projection of climate change impact on mortality. Our findings specifically highlight the urgent need for adaptive strategies to mitigate the impacts of extreme heat events, particularly in the cities like Ilam where adaptation scenario had an important role on the projection analysis.
PubDate: 2024-08-14
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- Levels, potential sources, and exposure assessment of polychlorinated
biphenyls in household dust from Kocaeli/ Turkiye-
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Abstract: Abstract The interest in the studies on Polychlorinated biphenyls (PCBs) levels indoors has increased with the banning or phase out of the use of PCBs in commercial products due to their adverse effects on human health. A comprehensive PCB source apportionment and risk estimation study was conducted for the first time using house dust in Turkey. Fifteen PCBs were measured in dust samples from 90 homes located in different neighborhoods of Kocaeli. The total concentrations of PCBs (Σ15PCBs) were measured in the range of 2.32–309.5 ng/g, with a median value of 22.82 ng/g. The concentrations varied greatly due to the availability of different types and quantities of PCB-containing product indoors. Possible pollution sources were identified using Principal Component Analysis (PCA) and questionnaire responses. The sources of PCB indoor dust include the use of PCBs for insulation, maintenance, and commercial purposes, as well as vehicular and heating combustion emissions. Considering the three exposure routes for the two groups, the risk of exposure through the inhalation of dust contaminated with PCBs was negligible compared with the dermal and non-dietary ingestion routes. Total carcinogen (R) and non-carcinogen risk (HI) through the three pathways were less than 1 for HI and 10− 6 for R, indicating that the measured PCBs would not be likely to cause potential risks for children and adults exposed to those pollutants. However measures to reduce PCBs exposure should be taken for children rather than adults due to the presence of the risk.
PubDate: 2024-08-14
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- Effect of Wet Scavenging on Black Carbon Aerosols over a Coastal Urban
Site in India-
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Abstract: Abstract The Black Carbon (BC) injected into the atmosphere from various sources not only adversely affects the air quality and human health but also significantly influences the earth atmosphere climate system by modulating the global radiation budget. The BC aerosols are mainly removed from atmosphere by the wet scavenging mechanism. The representation of wet scavenging in the models is highly uncertain due to the complex microphysical processes involved and also due to the limited observations available. In this study, based on the in-situ measurements of BC and rainfall observations, the wet scavenging of BC aerosols has been comprehensively studied over a coastal urban location, Chennai (12.81°N, 80.03°E) during the South-West (SW) and North-East (NE) monsoon for the period 2018 and 2019. The average BC concentration over Chennai during SW and NE during the study period was 1.45 ± 0.4 µgm−3 and 3.28 ± 1.2 µgm−3, respectively. By making use of the rain drop size distribution observations from a Laser Precipitation Monitor (LPM) disdrometer, the theoretical estimate of the wet scavenging is calculated (using a parameter Scavenging Coefficient-Sc(rc)) and comprehensively compared with the observed BC scavenging ratio (BCSr) for different rainfall duration and rainfall intensities during the SW and NE monsoon. It was found low BCSr values of the range 0–15% were more frequent. The peak Scavenging Coefficient for light rain and very heavy rain are 0.6 × 10–6 and 3.8 × 10–6 respectively. The theoretical estimate of the wet scavenging showed an increase with increase in rainfall intensity linearly with a correlation coefficient 0.84 at 0.01 level significance and the maximum scavenging of the BC aerosols was found to occur for the rain drop sizes ranging between 0.5 mm and 1.8 mm over the study location.
PubDate: 2024-08-13
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- Short-term effect of air pollution exposure on COPD exacerbations: a time
series study in Bogota, Colombia-
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Abstract: Introduction Air pollution poses a risk for people with Chronic Obstructive Pulmonary Disease (COPD). This study estimated the short-term effect of variations in air pollutant concentrations on exacerbations of COPD (COPD-E) in Bogotá, Colombia. Methods We performed an ecological time series study from 2014 to 2021 to evaluate the short-term effect of fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) levels on COPD-E treated in the emergency and hospitalization services. Daily counts of patients with COPD-E discharge diagnoses were obtained from the National Health Information System, and daily measurements of PM2.5, NO2, and O3 concentrations and meteorological data were obtained from air monitoring stations. A Generalized Additive Model was used with Distributed Lag Non-Linear Models to control for confounders. Results An increase of 10 μg/m3 in PM2.5 and O3 was associated with increased COPD-E admissions (lagged 0-3 days) with Relative Risk (RR) of 1.04 (95%CI: 1.02 -1.07) and RR:1.03 (95%CI:1.01 – 1.04), respectively. During the rainy season and minimum temperature of the series, for every 10 μg/m3 increase in PM2.5 concentration, COPD-E admissions (lagged 0-3 days) increased with RR 1.03 (95%CI: 1.01-1.06). A higher magnitude of association was observed in men (PM2.5, 1.04 95%CI:1.01 – 1.06 and O3, 1.04 95%CI:1.02 – 1.05, lag 0-7 days) than in women. Conclusions A higher air pollution was associated with more COPD-E. These results highlight the importance of actions aimed at improving air quality. Graphical
PubDate: 2024-08-13
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- Assessment of nitrogen dioxide concentrations and main sources in a
medium-sized city in Latin America using geographic information systems-
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Abstract: Abstract Studying atmospheric nitrogen dioxide (NO2) concentrations in urban areas is crucial for assessing air quality and caring for the population’s health; however, the background of studies on this gas in medium-sized cities is scarce, highlighting a significant knowledge gap in the field, especially in Latin America. This study aims to assess the levels of NO2 concentration in a medium-sized city in Argentina using passive samplers over six months. The Geographic Information Systems (GIS) was employed to analyse the spatial distribution of gas concentration using the Inverse Distance Weighting (IDW) interpolation method. Additionally, potential emission sources were evaluated by applying exploratory regression analysis. The study found that atmospheric concentrations of NO2 generally exceeded the values established by the World Health Organization (WHO) of 10 µg/m3. The highest mean concentration (30.4 µg/m3) was determined near a national route and industrial areas. Correlation analysis between the NO2 concentration at each site and possible emission sources suggests that industries are the main sources of this gas.
PubDate: 2024-08-10
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- Unveiling the invisible: first discovery of micro- and nanoplastic size
segregation in indoor commercial markets using a cascade impactor-
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Abstract: Abstract Micro and nanoplastics (MNPs) may enter the human body through food, drink, and air. Scientists have mainly focused on the first two routes, but little is known about the third. A cascade impactor having a size range of (> 2.5, 1.0–2.5, 0.50–1.0, 0.25–0.50, and < 0.25 μm) was used to study the size segregation of MNPs in different indoor commercial markets. The morphological characterization showed the presence of fibers, fragments, films, lines, foam, and pellets with different colors. Three hundred-seven particles were scanned for chemical description under Micro-Raman analysis, and 247 were identified and categorized into 52 MNPs . The standard MNPs found in the samples were PTFE, PE, PP, HDPE, PA, LDPE, and PAM. The SEM-EDX analysis showed that C, O, and F had the highest weight% among all elements seen, while C, O, F, Mg, and Al were the common elements. These MNPs are small enough to get inhaled easily. MNPs in these indoor environments showed vast sources that emit these polymeric particles and have harmful human health impacts, particularly on the employees working there. So, there is a need to take the necessary measures to minimize the release of these MNPs in these indoor environments and their impacts on human health.
PubDate: 2024-08-09
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- Size distribution of water-soluble ions and carbon content in the
Southwest Mediterranean Basin: results from the ChArMEx project-
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Abstract: Abstract In order to understand the origin and behaviour of aerosols in the west of the Mediterranean basin, a comprehensive investigation of water-soluble inorganic ions (WSII) with size segregation and Organic carbon (OC) and Element carbon (EC) in ultra fine fraction has been carried out in a coastal Algerian measurement station, namely BouIsmaïl, during seven months covering July 2013 to January 2014. A cascade impactor for six particle sizes with cut-off diameters of 0.49, 0.95, 1.5, 3, 7.2, and 10 µm was used for the whole campaign. The WSII were analysed by ion chromatography, and their distribution mode and potential sources were evaluated. The weekly mass concentration varied between 8.7 and 87 µg m−3 (with an average of 39.3 µg m−3). The three major ions were Cl−, Na+, and SO42−, contributing 65% of the total water-soluble inorganic ions (TWSII). Na+ and Cl− manifested comparable an unimodal distributions dominated in coarse mode, and the Cl−/Na+ molar ratio was close to that attributed to marine sources. Whilst SO42− and methane sulfonic acid (MSA) presented an inverted bimodal distribution mainly concentrated in the fine mode and contributed over 60%, ammonium (NH4+) showed strong and significant Pearson correlations with sulfate in the fine mode (r = 0.88, p-value < 0.01), indicating that NH4+ was an important neutralising agent of SO42− leading to the production of (NH4)2SO4 and NH4HSO4. The size distributions of the rest of the ions Cl−, NO3−, Na+, K+, Mg2+, and Ca2+ were unimodal mainly in the coarse mode, while oxalate and NH4+ were unimodal in the fine mode. The average concentrations of OC and EC during the investigated campaign were 4.5 and 1.3 μg m−3, respectively. Finally, according to the aerosol chemical composition and backwards trajectory analysis, BouIsmaïl air was affected by long-range air mass transported from the northwest and the west, and local emissions have an important impact on ions and carbonaceous particles in the aerosol of the investigated site.
PubDate: 2024-08-07
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- Comparative analysis of PM2.5 levels in various microenvironments
associated with common cooking practices in selected Asian countries-
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Abstract: Abstract Effects of real-life cooking activities on PM2.5 in different urban microenvironments of crowded and large metropolitan areas in Asia were comprehensively analyzed. The assessment was done based on monitoring data obtained for commercial cooking in a university campus in Thailand, restaurants in Taiwan, street food vendors, and residential cooking in Vietnam. Online instruments used for PM2.5 monitoring were priori calibrated against the reference equipment. The influence of cooking activities on indoor and outdoor PM2.5 levels was evaluated considering ventilation conditions and the type of fuel-cookstove of liquefied petroleum gas (LPG), charcoal, rice straw pellets (RSP), and honeycomb coal briquettes (HCB). Higher levels of PM2.5 were observed during intensive cooking periods than in non-cooking periods. Cooking with solid fuel (RSP, charcoal, and HCB) induced higher exposure levels of PM2.5 than LPG. The fuel stoking practice, size and design of stoves (with or without hood/exhaust fan), and type of food being cooked (steaming or meat grilling) were important factors affecting the PM2.5 levels. Other important factors especially affecting indoor PM2.5 levels included ventilation, outdoor emissions (traffic, nearby cooking activities), indoor sources (number of customers), and incense burning. The ambient pollution in the surroundings of the microenvironments may contribute significantly to measured PM2.5 levels, especially for the locations close to busy roads or in areas with heavy traffic. Further studies are required to assess the impact of exposure to cooking-induced PM2.5 emissions on human health to provide scientific evidence to foster clean cooking practices.
PubDate: 2024-08-02
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- Assessment of benzene and toluene emissions in National Capital Region
(NCR): Implications for health risks and ozone formation-
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Abstract: Abstract This study investigates benzene and toluene concentrations in Delhi and National Capital Region (NCR), India, assessing health risks and impacts on air quality, focusing on their role in ozone formation. Data from 56 monitoring stations identified 18 locations where benzene levels exceed the national safe limit, primarily due to traffic emissions and seasonal variations. Benzene concentrations peaked at 15.06 µg/m3 in Loni, Ghaziabad, during winter. Seasonal analysis indicated higher benzene levels during winter and post-monsoon periods due to lower planetary boundary layer heights (PBLHs) trapping pollutants near the ground. Health risk assessments revealed probable cancer risks for residents, with children facing higher risks than adults. Using the Ozone Formation Potential (OFP) metric and Maximum Incremental Reactivity (MIR) coefficients of 0.72 for benzene and 4.0 for toluene, the study predicted OFP values for various hotspots. Toluene's significant contribution to ozone formation was evident, with the highest concentration observed at Charkhi Dadri, Haryana (29.65 ± 2.26 µg/m3), surpassing the WHO’s air quality guidelines of 120 µg/m3, and the highest benzene concentration at Loni (7.3 ± 0.8 µg/m3). Toluene/benzene ratio and principal component analysis identified automobiles and industrial activities as significant pollution sources. The study underscores the urgent need for stricter emission controls, cleaner fuels, and improved urban planning to reduce these pollutant's negative impacts on the environment. Elevated VOC levels and associated health risks necessitate immediate action to protect public health and improve air quality in Delhi NCR. These results emphasize critical need for interventions to address benzene and toluene pollution comprehensively.
PubDate: 2024-08-01
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- Effect of lead exposure on respiratory health: a systematic review and
meta-analysis-
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Abstract: In recent years, the incidence of respiratory diseases such as asthma and pneumonia has increased significantly. However, the effect of lead (Pb) pollution on the respiratory system remains unclear. The aim of this study was to evaluate the effects of exposure to environmental and occupational Pb on respiratory health. Articles published in PubMed and Web of Science before September 2023 were systematically searched. The overall adjusted odds ratio (OR) and 95% confidence intervals (CIs) for the association between Pb exposure and respiratory diseases were extracted from each relevant article. The random effects model was applied to analyze the overall pooled effect estimates. Among the 36,373 search results, 36 related articles were screened for meta-analysis. The results of the meta-analysis suggested that Pb exposure increased the risk of respiratory diseases: OR = 1.12 (95% CIs: 1.05, 1.18). The funnel plot, Egger’s and Begg’s tests showed no publication bias. Sensitivity analysis confirmed that the meta-analysis was statistically reliable and stable. Environmental and occupational Pb exposure is associated with an increased risk of respiratory diseases including asthma. The study highlights the importance of further research on the harmful effects of Pb and the urgency of mitigating air pollution. Graphical
PubDate: 2024-07-31
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- Trace element profile of TSPM with depth within opencast coal mines for
risk assessment and their source apportionment-
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Abstract: Abstract This study presents source apportionment and toxicity level of trace element concentration in total suspended particulate matter (TSPM) fraction of settled dust at different benches of opencast coal mine. In opencast coal mine, various mining associated activities are responsible for emission of TSPM. It is significant to study these airborne TSPM and associated trace elements as mineworkers and surrounding environment are directly exposed to it. The order of mean concentration of trace elements shows that Pb ranked fourth at bench-2 & 4 and Cr ranked fourth at bench-3 whereas, Fe, Mn and Zn are among the top three at all benches. Whereas trace element concentration in haul road dusts are found higher than other locations. In this study, Spearman correlation and principal component analysis (PCA) is performed to observe the percentage contribution of exhaust & non-exhaust emission due to heavy earthmoving machineries (HEMMs) operation. A source apportionment indicates that possible contributing sources to the trace elements are geogenic (46.68%) > exhaust & non-exhaust emission (28.37%) > coal dust (10.24%). The trace elements associated to the TSPM add to the menace. Therefore, variability in toxicity of the TSPM (< 62 μm) fraction of dust within opencast coal mines was observed using the pollution indicators such as contamination factor, pollution load index, modified degree of contamination, geo-accumulation index and ecological risk index. The TSPM (< 62 μm) fraction of haul road dust is found more toxic in comparison to other locations at different depth.
PubDate: 2024-07-27
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- Investigations of aerosol types classification and PM2.5 concentrations: A
case study of two major cities in Pakistan-
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Abstract: Abstract In the atmosphere of Earth, aerosols are highly variable components that significantly affect Earth’s climate and human health. Due to their complex nature, these particles vary greatly in their form. Thus, in-depth analysis of aerosol classification is crucial for air quality and climate studies. Therefore, this study investigated the temporal distribution of atmospheric particles over two megacities of Pakistan (Lahore and Karachi). The study offers an aerosol-type classification based on the particle linear depolarization ratio (PLDR) and the single scattering albedo (SSA) at 1020 nm, retrieved from the Aerosol Robotic Network (AERONET) Version 3.0 Level 2.0 inversion products. The study also analyzed particulate matter (PM2.5) levels in Lahore and Karachi, which has recently experienced alarming air pollution. Temporal trends of PM2.5 in both cities were assessed using ground-based remote sensing. The dust ratio parameter (Rd) calculated from PLDR indicated that coarse-mode aerosols dominated, with occurrence rates of 86% in Lahore and 99% in Karachi. Pure dust (PD) and pollution-dominated mixture (PDM) plumes were more frequent in Lahore (43.16%) and Karachi (44.14%). Annually, dust-containing aerosols occur more frequently (28.47% in Lahore, 30.43% in Karachi) than dust-free types (25.62% in Lahore, 27.87% in Karachi). PM2.5 levels peak in autumn and winter, especially December 2021 (369.17 µg/m³). The highest seasonal (winter) PM2.5 averages were 284.99 µg/m³ (2022), 269.05 µg/m³ (2021), 264.99 µg/m³ (2023), and 222.34 µg/m³ (2020), contributing to smog and respiratory diseases in Lahore. Low PLDR values over Lahore are due to the large anthropogenic emissions, resulting in poor air quality as compared to Karachi.
PubDate: 2024-07-27
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- Quantitative evaluation of nicotine and particulate matter exposure for
passive- and non-smokers via a nicotine passive sampler and a particulate
matter sensor-
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Abstract: Abstract Passive smoking poses a major hazard to the health of non-smokers. Cigarette combustion emits environmental tobacco smoke (ETS) that contains various pollutants, including volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons, and particulate matter with particles < 2.5 μm in aerodynamic diameter (PM2.5). Therefore, to assess the risk of passive smoking, it is necessary to determine the exposure levels to ETS compounds caused by passive smoking. However, it is difficult to assess exposure to ETS compounds by excluding the effects of other sources of pollution. In this study, we assessed the individual exposure levels to ETS compounds using a nicotine passive sampler and PM2.5 sensor in 258 non-smokers. Median nicotine and PM2.5 concentrations were 0.065 and 7.5 µg m− 3, respectively. The median nicotine concentration was nearly identical to that found in non-smoking areas (0.05 µg m− 3). The median PM2.5 concentrations were below the standard value for indoor PM2.5 concentrations (12 µg m− 3). These results indicated that the effect of passive smoking was rather modest. Nicotine concentrations in individuals exposed to passive smoking indoors were significantly higher than in those not exposed to passive smoking. Nicotine exposure from domestic passive smoking was twice that from non-domestic passive smoking. There was no significant difference in PM2.5 exposure between passive smoking in domestic and non-domestic settings. Moreover, it was suggested that passive smoking was equivalent to the act of smoking 2.4 × 10− 3 cigarettes per day.
PubDate: 2024-07-27
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- Association of hypertension status and exposure to atmospheric ozone
improvement with cognitive decline in China-
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Abstract: Abstract The impact of improving atmospheric ozone on the state of hypertension on changes in cognitive function has not received much attention. Using data from the China Health and Retirement Longitudinal Study (CHARLS), which included 8,700 people who were first assessed in 2011 and followed through 2018, this study aimed to investigate this association. The cognitive function examination measured three dimensions: memory, executive function, and orientation, from which a global cognitive function score was calculated. The study defined atmospheric ozone improvement as the decrease in average ozone concentration between the three-year periods preceding and succeeding 2011. Linear mixed models were used to investigate the effect of atmospheric ozone and hypertension status on cognitive function changes. Subsequent subgroup and interaction analyses were performed to evaluate potential effect changes on the aforementioned connection. Using non-hypertensive participants with improved atmospheric ozone as a reference, and after adjusting for potential variables, the multivariable-adjusted beta values for global function from those with hypertension and improved atmospheric ozone, non-hypertensive and unimproved atmospheric ozone, and hypertensive and unimproved atmospheric ozone were − 0.012 (95% CI: -0.021, -0.002), -0.014 (95% CI: -0.022, -0.006), and − 0.027 (95% CI: -0.036, -0.018), respectively (P for trend < 0.001).Subgroup analysis revealed that the combined effects of hypertension and atmospheric ozone exposure status on cognition were more significant in older patients, females, non-exercisers, and people without depressive symptoms at baseline. Notably, none of the interactions between the subgroups were significant (all P-interaction > 0.05). In conclusion, our findings revealed a substantial joint influence of atmospheric ozone improvement and hypertension status on cognitive function change, implying that both health behaviors and environmental policies were crucial in the prevention of function impairment.
PubDate: 2024-07-23
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