High Concentrations Of Particulate Matter Research Articles

Relationship Between Synoptic Weather Pattern and Surface Particulate Matter (PM) Concentration During Winter and Spring Seasons Over South Korea

AbstractRegional air quality over East Asia, including South Korea, has recently become a center of public attention because of a few episodes of very high particulate matter (PM) concentrations. Predicting PM variation with lead time of a few hours up to days is one of the key areas that the governments are working on because it can benefit from an early warning system to short‐term mitigation effort. In this study, the influence of synoptic weather conditions on regional air quality was investigated with the occurrence frequencies of PM episodes as a function of various synoptic weather patterns during winter and spring. During winter, dry moderate (DM) types occur frequently alongside high PM cases (24 hr mean PM10 concentration >). The composite weather map showed a weak northwesterly wind field as a potential cause. On the contrary, it is interesting to note that dry polar types can be associated with low PM cases (24 hr mean PM10 concentration <) as well as high PM depending on near‐surface wind speed. Furthermore, DM and dry tropical types were found to be highly correlated with high (higher) PM concentrations during spring season, likely because of the enhanced static stability in the lower troposphere. It should be noted that PM concentration depends on the lower atmospheric stability. The close relationship between synoptic weather patterns and PM concentration suggests that synoptic weather can play an important role in regional air quality.

Spatial and Temporal Volatility of PM2.5, PM10 and PM10-Bound B[a]P Concentrations and Assessment of the Exposure of the Population of Silesia in 2018-2021.

Air pollution both indoors and outdoors is a major cause of various diseases and premature deaths. Negative health effects are more frequently observed in a number of European countries characterized by significant pollution. In Poland, especially in Upper Silesia, the most serious problem is the high concentration of particulate matter (PM) and PM10-bound benzo[a]pyrene (B[a]P). The main source of these two pollutants is so-called "low emissions" associated with the burning of solid fuels mainly in domestic boilers and liquid fuels in road traffic. This study examined the variability in the PM and PM10-bound B[a]P concentrations and their relationships with meteorological parameters, i.e., atmospheric pressure, air temperature and wind speed, in 2018-2021 at 11 monitoring stations. In many Silesian cities, the average annual concentrations of PM10, PM2.5 and B[a]P were much higher than those recorded in other European countries. At each station, the average daily PM10 concentrations were exceeded on 12 to 126 days a year. Taking into account the WHO recommendation for PM2.5, the highest recorded average daily concentration exceeded the permissible level by almost 40 times. The same relationships were observed in all measurement years: PM10 concentrations were negatively correlated with air temperature (R = -0.386) and wind speed (R = -0.614). The highest concentrations were observed in the temperature range from -15 °C to -5 °C, when the wind speed did not exceed 0.5 m·s-1. The calculated lifetime cancer risk (LCR) associated with the exposure to B[a]P in the Silesian Voivodeship suggested 30-429 cases per 1 million people in the heating season depending on the scenario used for the calculations (IRIS, EPA or WHO).

Haze Exposure Changes the Skin Fungal Community and Promotes the Growth of Talaromyces Strains.

Haze pollution has been a public health issue. The skin microbiota, as a component of the first line of defense, is disturbed by environmental pollutants, which may have an impact on human health. A total of 74 skin samples from healthy students were collected during haze and nonhaze days in spring and winter. Significant differences of skin fungal community composition between haze and nonhaze days were observed in female and male samples in spring and male samples in winter based on unweighted UniFrac distance analysis. Phylogenetic diversity whole-tree indices and observed features were significantly increased during haze days in male samples in winter compared to nonhaze days, but no significant difference was observed in other groups. Dothideomycetes, Capnodiales, Mycosphaerellaceae, etc. were significantly enriched during nonhaze days, whereas Trichocomaceae, Talaromyces, and Pezizaceae were significantly enriched during haze days. Thus, five Talaromyces strains were isolated, and an in vitro culture experiment revealed that the growth of representative Talaromyces strains was increased at high concentrations of particulate matter, confirming the sequencing results. Furthermore, during haze days, the fungal community assembly was better fitted to a niche-based assembly model than during nonhaze days. Talaromyces enriched during haze days deviated from the neutral assembly process. Our findings provided a comprehensive characterization of the skin fungal community during haze and nonhaze days and elucidated novel insights into how haze exposure influences the skin fungal community. IMPORTANCE Skin fungi play an important role in human health. Particulate matter (PM), the main haze pollutant, has been a public environmental threat. However, few studies have assessed the effects of air pollutants on skin fungi. Here, haze exposure influenced the diversity and composition of the skin fungal community. In an in vitro experiment, a high concentration of PM promoted the growth of Talaromyces strains. The fungal community assembly is better fitted to a niche-based assembly model during haze days. We anticipate that this study may provide new insights on the role of haze exposure disturbing the skin fungal community. It lays the groundwork for further clarifying the association between the changes of the skin fungal community and adverse health outcomes. Our study is the first to report the changes in the skin fungal community during haze and nonhaze days, which expands the understanding of the relationship between haze and skin fungi.

Intrinsic atmospheric circulation patterns associated with high PM2.5 concentration days in South Korea during the cold season

Based on observation data and a novel K-mean clustering method, we investigated whether intrinsic atmospheric circulation patterns are related with the occurrence of high particulate matter (PM) concentration days (diameters less than or equal to 2.5 μm (PM2.5)), in Seoul, South Korea, during the cold season (December to March). A simple composite map shows that weak horizontal and vertical ventilation over the Korean Peninsula can cause high PM2.5 concentration (High_PM2.5) days. Also, atmospheric circulations are quite different between one day of High_PM2.5 and periods longer than two days. We also found that two intrinsic atmospheric circulation patterns in Asia, which were obtained by adopting K-mean clustering to the daily 850 hPa geopotential height anomalies for 2005–2020, were associated with High_PM2.5 days. These results indicate that High_PM2.5 days in Seoul, South Korea, occur as a result of intrinsic atmospheric circulation patterns, therefore, they are unavoidable unless the anthropogenic emission sources over the Korean Peninsula, East Asia, or both are reduced. In addition, these two intrinsic atmospheric circulation patterns are more prominent for periods longer than two days while there are no favorable intrinsic atmospheric circulation patterns to induce one day of High_PM2.5, which indicates that a single day of High_PM2.5 tends to occur by a stochastic atmospheric circulation rather than the intrinsic atmospheric circulation patterns.

Acute health effects of bushfire smoke on mortality in Sydney, Australia

BackgroundBushfire smoke is a major ongoing environmental hazard in Australia. In the summer of 2019–2020 smoke from an extreme bushfire event exposed large populations to high concentrations of particulate matter (PM) pollution. In this study we aimed to estimate the effect of bushfire-related PM of less than 2.5 μm in diameter (PM2.5) on the risk of mortality in Sydney, Australia from 2010 to 2020. MethodsWe estimated concentrations of PM2.5 for three subregions of Sydney from measurements at monitoring stations using inverse-distance weighting and cross-referenced extreme days (95th percentile or above) with satellite imagery to determine if bushfire smoke was present. We then used a seasonal and trend decomposition method to estimate the Non-bushfire PM2.5 concentrations on those days. Daily PM2.5 concentrations above the Non-bushfire concentrations on bushfire smoke days were deemed to be Bushfire PM2.5. We used distributed-lag non-linear models to estimate the effect of Bushfire and Non-bushfire PM2.5 on daily counts of mortality with sub-analyses by age. These models controlled for seasonal trends in mortality as well as daily temperature, day of week and public holidays. ResultsWithin the three subregions, between 110 and 134 days were identified as extreme bushfire smoke days within the subregions of Sydney. Bushfire-related PM2.5 ranged from 6.3 to 115.4 µg/m3. A 0 to 10 µg/m3 increase in Bushfire PM2.5 was associated with a 3.2% (95% CI 0.3, 6.2%) increase in risk of all-cause death, cumulatively, in the 3 days following exposure. These effects were present in those aged 65 years and over, while no effect was observed in people under 65 years. ConclusionBushfire PM2.5 exposure is associated with an increased risk of mortality, particularly in those over 65 years of age. This increase in risk was clearest at Bushfire PM2.5 concentrations up to 30 µg/m3 above background (Non-bushfire), with possible plateauing at higher concentrations of Bushfire PM2.5.

Measuring and Regression Modeling of Gas–Particle Partitioning of Atmospheric Oxidized Mercury at a Coastal Site in Shanghai

Gas–particle partitioning between reactive gaseous mercury (RGM) and particle bound mercury (PBM) controls the fates of atmospheric oxidized mercury (namely reactive mercury, RM). We conducted a long-term observations of gaseous elemental mercury (GEM), RGM, PBM, and auxiliary parameters in Chongming Island, Shanghai, China, to understand the characteristics of speciated mercury and their gas–particle partitioning behaviors. The entire average abundances of GEM, RGM and PBM were 2.12 ± 0.94 ng/m3, 14.75 ± 9.94 pg/m3 and 21.81 ± 30.46 pg/m3, respectively. An observation data dependent empirical gas–particle partitioning relationship of partitioning coefficient and temperature log(1/KP) = −2692.20/T + 10.57 was obtained, and it varied in different season being by the temperature. To further evaluate the influences of temperature, particulate matter (PM), relative humidity on RGM and PBM partitioning process, the particulate fraction (φ = PBM/(PBM + RGM)) was used in this study. High φ values (φ > 0.8) mainly occurred at low temperature domain (<281 K), and high PM concentration enhanced this influence. In addition, high relative humidity shifts RGM from atmosphere partitioning to PBM in response to the diurnal valley φ values at 13:00–16:00 in the summer. Photochemical reactions were proposed to play important roles on partitioning processes between RGM and PBM. This study will benefit for the understanding of oxidized mercury fate and influencing factors in the complex atmospheric pollutants.

Inter-comparison of oxidative potential metrics for airborne particles identifies differences between acellular chemical assays

Oxidative potential (OP) has been identified as an important factor underlying the health effects of airborne particulate matter (PM). OP denotes the ability of PM to deplete antioxidants and to form reactive oxygen species (ROS) in the lung. OP can be quantified using a variety of chemical assays and analytical techniques. Despite the widespread use of various OP metrics, there is no consensus or comprehensive inter-laboratory assessment on how these assays compare. In this work for the first time, we compared 11 OP indicators from acellular assays using standard reference material of urban PM. The OP indicators included ascorbic acid, glutathione, glutathione disulfide, cysteine, cystine, dithiothreitol, H2O2, •OH, O2•-, and empirical and theoretical redox potential of simulated lung lining fluid (SLF). The indicators showed first-order kinetics at low PM concentration (25 μg mL−1), whereas the kinetics were non-linear at higher PM concentrations. The indicators demonstrated mainly linear dose-response relationships at PM concentrations 25–100 μg mL−1, following similar trends with water-soluble transition metals, but they were not always proportional to PM concentrations, and demonstrated substantial differences in their sensitivities to PM. The results indicate the importance of using reduced reaction time for reliable OP quantification due to non-linearity in assay responses at high PM concentrations. This work shows that the choice of molecular probes and measurement techniques must be carefully considered when planning studies on OP of ambient air and should importantly include the association of OP metrics with health outcomes.

Divergent Trends in the Prevalence of Children's Asthma, Rhinitis and Atopic Dermatitis and Environmental Influences in the Urban Setting of Zagreb, Croatia.

Previous studies have reported that the allergy epidemic in developed countries has reached its plateau, while a rise is expected in developing ones. Our aim was to compare the prevalence of allergic diseases among schoolchildren from the city of Zagreb, Croatia after sixteen years. Symptoms of asthma, allergic rhinitis (AR) and atopic dermatitis (AD) and risk factors were assessed using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. An allergic profile was determined by a skin prick test. The prevalence of current, ever-in-a-lifetime and diagnosed AR of 35.7%, 42.5% and 14.9% and AD of 18.1%, 37.1% and 31.1% demonstrated a significant increase. The asthma prevalence has remained unchanged. The allergen sensitivity rate has remained similar, but pollens have become dominant. Mould and dog exposure are risks for asthma (OR 14.505, OR 2.033). Exposure to cat allergens is protective in AR (OR 0.277). Parental history of allergies is a risk factor in all conditions. Over sixteen years, the prevalence of AR and AD, but not of asthma, have increased. The proportion of atopy has remained high. The AR/AD symptom rise is probably a consequence of increased pollen sensitisation united with high particulate matter concentrations. The stable asthma trend could be a result of decreasing exposures to indoor allergens.

Can the perceived risk of particulate matter change people's desires and behavior intentions?

Particulate matter (PM) is a hazardous airborne pollutant that encompasses all airborne particles with diameters ranging from 0.001 to 100 μm. It is composed of total suspended particles (TSPs), consisting of two main particle sizes: PM10 and PM2.5. PM poses various threats to human health because of its rapid mobility and its ability to spread over a wide area. In particular, it has long-term negative effects on such organs as the lungs and heart. China and South Korea, located in Northeast Asia, are representative of the countries at risk of PM, and their populations live with an awareness that the harms of PM go beyond physical risks. Therefore, based on previous studies, this study classifies the perceived PM risks into physical, psychological, financial, functional, and time risks. It has tried to verify the effect of this risk perception on the behavior intention of Chinese and Koreans and examine the moderating effect according to the difference in nationality. The study's conceptual model was constructed by applying Ajzen's proven theory of planned action. Utilizing AMOS 22.0 and SPSS 22.0, an analysis was performed. Following this analysis, it was determined that there was a significant causal relationship between perceived PM risk and behavioral attitudes, subjective norms, and perceived behavioral control. Additionally, it was discovered that perceived PM risk significantly impacted desire and behavioral intention. These findings demonstrate that when persons are exposed to high concentrations of PM, they perceive a variety of risks that go beyond the merely physical, and they can form different attitudes depending on their nationality. This study greatly contributes to the theoretical and practical implications by presenting more diverse perspectives on PM risk.

Assessment of Coarse, Fine, and Ultrafine Particles in S-Bahn Trains and Underground Stations in Stuttgart

The Stuttgart S-Bahn network comprises six subway lines and is used by approximately 425,000 people on a daily basis. In previous studies in other cities, it was found that subways can be a source and collection point of particulate matter (PM), which is detrimental to human health. This study focused on making an initial assessment of the pollution situation inside the trains and on the underground platforms. Real-time measurements were performed with high time-resolution instruments inside the S-Bahn trains, two underground stations, and two outdoor stations in the Stuttgart subway network in November 2019. Firstly, the variation in concentration inside the train as it traveled through the tunnel was investigated, and it was recurrently observed that the pollutant concentration in the train increased while traveling through the tunnel and then decreased when nearing the tunnel exit. Secondly, the measurement location with the highest particulate matter concentrations was determined. The particulate matter concentrations on underground platforms were higher than those on the train and on the outdoor platforms. In addition, the dominant fraction of the particulate matter measured was in the range of ultrafine particles (UFP). Finally, the wind speed and wind direction data were analyzed in conjunction with specific locations along the platforms. From the wind measurement results, it was assumed that the combined airflows led to higher particle resuspension and particulate matter concentrations in these areas. In conclusion, it was determined that subway users were exposed to higher particle concentrations, particularly UFP (10–116 nm), while standing on underground platforms and when traveling through underground tunnels. It was found that the PNCs inside the train wagons as well as PM and BC mass concentrations increase when passing through the tunnel. Additionally, the average number concentration of UFPs on underground platforms was significantly higher than in other locations by factors of around 1.7 to 1.9 for UFPs and 1.6 to 2 for coarse and fine particles.

Advanced Strategies for Mitigating Particulate Matter Generations in Poultry Houses

Poultry farming plays a key role in agricultural air emissions. Particulate matter (PM) level tends to be high in broiler and cage-free layer houses, that may impair health and welfare of animals and their caretakers. To protect public health and welfare, the occupational exposure limit for PM10 and PM2.5 (i.e., PM diameters that are generally ≤10 and 2.5 μm, respectively) are suggested not to exceed 150 µg m−3 and 35 µg m−3, respectively, based on 24-h concentrations thresholds as suggested by US. EPA. However, the levels of PM10 and PM2.5 in poultry houses could be 100 times higher than that limit. For instance, PM10 and PM2.5 levels in cage-free henhouses are higher than 15,000 µg/m3 and 3500 µg/m3 in wintertime. Therefore, it is critical to identify the primary factors affecting PM generation in poultry houses and apply corresponding mitigation strategies. This review paper summarizes PM emission factors, mitigating strategies, and impacts on birds’ and caretakers’ health, and welfare. Generally, PM emissions are affected by various factors, including housing types, seasonal and diurnal variation, manure management, bedding materials, ventilation rates, and birds’ activities. High PM concentrations in poultry houses impair birds’ and caretakers’ liver, kidneys, and respiratory systems. Thus, different mitigating strategies are discussed in this study for addressing those issues. Effective mitigation strategies include frequent house cleaning, optimum light intensity, liquid spraying, bedding management, and air filtration systems. However, mitigation strategies can be cost-prohibitive and have side effects. Therefore, poultry farms should select mitigation strategies based on farm location, climate conditions, environmental policies, and available resources (government assistance programs).

Relationship between Leaf Traits and PM-Capturing Capacity of Major Urban-Greening Species

High concentrations of airborne particulate matter (PM) in urban areas are of great concern to human health. Urban greening has been shown to be an effective and eco-friendly way to alleviate particle pollution, and attention to its role in mitigating particle pollution has increased worldwide. The species-specific PM-capturing capacity of ten urban-greening species in Seoul was evaluated by leaf functional traits (average leaf area (ALA), specific leaf area (SLA), and leaf width-to-length ratio (W/L)), microstructures (roughness, stomata, and trichomes), and physicochemical traits (contact angle (θw), surface free energy (rs), the work of adhesion for water (Wa), and epicuticular wax loads (EWL)). The relationships between leaf traits and PM adsorption by leaves were revealed by Pearson’s correlations and principal component analysis (PCA). A gravimetric method was used to quantify, by particle size, the PM adsorbed on leaf surfaces or embedded in leaf epicuticular wax layers. The key factors for PM adsorption on leaf surfaces were the SLA, the mean roughness value (Ra), and stomatal size. The SLA and Ra of adaxial leaf surfaces were negatively correlated with PM accumulation on leaf surfaces, while stomatal length and width were positively correlated with surface PM load. The rs and EWL positively affected the in-wax PM load. Species-specific PM deposition was the result of complicated mechanisms of various leaf traits. Three evergreen shrub species, Buxus sinica (Rehder & E.H. Wilson) M.Cheng var. insularis (Nakai) M.Cheng, Taxus cuspidata Siebold & Zucc., and Euonymus japonicus Thunb., were efficient in capturing both surface PM and in-wax PM. The PCA revealed that the high PM accumulation efficiency of these three species might be attributable to the interaction between stomatal size and EWL. Aesculus turbinata Blume, Chionanthus retusus Lindl. & Paxton, and Rhododendron schlippenbachii Maxim. had intermediate PM adsorption ability, which might be a result of interactions among stomatal density, the Wa of adaxial surfaces, and ALA. Magnolia denudata Desr., Styphnolobium japonicum (L.) Schott, Liriodendron tulipifera L., and Ginkgo biloba L. had low PM accumulation efficiency. These four species exhibited correlations among SLA, the Ra of adaxial leaf surfaces, and W/L, which had negative effects on PM adsorption.

Investigation of dust pollutants and the impact of suspended particulate matter on the performance of photovoltaic systems

The purpose of this study is to investigate the potential of airborne particulate matter (PM10 and PM2.5) and its impact on the performance of the photovoltaic (PV) system installed in the Sargodha region, being affected by the crushing activities in the hills. More than 100 stone crushers are operating in this region. Four stations within this region are selected for taking samples during the summer and winter seasons. Glass–fiber papers are used as a collection medium for particulate matter (PM) in a high-volume sampler. The concentration of PM is found above the permissible limit at all selected sites. The chemical composition, concentration, and the formation of particulate matter (PM10 and PM2.5) layers on the surface of the photovoltaic module varies significantly depending on the site’s location and time. The accumulation of PM layers on the PV module surface is one of the operating environmental factors that cause significant reduction in PV system performance. Consequently, it leads to power loss, reduction of service life, and increase in module temperature. For the PV system’s performance analysis, two PV systems are installed at the site, having higher PM concentration. One system is cleaned regularly, while the other remains dusty. The data of both PV systems are measured and compared for 4 months (2 months for the summer season and 2 months for the winter season). It is found that when the level of suspended particulate matter (PM10 and PM2.5) increases, the energy generation of the dusty PV system (compared to the cleaned one) is reduced by 7.48% in May, 7.342% in June, 10.68% in December, and 8.03% in January. Based on the obtained results, it is recommended that the negative impact of PM on the performance of the PV system should be considered carefully during the decision-making process of setting solar energy generation targets in the regions with a high level of particulate matter.

Analysis of the Air Quality of a District Heating System with a Biomass Plant

Heating is one of the major causes of pollution in urban areas, producing high concentrations of aero-dispersed particulate matter (PM) that can cause serious damage to the respiratory system. A possible solution is the implementation of a district heating system, which would decrease the presence of conventional heating systems, reducing PM emissions. The case study considered involves the municipality of Serra San Bruno (Italy), located near a biomass plant, which could play the role of a thermal conversion plant for a possible district heating network. To determine the heating incidence on pollution, the large users in the area were identified. The large users’ consumption estimation was carried out, obtaining the thermal energy requirement linked to the residential, which is about 3.5 times that of all the large users. Through air quality measuring devices, PM concentrations were measured for the winter and the summer period. PM emissions were then estimated using emission factors and the decreases in PM concentrations were calculated if part of the domestic users were converted to district heating, compatibly with the possibility of supplying energy to the biomass power plant. The replacement of conventional plants in favor of a district heating network has a positive impact on PM pollution.

Spatial patterns and influencing factors of intraurban particulate matter in the heating season based on taxi monitoring

ABSTRACT Urbanization has introduced a series of environmental problems worldwide, and particulate matter (PM) is one of the main threats to human health. Due to the lack of high-resolution, large-scale monitoring data, few studies have analyzed the intraurban spatial distribution pattern of PM at a fine scale. In this study, portable air monitors carried by five taxis were used to collect the concentrations of PM1, PM2.5 and PM10 for five months in Shenyang during the heating season. The results showed that high concentrations of PM were distributed in the suburbs, while relatively low concentration areas were found in the central area. Agricultural, industrial and development zones had higher concentration values among the eight observed types. The PM concentration exhibited strong spatial autocorrelation based on Moran’s I index analysis. Meteorological factors were the most important influencing factors of the three pollutants, and their total contribution rate accounted for more than 80% among the 13 factors according to boosted regression trees analysis. The taxi monitoring method we proposed was a more efficient and feasible method for monitoring urban air pollution and could obtain higher spatial-temporal resolution data at a lower cost to elucidate the region’s dynamic air pollution distribution patterns.

Characteristics of Atmospheric Compounds based on Regional Multicorrelation Analysis in Honam Area

Particulate Matter (PM) in the atmosphere has serious impacts on human health and the global environmental systems. To reduce anthropogenic PM emissions is of importance to protect public health. In this study, the variation of concentrations in PM<sub>2.5</sub>, NO<sub>2</sub>, and O<sub>3</sub> of Honam region over the past 6 years (2016-2021) was investigated. A statistical approach (i.e., hierarchical cluster analysis) was performed to present their spatial relationships. As a result, the high concentration of PM<sub>2.5</sub> in Iksan-si was found in sources of primary pollutants emitted from industrial complexes and ammonia from large-scale livestock complexes. The high concentration periods of PM<sub>2.5</sub> with lower concentrations of NO<sub>2</sub> and O<sub>3</sub> can be seasonal and secondary PM product contributions. In addition, the concentration of O<sub>3</sub> in Buan-gun and Wanju-gun with lower PM levels can be the effect of emission of volatile organic compounds (VOC<sub>S</sub>) from sources. It is necessary to strengthen management for reducing emissions by sources and to establish a policy to control precursors of the atmospheric contaminants.

Assessment of Individual-Level Exposure to Airborne Particulate Matter during Periods of Atmospheric Thermal Inversion.

Air pollution exposure is harmful to human health and reducing it at the level of an individual requires measurements and assessments that capture the spatiotemporal variability of different microenvironments and the influence of specific activities. In this paper, activity-specific and general indoor and outdoor exposure during and after a period of high concentrations of particulate matter (PM), e.g., an atmospheric thermal inversion (ATI) in the Ljubljana subalpine basin, Slovenia, was assessed. To this end, personal particulate matter monitors (PPM) were used, worn by participants of the H2020 ICARUS sampling campaigns in spring 2019 who also recorded their hourly activities. ATI period(s) were determined based on data collected from two meteorological stations managed by the Slovenian Environmental Agency (SEA). Results showed that indoor and outdoor exposure to PM was significantly higher during the ATI period, and that the difference between mean indoor and outdoor exposure to PM was much higher during the ATI period (23.0 µg/m3) than after (6.5 µg/m3). Indoor activities generally were associated with smaller differences, with cooking and cleaning even having higher values in the post-ATI period. On the other hand, all outdoor activities had higher PM values during the ATI than after, with larger differences, mostly >30.0 µg/m3. Overall, this work demonstrated that an individual-level approach can provide better spatiotemporal resolution and evaluate the relative importance of specific high-exposure events, and in this way provide an ancillary tool for exposure assessments.

Does Exposure To Environmental Pollution Increase The Incidence Of CNS Tumors In Children?

Purpose: The postulated risk factor of CNS tumors might be air pollution. In Poland, especially in the Silesian voivodship, air quality is inferior compared to other European countries. The study aimed to evaluate the effect of selected air pollution parameters on the incidence of central nervous system tumors in children. Material and methods: A group of 460 children (251 boys, 209 girls) aged 0-18 (0.17-18.75) years, diagnosed with CNS cancer were included. The age Standardized Incidence Ratios (SIR) for CNS malignancies in children were calculated. Based on the data concerning air quality, the number and location of air quality monitoring stations for 2003-2016 published by the Regional Inspectorate for Environmental Protection in Katowice, the mean concentrations of benzene (C6H6), Nitrogen dioxide (NO2), benzoalphapyrene (BaP) and particulates matter with a diameter of 2.5 micrometers (PM 2.5) and 10 micrometers (PM10) were calculated. Results: The highest PM10 (50.62µg/m3), PM2.5 (36.14µg/m3), BaP (10.9ng/m3) and C6H6 (3.67µg/m3) concentrations were recorded in the Rybnik area. The highest age-standardized CNS tumor incidence ratio (n/100,000) was also demonstrated in the Rybnik area (3.24). The analysis showed a significant positive correlation between the SIR and the concentration of PM2.5 (r=0.89, p=0.039) and PM10 (r=0.93, p=0.007). There was no significant correlation between SIR and NO2 (r=0.41, p=0.41), BaP (r=0.56, p=0.24), C6H6 (r=0,79, p=0,2). Conclusion: Exposure to high concentrations of particulate matter may increase the risk of developing CNS cancers in children. Further research is needed, especially in the pediatric population.

Tracing terrestrial versus marine sources of dissolved organic carbon in the largest monsoonal Godavari estuary in India using stable carbon isotopes

To examine the sources of dissolved organic carbon (DOC) and its modifications within the estuary, time-series sampling was conducted at 10 stations covering the entire salinity range in the Godavari estuary. The salinity of the upper estuary was close to zero and increased to 32 at the lower estuary during the dry period whereas the entire estuary was filled with fresh water during the wet period. The estuary received a high concentration of suspended particulate matter (SPM) during the wet compared to the dry period. The concentration of DOC and DON was 1.5–3 times higher during the wet than dry period with DOC: DON ratios of 5–20. The depleted isotopic composition of DOC (δ13CDOC) was observed during the dry period in the upper estuary and it was enriched towards the lower estuary suggesting that terrestrial organic matter (mainly C3 plant) is the source in the upper and marine sources in the lower estuary. Highly enriched δ13CDOC values were noticed during July–August, which was associated with peak discharge, suggesting that soil organic matter may be a potential source. Enhanced phytoplankton biomass was observed during October–November associated with depleted δ13CDOC from that peak discharge period suggesting DOC released by phytoplankton bloom by phytoplankton bloom (Merismopedia sp.) by freshwater algae may be contributed significantly to the DOC pool. Based on the deviation from the simple mixing line between the upper and lower estuary, the removal of DOC seems to be occurring through microbial decomposition and photo-oxidation during the dry period. The modification of DOC within the estuary may be minimal due to the low residence of water (<1 day) during the wet period. As a result, a significant amount of terrestrial carbon is transported to the coastal ocean during the wet period and its impact is reported to be seen up to 15–25 km from the coast in the coastal Bay of Bengal.

Characteristics of PM2.5 and PM10 Spatio-Temporal Distribution and Influencing Meteorological Conditions in Beijing

PM2.5 and PM10 in the atmosphere seriously affect human health and air quality, a situation which has aroused widespread concern. In this paper, we analyze the temporal and spatial distribution of PM2.5 and PM10 concentrations from 2016 to 2021 based on real-time monitoring data. In addition, we also explore the influence of meteorological conditions on pollutants. The results show that PM2.5 and PM10 concentrations are similarly distribution in temporal and spatial from 2016 to 2021, and the average concentrations of both show a decreasing trend. The ratio of PM2.5 to PM10 is decreasing, indicating that the proportion of fine particles is declining. PM2.5 and PM10 concentrations are higher in spring and winter, but lower in summer. Spatially, it shows a gradual shift from the characteristic of “high in the south and low in the north” to a uniform homogenization across districts. The spatial distribution of PM2.5 and PM10 mass concentrations is synchronous by applying empirical orthogonal functions (EOF). The first EOF pattern exhibits a consistent characteristic of high in the southeast and low in the northwest. The second pattern EOF reflects the effect of impairing PM2.5 concentrations in the southeast during the winter of 2016–2018. The PM2.5 and PM10 concentrations are significantly negatively correlated with wind speed and precipitation in both spring and winter. On the other hand, from the perspective of the circulation situation, the southeasterly and weak westerly wind in spring produce convergence resulting in higher particulate matter concentrations in the south than in the north in Beijing. The westerly wind is flatter at 700 hPa geopotential height, which is conducive to the formation of stationary weather. The vertical direction of airflow in spring and winter is dominated by convergence and sinking, indicating the weak dispersion ability of the atmosphere. The reason for the accumulation of particulate matter at the surface is investigated, which is beneficial to provide the theoretical basis for air quality management and pollution control in Beijing.