High Levels Of Air Pollution Research Articles

Nationwide analysis of air pollution hotspots across India: A spatiotemporal PM2.5 trend analysis (2008–2019)

IntroductionIndia experiences high levels of air pollution as measured by fine particulate matter <2.5 μm (PM2.5) across the country. With limited resources, it is imperative to identify the most impacted areas. We aimed to identify air pollution hotspots in India and analyze temporal trends. MethodsWe conducted a geospatial analysis using Getis-Ord Gi statistics on gridded-annual levels of PM2.5 disaggregated for every state/UT and three largest cities [Delhi, Kolkata & Mumbai] of India from 2008 to 2019. The annual average PM2.5 was derived from a validated and robust nationwide spatiotemporal model(1kmx1km). Hotspots were identified annually using Gi∗ score and p-value and temporal trends across 2 periods [T1:2008–2013 & T2:2014–2019] for each spatial unit. We classified temporal trends based on the number of occurrences of hotspots in T1 and in T2 as consistent (similar in T1 & T2), declining (decreasing in T2) and emerging (increasing in T2) hotspots. ResultsWe identified consistent hotspots in 9.9% followed by emerging hotspots in 2.6% of the country where 16% and 4.9% people live. In addition, we identified declining hotspots in 2.6% area with 3.4% of the population. Rajasthan had largest share of area identified as consistent hotspots while Uttar Pradesh had densely populated consistent hotspots. Maharashtra had both higher number of areas identified as emerging and declining hotspots. Among the largest cities, Kolkata had highest proportion of consistent hotspots. We identified 170 additional cities with either consistent or emerging hotspots beyond the non-attainment cities as defined by the National Clean Air Programme. ConclusionIndia continues to have large areas of consistent and emerging hotspots of air pollution where close to a fifth of India's population live. Identifying hotspots can inform strategic approach for targeted action in air quality management, appropriate resource allocation and a baseline for assessing intervention effectiveness and future programs and policies, including health.

Associations of long-term exposure to fine particulate matter and its constituents with gynecologic cancer incidence: A prospective cohort study from Beijing

BackgroundThere is limited evidence of the association between long-term exposure to particulate matter with aerodynamic diameter ≤2.5 μm (fine particulate matter, PM2.5) and gynecologic cancer incidence, particularly in developing countries with high air pollution levels. The present study aimed to investigate the associations of long-term exposure to PM2.5 and its constituents with the incidence of gynecologic cancer, and to identify the primary constituent. MethodsA total of 85,500 women from the National Urban Cancer Screening Program in Beijing (2013–2019) were included. 5-year average concentrations of PM2.5 mass and its constituents, namely carbon black (BC), ammonium (NH4+), nitrate (NO3−), organic matter (OM), and sulfate (SO42−), were obtained from the Tracking Air Pollution in China (TAP) dataset. Cox proportional hazard models were used to analyze the association between long-term exposure to PM2.5 and its constituents and gynecologic cancer incidence. Mixture exposure models, including quantile-based g-computation (Qgcomp) and explanatory machine learning model (SHapley Additive exPlanations, SHAP), were used to assess the effect of each constituent. ResultsDuring a mean follow-up of 6.22 years, 524 participants were diagnosed with gynecologic cancer. The adjusted hazard ratios (HRs) for gynecologic cancer incidence associated with 1 standard deviation (SD) increment was 1.10 (95% CI: 1.00–1.22) for PM2.5, 1.12 (95% CI: 1.01–1.23) for BC,1.11 (95% CI: 1.00–1.23) for NH4+, 1.12 (95% CI: 1.01–1.23) for OM, 1.12 (95% CI: 1.01–1.23) for SO42−, and 1.08 (95% CI: 0.98–1.19) for NO3−. The Qgcomp model indicated the association between a mixture of PM2.5 constituents and gynecologic cancer incidence, with positive weights assigned to BC (61.6%), SO42− (35.9%), and NO3− (2.5%). The SHAP model showed that SO42− was the most important constituent, with the mean |SHAP| value of 0.0322, followed by BC (0.0270), OM (0.0232), NO3− (0.0212) and NH4+ (0.0190). ConclusionsLong-term exposure to PM2.5 was associated with gynecologic cancer incidence, with SO42− and BC contributing significantly to the association.

Assessment of Mortality Attributable to Air Pollution in the Urban Area of Pisa (Central Italy) Characterized by Multi-Source Exposures

Air pollution is one of the main risk factors for human health. The aim of this study was to provide an Integrated Environmental and Health Impact Assessment (IEHIA) tool to estimate the impacts on both environment and human health in Pisa municipality (central Italy). For each pollutant considered (PM2.5, PM10, and NO2), both Population-Weighted Exposure (PWE) and Attributable Deaths (ADs) were calculated considering the difference between the PWE and the latest air quality guidelines suggested by the World Health Organization. The PWEs were 16.1 µg/m3, 24.9 µg/m3, and 25.9 µg/m3 for PM2.5, PM10, and NO2, respectively. The ADs from natural causes due to exposure to PM2.5, PM10, and NO2 were 63, 29, and 51, respectively. The AD distribution was mainly concentrated in urban areas for particulate matter and in urban and suburban areas for NO2. The results highlighted significantly higher levels of air pollution than the reference levels, with a percentage of ADs from natural causes of approximately 6% of the total mortality in Pisa. IEHIA offers support for environmental and health policies and territorial planning. The authors recommend the adoption of prevention measures aimed at mitigating air pollution in critical areas, with a consequent reduction in avoidable mortality.

Near-surface ozone concentration variability analysis in the Karadag Nature Reserve

The article presents the results of a study of a near-surface ozone concentration variability in the Crimea at the background environmental monitoring station in the Karadag Nature Reserve for 2012–2021 years with a more detailed analysis of the last six years from 2016 to 2021. A significantly high level air pollution of а near-surface ozone was revealed in the observation region, despite the absence of nearby sources of industrial emissions. The relationship of near-surface ozone concentration and meteorological parameters was investigated. Wind directions leading to increased levels of near-surface ozone pollution are established. Intra-annual variations of near-surface ozone concentration are analyzed, the factors causing the local summer minimum of surface ozone concentration in some years are established. By using the NOAA HYSPLIT model and ERA5 reanalysis, a spatial analysis of the atmospheric circulation pattern in the region was carried out. The recurrence of episodes of exceeding the ozone concentration 100 micrograms/m3 during 8 or more hours (WHO recommendation) was estimated. Possible causes of these episodes were determined. The mechanisms of long-range transport and its contribution to the near-surface ozone regime in the area of the station have been established. Annual trends of near-surface ozone concentration in the period 2012–2021 years are estimated as statistically insignificant.

Commuter exposure to smoke and particulate matter air pollution in Auckland during the 2019 New Zealand International Convention Centre fire

ABSTRACT Human mobility typically exhibits temporal and spatial predictability. However, during hazardous events, roadways, footpaths and public transport networks can be disrupted by detours, closures and congestion. Urban fires, exemplified by the October 2019 New Zealand International Convention Centre (NZICC) fire in Auckland, New Zealand, are on the rise, posing threats to life, property and mobility. In this study, we employ geospatial analyses to investigate the impact of the NZICC fire on human mobility, encompassing both driving and walking. We generate predicted surfaces of particulate matter (PM2.5 and PM10) from seven local fixed air monitoring stations to estimate network-based exposure and inhalation dosage during travel. High levels of air pollution during the fire exceeded baseline concentrations, surpassing National Environmental Standards for Air Quality (NESAQ) and World Health Organization (WHO) limits for both PM2.5 and PM10. Private car commuters faced delays and congestion due to road closures, prolonging smoke exposure. Pedestrians, including those accessing essential public transportation infrastructure, experienced unavoidable exposure to smoke along the fastest routes from NZICC to places like Britomart train station and the Downtown Ferry. We recommend increasing the availability and dissemination of air pollutant monitoring data to enhance public awareness of the health risks associated with smoke exposure.

Exposure to air pollution, genetic susceptibility, and prevalence of sarcopenia in the UK

BackgroundThe role of environmental factors, particularly air pollutants, in the prevalence of sarcopenia remains unclear. ObjectivesThis study explored the relationship between the prevalence of sarcopenia and prolonged exposure to air pollutants, and investigated potential interactions with genetic susceptibility and inflammation. MethodsData from 408,117 people at baseline and 35,060 participants in the longitudinal analysis in the UK Biobank were used in this prospective cohort study. Utilizing land use regression models, air pollutants (nitrogen dioxide (NO2), nitric oxides (NOx), and particulate matter with aerodynamic diameters of ≤2.5 μm (PM2.5) and ≤10 μm (PM10) were estimated and classified into quartiles. Alterations in body composition were among the secondary results. ResultsLastly, 3353 people (0.8 %) developed sarcopenia. Higher levels of air pollutants were linked to an increased prevalence of sarcopenia after controlling for confounding variables (highest vs lowest quartile: NOx, OR, 1.21 [95 % CI, 1.16–1.26]; NO2, OR, 1.22 [95 % CI, 1.16–1.27]; PM2.5, OR, 1.17 [95 % CI, 1.12–1.22]; PM10, OR, 1.15 [95 % CI, 1.10–1.20]; all P<.001). Longitudinal analysis revealed that air pollutants had adverse changes in body composition, including increased muscle fat infiltration and decreased muscle mass. At baseline, the probability of sarcopenia was strongly correlated with NOx, NO2, PM2.5, and PM10, and increased with elevated PRSBMI or CRP levels in subgroup analyses. ConclusionAir pollutants may contribute to accelerated muscle aging and highlight the importance of environmental factors in sarcopenia development.

THE RELATIONSHIP BETWEEN AIR POLLUTION AND CORONARY ARTERY DISEASE: A SYSTEMATIC REVIEW

Several previous research studies have shown that air pollution has broad impacts on human health, particularly in the cardiovascular field. Exposure to air pollution entering the respiratory system can trigger inflammatory responses and increase the risk of cardiovascular diseases such as coronary artery disease. This systematic review aim to determine the relationship between air pollution and the occurrence of Coronary Artery Disease (CAD). Journal searches were conducted on five electronic databases, namely Pubmed, Science Direct, Europe PMC, Wiley Online Library, and Cochrane, following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) method. The search results get six original articles that meet the inclusion and exclusion criteria for analysis. Based on the results of the analysis shows that there is a significant relationship between air pollution in the form of gas components or particulate matter with the incidence of coronary artery disease. High levels of air pollution in an area can also increase the risk of CAD higher than areas with lower levels of air pollution.

Mobile laboratory measurements of air pollutants in Baltimore, MD elucidate issues of environmental justice

ABSTRACT The City of Baltimore, MD has a history of problems with environmental justice (EJ), air pollution, and the urban heat island (UHI) effect. Current chemical transport models lack the resolution to simulate concentrations on the scale needed, about 100 m, to identify the neighborhoods with anomalously high air pollution levels. In this paper we introduce the capabilities of a mobile laboratory and an initial survey of several pollutants in Baltimore to identify which communities are exposed to disproportionate concentrations of air pollution and to which species. High concentrations of black carbon (BC) stood out at some locations – near major highways, downtown, and in the Curtis Bay neighborhood of Baltimore. Results from the mobile lab are confirmed with longer-term, low-cost monitoring. In Curtis Bay, higher concentrations of BC were measured along Pennington Ave. (mean [5th to 95th percentiles] = 2.08 [2.0–10.9] μg m−3) than along Curtis Ave. just ~ 150 m away (0.67[0.1 – 1.8] μg m−3). Other species, including criteria pollutants ozone (O3), carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and fine particulate matter (PM2.5), showed little gradient. Observations with high spatial and temporal resolution help isolate the mechanisms leading to locally high pollutant concentrations. The difference in BC appears to result not from heavier truck traffic or slower dispersion but from the interruptions in traffic flow. Pennington Ave. has three stoplights while Curtis Ave. has none. As heavy-duty diesel-powered vehicles accelerate, they experience turbo-lag and the resulting rich air-fuel mixture exacerbates BC emissions. Immediate mediation might be achieved through smoother traffic flow, and the long-term solution through replacing heavy-duty trucks with electric vehicles. Implications: We present results documenting the locations within Baltimore of high concentrations of Black Carbon pollution and identify the likely source – diesel exhaust emissions exacerbated by stop-and-go traffic and associated turbo-lag. This suggests solutions (smoother traffic, retrofit particulate filters, replacement of diesel with electric vehicles) that would enhance Environmental Justice (EJ) and could be applied to other cities with EJ problems. Synopsis: This paper presents observations of atmospheric black carbon aerosol showing impacts on environmental justice, then identifies causes and suggests solutions.

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.

Air Pollution and Solar Photovoltaic Power Generation: Evidence from South Korea

Solar energy, with its declining costs and enhanced efficiency, is a viable alternative to traditional fossil fuels. However, its effectiveness is compromised by atmospheric and meteorological conditions, particularly air pollution, which reduces solar radiation and panel efficiency. This study estimates the impact of air pollution on solar photovoltaic (PV) power generation in South Korea, a rapidly industrializing nation with high levels of air pollution and a growing focus on renewable energy. Using hourly power generation data from 2006 to 2013 and addressing potential endogeneity of PM10 with an instrumental variable approach, we find that a 10 mg/m3 increase in PM10 reduces solar power generation by 2.17 MWh, resulting in an estimated annual economic loss of approximately USD 2.2 million during the study period. These findings highlight the urgent need to mitigate air pollution to enhance solar power efficiency and maximize the social benefits of renewable energy.

Air pollution and firms' export product quality: Evidence from China

AbstractThis study provides causal estimates of the effect of air pollution on firms' export product quality, based on China's experience. Using thermal inversions as an instrument, a 1% increase in PM2.5 is associated with a 0.25% decrease in export product quality. A series of tests indicates the robustness of our main result. Heterogeneity analysis reveals that the negative impact of air pollution on export product quality is only significant among regions with high levels of air pollution. In addition, we find that air pollution also reduces firms' export sales, share and probability. Our study provides original evidence for the relationship between air pollution and firms' export product quality, offering a unique perspective for countries to enhance export competitiveness.

Air pollution: a latent key driving force of dementia

Many researchers have studied the role of air pollutants on cognitive function, changes in brain structure, and occurrence of dementia. Due to the wide range of studies and often contradictory results, the present systematic review was conducted to try and clarify the relationship between air pollutants and dementia. To identify studies for this review, a systematic search was conducted in Scopus, PubMed, and Web of Science databases (without historical restrictions) until May 22, 2023. The PECO statement was created to clarify the research question, and articles that did not meet the criteria of this statement were excluded. In this review, animal studies, laboratory studies, books, review articles, conference papers and letters to the editors were avoided. Also, studies focused on the effect of air pollutants on cellular and biochemical changes (without investigating dementia) were also excluded. A quality assessment was done according to the type of design of each article, using the checklist developed by the Joanna Briggs Institute (JBI). Finally, selected studies were reviewed and discussed in terms of Alzheimer's dementia and non-Alzheimer's dementia. We identified 14,924 articles through a systematic search in databases, and after comprehensive reviews, 53 articles were found to be eligible for inclusion in the current systematic review. The results showed that chronic exposure to higher levels of air pollutants was associated with adverse effects on cognitive abilities and the presence of dementia. Studies strongly supported the negative effects of PM2.5 and then NO2 on the brain and the development of neurodegenerative disorders in old age. Because the onset of brain structural changes due to dementia begins decades before the onset of disease symptoms, and that exposure to air pollution is considered a modifiable risk factor, taking preventive measures to reduce air pollution and introducing behavioral interventions to reduce people's exposure to pollutants is advisable.

Commuter exposure to ultrafine particles (UFPs), lung deposited surface area (LDSA), and noise in Ho Chi Minh City, Vietnam

IntroductionTransport is a main contributor to air and noise pollution, particularly in urban areas with the high number of motorized vehicles. Promoting active transport (i.e., cycling and walking) and public transport is an instrumental factor in reducing traffic-related air and noise pollution. However, commuters of these transport modes are often exposed to high air and noise pollution than other commuter groups. MethodsThe levels of exposure to UFP, LDSA, and noise during commuting of different transport modes in Ho Chi Minh City (HCMC) were measured and compared. Then, the dose of inhaled pollutants during commuting was calculated for each commuter group by considering the travel time and minute ventilation. ResultsThe level of exposure to air and noise pollution varies across transport modes. Cyclists and motorcyclists were exposed to the highest level of air and noise pollution. Motorcyclists and cyclists were exposed to the highest UFP number concentrations during their trips, 3.6*105 and 3.1*105 particles/cm3, respectively. Car commuters were exposed to the lowest air and noise pollution level, followed by bus commuters. When considering the minute ventilation and travel time, cyclists inhaled significantly higher levels of air pollution than other commuters, followed by pedestrians, motorcyclists, bus commuters, and car users. As a result, the health impacts of exposure to traffic-related air and noise pollution for active commuters could be greater than other commuter groups. ConclusionsPromoting active and public transport is a promising approach to improving air quality and reducing congestion in HCMC. Using these transport modes also has potential positive health effects on commuters through physical activities. However, active commuters are faced with the highest risk of exposure to high air and noise pollution levels. To promote active transport and public transport in HCMC, measures to reduce the level of exposure to air and noise pollution for these commuter groups are needed.

Determining priority control factors for heavy metal management in urban road dust based on source-oriented probabilistic ecological-health risk assessment: A study in Xi'an during peak pollution season

Urban road dust (URD) is essential for transporting heavy metals (HMs), which can be a major danger to both the environment and human health. Moreover, URD has the potential to be carried into bodies of water, leading to contamination of the aquatic ecosystem. A study was conducted in Xi'an, a city in northwestern China known for high air pollution levels, during January 2024 - a period characterized by peak pollution due to frequent low wind speeds and temperature inversions. The research investigated the presence of 10 types of HMs (Cu, Zn, Cd, Cr, Pb, As, Ni, Hg, Co, and Mn) in URD. Findings revealed elevated levels of Cu, Zn, Cd, Cr, Pb, As, and Hg in URD compared to background levels. Hg showed the most significant contamination (moderate to heavy), followed by moderate contamination of Cd, and lower levels of As, Zn, and Cu. The main sources of HMs were traffic (58.2%), mixed natural and industrial (30.3%), and industrial (11.5%). The ecological risk in the area was deemed to be very high, primarily because of Hg and Cd. Based on probabilistic health risk assessments, it was determined that non-carcinogenic risks were deemed acceptable for all groups. Nevertheless, the possibility of carcinogenic risks should not be disregarded. Strategies for controlling ecological-health risks prioritize mixed natural and industrial sources, with a focus on Hg, Cd, and As in URD. The results offer a foundation for policymakers to create specific control strategies.

Worried (and) sick: how environmental hazards affect Americans’ health-related risk attitudes

This study explores risk attitudes towards environmental hazards by adapting the Comprehensive Conceptual Risk Perception Model (CCRPM) and applying it in the context of health-related implications of these hazards. We argue that personal experience and a deeper understanding of environmental hazards increase risk perceptions, while a strong social context reduces health concerns. Utilizing data from a national survey (N = 1207), our findings reveal higher health-related risk perceptions among individuals with pre-existing health conditions. Additionally, those with greater knowledge of environmental threats exhibit heightened concern about health complications. Conversely, individuals in communities with robust social ties report lower risk attitudes. An in-depth analysis further indicates that residents of high-risk communities, characterized by higher levels of air pollution, have increased risk perceptions compared to those in less polluted areas. These findings reinforce the dimensions described in the CCRPM and highlight the significance of structural conditions in shaping individuals' risk perceptions.

Trends in the cytogenetic and immunologic status of healthy persons; Kazakhstan, 2007–2022

Environmental pollution can affect immune health and genome stability. We have studied the immunological and cytogenetic status of healthy urban (Almaty City, which has high levels of air pollution) and rural residents of southern Kazakhstan, over the past 15 years. Differences between the groups in plasma immunoglobulin levels and chromosomal aberration frequencies were noted. Over the 15-year study period, decreases of immunoglobulin levels and increases of chromosomal aberration frequencies were observed and correlated with place of residence and ecological status of the region of residence; both ecological deterioration and the coronavirus pandemic are likely to have had negative effects.

Air Pollution Effects on Mental Health Relationships: Scoping Review on Historically Used Methodologies to Analyze Adult Populations

Air pollution’s effects on physical health, especially cardiovascular and respiratory, are well known. Exposure to air pollution may damage every organ and cell in the human body. New evidence is emerging showing that air pollution adversely affects human mental health. Current research suggests that high air pollution levels have long-term mental health effects, such as reduced mental capacity and increased cognitive decline, leading to increased stress, anxiety, and depression. Objectives: This scoping review aims to provide a comprehensive overview of the methods used in epidemiological literature to ascertain the existence of links between outdoor particulate matter (PM) and multiple adverse mental health (MH) effects (depression, anxiety, and/or stress). A better understanding of the practical research methodologies could lead to improved air quality (AQ) management and enhanced well-being strategies. Methods: This paper undertakes a scoping review. PubMed and EMBASE databases from 2010 to 2024 were searched for English-language human cohort observational studies stating methodologies used in analyzing the link between outdoor particulate matter (ultrafine (UFT) (&lt;0.1 μm), fine (&lt;2.5 μm), and course (&lt;10 μm)) and mental health outcomes (depression, anxiety, and stress) in adults (&gt;18 years), excluding vulnerable populations (i.e., elderly, children, and pregnant women). The study focuses on urban, suburban areas, and rural areas. Results: From an initial search of 3889 records, 29 studies met the inclusion criteria and were included in the review. These studies spanned various countries and employed robust quantitative methodologies to assess AQ and MH. All included studies investigated the impact of PM on mental health, with some (n = 19/65.52%) also examining nitrogen oxides (NOx), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and carbon monoxide (CO). Depression was the most frequently studied outcome (n = 10/34.48%), followed by anxiety and depression (n = 6/20.69%), and anxiety, stress, and depression, and stress (n = 4/13.79%, each). Depression, anxiety, and stress together were examined in a single study (n = 1/3.45%). Standardized questionnaires involving psychological scales such as Patient Health Questionnaire (PHQ) (n = 7/24.14%) and The Center for Epidemiological Studies-Depression (CES-D) (n = 3/10.34%) for depression and Generalized Anxiety Disorder Questionnaire (GAD) (n = 2/6.90%) for anxiety were commonly used MH tools. 27 out of 29 studies found a significant negative impact of air pollution on mental health, demonstrating a solid consensus in the literature. Two studies did not find a significant correlation. The results consistently indicated that higher levels of air pollution were associated with increased symptoms of depression, anxiety, and stress. Conclusion: Of the 3889 identified studies, 29 were suitable for inclusion in the scoping review per inclusion criteria. The results show the most preferred methods in assessing air quality and mental health in relevant studies, providing a detailed account of each method’s strengths and limitations used in studies. This scoping review was conducted to assist future research and relieve the decision-making process for researchers aiming to find a correlation between air quality and mental health. While the inclusion criteria were strict and thus resulted in few studies, the review found a gap in the literature concerning the general adult population, as most studies focused on vulnerable populations. Further exploration of the methodologies used to find the relationship between air quality and mental health is needed, as reporting on these outcomes was limited.

Impact of Exposure to Environmental Particulate Matter on the Onset of Giant Cell Arteritis.

The aim of this study was to investigate the association between exposure to particulate matter with an aerodynamic diameter ≤10 μm (PM10) and the development of giant cell arteritis (GCA) and its ischemic complications. This was case-crossover study on consecutive patients who received a diagnosis of GCA in three hospitals in northern Italy between 2013 and 2021. The PM10 hourly and daily average concentrations, collected in the Italian monitoring network and archived by Istituto Superiore per la Protezione e la Ricerca Ambientale, were determined using European reference. We used a Bayesian hierarchical model to determine patients' daily exposures to them. We employed conditional logistic regression to estimate the effect of exposure on GCA symptoms onset or ischemic complications. We included 232 patients. A positive association was observed between exposure to PM10 and GCA risk, with an incremental odd of 27.1% (95% confidence interval 5.8-52.6) for every 10-μg/m3 increase in PM10 concentration within a 60-day period. We did not find any significant association for shorter periods or with ischemic complications. Subgroup analysis found a significantly higher incremental risk at a 60-day lag for patients ≥70 years old. Comparing patients who were chronically exposed to high PM10 levels (26.9 ± 13.8 μg/m3) to those who were not (11.9 ± 7.9 μg/m3) revealed that only in the former group was there an association between GCA onset and increased PM10 levels in the preceding 60 days. Exposure to environmental PM10 in the preceding 60 days seems to be associated with an increased risk of developing GCA, especially in older individuals with prolonged exposure to high levels of air pollution.

Effect Modification of Heat-Related Mortality Risk by Air Pollutants in Shandong, China.

Although studies have reported the modification effect of air pollutants on heat-related health risk, little is known on the modification effect among various particulate matter with different particle size on mortality. We aimed to investigate whether the associations of hot temperatures with daily mortality were modified by different air pollutant levels in Shandong Province, China. Daily data of air pollutants, meteorological factors, and mortality of 1,822 subdistricts in Shandong province from 2013 to 2018 were collected. We used a time-stratified case-crossover model with an interaction term between the cross-basis term for ambient temperature and the linear function of particulate matter ≤1 µm (PM1), PM2.5, nitrogen dioxide (NO2), and ozone to obtain heat-mortality associations during the hot season. Results showed that the cumulative odds ratio of extreme heat on mortality over 0 to 10 days was 3.66 (95% CI: 3.10-4.31). The mortality risk during hot seasons was stronger at high air pollutant levels. The modification effect of particulate matters on heat-related mortality decreased by its aerodynamic diameter. Females and older adults over 75 years were more vulnerable to the modification effect of air pollutants, and significant differences were detected in the association between temperatures and mortality stratified by PM1 and PM2.5. Higher heat-related mortality risks were observed at high NO2 levels, especially for cardiorespiratory disease. The findings suggest that more consideration should be given to the combined effect of very fine particles and NO2 with ambient heat when developing healthcare strategies, and women and older adults should be given priority in health-related settings.

Variations in the leaf economics spectrum, anatomical, ultrastructural, and stomatal traits of five tree species in the urban-rural air pollution environment

Rapid urbanization has contributed to global increases in air pollution derived from urban areas. Unlike natural forests, urban forests are exposed to higher concentrations of airborne pollutants due to the strong urban-suburban-rural pollutant emission gradients. However, there remains a pressing lack of available information pertaining to the urban air pollution-related effects on the leaf economics spectrum, anatomical, ultrastructural, and stomatal traits of tree species along an urban-rural gradient. Here, the degree to which urban air pollution impacts the adaption of greening tree species and associated service functions was assessed by sampling five common tree species (Acer pictum, Fraxinus chinensis, Koelreuteria paniculata, Salix babylonica, Sophora japonica) along urban-rural-natural forests in the Beijing metropolitan region of China. These analyses revealed a significant reduction in leaf mass per unit area (–13.4 %), leaf thickness (–16.7 %), and stomatal area (–27.5 %) with increasing proximity to areas of greater air pollution that coincide with significant increases in leaf tissue density (+12.6 %), leaf nitrogen content (+10.1 %), relative chlorophyll content (+2.7 %), and stomatal density (+11.9 %). Higher air pollution levels were associated with organelle changes including gradual disintegration of chloroplasts, larger intercellular spaces and apparent starch and plastoglobuli deposition. Air pollution was conducive to the strengthening of the trade-off potential and adaptation strategies of trees in urban ecosystems, which are associated with trees with a rapid investment return strategy associated with thick leaves and strong photosynthetic capacity. These results provide strong empirical evidence of the profound air pollution-induced changes in leaf functional traits and adaption ability of urban forest tree species.