Contribution of anthropogenic pollutants to the increase of tropospheric ozone levels in the Oporto Metropolitan Area, Portugal since the 19th century

Assessment of ground-level ozone pollution in Türkiye according to new WHO limits

Ground-level ozone is a secondary pollutant and is attributable to respiratory diseases and mortality. For this reason, the World Health Organization (WHO) implemented a new long-term (peak season) limit value for ozone. The previous studies related to ozone in Türkiye were spatially limited to certain locations. In this study, annual mean and peak season ozone concentrations, and limit exceedances were investigated for Türkiye for the year 2021. Moreover, ozone peak seasons were determined for the first time for 126 air quality monitoring stations. The annual mean ozone concentration was determined as 44.3 ± 19.3 µg/m3 whereas the peak season average ozone level was 68.4 ± 27.2 µg/m3. April-September period was the most frequently observed ozone peak season. Among all stations, Erzurum Palandöken was by far the most polluted station in terms of annual mean and limit exceedances of ozone. Ankara Siteler stations have the highest rank in peak season mean. 87 and 83 stations exceeded the short-term and long-term recommendations of WHO, respectively. Four hotspot regions were revealed in terms of peak season exceedance: Adana and surrounding provinces, the surroundings of Burdur and Isparta provinces, and the northeastern and northwestern parts of Türkiye. To protect public health, WHO recommendations for 8-h and peak season limits should be immediately implemented in Turkish regulations.

Tension as a key factor in skin responses to pollution

Being the more apparent organ exposed to the outdoor stressors, the effect of pollution on the skin has been widely studied in the last few decades. Although UV light is known as the most aggressive stressor to which our cutaneous tissue is daily exposed, other components of the tropospheric pollution have also shown to affect skin health and functionality. Among them, ozone has been proven to be one of the most toxic due to its high reactivity with the epidermal lipids. Studying the cutaneous effect of pollution in a laboratory setting presents challenges, therefore it becomes critical to employ appropriate and tailored models that aim to answer specific questions. Several skin models are available nowadays: in vitro models (2D cell lines and 3D cutaneous tissues), ex vivo skin explants and in vivo approaches (animals and humans). Although in the last 20 years researchers developed skin models that closely resemble human skin (3D cutaneous tissues), ex vivo skin explants still remain one of the best models to study cutaneous responses. Unfortunately, one important cutaneous property that is not present in the traditional ex vivo human skin explants is the physiological tension, which has been shown to be a cardinal player in skin structure, homeostasis, functional properties and responses to external stimuli. For this reason, in this study, to confirm and further comprehend the harmful mechanism of ozone exposure on the integumentary system, we have performed experiments using the state of art in cutaneous models: the innovative TenSkin™ model in which ex vivo human skin explants are cultured under physiologically relevant tension during the whole experimental procedure. Specifically, we were interested in corroborating previous findings showing that ozone exposure modulates the expression of cutaneous antimicrobial peptides (AMPs). The present work demonstrates that cutaneous exposure to ozone induces AMPs gene and protein levels (CAMP/LL-37, hBD2, hBD3) and that the presence of tension can further modulate their expression. In addition, different responses between tension and non-tension cultured skin were also observed during the evaluation of OxInflammatory markers [cyclooxygenase-2 (COX2), aryl hydrocarbon receptor (AhR), matrix-metallo-proteinase 9 (MMP9) and 4-hydroxy-nonenal (4HNE)]. This current study supports our previous findings confirming the ability of pollution to induce the cutaneous expression of AMPs via redox signaling and corroborates the principle that skin explants are a good and reliable model to study skin responses even though it underlines the need to holistically consider the role of skin tension before extrapolating the data to real life.

An integrated analysis of air pollution and meteorological conditions in Jakarta

Air pollution and climate change are general problems for society. This paper proposes an integrated analysis of the Air Quality Index (AQI) and meteorological conditions in Jakarta. The column-based data integration model is applied to create integrated data of the Air Quality Index and meteorological conditions. The integrated data is then used to generate a causal graph using the PC algorithm. The causal graph reveals that there exist causal relationships between pollutants and meteorological conditions, e.g, humidity, rainfall, wind speed, and duration of sunshine affect particulate matter 10 (PM[Formula: see text]); wind speed affects sulfur dioxide (SO[Formula: see text]); temperature affects ozone (O[Formula: see text]). The historical data records that the average wind speed is decreased and the number of unhealthy days has risen. Ozone and particulate matter are two pollutants that mainly influence poor air quality in Jakarta. The integrated data is also used to train Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU) for forecasting. Experimental results show that LSTM using integrated data produces smaller errors for forecasting AQI and meteorological conditions.

Trends in Summer-Time Tropospheric Ozone during COVID-19 Lockdown in Indian Cities Might Forecast a Higher Future Risk

High concentrations of tropospheric ozone (O3) is a serious concern in India. The generation and atmospheric dynamics of this trace gas depend on the availability of its precursors and meteorological variables. Like other parts of the world, the COVID-19 imposed lockdown and restrictions on major anthropogenic activities executed a positive impact on the ambient air quality with reduced primary pollutants/precursors load. In spite of this, several reports pointed towards a higher O3 in major Indian cities during the lockdown. The present study designed with 30 pan-Indian mega-, class I-, and class II-cities revealed critical and contrasting aspects of the geographical location, source, precursor, and meteorological variable dependency of the spatial and temporal O3 formation. This unexpected O3 increase in the major cities might forecast the probable future risks for the National Air Quality policies, especially O3 pollution management, in the Indian sub-continent. The results also pointed towards the severity of the north Indian air quality, followed by the western and eastern parts. We believe these results will definitely pave the way for researchers and policy-makers for predicting/framing regional and/or national O3 management strategies in the future.

Comparative assessment of modeling deep learning networks for modeling ground-level ozone concentrations of pandemic lock-down period

Covid-19 pandemic lock-down has resulted significant differences in air quality levels all over the world. In contrary to decrease seen in primary pollutant species, many of the countries have experienced elevated ground-level ozone levels in this period. Air pollution forecast gains more importance to achieve air quality management and take measures against the risks under such extra-ordinary conditions. Statistical models are indispensable tools for predicting air pollution levels. Considering the complex photochemical reactions involved in tropospheric ozone formation, modeling this pollutant requires efficient non-linear approaches. In this study, deep learning methods were applied to forecast hourly ozone levels during pandemic lock-down for an industrialized region in Turkey. With this aim, different deep learning methods were tested and efficiencies of the models were compared considering the calculated RMSE, MAE, R 2 and loss values.

Evaluating the effect of ozone in UV induced skin damage

Air pollution represents one of the main risks for both environment and human health. The rapid urbanization has been leading to a continuous release of harmful manmade substances into the atmosphere which are associated to the exacerbation of several pathologies. The skin is the main barrier of our body against the external environment and it is the main target for the outdoor stressors. Among the pollutants, Ozone (O₃) is one of the most toxic, able to initiate oxidative reactions and activate inflammatory response, leading to the onset of several skin conditions. Moreover, skin is daily subjected to the activity of Ultraviolet Radiation which are well known to induce harmful cutaneous effects including skin aging and sunburn. Even though both UV and O₃ are able to affect the skin homeostasis, very few studies have investigated their possible additive effect. Therefore, in this study we evaluated the effect of the combined exposure of O₃ and UV in inducing skin damage, by exposing human skin explants to UV alone or in combination with O₃ for 4-days. Markers related to inflammation, redox homeostasis and tissue structure were analyzed. Our results demonstrated that O₃ is able to amplify the UV induced skin oxinflammation markers.

Spatio-temporal distribution of six pollutants and potential sources in the Hexi Corridor, Northwest China

Particulate matter (PM) concentrations are affected by anthropogenic emissions and sand transport jointly; however, the relative contributions from those two aspects are usually unknown. In our work, statistical analysis and back trajectories model were used to identify the dominant source in such area, by taking Yumen City as an example. We come to the conclusion that local emissions dominate the concentration of airborne pollutants, while sand transport plays a significant role on PM concentration. The conclusions were supported by the following results. (1) PM monthly mean concentrations at the two air quality stations, which are 70 km far away from each other, have the similar levels and variation trend; furthermore, a regression analysis of PM_2.5 and PM₁₀ daily concentrations between both stations indicated a significant correlation, suggesting that PM at both locations was influenced by the same emission sources; (2) statistical analysis results revealed that PM concentration has a positive correlation with wind speed, indicating the wind-blown dust and sand contribute mainly on PM concentration; (3) back-trajectory clustering analysis indicates that long-distance transport particulates from dust sources and their pathways had a significant impact on local PM concentrations.

Blueberry Extracts as a Novel Approach to Prevent Ozone-Induced Cutaneous Inflammasome Activation

The World Health Organization estimates that 7 million people die every year due to pollution exposure. Among the different pollutants to which living organism are exposed, ozone (O₃) represents one of the most toxic, because its location which is the skin is one of the direct tissues exposed to the outdoor environment. Chronic exposure to outdoor stressors can alter cutaneous redox state resulting in the activation of inflammatory pathways. Recently, a new player in the inflammation mechanism was discovered: the multiprotein complex NLRP1 inflammasome, which has been shown to be also expressed in the skin. The topical application of natural compounds has been studied for the last 40 years as a possible approach to prevent and eventually cure skin conditions. Recently, the possibility to use blueberry (BB) extract to prevent pollution-induced skin toxicity has been of great interest in the cosmeceutical industry. In the present study, we analyzed the cutaneous protective effect of BB extract in several skin models (2D, 3D, and human skin explants). Specifically, we observed that in the different skin models used, BB extracts were able to enhance keratinocyte wound closure and normalize proliferation and migration responses previously altered by O₃. In addition, pretreatment with BB extracts was able to prevent ozone-induced ROS production and inflammasome activation measured as NRLP1-ASC scaffold formation and also prevent the transcripts of key inflammasome players such as CASP1 and IL-18, suggesting that this approach as a possible new technology to prevent cutaneous pollution damage. Our data support the hypothesis that BB extracts can effectively reduce skin inflammation and be a possible new technology against cutaneous pollution-induced damage.

A Predictive Model for Steady State Ozone Concentration at an Urban-Coastal Site

Ground level ozone (O₃) plays an important role in controlling the oxidation budget in the boundary layer and thus affects the environment and causes severe health disorders. Ozone gas, being one of the well-known greenhouse gases, although present in small quantities, contributes to global warming. In this study, we present a predictive model for the steady-state ozone concentrations during daytime (13:00⁻17:00) and nighttime (01:00⁻05:00) at an urban coastal site. The model is based on a modified approach of the null cycle of O₃ and NO_x and was evaluated against a one-year data-base of O₃ and nitrogen oxides (NO and NO₂) measured at an urban coastal site in Jeddah, on the west coast of Saudi Arabia. The model for daytime concentrations was found to be linearly dependent on the concentration ratio of NO₂ to NO whereas that for the nighttime period was suggested to be inversely proportional to NO₂ concentrations. Knowing that reactions involved in tropospheric O₃ formation are very complex, this proposed model provides reasonable predictions for the daytime and nighttime concentrations. Since the current description of the model is solely based on the null cycle of O₃ and NO_x, other precursors could be considered in future development of this model. This study will serve as basis for future studies that might introduce informing strategies to control ground level O₃ concentrations, as well as its precursors' emissions.

Out-of-hospital cardiac arrest attributable to sunshine: a nationwide, retrospective, observational study

Aims

To investigate the population attributable risk of out-of-hospital cardiac arrest (OHCA) from non-optimal sunshine duration and the relative contribution of daily sunshine hours.

Methods and Results

National registry data of all cases of OHCA occurred between 2005 and 2014 in the 47 Japanese prefectures were obtained. We examined the relationship between daily duration of sunshine and OHCA risk for each prefecture in Japan using a Poisson regression model combined with a distributed lag non-linear model, adjusting for confounding factors. The estimated associations for each prefecture were pooled at the nationwide level using a multivariate random-effects meta-analysis. A total of 658 742 cases of OHCA of presumed cardiac origin met our inclusion criteria. The minimum morbidity sunshine duration varied from the 21st percentile in Okayama to the 99th percentile in Hokkaido, Gifu, and Hyogo. Overall, 5.78% [95% empirical confidence interval (eCI): 3.57-7.16] of the OHCA cases were attributable to daily sunshine duration. The attributable fraction for short sunshine duration (below the minimum morbidity sunshine duration) was 4.18% (95% eCI: 2.64-5.38), whereas that for long sunshine duration (above the minimum morbidity sunshine duration) was 1.59% (95% eCI: 0.81-2.21).

Conclusions

Daily sunshine duration was responsible for OHCA burden, and a greater number of OHCA cases occurred in patients who were only exposed to sunshine for short periods of time each day. Our findings suggest that public health efforts to reduce OHCA burden should take sunshine level into account.

Nitrogen oxides and ozone in Portugal: trends and ozone estimation in an urban and a rural site

This study provides an analysis of the spatial distribution and trends of NO, NO2 and O3 concentrations in Portugal between 1995 and 2010. Furthermore, an estimation model for daily ozone concentrations was developed for an urban and a rural site. NO concentration showed a significant decreasing trend in most urban stations. A decreasing trend in NO2 is only observed in the stations with less influence from emissions of primary NO2. Several stations showed a significant upward trend in O3 as a result of the decrease in the NO/NO2 ratio. In the northern rural region, ozone showed a strong correlation with wind direction, highlighting the importance of long-range transport. In the urban site, most of the variance is explained by the NO2/NOX ratio. The results obtained by the ozone estimation model in the urban site fit 2013 observed data. In the rural site, the estimated ozone during extreme events agrees with observed concentration.

Assessment of ozone variations and meteorological influences at a rural site in Northern Xinjiang

Ozone concentrations and meteorological data were continuously monitored online from June to December 2013 at the Akedala regional atmosphere station in an arid region of Central Asia. We present daily, monthly, and seasonal variations of ozone concentrations in the atmosphere and elucidate possible emission sources. The ozone concentrations of this region varied from 14.7 to 58.6 ppb. A remarkable seasonal variation of ozone in aerosols was observed with highest level in summer, followed by autumn and winter. The daily peak value of ozone was observed at 9:00-11:00 a.m. while the lowest was at 17:00-19:00 p.m. The backward trajectories of air masses showed potential emission sources to be from the northwest and south during the measurement period. The backward trajectory also revealed that ozone concentrations during the measurement period were likely attributable to the emission from anthropogenic activities, and medium-range atmospheric transport from cities in central Asia and the northern slope of the Tian Shan Mountains.

Spatial distribution of ground-level urban background O3 concentrations in the Metropolitan Area of Buenos Aires, Argentina

In this work, a recently developed urban-scale atmospheric dispersion model (DAUMOD-GRS) is applied to evaluate the ground-level ozone (O3) concentrations resulting from anthropogenic area sources of NOx and VOC in the Metropolitan Area of Buenos Aires (MABA). The statistical comparison of model results with observations (including new available data from seventeen sites) shows a good model performance. Estimated summer highest diurnal O3 1-h concentrations in the MABA vary between 15 ppb in the most urbanised area and 53 ppb in the suburbs. All values are below the air quality standard. Several runs are performed to evaluate the impact of possible future emission reductions on O3 concentrations. Under all hypothetical scenarios, the maximum diurnal O3 1-h concentration obtained for the area is slightly reduced (up to 4%). However, maximum diurnal O3 concentrations could increase at some less urbanised areas of MABA depending on the relative reductions of the emissions of NOx and VOC.

Health effects of ozone focusing on childhood asthma: what is now known--a review from an epidemiological point of view

Protecting the health of children and the environment is an essential objective for the health policies of any modern society, being also crucial for a sustainable development, according to the World Health Organization. Evaluating the risk of developing childhood asthma is one of the four priority issues identified by the European Commission, according to the European Union Environment and Health Action Plan. Accordingly, this review aimed to update information concerning the effects of exposure to ozone on childhood asthma, thus helping in the development of strategies for further research. Studies have been demonstrating strong associations between the exposure to ozone and asthma. However, the complexity of exposure patterns, the changes in the vulnerability of children at various stages of development, and the practical limitations of research, lead to a still incomplete understanding of the ozone impact on the health of children. Difficulties on the interpretation of epidemiological studies to evaluate chronic effects are mainly due to an absence of studies designed specifically to address this question and to inherent limitations in characterizing exposure. The more rigorous studies provided new evidences for chronic effects of ozone on small airway function and possibly on asthma, but substantial uncertainties remain.

Indoor air pollution on nurseries and primary schools: impact on childhood asthma--study protocol

Background

Several studies have demonstrated an association between the exposure to indoor air pollution (IAP) and childhood asthma. Evidence is suggesting that several air pollutants may contribute to both exacerbation and development of asthma, but some uncertainty remains concerning the specific causative role of IAP. This paper reports an epidemiologic study aiming to reduce the existing lacks on the association between long-term exposure to pollution mixtures and the development and exacerbation of childhood asthma.

Methods/design

Based on the implementation of the study in 8 nurseries and 8 primary schools, from which, 2 nurseries and 2 primary schools in sites influenced by traffic and other 2 nurseries and 2 primary schools in background sites at urban and rural areas, the study will analyse the exposure to both urban and rural pollution as well as to traffic emissions (some homes of the children will be included in the study). Furthermore, based on the answers to validated questionnaires (as those used in the International Study of Asthma and Allergies in Childhood - ISAAC) filled in by the parents and on medical exams, the study will assess the prevalence, incidence and exacerbation of asthma, thus considering both short and long-term effects. The approximate number of children in the study will never be less than 600, guaranteeing 80% of study power (significant at a 5% level).

Discussion

This study intends to contribute for the understanding of the role of environmental factors, namely indoor air pollution, on asthma considering a risk group of different ages, and for the development of preventive measures, which are considered priority issues by the European Commission, according to the European Environmental Agency and the World Health Organization.

Long-range ozone transport and its impact on respiratory and cardiovascular health in the north of Portugal

Ozone dynamics depend on meteorological characteristics such as wind, radiation, sunshine, air temperature and precipitation. The aim of this study was to determine ozone trajectories along the northern coast of Portugal during the summer months of 2005, when there was a spate of forest fires in the region, evaluating their impact on respiratory and cardiovascular health in the greater metropolitan area of Porto. We investigated the following diseases, as coded in the ninth revision of the International Classification of Diseases: hypertensive disease (codes 401-405); ischemic heart disease (codes 410-414); other cardiac diseases, including heart failure (codes 426-428); chronic obstructive pulmonary disease and allied conditions, including bronchitis and asthma (codes 490-496); and pneumoconiosis and other lung diseases due to external agents (codes 500-507). We evaluated ozone data from air quality monitoring stations in the study area, together with data collected through HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model analysis of air mass circulation and synoptic-scale zonal wind from National Centers for Environmental Prediction data. High ozone levels in rural areas were attributed to the dispersion of pollutants induced by local circulation, as well as by mesoscale and synoptic scale processes. The fires of 2005 increased the levels of pollutants resulting from the direct emission of gases and particles into the atmosphere, especially when there were incoming frontal systems. For the meteorological case studies analyzed, peaks in ozone concentration were positively associated with higher rates of hospital admissions for cardiovascular diseases, although there were no significant associations between ozone peaks and admissions for respiratory diseases.

Ozone exposure and its influence on the worsening of childhood asthma

BACKGROUND

It is well documented that high levels of many airborne pollutants can adversely affect many systems of the human body. The aim of this study was to evaluate the specific impact of ozone (O(3)) on the worsening of childhood asthma, comparing children living at regions with high and low O(3) concentrations (reference site) without the confounding effects of other pollutants.

METHODS

Pollutant concentrations were monitored and data concerning asthma prevalence were collected through a questionnaire. The studied population consisted of 478 children aged 6-13 years old enrolled in four schools of the municipalities where monitoring was performed. Remote sites were identified with very low concentrations of nitrogen dioxide and volatile organic compounds and high concentrations of O(3).

RESULTS

The prevalence of wheeze for lifetime period and in the past year was 15.9% and 6.3%, respectively. Asthmatic children were identified when dyspnoea and wheezing were simultaneously mentioned in the absence of upper respiratory infections; according to that, the lifetime prevalence of asthmatic symptoms at the remote sites was 7.1%. The comparison with other previous studies was difficult because the criteria for analysis are not conveniently established.

CONCLUSION

The prevalence of childhood asthmatic symptoms was about 4% higher at the high O(3) site than at the low O(3) site.

Diurnal, seasonal and weekdays-weekends variations of ground level ozone concentrations in an urban area in greater Cairo

Ground level ozone (O3) concentration was monitored during the period of December 2004 to November 2005 in an urban area in Greater Cairo (Haram, Giza). During the winter and summer seasons, nitrogen dioxide (NO2) and nitric oxide(NO) concentrations and meteorological parameters were also measured. The mean values of O3 were 43.89, 65.30, 91.30 and 58.10 ppb in daytime and 29.69, 47.80, 64.00 and 42.70 ppb in whole day (daily) during the winter, spring, summer and autumn seasons, respectively. The diurnal cycles of O3 concentrations during the four seasons revealed a uni-modal peak in the mid-day time, with highest O3 levels in summer due to the local photochemical production. The diurnal variations in NO and NO2 concentrations during the winter and summer showed two daily peaks linked to traffic density. The highest levels of NOx were found in winter. Nearly, 75%, 100%, 34.78% and 52.63% of the mean daytime concentrations of O3 during spring,summer, autumn and the whole year, respectively, exceeded the Egyptian and European Union air quality standards (60 ppb) for daytime (8-h) O3 concentration. About, 41.14% and 10.39% of the daytime hours concentrations and 14.93% and 3.77% of the daily hour concentrations in summer and the whole year, respectively, exceeded the Egyptian standard (100 ppb) for maximum hourly O3 concentration, and photochemical smog is formed in the study area (Haram) during a periods represented by the same percentages. This was based on the fact that photochemical smog usually occurs when O3 concentration exceeds 100 ppb. The concentrations of O3 precursors (NO and NO2) in weekends were lower than those found in weekdays, whereas the O3 levels during the weekends were high compared with weekdays. This finding phenomenon is known as the "weekend effect". Significant positive correlation coefficients were found between O3 and temperature in both seasons and between O3 and relative humidity in summer season, indicating that high temperature and high relative humidity besides the intense solar radiation (in summer) are responsible for the formation of high O3 concentrations.