European Air Quality Research Articles

Carbon pricing and power sector decarbonization: Evidence from the UK

Decreasing greenhouse gas emissions from electricity generation is crucial to tackle climate change. Empirically, however, little is known about the effectiveness of existing economic instruments in the power sector. This paper examines the impact of the UK Carbon Price Support (CPS), a carbon tax implemented in the UK power sector in 2013. Relative to a synthetic control unit built from other European countries, I find that emissions from the UK power sector declined by 20 to 26 percent per year on average between 2013 and 2017. The tax operated via three mechanisms: a decrease in emissions at the intensive margin; the closure of some high-emission plants at the extensive margin; and a higher probability of closure for plants already at risk due to European air quality regulations.

The risk of admission acute heart failure in ST-elevation myocardial infarction patients and air pollution with PM2.5

Abstract Introduction Air pollution, in particular exposure to particulate matter fine particles of less than 2.5 microns in diameter (PM2.5), increases the risk of cardiovascular events. Short-term exposure (hours to few days prior) to increased PM2.5 levels even may help trigger ST-elevation myocardial infarction (STEMI) and heart failure exacerbation in susceptible individuals. The risk of vascular events is increased even in exposures below the current European air quality limit values (mean annual levels for PM2.5 less than 10μg/m3, 24-hour mean level less than 25μg/m3). Purpose To evaluate predictive role of PM2.5 levels ≥20 μg/m3 one day prior to hospital admission for the risk of admission acute heart failure (AAHF) in STEMI patients. Methods In 290 STEMI patients (100 women, 190 men, mean age 65.5±12.9 years), treated by primary percutaneous coronary intervention (PPCI) in 2018, we retrospectively registered the AAHF, defined as classes II-IV by Killip Kimbal classification. Additionally, we registered admission clinical data, potentially contributing to AAHF in STEMI patients such as gender, age ≥65 years, prior resuscitation, admission cTnI ≥5 μg/L (normal levels up to 0.045 μg/L), comorbidities, time to PPCI, and mean daily levels of PM2.5 ≥20 μg/m3 one day before admission. Mean daily, freely available, levels of PM2.5 were measured and registered by Chemical analytic laboratory of Environmental agency of Republic Slovenia. We evaluated the predictive role of admission data for admission AHF in STEMI patients. Results AAHF was observed in 34.5% of STEMI patients with the mean daily PM2.5 level 15.7±10.9 μg/m3 on the day before admission. PPCI was performed in 92.1% of all STEMI patients, in AAHF in 87.1% and in non-AAHF patients in 94.7% (p=0.037). AAHF in comparison to non-AAHF was associated significantly with female gender (50.5% vs 25.9%, p<0.001), age over 65 years (71.3% vs 45%, p<0.001), prior diabetes (33.7% vs 14.8%, p<0.001), left bundle branch block (LBBB) (10.9% vs 0.5%, <0.001), admission cTnI ≥5 μg/L (46.7% vs 25.9%, p<0.001) and mean daily levels of PM2.5 ≥20 μg/m3 one day before admission (31.7% vs 19%, p=0.020), but nonsignificantly with arterial hypertension, prior myocardial infarction, anterior STEMI and time to PPCI. Logistic regression demonstrated that significant independent predictors of AAHF were age over 65 years (OR 3.349, 95% CI 1.787 to 6.277, p<0.001), prior diabetes (OR 2.934, 95% CI 1.478 to 5.821, p=0.002), admission LBBB (OR 10.526, 95% CI 1.181 to 93.787, p=0.03), prior resuscitation (OR 3.221, 95% CI 1.336 to 7.761, p=0.009), admission cTnI ≥5μg/l (OR 2.984, 95% CI 1.618 to 5.502, p<0.001) and mean daily levels of PM2.5 ≥20 μg/m3 (OR 2.096, 95% CI 1.045 to 4.218, p=0.038) one day before admission. Conclusion Mean daily levels of PM2.5 ≥20μg/m3 one day before admission were among significant independent predictors of AAHF in STEMI patients. Funding Acknowledgement Type of funding sources: None.

The regional impact of urban emissions on air quality in Europe: the role of the urban canopy effects

Abstract. Urban areas are hot spots of intense emissions, and they influence air quality not only locally but on a regional or even global scale. The impact of urban emissions over different scales depends on the dilution and chemical transformation of the urban plumes which are governed by the local- and regional-scale meteorological conditions. These are influenced by the presence of urbanized land surface via the so-called urban canopy meteorological forcing (UCMF). In this study, we investigate for selected central European cities (Berlin, Budapest, Munich, Prague, Vienna and Warsaw) how the urban emission impact (UEI) is modulated by the UCMF for present-day climate conditions (2015–2016) using two regional climate models, the regional climate models RegCM and Weather Research and Forecasting model coupled with Chemistry (WRF-Chem; its meteorological part), and two chemistry transport models, Comprehensive Air Quality Model with Extensions (CAMx) coupled to either RegCM and WRF and the “chemical” component of WRF-Chem. The UCMF was calculated by replacing the urbanized surface by a rural one, while the UEI was estimated by removing all anthropogenic emissions from the selected cities. We analyzed the urban-emission-induced changes in near-surface concentrations of NO2, O3 and PM2.5. We found increases in NO2 and PM2.5 concentrations over cities by 4–6 ppbv and 4–6 µg m−3, respectively, meaning that about 40 %–60 % and 20 %–40 % of urban concentrations of NO2 and PM2.5 are caused by local emissions, and the rest is the result of emissions from the surrounding rural areas. We showed that if UCMF is included, the UEI of these pollutants is about 40 %–60 % smaller, or in other words, the urban emission impact is overestimated if urban canopy effects are not taken into account. In case of ozone, models due to UEI usually predict decreases of around −2 to −4 ppbv (about 10 %–20 %), which is again smaller if UCMF is considered (by about 60 %). We further showed that the impact on extreme (95th percentile) air pollution is much stronger, and the modulation of UEI is also larger for such situations. Finally, we evaluated the contribution of the urbanization-induced modifications of vertical eddy diffusion to the modulation of UEI and found that it alone is able to explain the modeled decrease in the urban emission impact if the effects of UCMF are considered. In summary, our results showed that the meteorological changes resulting from urbanization have to be included in regional model studies if they intend to quantify the regional footprint of urban emissions. Ignoring these meteorological changes can lead to the strong overestimation of UEI.

Driving bans for diesel cars in German cities: The role of ENGOs and Courts in producing an unlikely outcome

AbstractDriving bans for diesel cars have been adopted, are looming or have been narrowly avoided in 41 major German cities as of April 2021. This paper analyses this highly unlikely outcome of a political process that began in 2010 by addressing a number of causal factors and qualifying the weight and the way in which they contribute to the overall result. First, in the category of institutions, there are the European Ambient Air Quality Directive and the right of environmental associations to sue; second, the striking failure to adopt alternative measures to significantly reduce NO2 concentration; third, in the category of actors there is the Deutsche Umwelthilfe (DUH) utilizing the right to take legal action in its “fight for clean air” as well as the German administrative courts which handled the legal cases filed by the DUH by placing great emphasis on health protection and compliance with European law.

Spatio-temporal modelling of changes in air pollution exposure associated to the COVID-19 lockdown measures across Europe

The lockdown and related measures implemented by many European countries to stop the spread of the SARS-CoV-2 virus (COVID-19) pandemic have altered the economic activities and road transport in many cities. To rigorously evaluate how these measures have affected air quality in Europe, we developed Bayesian spatio-temporal (BST) models that assess changes in the surface nitrogen dioxide (NO2) and fine particulate matter (PM2.5) concentration across the continent. We fitted BST models to measurements of the two pollutants in 2020 using a lockdown indicator covariate, while accounting for the spatial and temporal correlation present in the data. Since other factors, such as weather conditions, local combustion sources and/or land surface characteristics may contribute to the variation of pollutant concentrations, we proposed two model formulations that allowed the differentiation between the variations in pollutant concentrations due to seasonality from the variations associated to the lockdown policies. The first model compares the changes in 2020, with the ones during the same period in the previous five years, by introducing an offset term, which controls for the long-term average concentrations of each pollutant during 2014–2019. The second approach models only the 2020 data, but adjusts for confounding factors. The results indicated that the latter can better capture the lockdown effect. The measures taken to tackle the virus in Europe reduced the average surface concentrations of NO2 and PM2.5 by 29.5% (95% Bayesian credible interval: 28.1%, 30.9%) and 25.9% (23.6%, 28.1%), respectively. To our knowledge, this research is the first to account for the spatio-temporal correlation present in the monitoring data during the pandemic and to assess how it affects estimation of the lockdown effect while accounting for confounding. The proposed methodology improves our understanding of the effect of COVID-19 lockdown policies on the air pollution burden across the continent.

The Historical Trend of Air Pollution and Its Impact on Human Health in Campania Region (Italy)

The Campania region covers an area of about 13,590 km2 with 5.8 million residents. The area suffers from several environmental issues due to urbanization, the presence of industries, wastewater treatment, and solid waste management concerns. Air pollution is one of the most relevant environmental troubles in the Campania region, frequently exceeding the limit values established by European directives. In this paper, airborne pollutant concentration data measured by the regional air quality network from 2003 to 2019 are collected to individuate the historical trends of nitrogen dioxide (NO2), coarse and fine particulate matter with aerodynamic diameters smaller than 10 μm (PM10) and 2.5 μm (PM2.5), and ozone (O3) through the analysis of the number of exceedances of limit values per year and the annual average concentration. Information on spatial variability and the effect of the receptor category is obtained by lumping together data belonging to the same province or category. To obtain information on the general air quality rather than on single pollutants, the European Air Quality Index (EU-AQI) is also evaluated. A special focus is dedicated to the effect of deep street canyons on air quality, since they are very common in the urban areas in Campania. Finally, the impact of air pollution from 2003 to 2019 on human health is also analyzed using the software AIRQ+.

Analysis of existing air monitoring technologies

Atmospheric air monitoring is a systematic, long-term assessment of the level of certain types of pollutants by measuring their amount in the open air. Atmospheric air monitoring is an integral part of an effective air quality management system and is carried out through environmental monitoring networks, which should support timely provision of public information about air pollution, support compliance with ambient air quality standards and development of emission strategies, support for air pollution research.The work is devoted to existing air monitoring technologies: ground (sensors, diffusion tubes, etc.) and remote resources (satellites, aircraft, etc.). In addition, standards of air quality assessment (European and American) are described. As an example, we consider the European Air Quality Index (EAQI) and the Air Quality Index according to EPF standards: indicators by which these indices are calculated, the ranking of air status depending on the value of the index are described.AQI (Air Quality Index) is used as an indicator of the impact of air on the human condition. The European Air Quality Index allows users to better understand air quality where they live, work or travel. By displaying information for Europe, users can gain an understanding of air quality in individual countries, regions and cities. The index is based on the values of the concentration of the five main pollutants, including particles less than 10μm (PM10), particles less than 2.5μm (PM2.5), ozone (O3); nitrogen dioxide (NO2); sulfur dioxide (SO2). To conclude, ground stations give a more accurate picture of the state of the air at a point, while satellite image data with a certain error (due to cloud cover, etc.) can cover a larger area and solve the problem of coverage of stations in the area. There is no single standard for calculation. Today, the European Air Quality Index (EAQI) is used in Ukraine and Europe.

Assessing Douro Vineyards Exposure to Tropospheric Ozone

Tropospheric ozone (O3) can strongly damage vegetation. Grapevines (Vitis vinifera L.), in particular, have intermediate sensitivity to ozone. Wine production is an important economic activity, as well as a pillar to the cultural identity of several countries in the world. This study aims to evaluate the risk of Douro vineyards exposure to ozone, by estimating its concentration and deposition in the Demarcated Region of Douro in Portugal. Based on an assessment of the climatology of the area, the years 2003 to 2005 were selected among the hottest years of the recent past, and the chemical transport model CHIMERE was used to estimate the three-dimensional field of ozone and its dry deposition over the Douro region with 1 km2 of horizontal resolution. Model results were validated by comparison with measured data from the European air quality database (AirBase). The exposure indicator AOT40 (accumulated concentration of ozone above 40 ppb) was calculated and an exposure–response function was applied to determine the grapevine risk to ozone exposure. The target value for the protection of vegetation established by the Air Quality Framework Directive was exceeded on most of the Douro region, especially over the Baixo Corgo and Cima Corgo sub-regions. The results of the exposure–response functions suggest that the productivity loss can reach 27% and that the sugar content of the grapes could be reduced by 32%, but these values are affected by the inherent uncertainty of the used methodology.

Air Pollution and Surrounding Greenness in Relation to Ischemic Stroke: A Population-Based Cohort Study

Background: Evidence for the association between environmental exposures and ischemic stroke (IS) is limited and inconsistent. We aimed to assess the relationship between long-term exposure to air pollutants, residential surrounding greenness, and incident IS, and to identify population subgroups particularly vulnerable to these exposures. Methods: We used data from administrative health registries of the public healthcare system in Catalonia, Spain to construct a cohort of individuals aged 18 years and older without a previous stroke diagnosis at 1 st January, 2016 (n=3 521 274). We collected data on sociodemographic characteristics and cerebrovascular risk factors, and derived exposure at the participant’s residence to ambient levels of fine particulate matter (PM 2.5 ), black carbon (BC), nitrogen dioxide (NO 2 ), and Normalized Difference Vegetation Index (NDVI) in 300m buffer as an indicator of greenness. The primary outcome was IS diagnosis at any point during the follow-up. We used Cox proportional hazards models to estimate associations between environmental exposures and incident IS and stratified analyses to investigate effect modification. Findings: Between 1 st January, 2016 and 31st December, 2017, 10 865 individuals were admitted to public hospitals with an IS diagnosis. Individuals with a high residential exposure to air pollution were at greater risk of IS: HR 1·04 (95% CI:0·99-1·10) per 5µg/m 3 of PM 2.5 ; HR 1·05 (95% CI:1·00-1·10) per 1µg/m 3 of BC; HR 1·04 (95% CI:1·03-1·06) per 10µg/m 3 of NO 2 . Conversely, those individuals with higher residential surrounding green space (NDVI), had lower risk of IS (HR 0·84; CI 95%:0·7-1·0). There was no evidence of effect modification by individual characteristics. Interpretation: Higher incidence of IS was observed in relation to long-term exposures to PM 2.5 , BC and NO 2 in a region that meets European health-based air quality standards. Residential surrounding greenness was associated with lower incidence of IS.Funding: Spanish Ministries of Health, Science and Innovation and Economy and Competitiveness. Funding: The study was funded by the Spanish Ministry of Economy through the Carlos III Health Institute (ISCIII-FIS-FEDER-ERDF, PI18/00056). This project was also funded in part by the following sources: INVICTUS PLUS. FEDER, RD16/0019/0002 and the Spanish Ministry of Science and Innovation through the “Centro de Excelencia Severo Ochoa 2019–2023” Program (CEX2018- 000806-S). Carla Avellaneda-Gomez was funded by a Rio Hortega fellowship (CM18/00040) awarded by the Spanish Ministry of Science and Innovation. Cathryn Tonne is funded by a Ramon y Cajal fellowship (RYC-2015-17402) awarded by the Spanish Ministry of Economy and Competitiveness. Declaration of Interest: None to declare. Ethical Approval: We received approval from our local ethics committee (code 2018/7917/I).

Role of ammonia in European air quality with changing land and ship emissions between 1990 and 2030

Abstract. The focus of this modeling study is on the role of ammonia in European air quality in the past as well as in the future. Ammonia emissions have not decreased as much as the other secondary inorganic aerosol (SIA) precursors – nitrogen oxides (NOx) and sulfur dioxide (SO2) – since the 1990s and are still posing problems for air quality and the environment. In this study, air quality simulations were performed with a regional chemical transport model at decadal intervals between 1990 and 2030 to understand the changes in the chemical species associated with SIA under varying land and ship emissions. We analyzed the changes in air concentrations of ammonia, nitric acid, ammonium, particulate nitrate and sulfate as well as changes in the dry and wet deposition of ammonia and ammonium. The results show that the approximately 40 % decrease in SIA concentrations between 1990 and 2010 was mainly due to reductions in NOx and SO2 emissions. The ammonia concentrations on the other hand decreased only near the high-emission areas such as the Netherlands and northern Italy by about 30 %, while there was a slight increase in other parts of Europe. Larger changes in concentrations occurred mostly during the first period (1990–2000). The model results indicate a transition period after 2000 for the composition of secondary inorganic aerosols due to a larger decrease in sulfate concentrations than nitrate. Changes between 2010 and 2030 – assuming the current legislation (CLE) scenario – are predicted to be smaller than those achieved earlier for all species analyzed in this study. The scenario simulations suggest that if ship emissions will be regulated more strictly in the future, SIA formation will decrease especially around the Benelux area, North Sea, Baltic Sea, English Channel and the Mediterranean region, leaving more ammonia in the gas phase, which would lead to an increase in dry deposition. In the north of the domain, the decrease in SIA would be mainly due to reduced formation of particulate nitrate, while the change around the Mediterranean would be caused mainly by decreased sulfate aerosol concentrations. One should also keep in mind that potentially higher temperatures in the future might increase the evaporation of ammonium nitrate to form its gaseous components NH3 and HNO3. Sensitivity tests with reduced NOx and NH3 emissions indicate a shift in the sensitivity of aerosol formation from NH3 towards NOx emissions between 1990 and 2030 in most of Europe except the eastern part of the model domain.

Short-Term Associations of Nitrogen Dioxide (NO2) on Mortality in 18 French Cities, 2010–2014

We present an analysis of short-term associations between ambient NO2 and mortality according to cause, age-group, and period (cold and warm) in 18 areas in metropolitan France for the 2010–2014 period. Associations were estimated in each area using a generalized additive Poisson regression model, and effects were summarized in a meta-analysis. The percentage increase in mortality rate was estimated for a 10 µg m−3 increase in the NO2 level in each area for each complete calendar year and for cold (November to April) and warm periods (May to October) in each year. We found that the NO2 increase (lag of 0–1 days) was associated with a 0.75% increase of non-accidental mortality for all age-groups (95% confidence interval (CI): (0.4; 1.10)). During the warm period, this NO2 increase was associated with a 3.07% increase in non-accidental mortality in the ≥75 years old group (95% CI: 1.97; 4.18). This study supports the short-term effects of NO2 as a proxy of urban traffic pollution on mortality, even for concentrations below the maximum guideline of 40 µg m−3 set down by the European Air Quality Standards and the World Health Organization (WHO).

Impacts of nature-based solutions on the urban atmospheric environment: a case study for Eindhoven, The Netherlands

Nature-based solutions (NBS) can provide answers to the challenges that urban areas are currently facing, associated with urban densification and climate change. The benefits of NBS are recognized, and include improved quality of life, human health and air quality, amongst others. This study aims to assess how NBS can contribute to temperature attenuation and air quality improvement in the city of Eindhoven (The Netherlands), through the application of the state-of-the-art WRF-Chem online air quality modelling system. The city is thereby characterized in terms of air quality related data, such as climatology, atmospheric emissions and air pollutant concentrations. From this assessment, different NBS were selected according to city aspirations. The WRF-Chem model was applied for baseline and NBS scenarios over the study area with a spatial resolution of 1 km x 1 km and an hourly time resolution for August 2013. The baseline scenario (without NBS) was validated by comparing the model results with monitored data retrieved from the European air quality monitoring database, showing an adequate model performance. The scenario simulations (with NBS) were performed by changing the land use in the model setup, and results were compared with the baseline scenario. Reductions in hourly temperature values of approximately 1 °C and reductions in pollutant concentrations, namely nitrogen dioxide (NO2), of approximately 10% were estimated after the application of the NBS in the Eindhoven study area. These results are particularly important to support public planners and decision-makers in understanding the effects and importance of NBS in their planning for more sustainable and resilient cities.

On the association between high outdoor thermo-hygrometric comfort index and severe ground-level ozone: A first investigation

According to the European Environment Agency, the year 2015 was the warmest on record to that point, with a series of heat waves from May to September resulted in high levels of tropospheric ozone. The implications of such a year on the human well-being and health are therefore of multiple nature and can be quantified referring to the exceedances of the corresponding thresholds. This work focused on the analysis of the May–September period of 2015 in the city of Milan (Italy) in terms of Mediterranean Outdoor Comfort Index (MOCI) and ozone concentrations, recorded by monitoring stations and modeled through the Weather Research and Forecasting model. Main findings show that thermo-hygrometric stress events (periods of at least six consecutive days characterized by daily maximum values of the MOCI higher than 0.5) are characterized by daily ozone higher than the guideline level of the World Health Organization (equal to 100 μgm−3). This means that thermo-hygrometric stress conditions are added up to poor air quality conditions, with severe risks for human health. Moreover, a daily MOCI-daily ozone correlation coefficient equal to 0.6 was found for the whole period. The degree of correspondence between ozone events (defined according to the European Air Quality Directive) and MOCI events was also investigated pointing out that 86% and 95% of days during ozone events are correctly predicted by events of recorded and modeled MOCI respectively, with a corresponding false alarm rate of 3% and 9%.

Site-scale modeling of surface ozone in Northern Bavaria using machine learning algorithms, regional dynamic models, and a hybrid model.

Ozone (O3) is a harmful pollutant when present in the lowermost layer of the atmosphere. Therefore, the European Commission formulated directives to regulate O3 concentrations in near-surface air. However, almost 50% of the 5068 air quality stations in Europe do not monitor O3 concentrations. This study aims to provide a hybrid modeling system that fills these gaps in the hourly surface O3 observations on a site scale with much higher accuracy than existing O3 models. This hybrid model was developed using estimations from multiple linear regression-based eXtreme Gradient Boosting Machines (MLR-XGBM) and O3 reanalysis from European regional air quality models (CAMS-EU). The binary classification of extremely high O3 events and the 1- and 24-h forecasts of hourly O3 were investigated as secondary aims. In this study thirteen stations in Northern Bavaria, out of which six do not monitor O3, were chosen as test sites. Considering the computational complexity of machine learning algorithms (MLAs), we also applied two recent MLA interpretation methods, namely SHapley Additive exPlanations (SHAP) and Local interpretable model-agnostic explanations (LIME). With SHAP, we showed an increasing effect of temperature on O3 concentrations which intensifies for temperatures exceeding 17°C. According to LIME, O3 concentration peaks are mainly governed by meteorological factors under dry and warm conditions on a regional scale, whereas local nitrogen oxide concentrations control base O3 concentrations during cold and wet periods. While recently developed MLAs for the spatial estimation of hourly O3 concentrations had a station-based root-mean-square error (RMSE) above 27μg/m3, our proposed model significantly reduced the estimation errors by about 66% with an RMSE of 9.49μg/m3. We also found that logistic regression (LR) and MLR-XGBM performed best in the site-scale classification and 24-h forecast of O3 concentrations (with a station-averaged accuracy and RMSE of 0.95 and 19.34μg/m3, respectively).

Mapping the susceptibility of UNESCO World Cultural Heritage sites in Europe to ambient (outdoor) air pollution

Air pollution, particularly in urban areas, is a concern for its negative effects on the materials of the built environment. Cities are also home to a large part of our cultural heritage. Air pollution accelerates the natural processes of deterioration of the materials of historic buildings and monuments, causing premature aging and reducing their aesthetic value. The present paper aims to assess the current potential damage due to air pollution on different materials through Europe. Several corrosion and soiling maps were produced by applying widely used dose-response functions. One of the priorities of this study was to provide an estimate of the effects of air pollution on UNESCO World Heritage cultural sites throughout Europe. The potential risk for cultural heritage monuments was estimated on the basis of exceeding tolerable degradation thresholds suggested for each material. The results show that, despite the significant improvements in air quality in Europe over the past few decades, air pollution is still considerable and continues to be an important agent of degradation of cultural heritage, particularly in anthropized areas. Although the methodology used in this study provides a simplified assessment of the likelihood of damage to UNESCO's cultural heritage in Europe from air pollution, it provides a unique perspective and the potential risk is assessed on a common basis. The results obtained contribute to a better understanding of the existing risk deriving from atmospheric pollution and to highlighting those sites, generally located in areas where anthropogenic activity is relevant, that need particular attention. The present paper can serve as a basis for stimulating additional studies and site-specific analyzes, as well as highlighting the need for further measures and policies for atmospheric pollution reduction in cities and in the surroundings of sensitive historic buildings and monuments to prevent further damage.

Vegetative status of children as a territorial bio-indicator of ecological safety

Vegetative status of children as a territorial bio-indicator of ecological safety

Early spring near-surface ozone in Europe during the COVID-19 shutdown: Meteorological effects outweigh emission changes

This paper analyses the impact of the control measures during the COVID-19 lockdown in Europe (15 March–30 April 2020) on 1-h daily maximum nitrogen dioxide (NO2) and maximum daily 8-h running average ozone (MDA8 O3) observations obtained from the European Environment Agency's air quality database (AirBase). Daily maximum NO2 decreased consistently over the whole continent, with relative reductions ranging from 5% to 55% with respect to the same period in 2015–2019 for 80% of the sites considered (10th – 90th percentiles). However, MDA8 O3 concentrations showed a different pattern, decreasing over Iberia and increasing elsewhere. In particular, a large region from northwestern to central Europe experienced increases of 10–22% at urban background stations, reaching typical values of the summer season. The analysis of the expected NO2 and O3 concentrations in the absence of the lockdown, using generalised additive models fed by reanalysis meteorological data, shows that the low NO2 concentrations were mostly attributed to the emission reductions while O3 anomalies were dominated by the meteorology. The relevance of each meteorological variable depends on the location. The positive O3 anomalies in northwestern and central Europe were mostly associated with elevated temperatures, low specific humidity and enhanced solar radiation. This pattern could be an analogue to study the limits of pollution control policies under climate change scenarios. On the other hand, the O3 reduction in Iberia is mostly attributable to the low solar radiation and high specific humidity, although the reduced zonal wind also played a role in the proximity of the Iberian Mediterranean coast.

Changes in ozone and PM2.5 in Europe during the period of 1990–2030: Role of reductions in land and ship emissions

Air pollution is among the top threats to human health and ecosystems despite the substantial decrease in anthropogenic emissions. Meanwhile, the role of ship emissions on air quality is becoming increasingly important with the growing maritime transport and less strict regulations. In this study, we modeled the air quality in Europe between 1990 and 2030 with ten-year intervals, using the regional air quality model CAMx version 6.50, to investigate the changes in the past (1990–2010) as well as the effects of different land and ship emission scenarios in the future (2020,2030). The modeled mean ozone levels decreased slightly during the first decade but then started increasing again especially in polluted areas. Results from the future scenarios suggest that by 2030 the peak ozone would decrease, leading to a decrease in the days exceeding the maximum daily 8-h average ozone (MDA8) limit values (60 ppb) by 51% in southern Europe relative to 1990. The model results show a decrease of 56% (6.3 μg m−3) in PM2.5 concentrations from 1990 to 2030 under current legislation, mostly due to a large drop in sulfate (representing up to 44% of the total PM2.5 decrease during 1990–2000) while nitrate concentrations were predicted to go down with an increasing rate (10% of total PM2.5 decrease during 1990–2000 while 36% during 2020–2030). The ship emissions if reduced according to the maximum technically feasible reduction (MTFR) scenario were predicted to contribute up to 19% of the decrease in the PM2.5 concentrations over land between 2010 and 2030. Ship emission reductions according to the MTFR scenario would lead to a decrease in the days with MDA8 exceeding EU limits by 24–28% (10–14 days) around the coastal regions. The results obtained in our study show the increasing importance of ship emission reductions, after a relatively large decrease in land emissions was achieved in Europe.

Impact of Saharan dust exposure on airway inflammation in patients with ischemic heart disease

Epidemiological studies found that increases in the concentrations of airborne particulate matter (PM) smaller than 10 microns diameter (PM10) in the ambient air due to desert dust outbreaks contribute to global burden of diseases, primarily as a result of increased risk of cardiovascular morbidity and mortality. No studies have investigated the possible association between desert dust inhalation and airway inflammation in patients with ischemic heart disease (IHD). Induced sputum was collected in 38 patients and analyzed to determine markers of airway inflammation (Transforming Growth Factor-β1 [TGF-β1] and hydroxyproline) concentrations. For the purpose of the investigation, PM10 and reactive gases concentrations measured in the European Air Quality Network implemented in the Canary Islands were also used. We identified Saharan desert dust using meteorology and dust models. Patients affected by smoking, chronic obstructive pulmonary disease (COPD), asthma, pulmonary abnormalities, acute bronchial or pulmonary disease were excluded. The median of age of patients was 64.71 years (56.35-71.54) and 14 (38.84%) of them were women. TGF-β1 and hydroxyproline in sputum were highly associated to PM10 inhalation from the Saharan desert. According to a regression model, an increase of 1 µg/m3 of PM10 concentrations due to desert dust, results in an increase of 3.84 pg/gwt of TGF-β1 (R2 adjusted = 89.69%) and of 0.80 μg/gwt of hydroxyproline (R2 adjusted = 85.28%) in the sputum of patients. The results of this study indicate that the exposure to high PM10 concentrations due to Saharan dust events are associated with intense inflammatory reaction in the airway mucosae of IHD-patients.

Impacto del polvo sahariano en la incidencia de síndrome coronario agudo

Introduction and objectivesAsian desert dust has recently been recognized as a trigger for acute myocardial infarction. The inflow of dust from the Sahara into Spain impairs air quality due to an increase in particulate matter concentrations in the ambient air. The aim of the present study was to elucidate whether Saharan dust events are associated with the incidence of acute coronary syndrome (ACS) in patients living near North Africa, the major global dust source. MethodsWe prospectively collected data on hospitalizations due to ACS in 2416 consecutive patients from a tertiary care hospital (Canary Islands, Spain) from December 2012 to December 2017. Concentrations of particulate matter with an aerodynamic diameter 10 microns or smaller (PM10) and reactive gases were measured in the European Air Quality Network implemented in the Canary Islands. We applied the time-stratified case crossover design using conditional Poisson regression models to estimate the impact of PM10 Saharan dust events on the incidence of ACS. ResultsThe occurrence of Saharan dust events observed 0 to 5 days before the onset of ACS was not significantly associated with the incidence of ACS. Incidence rate ratios (IRR) of PM10 levels 1, 2, 3, 4 and 5 days before ACS onset (for changes in 10μg/m3) were 1.27 (95%CI, 0.87-1.85), 0.92 (95%CI, 0.84-1.01), 0.74 (95%CI, 0.45-1.22), 0.98 (95%CI, 0.87-1.11), and 0.95 (95%CI, 0.84-1.06), respectively. ConclusionsExposure to Saharan desert dust is unlikely to be associated with the incidence of ACS.