The pandemic caused by coronavirus COVID-19 is having a worldwide impact that affects health, the economy and indirectly affects the air pollution in cities. In Portugal, the number of cases ...increased continually (32700 confirmed cases as of May 31, 2020), which has affected the health system and caused movement restrictions which in turn affects the air pollution in the country. This article analyses the indirect effect produced by this pandemic on air pollution in Portugal, by comparison of data from a period of movement restriction of the citizens by the government – COVID lockdown period (March–May 2020) with data from baseline conditions (mean of the mirrored periods from the five previous years (March–May from 2015 to 2019)). Air quality data – in particular NO2 and PM10 hourly concentration - from more than 20 monitoring stations spread over mainland Portugal was used to perform this evaluation. The mean reduction observed on pollutant concentrations was higher for NO2 (41%) than for PM10 (18%). For NO2, mean reductions were more significant in traffic (reaching values higher than 60% in some monitoring stations) and background urban sites than in rural stations. The reduction of NO2 concentration observed in traffic sites were compared to the estimation of traffic contribution by the incremental method, suggesting that this latter approach is not consistent (lower in same sites and higher in others) and alerting to the careful use of this approach in future works.
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•The effect of COVID lockdown on air quality (NO2 and PM10) in Portugal was assessed.•Average reductions of 41% and 18% were observed for NO2 and PM10, respectively.•The NO2 and PM10 reductions occurred mainly at urban areas.•Based on observed reductions, NO2 concentrations traffic contribution reaches >60%.•Incremental method was tested and inconsistencies on traffic contribution were found.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Toxic metals as arsenic (As), cadmium (Cd), nickel (Ni), and lead (Pb) exist in the atmosphere as particulate matter components. Their concentration levels in the European Union (EU) are regulated by ...European legislation, which sets target and limit values as annual means, and by the World Health Organization (WHO) that defines guidelines and reference values for those metal elements. Modelling tools are recommended to support air quality assessment regarding the toxic metals; however, few studies have been performed and those assessments rely on discrete measurements or field campaigns. This study aims to evaluate the capability of air quality modelling tools to verify the legislation compliance concerning the atmospheric levels of toxic elements and to identify the main challenges and limitations of using a modelling assessment approach for regulatory purposes, as a complement to monitoring. The CAMx air quality model was adapted and applied over Porto and Lisbon urban regions in Portugal at 5 × 5-km
2
and 1 × 1-km
2
horizontal resolution for the year 2015, and the results were analysed and compared with the few measurements available in three locations. The comparison between modelled and measured data revealed an overestimation of the model, although annual averages are much lower than the regulated standards. The comparison of the 5-km and 1-km resolutions’ results indicates that a higher resolution does not necessarily imply a better performance, pointing out uncertainties in emissions and the need to better describe the magnitude and spatial allocation of toxic metal emissions. This work highlighted that an increase of the spatial and temporal coverage of monitoring sites would allow to improve the model design, contribute to a better knowledge on toxic metals atmospheric emission sources and to increase the capacity of models to simulate atmospheric particulate species of health concern.
Quantifying the impact of air pollution on the public's health has become an increasingly critical component in policy discussion. Recent data indicate that more than 70% of the world population ...lives in cities. Several studies reported that current levels of air pollutants in urban areas are associated with adverse health risks, namely, cardiovascular diseases and lung cancer. IARC recently classified outdoor air pollution and related particulate matter (PM) as carcinogenic to humans. Despite the air quality improvements observed over the last few years, there is still continued widespread exceedance within Europe, particularly regarding PM and nitrogen oxides (NOx). The European Air Quality Directive 2008/50/EC requires Member States to design appropriate air quality plans for zones where air quality does not comply with established limit values. However, in most cases, air quality is only quantified using a combination of monitored and modeled data and no health impact assessment is carried out. An integrated approach combining the effects of several emission abatement measures on air quality, impacts on human health, and associated implementation costs enables an effective cost-benefit analysis and an added value to the decision-making process. Hence, this review describes the basic steps and tools for integrating health into air quality assessment (health indicators, exposure-response functions). In addition, consideration is given to two major outdoor pollutants: PM and NO
2
. A summary of the health metrics used to assess the health impact of PM and NO
2
and recent epidemiologic data are also described.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
Particulate matter represents a serious hazard to human health, and air quality models contribute to the understanding of its dispersion. This study describes particulate matter with a ≤10 μm ...diameter (PM10) dynamics in an urban–industrial area, through the comparison of three datasets: modeled (TAPM—The Air Pollution Model), measured concentration (environmental control stations—ECS), and leaf deposition values. Results showed a good agreement between ECS and TAPM data. A steel plant area was used as a PM10 emissions reference source, in relation to the four sampling areas, and a distance/wind-based factor was introduced (Steel Factor, SF). Through SF, the three datasets were compared. The SF was able to describe the PM10 dispersion values for ECS and leaf deposition (r2 = 0.61–0.94 for ECS; r2 = 0.45–0.70 for leaf); no relationship was found for TAPM results. Differences between measured and modeled data can be due to discrepancies in one district and explained by a lack of PM10 inventory for the steel plant emissions. The study suggests the use of TAPM as a suitable tool for PM10 modeling at the urban scale. Moreover, tree leaves are a low-cost tool to evaluate the urban environmental quality, by providing information on whether and when data from leaf deposition can be used as a proxy for air pollution concentration. Further studies to include the re-suspension of particles as a PM10 source within emission inventories are suggested.
Atmospheric particles are a major environmental health risk. Assessments of air pollution related health burden are often based on outdoor concentrations estimated at residential locations, ignoring ...spatial mobility, time-activity patterns, and indoor exposures. The aim of this work is to quantify impacts of these factors on outdoor-originated fine particle exposures of school children.
We apply nested WRF-CAMx modelling of PM2.5 concentrations, gridded population, and school location data. Infiltration and enrichment factors were collected and applied to Athens, Kuopio, Lisbon, Porto, and Treviso. Exposures of school children were calculated for residential and school outdoor and indoor, other indoor, and traffic microenvironments. Combined with time-activity patterns six exposure models were created. Model complexity was increased incrementally starting from residential and school outdoor exposures.
Even though levels in traffic and outdoors were considerably higher, 80–84% of the exposure to outdoor particles occurred in indoor environments. The simplest and also commonly used approach of using residential outdoor concentrations as population exposure descriptor (model 1), led on average to 26% higher estimates (15.7 μg/m3) compared with the most complex model (# 6) including home and school outdoor and indoor, other indoor and traffic microenvironments (12.5 μg/m3). These results emphasize the importance of including spatial mobility, time-activity and infiltration to reduce bias in exposure estimates.
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•Exposure to outdoor PM2.5 varies considerably depending on the modelling approach.•Exposure occurs mainly indoors, although infiltration decreases the concentrations.•Inclusion of school and traffic microenvironments increased the exposure estimates.•Indoor-generated sources potentially important contributors to the total exposure.•Time-activity, spatial mobility and infiltration important in exposure modelling
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This study systematically examines the global uncertainties and biases in the carbon dioxide (CO2) mixing ratio provided by the Copernicus Atmosphere Monitoring Service (CAMS). The global greenhouse ...gas re-analysis (EGG4) data product from the European Centre for Medium-Range Weather Forecasts (ECMWF) was evaluated against ground-based in situ measurements from more than 160 of stations across the world. The evaluation shows that CO2 re-analysis can capture the general features in the tracer distributions, including the CO2 seasonal cycle and its strength at different latitudes, as well as the global CO2 trend. The emissions and natural fluxes of CO2 at the surface are evaluated on a wide range of scales, from diurnal to interannual. The results highlight re-analysis compliance, reproducing biogenic fluxes as well the observed CO2 patterns in remote environments. CAMS consistently reproduces observations at marine and remote regions with low CO2 fluxes and smooth variability. However, the model’s weaknesses were observed in continental areas, regions with complex sources, transport circulations and large CO2 fluxes. A strong variation in the accuracy and bias are displayed among those stations with different flux profiles, with the largest uncertainties in the continental regions with high CO2 anthropogenic fluxes. Displaying biased estimation and root-mean-square error (RMSE) ranging from values below one ppmv up to 70 ppmv, the results reveal a poor response from re-analysis to high CO2 mixing ratio, showing larger uncertainty of the product in the boundaries where the CAMS system misses solving sharp flux variability. The mismatch at regions with high fluxes of anthropogenic emission indicate large uncertainties in inventories and constrained physical parameterizations in the CO2 at boundary conditions. The current study provides a broad uncertainty assessment for the CAMS CO2 product worldwide, suggesting deficiencies and methods that can be used in the future to overcome failures and uncertainties in regional CO2 mixing ratio and flux estimates.
Urban mobility accounts for 38 and 19% of nitrogen oxide (NO
x
) and particulate matter (PM) emissions at European urban areas, respectively. Despite of all the technological development around ...automobile industry, urban areas are still facing problems related to exposure to high levels of air pollutants. Increasing the accuracy of both emissions and air quality modelling from road traffic is a key-issue for the management of air pollution in road transport sector. This study assessed the influence of using different road traffic emission models on the accuracy of air quality modelling with street-level resolution, having as a case study an urban area located on the centre region of Portugal. Two emission models, with different complexity levels regarding the ability to characterise the traffic dynamics were analysed, namely, transport emission model for line sources (TREM) and vehicle-specific power (VSP), based on data obtained in an experimental campaign. To perform the air quality simulations, the pollutant dispersion in the atmosphere under variable wind conditions (VADIS) model was used and two pollutants were analysed: NO
x
and PM10. The results showed that the magnitude of PM10 and NO
x
concentrations were result of a conjoint influence of traffic dynamics and meteorological conditions. Comparison between measured and modelled data showed that the VADIS model could track the evolution of NO
x
levels, for both emission models considered, displaying a high correlation (> 0.8) between traffic-related NO
x
emissions and NO
x
concentrations. For PM10, VADIS model is more sensitive to the differences in the emissions calculation; however, it was observed that the traffic-related PM10 emissions accounts 1.3–8.4% to the PM10 concentration levels at the study area.
The pandemic caused by coronavirus SARS-CoV-2 (associated to the disease named COVID-19) is having a global impact that affects health, the economy and the environment. These impacts are negative in ...most of the sectors but benefits also occurred in specific fields. Tourism was one of the most negatively affected economic sectors, and in terms of benefits, the improvement of air quality can be highlighted, with positive health implications. This paper aims to evaluate the impacts on these two particular fields—tourism and air quality—focusing on Portugal due to the relevance of tourism in the country. The research carried out in this paper enables us to find the most critical areas and identifies lessons learnt and recommendations for the post-COVID period. Tourism and air quality data were collected for both 2019 and 2020 and compared in terms of quantitative and spatial analysis. The Lisbon metropolitan area—the geographical area where the capital of the country is located—was the area that suffered the most negative impacts in terms of tourism activity but was also the one where highest benefits in terms of air pollution reduction and human exposure were felt. Recommendations for future strategies are suggested, including new concepts of tourism connected to the environment; the investment in online/virtual tourism activities; promotion of the domestic market; mitigation of the over-tourism problem and using environmental issues, such as air quality, as new attractiveness criteria for tourism destinations.
Air quality in Europe has been improving over the last decades. Notwithstanding, urban areas are still facing exceedances of the Air Quality Directive's limit and target values. In this study, we ...analyzed the effect of two mitigation measures on urban air quality: i) improvement of the biomass residential combustion appliances, and ii) electrification of passenger's cars fleet. Five European cities (Lisbon and Porto - Portugal, Athens - Greece, Kuopio - Finland, and Treviso - Italy) were used as case studies to evaluate the impact of the measures on the fine particle fraction (PM2.5) concentrations. To facilitate decision making and the quick test of new measures, the LIFE Index-Air tool was developed. In this tool, the air pollutant concentrations are predicted by Artificial Neural Networks trained using a set of air quality modelling simulations. The results indicate that the replacement of old biomass heating systems by new improved fireplaces can be more effective in Treviso. On the other hand, the replacement of gasoline and diesel passenger vehicles by electric ones seems to be more effective in reducing PM2.5 concentrations over Lisbon, Porto, and Athens. In Kuopio, both mitigation measures have an identical effect.
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•The scenario building module can quickly estimate PM2.5 concentrations.•In Athens, Porto and Lisbon, the focus should be on road traffic electrification.•In Kuopio and Treviso, the focus should be on residential combustion measures.•In addition to passenger vehicles, electrification of other vehicles is suggested.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Air quality degradation due to road traffic emissions is one of the topics of major interest for the scientific community and urban planners worldwide. Cabo Verde does not have regulations for ...traffic emission control or air quality guidelines, although the number of road vehicles has grown steadily over the past decade. Moreover, studies focusing on the impact of road transport on air quality in this archipelago are sparse. In this study, we present a first detailed air pollutant inventory of road traffic emissions through a bottom-up methodology, along with snapshots of the state of air quality on the islands of Santiago, São Vicente, and Sal. For the year 2017, emission estimates for the main island (Santiago) are 654 tons of CO, 35 tons of PM
10
, 562 tons of NO
x
, and 84 tons of NMVOCs. The air quality assessment was carried out using the TAPM model for a period of 6 months from January to July 2017. The results showed that the mean concentration values for Sao Vicente, Sal, and Santiago Islands ranged between 2.0 and 18 μg m
−3
for NO
2
and 3.8 and 5.6 μg m
−3
for PM
10
. NO
2
concentrations show an increasing trend from January to July in Santiago and Sal, and no clear trend in São Vicente Island. The simulated PM
10
concentrations showed values in the same range over the year, even though they appeared slightly higher in July than in January. It was observed that both NO
2
and PM
10
average concentrations have been consistently above healthful levels, according to air quality guidelines fixed by the WHO.
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