C. Gama

How healthy will be the air quality in 2050

The air quality standards defined by the World Health Organization (WHO), and updated in 2005, continue to be much more exigent than current EU legislation, namely regarding the most critical pollutants over Europe: ozone (O3) and particulate matter (PM10 and PM2.5). This work intends to evaluate the fulfilment of these WHO standards in the present and in the future, including climate change effects. This study will be focused on Portugal, where each year, the O3 and PM10 concentrations exceed the legislated limit values. For this, regional air quality simulations for present and future periods were conducted, with CAMx version 6.0, to investigate the impacts of climate change and anthropogenic emission projections on air quality over Portugal in 2050. The climate and emission projections for 2050 were derived from the Representative Concentrations Pathway 8.5 scenario. Modelling results show that, over Portugal, the WHO standards are already not being fulfilled and will continue to be surpassed in the future. When considering climate change and projected anthropogenic emissions and comparing them to the actual scenario, a reduction in the maximum 8-h daily O3 concentration is expected. For PM, the results indicate serious problems regarding the health impact expected for both long-term and short-term exposure. The annual averages for both PM10 and PM2.5 exceed the AQG over the country. The PM short-term exposure is already very high for current conditions and higher impacts are expected for future scenario, in particular regarding the PM10 values. This air quality degradation is caused by the warmer and dryer conditions and the increase of background concentrations of pollutants expected for the 2050 climate. The results evidence that human health protection will be even more critical in the future, particularly for particulate matter. Furthermore, urgent air quality management strategies need to be designed, with transboundary cooperation and implementation.

Towards an improved air quality index

Air quality indices (AQI) are commonly used to indicate the level of severity of air pollution to the public. A number of methods were developed in the past by various researchers/environmental agencies for the calculation of AQI, but there is no universally accepted method, appropriate for all situations. An updated review of the major air quality indices developed worldwide is presented in this paper. These methods differentiate mainly in the number of pollutants included, its sampling period and air quality classes and breakpoints. When applying different AQI to a common case study, important differences are found in terms of the classification of the quality of the air. The purposes of this research are to identify weaknesses of the current AQI and to discuss possible changes and updates with Portugal as case study. A survey, with 10 questions about the calculation and use of the AQI and its dissemination to public, was delivered to the five regional environmental agencies in Portugal and, based on results, modifications to the current AQI are proposed. Two main changes—inclusion of PM2.5 and specific urban/industrial AQI—were tested, comparing the current and the proposed AQI along the 2014 year. It is observed that a significant difference exists when specific urban and industrial sites are considered when calculating the AQI. On the other hand, and contrarily to other regional studies, the results show that the inclusion of fine suspended particulate (PM2.5) does not impact the final AQI value.

Investigating ozone episodes in Portugal: a wavelet-based approach

During the summer season, ozone concentrations regularly exceed the legislation limits in the North of Portugal, namely at Douro Norte monitoring station. The origin of such ozone episodes has been widely reported in several studies although uncertainties regarding its origin still remain. This work intends to investigate how the ozone concentrations measured at the Douro Norte nearest stations, located at west and east directions, are related to those measured at Douro Norte by means of coherence and phase transformations methods. The episodes were selected according to the magnitude of the hourly ozone peaks and the occurrence of exceedances of the threshold value at least in two sites. The results point out that 60 % of the selected episodes highlight significant dependence between Douro Norte station and the other two monitoring sites, with different phase signal and a delay range from 2 to 4 h.

How important are maritime emissions for the air quality: At European and national scale

Due to its dependence on fossil fuel combustion, emissions from the marine transport sector can significantly contribute to air pollution. This work aims to evaluate the impact of maritime transport emissions on air quality in Portugal using a numerical air quality modelling approach, with high-resolution emission data. Emissions from the European TNO inventory were compiled and pre-processed at hourly and high spatial (∼3 × 3 km2) resolutions. Scenarios with and without these maritime emissions were then simulated with the WRF-CHIMERE modelling system, extensively tested and validated for Portugal domain, in order to evaluate their impact on air quality. A simulation was performed for one year (2016) and the resulting differences were analysed in terms of spatial distribution, time series and deltas. The main deltas for NO2 and PM10 are located over international shipping routes and major ports, while O3 concentrations are impacted in a larger area. The modelling results also indicate that shipping emissions are responsible for deltas in the concentration of NO2 higher than 20% over specific urban areas located in the west coast of Portugal, and less than 5% for PM10. For O3 the relative contribution is low (around 2%) but this contribution is also observed at locations more than 50 km from the coast.

Correction to: How healthy will be the air quality in 2050?

The acknowledgment of the original article should read as follows:

Current European AQ Planning at Regional and Local Scale

This chapter provides a review, derived from the extended survey conducted within the APPRAISAL project, of the integrated assessment methodologies used in different countries to design air quality plans and to estimate the effects of emission abatement policy options on human health.