Ana Patrícia Fernandes

Air quality modelling as a supplementary assessment method in the framework of the European Air Quality Directive

According to the European Air Quality (AQ) Directive, member states must annually report their AQ to the European Commission (EC). This report can be based on modelling data if the concentration levels do not exceed the established lower assessment thresholds (LAT), or on combined data from modelling and monitoring systems (supplementary assessment methods) if concentrations levels are below the upper assessment threshold (UAT). This work presents and applies a methodology that combines air pollutant concentration values from monitored data and from a numerical modelling system to deliver AQ information for Portugal in 2010. This methodology produces improved information, especially for areas where the amount of fixed monitoring stations is sparse or non-existent, allowing obtaining a better and broader overview of the AQ in Portugal to support AQ reporting to the European Commission.

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.

Elemental Distribution in the Human Respiratory System and Excretion Organs: Absorption and Accumulation

In order to initiate a reference data base for the respiratory system and to understand the effects of airborne substances on human health, different sites of the respiratory ducts and respiratory tissue were analysed. Excretion organs related to the removal of inhaled constituents were also assessed in order to infer excretion rates of the chemical species found in the respiratory system. PIXE was applied to the determination of minor and trace elemental contents of trachea, bronchi, lung, liver and kidney samples. Two groups of elements were established: the constitutive elements, known to be essential to cellular metabolism (K, Ca, Mn, Fe, Cu, Zn, Se, Rb and Sr), and the accumulated elements of exogenous origin (Ti, V, Cr, Ni, Zr and Pb). The different patterns of elemental accumulation at excretion organs and in the respiratory system suggest differences in the aerodynamic properties and in the chemical affinities or reactivity of inhaled particulate matter with cells.

Hydrocarbons in particulate samples from wildfire events in central Portugal in summer 2010

In summer 2010, twenty eight (14 PM2.5 samples plus 14 samples PM2.5-10) smoke samples were collected during wildfires that occurred in central Portugal. A portable high-volume sampler was used to perform the sampling, on quartz fibre filters of coarse (PM2.5-10) and fine (PM2.5) smoke samples. The carbonaceous content (elemental and organic carbon) of particulate matter was analysed by a thermal-optical technique. Subsequently, the particulate samples were solvent extracted and fractionated by vacuum flash chromatography into three different classes of organic compounds (aliphatics, polycyclic aromatic hydrocarbons (PAHs) and carbonyl compounds). The organic speciation was performed by gas chromatography-mass spectrometry (GC-MS). Emissions were dominated by the fine particles, which represented around 92% of the PM10. A clear predominance of carbonaceous constituents was observed, with organic to elemental carbon (OC/EC) ratios ranging between 1.69 and 245 in both size fractions. The isoprenoid ketone 6,10,14-trimethyl-2-pentadecanone, a tracer for secondary organic aerosol formation, was one of the dominant constituents in both fine and coarse particles. Retene was the most abundant compound in all samples. Good correlations were obtained between OC and both aliphatic and PAH compounds. Pyrogenic processes, thermal release of biogenic compounds and secondary processing accounted for 97% of the apportioned PM2.5 levels.

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

The acknowledgment of the original article should read as follows:

Modelling Resilient Measures to Climate Change Impacts on Urban Air Quality

Considering different resilience measures such as the increase of urban green areas and the application of white roofs, a set of resilience scenarios were evaluated with a cascade of numerical models (MPI-ESM-LR/WRF/CAMx) using as case study a future heat wave occurring in Porto (Portugal) urban area. Meteorological forcing and boundary data was derived from the CMIP5 earth system model MPI-ESM (Representative Concentration Pathway RCP 8.5) downscaled to Porto urban area. The influence of different resilience scenarios on the air quality was quantified and compared for the different scenarios. The results show that all tested measures lead to an increased resilience to CC impacts, promoting the reduction of ozone concentrations. The application of green roofs was the measure that shows more benefits to air quality.