A.M. Costa

Procedures for estimation of modelling uncertainty in air quality assessment

The main objectives of this work focus, firstly, on a review of the current existent methodologies to estimate air quality modelling uncertainty, and, secondly, in the preparation of guidelines for modelling uncertainty estimation, which can be used by local and regional authorities responsible for air quality management. From the application exercise, it was concluded that it is possible to define a subset of statistical parameters able to reproduce the general uncertainties estimation. Concerning the quality indicators defined by EU directives, the results show that the legislated uncertainty estimation measures are ambiguous and inadequate in several aspects, mainly in what concerns the error measures for hourly and daily indicators based on the highest observed concentration. A relative error at the percentile correspondent to the allowed number of exceedances of the limit value was suggested and tested, showing that is a more robust and appropriate parameter for model performance evaluation.

COST 732 in practice: the MUST model evaluation exercise

The aim of this paper is to describe the use of a general methodology tailored to the evaluation of micro-scale meteorological models applied to flow and dispersion simulations in urban areas. This methodology, developed within COST 732, has been tested through a large modelling exercise involving many groups across Europe. The major test case used is the Mock Urban Setting Test (MUST) experiment representing an idealised urban area. It is emphasised that a full model evaluation is problem-dependent and requires several activities including a statistical validation that requires a careful choice of the metrics for the comparison with measurements.

INTEGRATED MODELING OF ROAD TRAFFIC EMISSIONS: APPLICATION TO LISBON AIR QUALITY MANAGEMENT

The application of three distinct modeling tools to deal with Lisbon atmospheric problems is presented. Information and forecasting system for private and public transport (VISUM), Transport Emission Model for Line Sources (TREM) and Variable Dispersion (VADIS) models were used to characterize the traffic fluxes, to quantify the emission amounts, and finally to evaluate the air quality in a specific area of the city characterized by intense traffic respectively. The results show the benefit of integrated use of the modeling tools VISUM and TREM to estimate the atmospheric emissions induced by traffic. On the other hand, the results obtained with VADIS are in acceptable agreement with the measured air quality data.

Advanced Numerical Methods for Complex Environmental Models: Needs and Availability

The understanding of lakes physical dynamics is crucial to provide scientifically credible information foron lakes ecosystem management. We show how the combination of in-situ dataobservations, remote sensing observationsdata and three15 dimensional hydrodynamic (3D) numerical simulations is capable of deliveringresolving various spatio-temporal scales involved in lakes dynamics. This combination is achieved through data assimilation (DA) and uncertainty quantification. In this study, we presentdevelop a flexible framework forby incorporating DA into lakes three-dimensional3D hydrodynamic lake models. Using an Ensemble Kalman Filter, our approach accounts for model and observational uncertainties. We demonstrate the framework by assimilating in-situ and satellite remote sensing temperature data into a three-dimensional3Dl hydrodynamic 20 model of Lake Geneva. Results show that DA effectively improves model performance over a broad range of spatio-temporal scales and physical processes. Overall, temperature errors have been reduced by 54 %. With a localization scheme, an ensemble size of 20 members is found to be sufficient to derive covariance matrices leading to satisfactory results. The entire framework has been developed for the constraintswith a goal of near real-time operational systems and near real-time operations (e.g. integration into meteolakes.ch). 25

Towards uncertainty mapping in air-quality modelling and assessment

The aim of this paper is to promote the use of uncertainty mapping when spatial assessments of air quality are made. A large number of air quality maps are produced for scientific and policy purposes but rarely are corresponding maps of their uncertainty included. The need for such maps and the methods to produce them are described. Several uncertainty parameters are discussed but it is recommended to use the probability density function as the basis of the uncertainty estimates. Several examples are provided discussing indicative uncertainty, ensemble methods, comparisons with observations, spatial representativeness, uncertainty in exceedances and probability of exceedance.

Recommendations for the spatial assessment of air quality resulting from the FP6 EU project Air4EU

Air4EU is an FP6 European project with the major aim of providing recommendations on methodologies for the spatial assessment of air quality on local, urban and regional scales. The emphasis is on methodologies that combine monitoring and modelling and on spatial assessment for regulatory purposes, i.e., the EU daughter directives. The recommendations coming from Air4EU are intended as guidance for authorities involved in air quality assessment at the city, national and European levels as well as institutes involved in air quality research and application. This paper provides some highlights from the recommendations and case studies that emerged from the project.

Improve screening of HCV infection by targeting high prevalence aged groups: analysis of a cohort of HCV and HIV co-infected patients

Hepatitis C constitutes a major public health burden. In Portugal, the prevalence is estimated at 1–1.5% [ 1 ]. Of these, only 30% are presumed to be diagnosed, which reveals that most infections go unknown. The objective of this study is to identify the age‐range distribution at HCV diagnosis and to identify the high‐prevalence birth groups that could be targeted for screening, as a strategy to increase diagnosis and identify patients who would benefit most from treatment.

Urban Population Exposure to Particulate Air Pollution Induced by Road Transport

In the last years, there has been an increase of scientific studies confirming that longand short-term exposure to particulate matter pollution leads to adverse health effects. The determination of accumulated human exposure in urban areas (in the present study focused on Lisbon) is the main objective of the current work combining information on concentrations at different microenvironments and population timeactivity pattern data. A link between a mesoscale meteorological model and a local scale model (Computational Fluid Dynamics’ based) was developed to define the boundary conditions for the local scale application. The time-activity pattern of the population was derived from statistical information for different sub-population groups and linked to digital city maps. Finally, the hourly PM10 concentrations for indoor and outdoor microenvironments were estimated for the Lisbon city centre based on the local scale air quality model application for a chosen day. The developed methodology is a first approach to estimate population exposure, calculated as the total daily values above the thresholds recommended for longand short-term health effects. Obtained results reveal that, in fact, in Lisbon city centre a large number of persons are exposed to particulate matter (PM) levels overpassing the legislated limit value. To get more accurate and consistent conclusions, a larger study, including a series of single days, should be performed.

Air Pollution and Health Effects

The quality of the air we breathe is still a major concern to human health. Notwithstanding the air pollution mitigation efforts that have been pursued since the last half of the twentieth century, the World Health Organization estimates that more than two million premature deaths each year can be attributed to the effects of urban outdoor air pollution and indoor air pollution. This chapter addresses the evolution of knowledge on the relationship between air pollution and human health, since the first records until nowadays. It also reviews the current approaches to do health impact assessment and the common air pollution – health indicators. A particular case study based on a chain of events, from emissions to the atmosphere until health, passing through exposure and inhaled dose, illustrates how this approach can be explored, providing useful and concrete information.