Impact of bioethanol fuel implementation in transport based on modelled acetaldehyde concentration in the urban environment.

This study shows the results obtained from emission and air dispersion modelling of acetaldehyde in the city of Oslo and associated with the circulation of bioethanol vehicles. Two scenarios of bioethanol implementation, both realistic and hypothetical, have been considered under winter conditions; 1) realistic baseline scenario, which corresponds to the current situation in Oslo where one bus line is running with bioethanol (E95; 95% ethanol-5% petrol) among petrol and diesel vehicles; and 2) a hypothetical scenario characterized by a full implementation of high-blend bioethanol (i.e. E85) as fuel for transportation, and thus an entire bioethanol fleet. The results indicate that a full implementation of bioethanol will have a certain impact on urban air quality due to direct emissions of acetaldehyde. Acetaldehyde emissions are estimated to increase by 233% and concentration levels increase up to 650% with regard to the baseline.

Spatial mapping of ozone and SO2 trends in Europe.

This article investigates the spatial mapping of temporal trends in air quality for all of Europe. Such spatially distributed maps provide information for policy making and for understanding the spatial character of air quality trends. Previous trend studies have concentrated on individual, or groups of, monitoring sites looking at the trends of these. In this study use is made of statistical interpolation methods that combine observed and modelled data in an optimised way. Log-normal residual kriging with multiple linear regression is used to produce annual maps of air quality indicators for ozone (AOT40; Accumulated Dose of Ozone Over a Threshold of 40 ppb) and SO(2) (annual mean) for the period 1996-2005. Trends in these maps are then calculated and their significance and uncertainty are assessed. The methodology is effectively used for mapping SO(2) trends to a significant level in most of Europe. However, trends in AOT40 are less clearly defined since the uncertainty is generally of the same order as, or greater than, the calculated trends. A general north to south gradient in AOT40 trends can be seen, with downward trends in the UK and Scandinavia but upward trends in the Mediterranean region.