Issue 2

The surface ozone is a pollutant of major concern due to its impact on receptors, at currently occurring ambient levels in many regions of the world. The aim of this work is to present the results derived from an analysis of hourly surface ozone concentrations, measured at the urban station of Volos, a coastal medium-sized city at the eastern seaboard of Central Greece, during the 8-year period 2001-2008. The regional climate that is characterized by hot and dry summers with intense sunshine plays an important role in the observed exceedances of the air quality ozone limits. The analysis showed that, ozone diurnal patterns depict daytime photochemical ozone built up, during the sunlight hours of the day. It is remarkable that the maximum daily 8-h averages often exceeded the standard value that is assigned by the EU Directive for human health protection, during almost the warm period of the year, mainly at noon and afternoon hours.

Abstract

Spatial and temporal variation of fine particulate pollution in a complex small coastal city, Macau, was investigated by using a mobile air quality monitoring platform. Real-time street level measurements of aerosol size distribution were carried out three times per day by using an on-board wide-range particle spectrometer along a designed route covering the main area of the city for one week. The measured distributions were then transformed into PM2.5 mass concentrations for assessment based on an empirical relation estimated from a co-located measurement calibration process. Within this week, the averaged PM2.5 mass concentrations of the morning, afternoon, and evening sessions are 51.76 μg m-3, 28.87 μg m-3 and 30.77 μg m-3, respectively. By comparing the spatial statistics of the estimated PM2.5 concentrations with the US 24-hour primary NAAQS as a reference, a significant probability of exceedance (> 86%) was observed in 1/3 of the monitoring sessions, particularly in the morning of high traffic volume. Meanwhile, majority of the hotspots were found in the districts of the Macau peninsula. In addition, by performing analysis of the backward trajectories, daily MODIS images, and comparison of the PM2.5 patterns of the entire route of three selected measuring sessions during weekdays and weekend, it was observed that long range transport of fine particulates may affect Macau in a larger scale. Therefore, regional land source influence could shadow the local one when the ambient conditions are met.

Quantifying the contribution of individual sources to air pollution in one area is the first essential step in managing air quality in this region. This is of great interest especially in areas with combined urban and industrial emission sources. The area of Western Macedonia is a very complex in terms of air quality management problem because of large and complex pollution sources operating in the region. The emissions from five lignite power plants (LPP) operating in this region, the corresponding opencast lignite mining, as well as the urban activities in the industrial axis, is a complex problem to quantify the contribution of these sources in a spatial and temporal scale in the region. This paper attempts to quantify the contribution of LPP to the particulate pollution of this region, using PM10 concentrations measurements and simulations. Specifically were used: a) suspended particulate PM10 concentration measurements for a two years period (2009-2010) at various locations in the region and b) simulations of atmospheric dispersion. The results showed that the LPPs contribution to the PM10 concentrations of the regions studied ranged from 27-84% when the background was removed. These results were also confirmed by the corresponding Index of Agreement (IOA) between the mean monthly model calculations and the station measurements after removing the background. The LPPs contribution to the PM10 concentrations was a factor of the distance between the receptor area and the LPP, while the presence of other PM10 sources was found also to contribute at a higher or a lesser extent, depending on the area’s activities (e.g. urban, agricultural etc) and seasonal characteristics.

This study offers a combined analysis of personal exposure to noise and air pollution within the metropolitan centre of Thessaloniki, Greece. The area is selected on the grounds that it is considered as one of the most polluted cities in Europe, especially with respect to air pollution. An extensive survey has been designed to provide detailed information on CO and VOC concentrations and noise pollution levels in the main modes of transport and along heavy traffic routes inside the core of the urban area under consideration. Air pollution and noise measurements were performed simultaneously along several commuting routes, during morning and evening rush hours. Personal portable devices were used. The results highlight the magnitude of air and noise urban scale personal exposure, since they depict a considerable environmental burden for the citizens of Thessaloniki, especially for VOCs and noise pollution levels. Furthermore, they provide, for the first time, a combined exposure assessment to these environmental pollutants for Thessaloniki and in this sense they are of importance for local public authorities and decision makers. The material herein points out the importance of micro-environmental monitoring and the necessity of considering environmental pollution in urban areas in a more holistic way.