『Abstract
　Ambient aerosol concentrations have been implicated in human health effects, in visibility reduction in urban and regional areas, in acid deposition and in perturbing the Earth's radiation balance. The main concern of the air quality managers is to achieve compliance to the established air quality standards (AQS). As AQS are exceeded in numerous sites worldwide, it is essential to reduce the emissions. Having decided which statistical distribution fits well to the PM10 parent distribution, it is feasible to estimate the reduction in emissions that is required in order to meet AQS. in this study, it is verified that the PM10 concentration distribution can be adequately simulated by lognormal distribution, a conclusion drawn by the calculation of several statistical indexes. The study area is the city of Volos in central Greece, which is experiencing an unpleasant situation concerning the levels of PM10 pollution. The probability density function of lognormal distribution is capable to predict the number of days when the European Union (EU) AQS for PM10 concentration are exceeded in Volos area. Furthermore, the minimum reduction in current emission sources of PM10 required in order to meet the air quality regulations that are established by the EU is calculated for the study area and is found to be 〜33％. The results could be utilized as reference for air pollution control strategy.

Keywords: PM10; Lognormal distribution; Emission sources reduction; Air quality standards』

1. Introduction
2. Study area and data origin
3. Methods
　3.1. Parameters and probability density function of the lognormal distribution
　3.2. Evaluation of the relationship between parent and observed distribution
　3.3. Reduction in emissions to meet AQS
4. Results and discussion
　4.1. PM10 levels
　4.2. Lognormal distribution of the PM10 levels
　4.3. Estimating the probability to exceed AQS
　4.4. Estimating the ESR
5. Conclusions
Acknowledgments
References