Progress of Cryogenics and Isotopes Separation , ISSN: 1582-2575
2011, Volume 14, Issue 2

Log-Normal Distribution of PM10 – Application in Craiova (Romania) During the First Six Month of 2011

Abstract

In Dolj County (as well as in the other Romanian counties), air quality is analyzed by means of automatic air quality monitoring stations. The current study presents statistical processing of all data regarding PM₁₀ concentration values – gathered from one of the five such stations situated in Dolj County – during a period of half a year, a hundred data being available (however, it should be noted that nephelometric measurements – i.e., automatically recorded data – must be validated by gravimetric means, so that only validated data are reported to the European Commission). The paper shows that a log-normal distribution results from taking into account these nephelometric data and that some specific parameters may be consequently calculated, in order for the log-normal statistical distribution function to fit to the experimental curve. The value of PM₁₀ concentration was only once close to the critical value of 120 µg/m³, which is the maximum admitted eight hours average. Half of data are above the annual admitted average(40 µg/m)³, but this requires no concern, as the average concentration value was significantly below it. However, attention must be paid to the fact that the daily admitted value of 50 µg/m³(which should no more than 35 times a year be exceeded according to the Law no. 104/June 15 2011) was already exceeded for 27 times during the first six month of the year 2011.