Application of the “Six Sigma” Method for the Analysis of the Improvement of the Environmental Air Quality Parameters at the Municipality of Bucharest, by Monitoring the Pollutances of Nox Pollutants

This paper analyzes the improvement of ambient air quality indicators by monitoring the NOx concentration in one of the most polluted areas of Bucharest, using the statistical method “SIX SIGMA” (6σ). By applying the methodology of this statistical approach, the aim is to reduce non-conformities within the specified limits (according to the standards and legislative norms in force) and respectively, to ensure maximum efficiency (99,99%), equivalent to a yield of 3.4 defects per million opportunities (DPMO). As high concentrations of air pollutants have a major impact on human health, the most harmful effect has been found to be caused by nitrogen dioxide (NO2), mainly from ground-level ozone. Using the “6σ” method, the optimal solutions for eliminating non-conformities and implicitly for reducing the NO2 concentration and ensuring the improvement of the ambient air quality can be identified.