The air quality in the Municipality of Piatra Neamt from the North Eastern Region, Romania

The analysis of the air quality represents an essential component of the tourist resources evaluation in a city declared a tourist resort of national interest, as Piatra Neamt is, also called the Pearl of Moldova. The chemical particularities of the urban atmosphere are being influenced, in different extents, by the size of the city, the anthropic activities and are modulated by the geographical peculiarity of the place. Piatra Neamt is located in the NE of Romania in an area of depressive widening of Bistrita valley, at 345 m altitude. The coniferous vegetation, the presence of the water reservoirs along Bistrita river, the climate of shelter and so on are elements that contribute to the self-purification of the air. The city had 85,055 inhabitants according to the 2011 census, being an important economic and tourist center of the NE region of Romania.

The aims of the study conducted has as goal the evaluation of the air quality in the Municipality of Piatra Neamt, on the basis of the hourly data from the station NT1 (urban background) from the interval January 2009 - October 2019, relying on five chemical indicators: Nitrogen dioxide (NO₂), Sulfur dioxide (SO₂), Carbon monoxide (CO), Ozone (O₃) and PM10 sedimentable particles.

The main objectives aimed at the identification of the variations in time of the average hourly or daily concentrations of these pollutants, with the outlining of their daily or annual progress, with the explanation of their causality and with the identification of some episodes of pollution, but also at the releasing of some accurate assessments based on data, observations and findings of duration which to include the air inhaled by the inhabitants of the city and by the tourists in different intervals of quality.

The results obtained show that in Piatra Neamt the concentrations of NO₂ (with 94.36% of the hours of observations with indices of air quality evaluated as excellent), SO₂ (with 99.59% of the hours of observations with excellent indices of air quality) and CO (with 99.78% of the hours of observations with indices of air quality also excellent) do not cause real problems to human health. For the O₃ in 0.8% of the hours of observation from NT1, the concentration of this gas has exceeded the threshold of 120 μg / mc which, according to the European directives, is the target value for the protection of human health. Neither the concentration of PM10 sedimentable particles causes problems (the amount of time with exceedings of the daily limit value for the protection of human health being on average 2.8 days a year^-1). The October-March interval, with thermal inversions, with radiation fog and persistent stratiform clouds is more favorable for keeping this pollutant in suspension.

Conclusion.. The quality of the air from the city of Piatra Neamt atmosphere is excellent. The sedative-indifferent bioclimate and the sanogenous atmosphere of this city at the contact between the Eastern Carpathians - Subcarpathians of Moldova increase the tourist assets of the municipality.