Air pollution by nitrogen oxides in Sarajevo from 2005 to 2010

© 2013 Suad Habeš et al.; licensee University of Sarajevo Faculty of Health Studies. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. UNIVERSITY OF SARAJEVO FACULTY OF HEALTH STUDIES ABSTRACT


INTRODUCTION
Th e environment is a specifi c medium in which easiest thing is recognizing negative human activities (1).
Th erefore, the increase in public interest in thematic areas of protecting the nature and improvement of environmental conditions is apparent.Development of awareness of the citizens is evident through increased interest in environmental activism with goal of solving general and specifi c problems.Most of the pollutants that pollute the atmosphere originate from industrial activities, but a signifi cant part originates from the traffi c (2).Before the war in our country, industry was the most signifi cant air pollutant.Most industrial plants have stopped operating during the war and still have not reached pre-war level.As a result, it is expected that the pollution of the atmosphere is now much lower.Environmental sustainability implies that the degree of pollutants that are emitted, do not overcome the ability of air, water and land to absorb and process them (3).At the same time this implies a permanent conservation of biological diversity, human health, and the quality of air, water and land, according to the standards that are still suffi cient for the life and wellbeing of people, and the preservation of fl ora and fauna (4).Air pollution is created by emissions of harmful gaseous and particulate matters, usually as a result of human activity, but also from the emissions from natural sources (5).During the burn of the fuel in all furnaces and engines, formation of nitrogen oxides at high temperatures occurs (6).In addition to the two basic components that make up the atmosphere: oxygen (circa 20%) and nitrogen (circa 78%), small amounts of gases, vapors and particles are naturally present in the atmosphere (7).If in the air, same or other components in concentrations which are higher than naturally present concentration occur, then we have the pollution of air appearance.Th is phenomenon came to the expression in the previous and current century due to the rapid development of industry, energetic and traffi c.Allowed NOx emissions from power plants (fi reboxes) depends on the fuel type and the capacity of the fi rebox, and that is prescribed by the legislation on permitted emissions into the environment, the Air Protection Act (Sl.Novine FBiH, No. 33/03) (8).Air pollution occurs when the concentration of certain substances (pollutants) reaches a size that affects its toxicity, or in other words, begins to cause harm to human health, fl ora and fauna (8).Nitrogen oxides are binary compounds of nitrogen and oxygen, which are: nitric oxide, NO, nitrogen dioxide, NO2; dinitrogen trioxide, N2O3; dinitrogen tetroxide, N2O4; dinitrogen pentoxide, N2O5 (9).Among them, there is the nitrous oxide N2O known as "laughing gas" or "heavenly gas."Although nitrogen oxides make up a large group, the expression NOX is commonly used for a mixture of NO and NO2, which are considered major polluters of the atmosphere.Th ese two nitrogen oxides occur from fossil fuel combustion, especially at high temperatures over 1000 ° C (10).Th e aim of this study was to determine the pollution of the atmosphere caused by nitrogen oxides NO and NO2 in Sarajevo from 2005 to 2010, and based on the obtained results, suggest preventive measures that aff ect the reduction of atmospheric pollution by nitrogen oxides.

Concentration of nitrogen oxides NO and NO2
and total nitrogen oxides NOx was determined by the Griess-Saltzmanna method, with the help of automatic station for measurement.Method by Griess-Saltzmanna is based on standard techniques of collecting samples in the absorbing solution, in which the nitrogen is determined spectrophotometrically.Th e air is vacuumed through the absorbing solution, which was consisted of sulfanilic acid.Nitrogen dioxide from the air fi rst reacts with sulfanilic acid forming diazonium salt.Th at salt combines with the N-(l-naphthyl)-ethylene-diamine-dichloride giving an intense red-purple color, from which the concentration is directly proportional to the concentration of NO2 concentration.Due to the rapid formation of the color, sampling time is not more than 30 minutes.Th e method is suitable for determining the concentration of atmospheric NO2 -oxide from 40 to 1500 g/m 3 .Th is method is adapted to the automatic analysis used by the automatic station Bjelave.Also, this method determines NOx, in other words; sum of NO + NO2, with condition that the sample was previously released through the KMnO4 solution which performs the oxidation of NO to NO2.Calculated concentrations of NO and NO2 in the atmosphere are reduced to normal atmospheric conditions of 293 K (Kelvin) and pressure of 101.3 kPa (kilopascal).Displayed values for nitrogen oxides (24 -hour samples) obtained by this method are compared with the limit values prescribed by the Regulation on limit values for air quality (11).Th e study used the data from the Federal Hydrometeorological Institute BiH in the period from 2005 to 2010.

RESULTS
In accordance with the established dynamics and methodology of the research, measurement of atmo-spheric pollution by nitrogen oxides was conducted in Sarajevo at the measuring station Bjelave period from period of 2005th to 2010th year.All data are appropriately processed and presented in tables and graphs.Th e results are compared with the limit values prescribed by the Rulebook on air quality (GV) in aim to protect human health (Table 1) and the limit values of air (GV) in order to protect the ecosystem (Table 2).By using automatic station Bjelave, concentrations of pollutants NOx, NO2, NO, are obtained, which are presented as the mean annual value-CSR maximum hourly value-Cmax and percentile values-C-50, C-95, C-98, C-99.9.Percentile values indicate the number of exceeding concentration of some pollutant in a specifi ed number of hours in a year.In the course of one year is 8760 hours, and the C-50 = 4380 hours, C-95 = 438 hours, C-98 = 175 hours = 99.9C-9 hours.In the stated tables, number of samples taken in the course of one year is given, as well as the percentage of valid samples (Source: Automated station Bjelave -Sarajevo).In Table 3, the highest maximum concentration value is measured in year 2005 and amounted was 692 g/m 3 and the maximum measured mean value of nitric oxide was 43 g/m 3 and it was measured in year 2005.Shown values of NO concentration in Table 3 do not meet the limit values prescribed by the Rulebook on limit values for air quality.In Table 4    it was 299 g/m 3 , as well as the largest annual mean concentration which was 26 g/m 3 .Th e minimum values were measured in the 2010 year.Cmaxwas 119 g/m 3 , while in the year of 2009 Csr was 9 g/m 3 .Shown concentrations of NO2 shown in the Table 4 correspond to limit values prescribed by the rulebook.
In the Table 5, we see that in the 2005, the highest concentrations of nitrogen oxides was measured, in the reporting period.Th e maximum concentration of NOx was 692 g/m 3 and the average concentration was 43 g/m 3 .Shown concentrations of total nitrogen oxides in we see that in 2005 the highest maximum concentration of nitrogen dioxide was measured and

TABLE 1 .
Limit values (LV) of air quality in order to protect human health a must not exceed more than 24 times in a calendar year.b must not exceed more than 7 times in a calendar year (98th percentile).c must not exceed more than 18 times in a calendar year.d must not exceed more than 21 times in a calendar year (

TABLE 2 .
Limit values (LV) of air in order to protect the ecosystem are: a must not exceed more than 24 times in a calendar year.b must not exceed more than 7 times in a calendar year (98th percentile).

TABLE 5 .
Statistical overview of the concentration of total nitrogen oxides NOx (hourly samples) Sarajevo-automatic station Bjelave