O3 concentrations

Dátum poslednej aktualizácie:16.01.2024

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Definícia indikátora

The indicator describes the level of air pollution in Slovakia, i.e. the fulfillment of the target values of air pollution for  O3.

Jednotka indikátora

µg/m3

Metadáta

Definitions related to the indicator:

The aim in air quality is to maintain air quality in places where air quality is good, and in other cases to improve air quality. Good air quality is the level of air pollution lower than the limit value and the target value. Air quality assessment is the determination of the level of air pollution using methods of measurement, calculation, prediction or estimation.

Emission - the penetration of air pollutants in the ground layer from the place of origin to another place is a consequence of the emission
Limit value - the level of air pollution determined on the basis of scientific knowledge in order to prevent, prevent or reduce harmful effects on human health or the environment, which is to be achieved at a given time and is not to be exceeded from that time. The limit value must not be exceeded by more than the tolerance limit from the established dates. The tolerance limit is the percentage of the limit value by which the limit value can be exceeded in accordance with the established conditions.
Target value - the level of air pollution determined in order to prevent, prevent or reduce harmful effects on human health or the environment, to be achieved at a given time, if possible. A critical level is a level of air pollution determined on the basis of scientific knowledge, when exceeding which direct adverse effects may occur on trees, other plants or natural ecosystems in addition to humans.
Total deposition - the total amount of pollutants that have been transferred from the atmosphere to the surface of soil, vegetation, water and buildings in a given area and at a given time
EMEP – European Monitoring and Evaluation Program – Program for monitoring and evaluation of long-range pollution transmission in Europe

AOT40 – target value of ozone exposure index for vegetation protection. AOT40 expressed in μg/m3.h is the sum of the differences between hourly concentrations greater
as 80 μg/m3 (= 40 parts per billion) and 80 μg/m3 during the given period using only 1-hour values measured each day from 8:00 a.m. to 8:00 p.m. Central European Time (CET). The target value is 18,000 µg/m3.h (5-year average). The AOT40 value for forest protection is calculated in the same way as the AOT40 for vegetation protection, but for the period from April 1 to September 30. The reference level for reporting to the EC is 20,000 µg/m3.h. This value only applies to suburban, rural and background stations.

The program and the integrated air quality improvement program determine air quality improvement measures in air quality management areas for the purpose of achieving good air quality at a given time. In areas of air quality management in which limit values or target values for which the deadline for their achievement has already expired are exceeded, the program or integrated program shall determine appropriate measures to shorten the period during which the specified values are exceeded as much as possible . Programs can also include measures that are applied in action plans to ensure air quality, as well as special measures aimed at protecting sensitive groups of the population, including children.

Methodology:

Air quality is generally determined by the content of pollutants in the outdoor air. Air quality assessment is carried out in accordance with Act no. 146/2023 Coll. on air protection. The basic starting point for the assessment of air quality in the Slovak Republic are the results of measurements of the concentrations of pollutants in the air, which are carried out by the Slovak Hydrometeorological Institute (SHMÚ) at the stations of the National Air Quality Monitoring Network (NMSKO).

National Air Quality Monitoring Network (2022)


Source: SHMI

Zones and agglomerations form large territories and collectively cover the entire territory of Slovakia. In each zone, the spatial distribution of pollutant concentrations is quite variable – it usually includes areas with significant sources of emissions and degraded air quality, but also relatively clean areas without sources. In order to facilitate the management of air quality, the so-called areas of air quality management. These areas are a subset of individual zones - each zone can contain several.

If the measured concentrations of any pollutant in the air at a given monitoring station exceed the limit or target value in the monitored year, the relevant territory that the station represents with its measurement is, according to Act no. 146/2023 Coll. on air protection, declared to be the area of air quality management. The district office in the authority of the region is obliged to develop a Program for improving air quality for this area. If limit values or target values are exceeded for several pollutants, the district office in the regional headquarters will develop an integrated program for those areas. Monitoring and assessment of air quality is carried out by the Slovak Hydrometeorological Institute (SHMI) as an authorized organization in all agglomerations and zones for polluting substances for which limit values or target values are determined and for ozone precursors.
SHMI annually proposes a list of air protection areas based on air pollution monitoring (for a period longer than one year), while the list of zones and agglomerations remains unchanged. A pollutant is removed from the air protection areas list only after the concentrations of the pollutant at the station do not exceed the limit value for three years in a row.

Air quality assessment is being carried out
a) by permanent measurement in agglomerations or in zones where the level of air pollution by a given polluting substance is higher than the upper limit for assessing the level of air pollution, and in the case of arsenic, cadmium, nickel and benzo(a)pyrene, also in zones and agglomerations, in which the level of air pollution is between the upper limit and the lower limit for assessing the level of air pollution; permanent measurement can be supplemented by modeling techniques or indicative measurements in order to provide adequate information on the spatial distribution of air quality,

b) by a combination of permanent measurements, indicative measurements and modeling techniques in agglomerations and zones in which the level of air pollution is the same or higher than the lower limit for the assessment of the level of air pollution and the same or lower than the upper limit for the assessment of the level of air pollution,

c) by a combination of permanent measurements, indicative measurements and modeling techniques in agglomerations and zones in which the level of air pollution in a representative time period is between the upper limit and the lower limit for assessing the level of air pollution, if it concerns arsenic, cadmium, nickel and benzo(a )pyrene,

d) modeling techniques or objective estimation techniques in agglomerations and zones in which the level of air pollution is lower than the lower limit for assessing the level of air pollution.

Source of data:

SHMI
 

Related indicators:

Related indicators on an international scale:

Links to the issue:

Väzba indikátora k rozvojovým dokumentom a cieľom

Limit values for assessing the level of air pollution according to Decree of the Ministry of the Interior of the Slovak Republic no. 250/2023 Coll. on air quality

Target values for ozone

Goal Average period Target value
Protection of human health
the largest daily 8-hour mean value1)
 
120 μg.m-3 is not exceeded more than 25 days per calendar year in a three-year average2)
Vegetation protection from May to July AOT40 calculated from 1-hour values 18000 (μg.m-3) × h averaged over five years2)

Notes:
1) The largest daily 8-hour mean concentration value is selected by examining 8-hour floating averages calculated from hourly data and updated hourly. Each 8-hour average calculated in this way is assigned to the day on which it ends, i.e. j. the first calculation period for any day
is the period from 5:00 p.m. the previous day until 1:00 a.m. of the given day; the last calculation period for any one day is the period from 4:00 p.m. until the end of the given day.
2) If three-year or five-year averages cannot be determined on the basis of complete and consecutive sets of annual data, the smallest annual data required to check compliance with the target values are those for
target value for protection:
a) human health: valid data for one year,
b) vegetation: valid data for three years.

Long-term goals for ozone

Goal Average period Long-term goal1)
Human health protection
the largest daily 8-hour mean value in a calendar year
 
120 μg.m-3
Protection of vegetation from May to July AOT40 calculated from 1-hour values 6000 (μg.m-3) × h

Notes:
1) The date by which the long-term goals should be achieved is not determined.

 

Kľúčová otázka

Is good air quality being achieved, is the pollution level below the target value for O3?

Kľúčové zistenia

  • The target value of ground-level ozone was exceeded by measurements at two stations: Bratislava, Jeséniova and Chopok, EMEP.
  • In 2022, one notification was issued about the occurrence of a smog situation for O3 (the information threshold was exceeded on 17 August 2022 at Bratislava, Jeséniova station). The warning threshold for O3 in Slovakia was not exceeded.
  • At 6 monitoring stations, the permitted values of ground-level ozone concentration for the protection of vegetation and forests were exceeded.
Zmena od roku 2005 Zmena od roku 2015 Posledná medziročná zmena
emo_smile emo_neutral emo_sad
A clearly positive trend was recorded. Despite the slightly positive development, exceedances of permitted values are still recorded. Compared to 2021, more exceedances of the permitted values of ground-level ozone concentration for the protection of vegetation and forests were recorded.

 

Sumárne zhodnotenie

Average annual concentrations of ground-level ozone (µg.m-3) (2022)

Station

Concentrations

Bratislava, Jeséniova

65

Bratislava, Mamateyova

50

Košice, Ďumbierska

53

Banská Bystrica, Zelená

57

Jelšava, Jesenského

38

Kojšovská hoľa

79

Nitra, Janíkovce

59

Humenné, Nám. slobody

51

Stará Lesná, AÚ SAV, EMEP

49

Gánovce, Meteo. st.

54

Starina, Vodná nádrž, EMEP

55

Prievidza, Malonecpalská

41

Topoľníky, Aszód, EMEP

54

Chopok, EMEP

91

Žilina, Obežná

36

Ružomberok, Riadok

37

Bardejov, Pod Vinbargom

45

Trebišov, T.G. Masaryka

49

Plášťovce

47

Komárno, Vnútorná Okružná

46

Senec, Boldocká

49

Pezinok, Obrancov mieru

  58

Lučenec, Gemerská cesta

 42

Ošcadnica

 48

Priemer

50

Note:

        > = 90% of required valid measurements
Source: SHMI

Number of days exceeding the target value for the protection of human health

Station

2020

2021

2022

Average  2020 – 2022

Bratislava, Jeséniova

17

23

 37

26

Bratislava, Mamateyova

12

15

 25

17

Košice, Ďumbierska

0

0

 7

2

Banská Bystrica, Zelená 

0

3

9

4

Jelšava, Jesenského  

2

2

7*

2

Kojšovská hoľa

2

4

 16

7

Nitra, Janíkovce

9

15

 31

18

Humenné, Nám. slobody

3

1

 5

3

Stará Lesná, AÚ SAV, EMEP

5

0

 0

2

Gánovce, Meteo. st. 

0

0

 2

1

Starina, Vodná nádrž,  EMEP

4

0

 1

2

Prievidza, Malonecpalská 

2

3

3*

3

Topoľníky, Aszód, EMEP

0

3

 9

4

Chopok, EMEP

33

22

 34

30

Žilina, Obežná 

0

0

 3

1

Ružomberok, Riadok

0

0

 0

0

Bardejov, Pod Vinbargom

 

0

 3

2

Trebišov,  T.G. Masaryka

 

2

 5

4

Plášťovce

 

19

 21

20

Komárno, Vnútorná Okružná 

 

7

 11

9

Senec, Boldocká

 

2

 11

11

Pezinok, Obrancov mieru

     21 21

Lučenec, Gemerská cesta

     6 6

Ošcadnica

     8 8

Note:

Red bold values mean exceeding the target value

        > = 90% of required valid measurements * the given year was not included in the average, due to the lack of data in the summer period

Source: SHMI

AOT 40 values for vegetation protection (µg.m-3.h)

Station

2022

Average 2018 – 2022

Bratislava, Jeséniova

23 763 20 250

Bratislava, Mamateyova

20 072 18 076

Košice, Ďumbierska

12 662 9 887

Banská Bystrica, Zelená

*19 716 12 218

Jelšava, Jesenského

*17 622 8 600

Kojšovská hoľa

19 435 13 720

Nitra, Janíkovce

24 322 18 869

Humenné, Nám. slobody

16 047 11 753

Stará Lesná, AÚ SAV, EMEP

6 210 9 539

Gánovce, Meteo. st.

11 317 7 557

Starina, Vodná nádrž, EMEP

9 560 10 217

Prievidza, Malonecpalská

*15 529 10 547

Topoľníky, Aszód, EMEP

16 686 15 860

Chopok, EMEP

26 536 24 505

Žilina, Obežná

5 338 7 171

Ružomberok, Riadok

2 935 3 414

Bardejov, Pod Vinbargom

12 711 11 659

Trebišov,  T.G. Masaryka

15 806 14 088

Plášťovce*

19 720 19 720

Komárno, Vnútorná Okružná*

12 824 12 824

Senec, Boldocká

14 893 14 893

Pezinok, Obrancov mieru

19 368 19 368

Lučenec, Gemerská cesta

14 834 14 834

Ošcadnica

14 893 14 893

Note:

*the given year was not included in the average due to the lack of data in the summer period

Red bold values mean exceeding the target value
Source: SHMI

Podrobné zhodnotenie

Ground level ozone

The issue of tropospheric ozone has a regional character, as ozone and its precursors are subject to long-distance transport in both horizontal and vertical directions. The situation is also complicated by the chemistry of its formation and degradation in the atmosphere – ozone is formed in the presence of sunlight, for example, from nitrogen oxide (from road traffic) and volatile organic hydrocarbons (from various combustion processes, coatings, and solvents, but also from biogenic sources) or CO (from road transport or industrial sources). The amount of ozone formed depends on the concentration ratio of its precursors. However, in the presence of nitric oxide, ozone also decomposes, which is why ozone concentrations are usually lower near busy roads. Unlike other pollutants, the seasonality of tropospheric ozone concentrations is characterized by a significant maximum in the summer.
Ground-level ozone is formed during photochemical reactions, for example, from nitrogen or carbon dioxide and volatile organic substances. The reaction depends on the intensity of sunlight. In high mountain locations (for example on Chopok) ozone concentrations are the highest. The target value of ground-level ozone was exceeded by measurements at two stations: Bratislava, Jeséniova, and Chopok, EMEP. In 2022, the information threshold was exceeded for one hour at AMS Bratislava, Jeséniova.

The annual averages of ground-level ozone concentration in Slovakia in 2021 ranged from 36 to 91 µg.m-3. The Chopok station had the highest average annual concentrations of ground-level ozone in 2022 (91 µg.m-3).

Average annual concentrations (µg.m-3) of ground-level ozone (2022)

Source: SHMI
 

The target value of the concentration of ground-level ozone for the protection of human health is according to the decree of the Ministry of the Environment of the Slovak Republic no. 250/2023 Coll. on air quality 120 µg.m-3 (greatest daily 8-hour value). This value must not be exceeded on more than 25 days a year, on average over three years. The following table provides an overview of exceeding this target value for the period 2020-2022. The warning limit threshold (240 µg.m-3) and the information limit threshold (180 µg.m-3) for the notification to warn the public were not exceeded in 2022.

Number of days in which the target value of ozone for the protection of human health (120 µg.m-3) was exceeded (2020-2022)


Source: SHMI

 

The target value of the exposure index for vegetation protection AOT40 is 18,000 µg.m-3.h. This value refers to concentrations that are calculated as an average over a period of five years. The average for the years 2018 – 2022 was exceeded at the stations Bratislava-Jeséniova, Bratislava-Mamateyova, Nitra-Janíkovce, Chopok, Plášťovce and Lučenec, Gemerská cesta. Exceeding the permitted concentrations of ground-level ozone for the protection of vegetation and forests has a negative effect on vegetation, especially through defoliation.


Average values of AOT40 (µg.m-3.h) for a period of five years (2018 – 2022) for vegetation protection


Source: SHMI

Kontakt na spracovateľa

Ing. Dorota Hericová, SAŽP, dorota.hericova@sazp.sk