KAZALCI OKOLJA

You are here

Key message
Bad

In recent years, the level of air pollution with ozone has been above the target value in most locations, including rural areas and higher altitudes, while (due to less sunny and cooler summers) the information threshold has been exceeded only in the Primorska region and in some places at higher altitudes. The highest ozone concentrations have been recorded in the Primorska region due to weather patterns that are favourable for ozone formation and the transport of ozone and its precursors from northern Italy.


This indicator shows the number of days with exceeded ozone target value and the number of hours with exceeded information value within a calendar year.

Tropospheric ozone differs from some other pollutants, as it is a product of photochemical reactions. Ozone precursors, especially nitrogen oxides and hydrocarbons, are substances from which ozone is formed in photochemical reactions. Consequently, high ozone concentrations do not occur in the immediate vicinity of large sources of precursors but in their wider surroundings. Under stable weather conditions during anticyclones, ozone clouds with high ozone concentrations can have a diameter of hundreds of kilometres and can be several kilometres high. Ozone concentrations above the information value may cause health problems (chest pain, coughing, vomiting, irritated eyes) in children and in people with chronic respiratory and cardio-vascular diseases. Repeated exposure to high ozone concentrations may cause permanent lung damage.


Charts

Figure ZR07-1: Number of days with exceeded target value for ozone in Slovenian urban areas with highest average 8-hour floating value > 120 μg/m3 (annual limit value 25 days)in the period of 2004-2015
Sources: 

Automatic Air Quality Measurement Database (ANAS), Environmental Agency of the Republic of Slovenia, 2015.

Show data
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Urban background number of days 43 46 35 39 33 26 24 33 40 41
Ljubljana Bežigrad number of days 42 47 37 41 35 29 22 30 37 40
Hrastnik number of days 31 32 25 29 26 20 22 29 34 32
Celje number of days 40 45 33 38 28 22 19 27 33 33
Nova Gorica number of days 59 61 46 48 42 34 32 46 57 60
Koper number of days np np np 55 60 55 57 65 66 69
Suburban background number of days 25 26 16 20 18 15 17 22 22 19
Trbovlje number of days 25 26 16 20 18 15 17 22 22 19
Rural background number of days 47 59 53 61 66 60 48 53 55 41
Iskrba number of days 47 59 53 61 53 47 39 40 42 41
Otlica number of days np np np np 78 72 57 66 68 69*
Urban-traffic type number of days 11 12 8 9 7 3 3 9 8 14
Maribor center number of days 8 6 3 3 3 2 2 2* 3 np
Rural/Agricultural type number of days 50 48 24 30 23 19 15 27 38 39
Murska Sobota - Rakičan number of days 50 48 24 30 23 19 15 27 38 39
permitted exceedance number of days 25 25 25 25 25 25 25 25 25 25
2014 2015
Urban background number of days 31 30
Ljubljana Bežigrad number of days 28 26
Hrastnik number of days 25 24
Celje number of days 23 20
Nova Gorica number of days 48 48
Koper number of days 56 62
Suburban background number of days 15 14
Trbovlje number of days 15 14
Rural background number of days 37 31
Iskrba number of days 37 31
Otlica number of days 54* 48*
Urban-traffic type number of days 9 9
Maribor center number of days np np
Rural/Agricultural type number of days 27 22
Murska Sobota - Rakičan number of days 27 22
permitted exceedance number of days 25 25
Figure ZR07-2: Number of days with exceeded warning value for ozone in Slovenian urban areas (highest 1-hour value > 180 μg/m3) in the period of 1995-2015
Sources: 

Automatic Air Quality Measurement Database (ANAS), Environmental Agency of the Republic of Slovenia, 2015.

Show data
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
Urban background number of hours 4 20 3 1 0 2 1 8 30 7
Ljubljana Bežigrad number of hours 4 20 7 2 0 3 1 4 18 4
Hrastnik number of hours np np 0 2 0 2 0 0 1 0
Celje number of hours np np 1 0 0 0 3 0 2 0
Nova Gorica number of hours np np np np np np np 26 100 25
Koper number of hours np np np np np np np np np np
Suburban background number of hours np np np 0 0 0 np 0 6 0
Trbovlje number of hours np np np 0 0 0 np 0 6 0
Rural background number of hours np np np np np np np np 11 1
Iskrba number of hours np np np np np np np 0 11 1
Otlica number of hours np np np np np np np np np np
Urban-traffic type number of hours np np 0 0 0 0 0 0 0 0
Maribor center number of hours np np 0 0 0 0 0 0 0 0
Rural/Agricultural type number of hours np np np np np np np 0 6 0
Murska Sobota - Rakičan number of hours np np np np np np np 0 6 0
2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
Urban background number of hours 12 17 7 0 1 0 1 7 9 0
Ljubljana Bežigrad number of hours 11 9 7 0 0 0 0 3 1 0
Hrastnik number of hours 0 4 0 0 0 0 0 1 0 0
Celje number of hours 0 3 0 0 0 0 0 1 0 0
Nova Gorica number of hours 31 33 18 0 0 0 2 18 20 0
Koper number of hours 16 36 9 0 3 2 4 13 22 0
Suburban background number of hours 0 1 0 0 0 0 0 1 0 0
Trbovlje number of hours 0 1 0 0 0 0 0 1 0 0
Rural background number of hours 0 34 25 3 1 2 1 6 0 0
Iskrba number of hours 0 1 7 0 0 0 0 0 0 0
Otlica number of hours np 67 43 5 2 3 1 12 33* 0
Urban-traffic type number of hours 0 0 0 0 0 0 0 0 0 0
Maribor center number of hours 0 0 0 0 0 0 0 0 * np
Rural/Agricultural type number of hours 1 0 0 0 0 0 0 0 0 0
Murska Sobota - Rakičan number of hours 1 0 0 0 0 0 0 0 0 0
2015
Urban background number of hours 3
Ljubljana Bežigrad number of hours 0
Hrastnik number of hours 0
Celje number of hours 0
Nova Gorica number of hours 6
Koper number of hours 9
Suburban background number of hours 0
Trbovlje number of hours 0
Rural background number of hours 0
Iskrba number of hours 0
Otlica number of hours 0
Urban-traffic type number of hours 0
Maribor center number of hours np
Rural/Agricultural type number of hours 0
Murska Sobota - Rakičan number of hours 0

Goals

  • Meeting the ozone target value for human health protection: the maximum daily 8-hour mean value for ozone (120 µg/m3) must not be exceeded more than 25 days within a calendar year (calculated as the average for the last three years);
  • meeting long-term goals as regards ozone values for human health protection: the maximum daily 8-hour mean value for ozone (120 µg/m3) must not be exceeded;
  • the information value of hourly ozone concentration for human health protection is 180 µg/m3, while the alert value is 240 μg/m3.

Ozone concentrations have a distinct annual cycle, which is associated with the way in which ozone is formed, requiring sufficient sunlight. The level of outdoor air pollution with ozone is significantly affected by transboundary transport of ozone concentrations. This is particularly characteristic of the Primorska region. Lowlands in northern Italy are among the areas in Europe where the largest amounts of ozone are formed. Thus, the highest concentrations occur during the summer along the coast and in the Primorska region, generally during periods of moderate westerly and south-westerly winds. The measurements of ground-level ozone show overages at almost all measurement sites in Slovenia except at those exposed to emissions of nitrogen oxides from traffic. At those measurement sites, ozone decomposes to O2 oxygen molecules. The lowest ozone concentrations were measured at the Maribor centre and Zagorje measurement sites, where the volume of traffic is high. The largest number of target value overages was recorded at the rural measuring sites of Iskrba and Otlica, where emissions of ozone precursors are low, which reduces the possibilities of reactions with ozone.

A multi-year data series does not reveal a discernible trend. Ozone concentrations depend on emissions of ozone precursors and, most of all, weather conditions during the summer months. Weather dependence is also evident from the number of overages of information values by year. The Slovenian Environment Agency forecasts ozone concentrations for all of Slovenia two days in advance. When an hourly information value is exceeded, the public is informed thereof on the ARSO website and the notification is sent to various addresses (hospitals, health clinics, the media, rescue centres, municipalities, schools, kindergartens). Along with the notification, information on potential effects on health, recommendations for the general population and the predicted duration of elevated concentrations is provided.



TWITTER