Sustainable Development Indicators in 2003

11. Air quality

Indicators 11.1. Average concentrations of sulphur dioxide per year 11.2. Average concentrations of nitrogen dioxide per year 11.3. Average concentrations of ground level ozone per year 11.4. Average concentrations of solid particles PM10 per year

Air polluting substances change environmental conditions, performance of preventative measures. They determine impact on life processes, cause various illnesses and cause national air quality standards, procedures for the prevention harm to buildings and monuments. In order to prevent the of air pollution and air protection measures. In recent years unfavourable impact of air pollution, the new Cabinet of a number of regulatory enactments in relation to both Ministers Regulations on air quality provide for the stationery and mobile air polluters have been adopted.

11.1. Average concentrations of sulphur dioxide per year

The annual average values for sulphur dioxide in 2001 In March, the single maximum 10 minutes SO2 concentra- fluctuated from 2 µg/m3 in district of Imanta to 11 µg/m3 tions were recorded in Nîgrande parish and Rçzekne, which in the centre of Riga (Figure 11.1.3). In the winter period reached the limit value for the protection of human health of (October - March) the highest average concentration was in 500 µg/m3. Rîga centre (12 µg/m3), Rçzekne (11 µg/m3), (10 µg/m3) and (9 µg/m3).

In Nîgrande parish in 2001, the SO2 hourly value similar to previous years was higher than in cities. The maximum values were recorded on 14 July (296 µg/m3) and 7 April (250 µg/m3), winds blowing from a south-western direction from . However, the limit value for the protection of human health of 350 µg/m3, which shall come into effect in 2005, was not exceeded.

LEGEND:

Figure 11.1.1. Average concentrations of sulphur dioxide per year, µg/m3 Source: Latvian Hydrometeorological Agency

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11.2. Average concentrations of nitrogen dioxide per year

The annual average values of nitrogen dioxide fluctuated In terms of a daily dynamic, the largest hourly values in Rîga from 4 µg/m3 in Nigrande parish to 43 µg/m3 in the centre of centre are observed from 10 a.m. to 8 p.m., in district Riga (Figure 11.2.1). In the centre of Riga the anticipated Íengarags - during morning and evening hours, which attests limit value for the protection of human health - 40 mg/m3 to impact of intensive motor transport movements on the (will come into force in 2005) was exceeded. However, the level of nitrogen dioxide pollution. 2001 specified limit value 58 µg/m3 was not exceeded. Other high average values were determined in Riga district Kengarags, Jelgava, Rezekne and Liepaja (21-26 µg/m3).

LEGEND:

Figure 11.2.1. Average concentrations of nitrogen dioxide per year, µg/m3 Source: Latvian Hydrometeorological Agency

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11.3. Average concentrations of ground level ozone per year

The annual average values of ground level ozone fluctuated In 2001 in Latvia 12 cases of exceeding the human health from 49 µg/m3 in Riga district of Imanta to 69 µg/m3 in protection 8 hour limit value were registered: Liepaja - 8, Nigrande parish (Figure 11.3.1). Ozone concentrations in - 3, Olaine - 1 and Riga centre - 1 case (Figure Riga in the spring and summer periods (55-60 µg/m3) were a 11.3.2). little higher than in the winter period (42-48 µg/m3) and similar trends were observed also at other monitoring stations. The highest average concentrations over a 24-hour period were observed in July in Jelgava (105 µg/m3) and in April in the Riga district of Imanta (104 µg/m3).

LEGEND:

Figure 11.3.1. Average concentrations of ground level ozone per year, µg/m3 Source: Latvian Hydrometeorological Agency

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11.4. Average concentrations of solid particles PM10 per year

The average concentration of solid particles PM10 in 2001 in The largest 24-hour average value was registered in March in Rîga centre was 56 µg/m3, exceeding the human health Rîga 176 µg/m3, as well as in December in Rçzekne (158 protection limit value of 40 µg/m3, which will come into µg/m3) and Liepâja (126 µg/m3). The spreading of sand on force in 2005, as well as the standard specified for 2001 of streets in the winter period is one of the reasons, which 3 46 µg/m . In Liepâja the average PM10 concentration was 41 promotes a heightened dust concentration in the air during µg/m3 and in Rçzekne - 36 µg/m3 (Figure 11.4.1). the spring months.

PM10 24-hour average value exceeded the 2001 specified limit value 70 µg/m3 in Rîga centre (46 days), Liepâja (16 days) and Rçzekne (7 days). During a year the limit value referred to is allowed to be exceeded no more than 35 days.

LEGEND:

3 Figure 11.4.1. Average concentrations of solid particles PM10 per year, µg/m Source: Latvian Hydrometeorological Agency

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Table 11.5 Air quality standards Source: Cabinet of Ministers Regulations No. 286 on air quality (2002)

Source: Latvian Hydrometeorological Agency. Environmental Author: Ilze Opermane Quality Observation Department. The Air Quality in Latvia Consultant: Normunds Kadiíis 2001.

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