Improving air quality is one of the main priorities of Latvia’s environmental policy[1]. Air pollution has a significant impact on human health. In 2000, it was estimated that fine particle (PM_2.5) air pollution reduced life expectancy by 4–6 months[2] and, as such, was the greatest risk to public health in Latvia.

In Latvia, the impact of air pollution on ecosystems mainly relates to an excess of the nutrient nitrogen in the form of ammonia and nitrogen oxides. These pollutants can  disrupt plant communities and leach into fresh water, leading to eutrophication, a loss of biodiversity and the production of ground-level ozone resulting in physical damage and the reduced growth of agricultural crops, forests and plants.

Exceedance of air quality limit values in urban areas

Particulate matter (PM₁₀)

Preliminary data for the centre of the capital city, Riga, from 2004 to 2008 indicate that the mean annual concentration of PM₁₀ exceeds the limit value for the protection of human health. Meanwhile, at urban and rural stations throughout Latvia limit values for human health protection were not exceeded (Figure 1).

Several of the recorded 24-hour PM₁₀ values in Riga and Liepaja were also above the limit value (Figure 2).

 Figure 1: Annual average PM₁₀ concentrations (annual limit value is 40 μg/m³)

Source: Latvian Environment, Geology and Meteorology Centre

Figure 2: Number of days on which the PM₁₀ daily limit value for human health protection (50 μg/m³) was exceeded (limit may not be exceeded more than 35 times per calendar year).

Source: Latvian Environment, Geology and Meteorology Centre

Latvia began measuring PM_2.5 in 2008 in the Riga metropolitan area, at Milgravis and Brivibas Street stations and at other stations across Latvia (Ventspils and Liepaja).

Nitrogen dioxide (NO₂)

Annual average limit values of nitrogen dioxide for human health protection in Latvia were only exceeded at one traffic station in Riga (Valdemara Street). During 2008, nitrogen dioxide concentrations reached the limit value (44 μg/m³) for the protection of human health (within the margin of tolerance) (Figure 3).

Figure 3: Nitrogen Dioxide (NO₂) annual average concentration (annual limit value is 40 μg/m³)

Source: Latvian Environment, Geology and Meteorology Centre

Exposure of ecosystems to acidification, eutrophication and ozone

Deposition from the atmosphere is a major indicator of precipitation, ambient air quality and ecosystem status. Between 2004 and 2008, there was no significant change in the total deposition of sulphur and nitrogen at Latvian rural background stations (Figure 4).

Figure 4: Total deposition (mg/m² year) of sulphur (S_tot) and nitrogen (N_tot) at the rural background stations Rucava and Zoseni

Source: Latvian Environment, Geology and Meteorology Centre

The computed area at risk of eutrophication covers all ecosystems in Latvia, but the area at risk of acidification is 16 % of the total ecosystem area (Figure 5).

  Figure 5: Damage to Latvian ecosystems as a result of acidification and eutrophication

Source: Latvian Environment, Geology and Meteorology Centre

Figure 6: AOT40 index, rural background station Rucava

Source: Latvian Environment, Geology and Meteorology Centre

Assessment of the impact of surface ozone on vegetation using the internationally-recognised AOT40 index shows that the critical level (6 000 µg/m³×h) was exceeded at the Rucava rural background station in 2006 and 2008 (Figure 6). In 2006, observations of visible ozone damage to white clover under the ICP Vegetation programme registered a medium degree of leaf damage (5–25 %). During the period 2004–2008, there was no exceedance of the target value (18 000 µg/m³×h) for the protection of vegetation

In general, the fall in emissions during the 1990s was due to a decrease in total fuel consumption caused by the transformation of the national economy, increased energy efficiency and a switch from solid fuels and liquid fuels to natural gas and biomass fuels. In recent years, emission levels have remained relatively stable.

The energy sector is the main source of sulphur dioxide emissions in Latvia.

Domestic heating and the use of solvents and other products represent significant sources of volatile organic compounds (VOCs).

The largest proportion of nitrogen oxide emissions originates from the transport sector (particularly road transport) and the number of registered motor vehicles per 1 000 inhabitants continues to increase (Figure 7).

Almost all NH₃ emissions originate from agricultural activity.

Overall, air pollution decreased between 1990 and 2005 − SO₂ by 96 %, VOCs by 34 %, and NH₃ by 70 % (Figure 8). During this period, the relative influence of the transport sector on nitrogen oxide emissions grew, while the influence of energy production fell by almost 50 %

Figure 7: Number of registered motor vehicles per 1 000 inhabitants

Source: Latvian Environment, Geology and Meteorology Centre

General trend in air pollutant emissions

Figure 8: SO₂, NOx, NMVOC, NH₃ emissions, 1990–2008 (1 000 tonnes)

Source: Latvian Environment, Geology and Meteorology Centre

Figure 9: Emissions of particulate matter,  2000–2008 (1 000 tonnes)
Source: Latvian Environment, Geology and Meteorology Centre

State of the Environment, National Report 2008 [in Latvian]

Sustainable Development Indicators in Latvia 2006 [in Latvian]

Projected emissions in 2010

According to informationlv submitted by Latvia on the National Emissions Ceilings Directive[1] in 2009, emission projections for 2010 are as follows:

The implementation of all current legislation on SO₂, NOx, NH₃ and VOC emissions, including measures taken within the framework of climate change policy, will enable Latvia to meet the 2010 emission ceilings for these pollutants.

Projected emissions in 2020

If effective reduction measures are implemented, it is assumed that by 2020 SO₂ emissions will not exceed the European Commission’s proposed ceilings for 2020 as there are no economic sectors in Latvia producing significant SO₂ emissions.

Nevertheless, current studies show that it will be difficult to meet the proposed NOx and VOC emission ceilings for 2020, even if additional measures are implemented and prove to be effective.

The projection for NH₃ emissions is that they will decrease but they could still exceed the emission ceilings for 2020 proposed by the European Commission. The level of NH₃ emissions will largely depend on national environmental policy and the application of legislation relating to agriculture. However, the implementation of efficient NH₃ emission reduction measures may be expensive.

It is assumed that emissions of PM_2.5 will also exceed defined emission ceilings in 2020, which is why it will be necessary to put in place additional measures to reduce the emissions of PM_2.5.

Latvia has no significant problems with the implementation of current EU policy (IPPC Directive, Large Combustion Plants Directive and Directive 2001/81/EC on National Emission Ceilings). However, concentrations of particulate matter PM₁₀ and nitrogen oxides in some Latvian cities − Riga metropolitan area and Liepāja − exceed the standards imposed in the Air Quality Directive.

The following measures are therefore planned at national level:

• the establishment of new techniques and sustainable use of resources, thereby achieving reductions in air pollutant emissions from energy and manufacturing industries, commercial and institutional services, households, transport and agriculture
• to coordinate the establishment of Best Available Techniques (BAT), environmentally-friendly techniques and cleaner production in the industrial sector
• the replacement of inefficient and outdated combustion plants for individual heating with more environmentally-friendly alternatives
• an increase in tax rates for air pollution emissions and the establishment of a tax on heavy duty vehicles (depending on the type of engine, age and emissions) is also under consideration
• to inform citizens, drivers and employers about air pollution and action to reduce it.