SO₂ concentration in the Netherlands (annual and winter averages), 1992-2002

In 2000, the average annual concentration of sulphur dioxide (SO₂) did not exceed the limit value anywhere in the Netherlands. Concentrations in the south-west of the Netherlands are higher than in the rest of the country due to the proximity of large sources in the Rijnmond area.

• SO₂ concentration in the Netherlands: winter average 1992-2002

Sulphur dioxide concentration continues to fall

The annual average SO₂ concentration continued to fall in 2002. The limit value for the SO₂ concentration for the protection of ecosystems (20 µg/m³) was not exceeded anywhere in the Netherlands in 2002.
The annual average SO₂ concentration fell in the last ten years by approximately 7% a year. This is the result of emission reductions in the Netherlands and abroad from the main sources of SO₂, such as electricity plants, refineries and traffic. Because the first two sources generate most emissions by far, urban concentrations are higher than street concentrations.
The concentrations in the winter have increased slightly because of a number of processes associated with the lower temperatures: increased amounts from elsewhere due to continental winds, higher emissions as a result of space heating, less favourable atmospheric distribution and a lower deposition of sulphur dioxide when there is snow on the ground.

Highest concentrations in south-west of the Netherlands

The highest levels were observed in the Rijnmond area, Zeeland and in the south-west of North Brabant. They are linked to local industry and shipping and possibly also the proximity of sources in West Flanders.

European standards for exposure to sulphur dioxide

The EU has adopted a number of limit values for SO₂ concentrations for the protection of public health and ecosystems (EU, 1999).

• To protect ecosystems against the impact of prolonged exposure, a limit value has been set of 20 µg/m³. This applies to both the average for the calendar year and to the winter half of the year (see figures above).
• The EU has adopted two limit values to protect humans against peak concentrations of SO₂. The 24-hour average SO₂ concentration must not exceed the limit of 125 ug/m³ more than 3 times a year; the hourly average concentration must not exceed 350 ug/m³.

• SO2 concentration in the Netherlands tested using the standard for public health 1992-2002

In addition to the limit value for the SO₂ concentration, the EU has also adopted a maximum for emissions of sulphur dioxide per EU country (National Emission Ceiling: NEC). If the target values and long-term objectives are not achieved, the emission ceiling for sulphur dioxide will be lowered. The Clean Air For Europe (CAFE) programme supports this integrated policy approach.

Sources of sulphur dioxide

Emissions of SO₂ to air usually occur as a result of the use of sulphurous motor fuels. The main sources are electricity plants, refineries and traffic.

Impact of sulphur dioxide on people and nature

High concentrations of SO₂ have a negative impact on humans, animals and plants. For example, SO₂ contributes to the acidification of ecosystems.

References

• EU (1999). Council directive 1999/30/EC of 22 April 1999 relating to limit values for sulphur dioxide, nitrogen dioxide and nitrogen oxide, particulate matter and lead in ambient air (link to PDF file). Official Journal of the European Communities No L 163/41.
• LML. National Air Quality Measurement Network. RIVM, Bilthoven.
• RIVM (2003). Data based on measurements from the National Air Quality Measurement Network processed by the Netherlands Environmental Assessment Agency. RIVM, Bilthoven.
• Staatsblad (2001). Besluit van 11 juni 2001, houdende uitvoering van de richtlijn 1999/30/EG van de Raad van de Europese Unie van 22 april 1999, betreffende grenswaarden zwaveldioxide, stikstofdioxide en stikstofoxiden, zwevende deeltjes en lood in de lucht (PbEG L 163) en de richtlijn 92/62/EG van de Raad van de Europese Unie van 27 september 1996 inzake de beoordeling van de luchtkwaliteit (PbEG L 296) (Air Quality Decree). Bulletin of Acts, Orders and Decrees 269, 1-58. (Link naar website overheid.nl; gebruik trefwoord 'Besluit luchtkwaliteit'.)

Relevant sections and indicators in the Environmental Data Compendium

• SO2 concentration in the Netherlands tested using the standard for public health 1992-2002
• Dutch air quality: policy and standards
• Guide to the environmental pressure section, Acidification and transboundary air pollution theme
• Overview impact of environmental aspects on public health

Relevant information outside of the Environmental Data Compendium

• RIVM (2001). Jaaroverzicht luchtkwaliteit 1998 en 1999. RIVM, report 725 301 006, Bilthoven.
• RIVM (2002). Jaaroverzicht luchtkwaliteit 2000. RIVM, report 725 301 008, Bilthoven.
• RIVM (2002). Jaaroverzicht luchtkwaliteit 2001. RIVM, report 725 301 009, Bilthoven.
• More information about concentrations of substances in the air can be found on the site of the National Air Quality Measurement Network.
• Information about current and future developments relating to local air pollution can be found in Environmental Balance 2003 and the National Environmental Outlook 2000-2030.