1.3 million people exposed to road traffic noise

These are the main results from a pilot project carried out by Statistics Norway and commissioned by the Norwegian Pollution Control Authority.

The Storting has decided that noise annoyance shall be reduced by 25 per cent by 2010 relative to the base year 1999. Statistics Norway has developed a model to monitor the development. The model calculates how many persons are exposed to noise from different sources, and transforms this into a noise annoyance index (SPI) . The environmental protection authorities have decided that this index shall be used to monitor progress towards the noise annoyance reduction target. The figures presented in table 1 show only small changes in the noise annoyance index from 1999 to 2001. There are also only small changes in the number of exposed persons . There are significant uncertainties in the calculations, but it seems clear that a number of measures must be implemented in order to achieve the noise reduction target.

Road traffic is responsible for 73 per cent of calculated noise annoyance in 2001. Manufacturing industries are the next largest source to noise annoyance, with 13 per cent of the total. Railways and air traffic contributed with 4 per cent, and building and construction with 3 per cent. Noise from shooting ranges, products (e.g. lawn mowers, snow scooters, etc.), trams and subways is not included in this first version of the noise model, but is planned to be included in future versions.

1.3 million exposed to road traffic noise

As mentioned above, road traffic is by far the most important source of noise annoyance in Norway. Approximately 1.3 million persons, or 28 per cent of the total population, are exposed to noise levels above 55 dBA (decibel, unit of measure for noise) from this source. Half the population of Oslo is exposed to such noise levels. Not surprisingly, people living in highly populated areas with heavy traffic are most annoyed by road traffic noise. 36 000 persons were exposed to noise levels above 70 dBA in 2001 and classified as “most annoyed by noise”. Far more than half of these, 21 000 persons, lived in Oslo.

The calculations of road traffic noise are based on the Directorate of Public Roads surveys of noise levels in dwellings. Statistics Norway has made additional calculations for dwellings not covered by the surveys.

In Statistics Norways 1997 Survey of living conditions, 33 per cent stated that they thought noise from road traffic was somewhat, significantly or highly annoying outside their dwellings. The figures are not quite comparable to Statistics Norways new noise annoyance calculations, but they seem to indicate that the new results are reasonable. The noise annoyance index described above also refers to noise levels outside the dwellings. In the above-mentioned survey of living conditions 16 per cent stated that they were exposed to road traffic noise inside the dwelling.

Less noise from air traffic

The noise annoyance from air traffic decreased by 6 per cent from 1999 to 2001. This was caused by a reduction in the number of flights both before and after the 11 ^th of September 2001. The number of landings and takeoffs at the civilian airports went considerably down in the period. Both at Oslo airport Gardermoen and Bergen airport Flesland the number of flights decreased by 10 per cent. It is not expected that this will be a lasting trend, and the traffic and consequently the noise annoyance from planes will most likely increase.

Air traffic constituted 4 per cent of the estimated noise annoyance in 2001, and fighter planes around military airports contributed substantially to this noise annoyance index level. Although air traffic is a small source of noise measured as per cent of the total noise annoyance index, it is bothersome enough for those who are exposed. The counties of Rogaland, østfold and Nordland are the three counties with the highest noise annoyance index level caused by air traffic. In each of these counties air traffic made up 21-22 per cent of the index value. While the noise annoyance in the counties Nordland and Rogaland is associated with different kinds of airports, the whole of the noise annoyance index contribution from air traffic in the county of østfold comes from the military airport Rygge. This airport is surrounded by densely populated areas in the municipalities Rygge, Råde and Moss. A total of 14 900 persons were exposed to noise levels above 50 dBA from this airport in 2001.

Stamp mills and car scrapping dominate industrial noise

Noise from industries constituted 13 per cent of the estimated noise annoyance index level in 1999. Until 2001 the noise annoyance from this source increased by one per cent. This was caused by increased activity levels in some of the most noise generating industrial sectors. The concept of industrial noise includes noise from both mining and quarrying, manufacturing industries and other industries. The highest SPI-level was recorded in Oslo, closely followed by Rogaland. We find typical manufacturing industry counties like østfold and Telemark a further down on the list. Car scrapping plants and stamp mills have the highest noise emission levels. Shipyards and j0unk shops also generate a lot of noise. The more traditional manufacturing industries such as metallurgic industry and the production of paper and chemical pulp have lower noise levels.

About the model

Commissioned by the Norwegian Pollution Control authority and in close cooperation with the Directorate of Public Roads, the Norwegian Air Traffic and Airport Management (from 1 January 2003: Avinor), the Norwegian National Rail Administration and Forsvarsbygg (a public enterprise placed under the Ministry of Defense), Statistics Norway has developed a model to calculate noise exposure and noise annoyance in Norway. The model calculates data for noise exposure (measured as the number of people exposed to different noise levels, L _{e q} ) and noise annoyance (expressed by the noise annoyance index) in Norway in 1999 and subsequent years. The model shall quantify noise exposure and noise annoyance from road traffic, railways, air traffic, industries and other important sources. The main goal is to present annual status and trend for noise exposure at national and county levels and for the most densely populated municipalities as a statistical input to the national key figures for noise as defined by the environmental authorities. The work so far can be described as a pilot project, due to the significant uncertainties that are still associated with the first version of the model and because some important sources of noise are not yet included.

A GIS (Geographical information system) model has been developed where the noise level of each dwelling in Norway is calculated and recorded. So far, only noise data for road traffic, industries and air traffic have been calculated. Later on calculations for railway noise and some other minor sources of noise will be carried out. The model input data is based on existing noise surveys carried out by sector authorities and research institutions, and additional calculations for dwellings not covered by existing surveys.

The exposure and annoyance index calculations refer to the dwellings. That is to say that the results presuppose that all persons in Norway at any time reside at their permanent address as recorded in the Population register. This is evidently not a true picture of the reality, as noise annoyance at working places, schools, recreational areas, etc. are not included in the calculations. Further developments in the model will need to be considered in order to be able to give a more precise picture of actual noise annoyance.

See also: Health effects of noise

Tables:

• Tabell 1 Noise annoyance index (SPI) by source. 1999 and 2001
• Tabell 2 Number of persons exposed to different noise levels, by source of noise. 2001
• Tabell 3 Number of residents exposed to noise levels above 55 dBA, and SPI by county. Road traffic. 2001*