Environmental noise

The "Environmental noise" fact sheet assembles the information collected in the Strategic Noise Maps in mainland Portugal and the evolution of the population overexposed to noise levels above 55 dB(A) during night-time.

Noise is associated with many human activities, and the noise caused by road, rail and air traffic has a high impact on human health. Environmental noise is an underestimated threat that causes discomfort and short- and long-term health problems, such as sleep disturbances, cardiovascular diseases, poor performance at work and school, among others.

Strategic Noise Maps (MER) are diagnostic tools for the acoustic quality of the territory and the resident population overexposed to noise. Action Plans (PA) are the response to this diagnosis since they contain the measures whose implementation will result in the reduction of the number of people affected.

Thus, through the analysis of the information provided by the MER of Road, Rail and Air Large Transport Infrastructures (GIT), and by agglomerations (The municipalities Lisbon, Oeiras, Odivelas, Amadora, Porto and Matosinhos), whose five-year report to the European Commission (EC) is mandatory, it is possible to obtain the development of the population exposed to critical sound levels.

Fifty-five decibels [55 dB(A)] was considered the critical threshold during night-time (11 p.m. - 7 a.m.), since this is the limit established in the national legislation, known as “Regulamento Geral do Ruído” or, in English, General Noise Regulation, for mixed areas. In addition, a threshold of 45 dB(A) was considered at night because it is the limit established in the RGR for sensitive areas, delimited in agglomerations, and also because it is close to the recent recommended values by the World Health Organization, for the main sound sources.

This indicator concerns mainland Portugal and shall be updated on an annual basis.

Objectives and targets: 

In the case of environmental noise, the objective associated with GIT and agglomerations is to reduce the number of people exposed to the threshold limit values established in national regulations. The targets to be achieved are:

  • To obtain the complete diagnosis of the national situation (100% of the MER submitted and reported to the EC);
  • To obtain the responses to the diagnostic (100% of the PA submitted and reported to the EC).
Progress analysis:
Last update: 
Friday, 3 May, 2019