Case studies

Environmental noise is expected to become one of the major environmental health issues in Europe. In 1998 it was estimated that 32 % of the European population was exposed to noise levels over 55 dB(A) (LDN) and 13 % to noise levels over 65 dB(A) (LDN). At present the health impact of road traffic noise on the whole European population can not be estimated due to the lack of current exposure data at European level.

A Health Impact Assessment (HIA) case study in children (0-14 yrs) on health effects induced by road traffic noise was conducted in two German cities in North Rhine-Westphalia, one small town (city A), the other a larger city in a highly compressed area (city B). 17 %– 34 % of children in these cities are estimated to be exposed to noise levels of more than 60 dB(A) during the day (see Figure 1). At night, 21 % – 34 % of children are estimated to be exposed to noise levels of more than 50 dB(A).

Figure 1. Traffic noise exposed children (0-14 years) in two cities in NRW during daytime

By HIA analyses we estimated the fraction of highly annoyed and highly sleep disturbed children per 1000 children in both North Rhine-Westphalian cities, for: i) the current situation; ii) for scenario 1 (assuming that noise exposure does not exceed 60 dB(A) during daytime and 50 dB(A) at night); iii) and for scenario 2 (assuming noise levels L(DN) decreased by 5 dB(A)).

In the current scenario the estimated proportion of highly annoyed children due to road traffic noise is 5.4 % in the small city (city A) and 10.1 % in the urban city (city B). The estimated proportion of children that is highly sleep disturbed due to road traffic noise is 4.6 % in city A and 5.2 % in the city B.

Compared to the current scenario, scenario 1 shows that the proportion of highly annoyed children could be reduced by about 10 per 1000 (city A) and 30 per 1000 (city B) (Figure 2). In scenario 2 the proportion of highly annoyed children could be reduced by about 20 per 1000 (city A) and 39 per 1000 (city B), compared to the current situation (Figure 2).

Figure 2. Estimated fraction of highly annoyed children (per 1000) in two North Rhine-Westphalian cities, for the current situation, for scenario 1 (assuming that noise exposure does not exceed 60 dB(A) during daytime and 50 dB(A) at night), and for scenario 2 (assuming noise levels L(DN) decreased by 5 dB(A))

The proportion of highly annoyed or highly sleep disturbed children (in %) which could be avoided by the exposure reduction measure was calculated (Table 1) This can be interpreted as a health gain. The health gain for annoyance would vary between 19 % and 38 % for both scenarios and cities. The proportion of avoided highly sleep disturbed children would vary between 19 % and 28 % for both cities and scenarios (Table 1).

Table 1 Proportion of highly annoyed and highly sleep disturbed children (current situation, scenario 1, and scenario 2) in absolute numbers for both cities. For scenario 1 and 2, the health gain (in percent) is presented.

Compared to the current situation, scenario 1 and scenario 2 both show a clear decrease of the negative health outcomes in both cities. Therefore preventive actions to reduce traffic noise exposure as suggested in the END (Environmental Health Directive) should be strengthened in Europe. It was also discussed to what extent uncertainties of the applied method might result in an over- or underestimation of the health impacts.

• Fact sheet indicator Children living in the proximity of heavily trafficked roads
• WHO/Europe: noise and health: http://www.euro.who.int/Noise
• EU Directive 2002/49/EC - Environmental Noise Directive (END) : http://eur-lex.europa.eu/pri/en/oj/dat/2002/l_189/l_18920020718en00120025.pdf

Authors: Odile Mekel (LOEGD), Sarah Sierig (LOEGD) and Thomas Claßen (LOEGD)

Reviewers: Elise van Kempen (RIVM), Danny Houthuijs (RIVM), Sylvia Medina (InVS)

Long paper available on request, please e-mail to info@ecehbonn.euro.who.int

HIA guidelines on road traffic noise (.pdf)