The 2002 Environmental Noise Directive seeks to provide a uniform
basis for measuring and addressing noise pollution, one of the
most important urban
for the EU. New research has assessed
city-dwellers' exposure to noise and proposes traffic management
strategies to reduce harmful levels. Clear evidence is growing for
negative health effects of noise pollution
emotional responses such as anger, anxiety and depression,
, motivation and attention problems
(particularly in children) and
All may be related to sleep disturbance, which has measurable
psychological and physiological effects. In order to design
, it is important to understand exposure
to noise pollution.
The study centred on
kilometre in the centre of
Dublin, Ireland. This is a relatively quiet area
surrounded by roads with very
believed to be representative of urban areas across the EU. The
EU Harmonoise2 model was used to predict road traffic noise.
This model is expected to become the standard EU model by 2012.
Traffic was characterised as light/medium/heavy vehicles, as
obtained from recorded
traffic flow data
made available by
Dublin city council. Geographic Information System (GIS)
data, which provides a special map of the area including details
of building height and road profiles, were then used to map
populations and noise levels at different times.
Of particular concern, the study found that 90 per cent of
central Dublin were affected by night-time noise
Health Organisation guidelines3. Furthermore, 53 per cent
of workers and 28 per cent of residents exceeded daytime noise
WHO guideline levels for daytime exposure to noise are 70
decibels (dB), compared with 45dB for night-time levels. The
daytime population of the area studied, including workers, is
around 10 times greater than the overnight population. Therefore
although the proportion of the population exceeding the
guidelines is higher at night, excessive noise affects a greater
number of people during the day.
The researchers also modelled the effects of simple traffic
management measures, such as diverting traffic from residential
areas at night. They found that the number of residents exposed
to high levels of noise (60-70 dB) at night could be reduced
considerably (from an estimated 3500 residents to around 2700).
They suggest that
night time noise reduction measures should focus on
preventing traffic from travelling along inner city links where
there are high numbers of residents. Good urban design with
coherent traffic management plans could therefore have positive
health benefits, even with little or no change to existing
infrastructure or environment.