Health and Sensitivity Effects associated with Land Transport Noise
Health Effects
Noise causes stress-type responses. The most common issues arising from exposure to noise is the interruption of speech, decreased concentration and sleep disturbance. Average noise levels above 65 dBA are highly undesirable
Effects rise in tandem with the level of noise and length of exposure experienced. Noise exposure can also have temporary or permanent impacts on psychological and physiological functions. Acute noise exposure activates the nervous and hormonal systems leading to increased blood pressure, increased heart rate and the narrowing of blood vessels. After prolonged exposure susceptible individuals may develop permanent effects such as high blood pressure.
Sensitive Activities
Sensitive activities are activities that are sensitive to noise interference. Examples of sensitive activities include teaching, which requires communication and interaction through speech, and sleep, which generally requires peace and quiet.
Sensitive receivers have been defined by the Environment Court in Robinsons Bay Trust, National Investment Trust v Christchurch City Council and Others (C060/04) as:
International definitions extend this to include places of worship and areas preserved for their quiet value, such as parks and reserves. The WHO guidelines on community noise included recommended noise levels for sensitive activities.
Reverse Sensitivity
Reverse sensitivity refers to the effects of sensitive activities on nearby existing activities, for example road and rail corridors, and can lead to restraints on those activities. Noise is a key reverse sensitivity issue. When a new land use is established near a road or railway corridor the new land use may be affected to some degree.
Land use planning can address reverse sensitivity by restricting certain land uses near existing or planned road and rail corridors and placing conditions, where appropriate, on resource consents.
