Noise levels of vehicles in the City of Colombo, Sri Lanka
Pollution by noise is a public health problem in the city of Colombo Sri Lanka. Though there is widespread concern about the contribution of vehicular traffic towards noise pollution in the City of Colombo there is no reliable data on the noise emitted by different types of vehicles.
Objective of this study was to determine the levels of noise, emitting from vehicles which travel within the city of Colombo.
METHODS:
Vehicles that travel within the city of Colombo could be classified into sixteen categories based on the type (bus, motor-car, three-wheeler etc), technology (two-stroke/ four-stroke, petrol/ deisel) and size (light, heavy etc) of the vehicle. Nine to 16 vehicles from each category were selected (convenient sampling). Sound pressure level(SPL-the magnitude of sound) and Maximum sound level(LAmax) of engine and horn were measured in every selected vehicle.[A1] All measurements taken according to ISO 5130:2007(E) standerds.
[A1]Expand this section. Selection of vehicles & measurements (distance from the vehicle). Explain SPL, Lamax.
RESULTS:
Diesel three-wheelers recorded the highest SPL (105.2dB) while cars recorded lowest (80.2dB). SPL of six categories of vehicles were more than 100dB. SPL of four and two stroke petrol three-wheelers and diesel three-wheelers were 97.2, 102.1 and 105.2dB respectively. SPL of large-buses with turbo engines were 95.0dB and 103.6dB in large-buses with normal engines. LAmax level of engines took same hierarchy as SPLs. LAmax of horns ranged from 100.1-113.3dB. Maximum permissible noise level in a municipal council area during day time is 63dB.
CONCLUSIONS:
Diesel and two stroke petrol three-wheelers and large buses with normal engines are the vehicles which emit more noise in the city of Colombo.