Soil & Environ. 27(2): 236-240, 2008 www.se.org.pk Short Communication Assessment of noise pollution from traffic in Faisalabad, its sensitivity precision and statistical interpretation M.Y. Hussain 1* , Islam-ud-Din 2 , Inam-ul-Haq 1 , T. Hussain 1 , R. Shabbir 1 and S. Sattar 1 1 Department of Physics, University of Agriculture, Faisalabad-38040, Pakistan 2 Department of Mathematics and Statistics, University of Agriculture, Faisalabad-38040, Pakistan Abstract Noise pollution, at first attacks on the human auditory system, but other ailments like headache, hypertension, depression, mental irritation, sleeplessness, restlessness, cardiovascular problems and so forth are also the noise- based problems of modern era. The objective of this study was to make a general assessment of traffic noise pollution in the “Katchehry Bazaar”, Faisalabad (one of the busiest roads of the city) to figure out the category of noise pollution and a mathematical model for equivalent noise level which will help to make an assessment of noise pollution only by asserting the parametric values in the model. At the observational site, the noise level was measured at 5m from center of the road by using the NA-24 RION noise level meter. The number of vehicles was counted to calculate T eq (Average traffic density/hour) on the road. The data were taken from 7:00 am to 7:00 pm at a regular interval of 5 minutes. In order to remove the personal, random or systematic errors, this process was repeated thrice in a week (i.e., Saturday, Sunday and Monday). Noise levels, L’s in dB(A), vehicle flow, T, were observed and net traffic density, T eq , was also calculated. Mathematical models for L eq , L 10 , L 50 and L 90 for the existing noise levels were developed and their calculated values were 93.5, 96.5, 90.3 and 79 dB(A), respectively. It was, hence, found that the inhabitants living around this place were exposed for about 10-12 hours/day constantly to the noise level which falls in the very bad category that have potential to hamper their healths. Key words: Traffic noise, noise pollution, statistical noise level, statistical model Faisalabad, the Manchester of Asia, is the third largest city of Pakistan with an estimated population of 2,008,861 in 1998 with annual growth rate 3.58, according to the Ministry of Economic Affairs and Statistics, Pakistan (Population Census Organization, 1998). This city has been progressing constantly for the last 35 years. Due to consistent progress, the population of the city has increased causing a huge structural development. As the number of inhabitants has increased, so a huge amount of traffic has to circulate in the city in order to meet their commuting requirements. The urban noise pollution and its consequences for the environment have motivated researchers in several countries to deal with this problem (Zannin et al., 2002). This study presents the results obtained in a research conducted for “Katchehry Bazaar” (one of the busiest places in the heart of the Faisalabad city). The collected data were analyzed statistically, in order to assess the amount of noise to which the residents of this bazaar are exposed. It has been concluded from the results that the noise generated by the vehicular traffic is very annoying for the local dwellers. Experts have reported that a continued exposure to the noise above 85 dB(A) over time, causes hearing loss and the louder the noise, the lesser the time required for hearing loss. The aim of this survey was to calculate the equivalent and statistical noise levels, to determine the level of noise emitted by the traffic through our designed mathematical models based on the parameters of traffic flow and its composition. The traffic noise was assessed by using the noise level meter NA-24 RION, manufactured by RION Co., Tokyo, Japan, having range 30-130 dB while placing it 1.5 m above the ground level and keeping at 5 m from the centre of road (Givargis, 2009). At each time of noise level meter’s reading, number of vehicles such as (Buses, Mazdas, Rickshaws, Cars, Motorcycles, Motorcycle Rickshaws (Qingqi), Oil Tankers, Jeeps, Pajeros etc.) were also counted in order to check Teq (Net traffic density/hour). These readings were taken from 7:00 am to 7:00 pm at a regular interval of 5 minutes. To minimize the personal, random or systematic errors, this process was repeated thrice in a week (on Saturday, Sunday and Monday). For each day, the number of auto vehicles which passed the observation point during the time interval of each measurement, the equivalent and statistical levels in dB (A); L eq , L 10 , L 50 and L 90 emitted by the traffic were measured. Some variables of the process were fixed for representation of the collected data in a single matrix. In the developed model, by entering the input data (vehicles flow, *Email: myh_49@yahoo.co.uk © 2008, Soil Science Society of Pakistan (http://www.sss-pakistan.org)