Browsing by Author "Nagodawithana, N.S."

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Environmental noise levels in the city of Colombo, Sri Lanka
(Sri Lanka Medical Association, 2013) Nagodawithana, N.S.; Pannila, A.S.; Gurusinghe, R.D.; Kalansuriya, C.; Sathiakumar, N.; Wickremasinghe, A.R.; Pathmeswaran, A.
INTRODUCTION AND OBJECTIVES: Noise is a physical pollutant, which causes adverse health effects. Noise levels in most cities are higher than that recommended by environmental regulatory authorities of the relevant countries. Objective of this study was to determine the level of environmental noise at identified locations in the city of Colombo. METHODS: Colombo Municipal Council area is divided into 15 divisions. Sixty places with high traffic density, four from each of the 15 divisions, were purposively selected. At each selected site, equivalent continuous sound pressure level (LAeq) was measured for six hours during day time (three hours each from peak and non-peak traffic hours) using a Class-I Sound Level Meter on week days. LAeq for eight hours (LAeq [8hrs]) was calculated and taken as the average noise level of that place. L10, L50, and L90 measurements were also taken. RESULTS: LAeq (8hrs) within the Colombo city ranged from 76.6dB (at BOC roundabout, Colombo 12) to 84.0dB (at Lipton’s roundabout, Colombo 07), well above the maximum permissible noise level (63dB) for municipal council areas. All recorded LAeq values were more than 80dBs in Colombo 5, 9, 10, 13 and 14. Median LAeq value for the entire city was 81.0dB. Median LAeq value for peak traffic hours was 81.1dB and for off-peak traffic hours 80.4dB. Median values for L10, L50 and L90 for the city were 83.1dB, 76.6dB and 71.9dB respectively. CONCLUSIONS: Environmental noise levels in Colombo city are well above (13.3dB to 21.0dB) the levels recommended in the National Environmental (Noise pollution) Act of Sri Lanka.
Environmental pollution by traffic noise in the city of Colombo, Sri Lanka
(IOS Press, 2016) Nagodawithana, N.S.; Pathmeswaran, A.; Pannila, A.S.; Wickremasinghe, A.R.; Sathiakumar, N.
Traffic noise levels in most cities of the world are higher than the recommended levels. Exposure to high levels of noise may cause adverse health effects such as ischemic heart diseases and noise induced hearing loss. We conducted a cross-sectional study to determine road traffic noise levels at 60 selected locations in the city of Colombo, Sri Lanka. On randomly selected days we measured equivalent continuous sound pressure level (LAeq) for six hours during the day. From these measurements LAeq for eight hours were calculated and used as the average noise level of a particular location. LAeq (8 hrs) within Colombo ranged 76.6 to 84.0 dB; well above the Sri Lankan recommendation of 63.0 dB (an increase of 13.3 to 21.0 dB), and the WHO recommendation of 55.0 dB (an increase of 21.6 to 29.0 dB). These levels translate into increase of sound pressure level by 21.4 to 794.3 times above the recommendations on the logarithmic scale of dB. Thirty-eight of 60 locations recorded levels more than 80.0 dB. Road traffic noise levels in Colombo were well above the recommended levels. Though the increase in measured decibels might not appear to be too high, in reality this translates into an increase manifold times in the sound pressure level that reaches the ear
Noise levels of vehicles in the city of Colombo
(Sri Lanka Medical Association, 2013) Nagodawithana, N.S.; Pannila, A.S.; Gurusinghe, R.D.; Kalansuriya, C.; Sathiakumar, N.; Wickremasinghe, A.R.; Pathmeswaran, A.
INTRODUCTION AND OBJECTIVES: Though there is concern that vehicular traffic contributes to 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 noise emitted by vehicles within the city of Colombo. METHODS: Vehicles in 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, diesel) and size (light, heavy etc). Nine to 16 vehicles from each category were selected by quota sampling. Sound pressure level (SPL-the magnitude of sound) and maximum sound level (LAmax) of the engine and horn of the selected vehicles were measured according to ISO 5130:2007(E) standards. RESULTS: Diesel three-wheelers recorded the highest SPL (105.2dB) while cars recorded the lowest SPL (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 and normal engines were 95.0dB and 103.6dB respectively. Ranking order of the LAmax level of engines were the same as for SPLs. LAmax of horns ranged from 100.1dB to 113.3dB. Maximum permissible noise level in a municipal council area during day time is 63dB. CONCLUSIONS: Diesel three-wheelers, two stroke petrol three-wheelers and large buses with normal engines are the noisiest vehicles in the city of Colombo
Noise levels of vehicles in the city of Colombo
(College of the Community Physicians of Sri Lanka, 2013) Nagodawithana, N.S.; Pathmeswaran, A.; Pannila, A.S.; Sathiakumar, N.; Wickremasinghe, A.R.
INTRODUCTION: Though there is concern that vehicular traffic contributes to noise pollution in the city of Colombo there is no reliable data on the noise emitted by different categories of vehicles. OBJECTIVES: Objective of this study was to determine the noise emitted by different categories of vehicles within the city of Colombo. METHODS: Vehicles in 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, diesel) and size (light, heavy etc). Nine to 16 vehicles from each category were selected by quota sampling. Sound pressure level (SPL-the magnitude of sound) and maximum sound level (LAmax) of the engine and horn of the selected vehicles were measured according to ISO 5130:2007(E) standards. RESULTS: Measurements were made on 184 vehicles. Median SPL of vehicles ranged from 80dB in cars to 105dB in diesel three-wheelers. 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 and normal engines were 95.0dB and 103.6dB respectively. Rank order of the vehicles according to LAmax level and SPL of engines was the same. LAmax of horns ranged from 100.1dB to 113.3dB. There was no relationship between the category of vehicle and the LAmax of the horn. CONCLUSIONS AND RECOMMENDATIONS: Diesel three-wheelers, two stroke petrol three-wheelers and large buses with normal engines are the noisiest vehicles while cars, jeeps and pickups were the least noisy vehicles in the city of Colombo. Prohibition of importation of diesel three-wheelers and large busses with normal engines will help to make the county less noisy.
Noise-induced hearing loss among traffic policemen in the city of Colombo, Sri Lanka
(IOS Press, 2015) Nagodawithana, N.S.; Pathmeswaran, A.; Pannila, A.S.; Wickremasinghe, A.R.; Sathiakumar, N.
Noise-induced hearing loss (NIHL) is a high frequency sensory-neural hearing loss and exposure to traffic noise by traffic policemen makes them susceptible to develop NIHL. The objective of this study was to determine the prevalence and correlates of NIHL among traffic policemen in the city of Colombo, Sri Lanka. A cross sectional study was carried out using 350 traffic policemen who are working in the city at least six months of duration. Pure-tone audiometry test and interviewer-administered questionnaire were used to assess hearing and correlates of NIHL, respectively. The chi-square test and logistic regression was used to analyze the relationship between risk factors and NIHL. 287 policemen attended pure-tone audiometry test to check their hearing. Of 287 subjects, the prevalence of NIHL was found in 118 policemen (41%; 95% CI: 36%-47%). Of those with any type of NIHL, 33% (39/118) had major NIHL while 67% (79/118) had minor NIHL. In bivariate analysis 23 variables showed statistically significant association with mild and major NIHL. Multivariate logistic regression modelling found statistically significant association between “duration of employment as a policeman” and any type of NIHL (OR = 1.007; 95% CI = 1.005-1.009), adjusted for 23 variables including age. The prevalence of NIHL among traffic policemen in the city was high. Of those with any type of NIHL, one-third had major NIHL. Traffic policemen should undergo periodic hearing assessment. The police department should explore the feasibility of reducing the number of hours per day spent on the road by traffic policemen.
Prevalence and correlates of noise induced hearing loss among traffic policemen in the city of Colombo
(College of the Community Physicians of Sri Lanka, 2013) Nagodawithana, N.S.; Pathmeswaran, A.; Pannila, A.S.; Sathiakumar, N.; Wickremasinghe, A.R.
INTRODUCTION: Noise induced hearing loss (NIHL) is a high frequency sensory-neural hearing loss in subjects who are exposed to environmental noise, but this diagnosis is made only after excluding other reasons for the hearing. Traffic policemen are exposed to environmental noise due to the nature of their duty and are susceptible to develop NIHL. OBJECTIVE: The objective of this study was to determine the prevalence and correlates of NIHL among traffic policemen in the city of Colombo. METHODS: This was a cross sectional study and traffic policemen working in the city of Colombo were selected for study. Cluster sampling method was adopted to select 350 participants. Pure tone audiometry test was performed to assess the level of NIHL. The test was performed in an audiology laboratory or in a sound treated, air-conditioned conference hall. Hearing levels of participants were classified according to a classification obtained by modifying the Clark’s classification. Correlates of NIHL were assessed using information collected using an Interviewer Administered Questionnaire (IAQ). RESULTS: Pure tone audiometry was performed on 287 policemen. High frequency hearing of, 169 participants (58.9%) was normal. Seventy nine participants (27.5%) had minor NIHL and 39 participants (13.6%) had major NIHL. In bivariate analysis 23 variables showed statistically significant association with mild and major NIHL of traffic policeman in the city of Colombo. However according to multi-variate analysis only age had statistically significant association with major NIHL with odds-ratio (OR) of 1.088 while only “duration of work as a policeman” had statistically significant association with any NIHL (major or minor) with OR of 1.007. CONCLUSIONS AND RECOMMENDATIONS: Prevalence of NIHL among traffic policemen working in the city of Colombo was 41.1% (95% CI=35.5%–46.9%). A third of those having NIHL had major NIHL. Traffic policemen should undergo periodic hearing assessment. The police department should explore the feasibility of reducing the number of hours per day spent on the road by traffic policemen. Traffic policemen with NIHL must be transferred to a different division immediately.
Prevalence and correlates of noise induced hearing loss among traffic policemen in the City of Colombo
(Asia-Pacific Academic Consortium for Public Health, 2013) Nagodawithana, N.S.; Pathmeswaran, A.; Pannila, A.S.; Sathiakumar, N.; Wickremasinghe, A.R.
BACKGROUND AND OBJECTIVE: Noise induced hearing loss (NIHL) is a high frequency sensory-neural hearing loss in subjects who are exposed to environmental noise, but this diagnosis is made only after excluding other reasons for the hearing. Traffic policemen are exposed-to environmental noise due to the nature of their doty and are susceptible to develop NIHL The objective of this study was to determine the prevalence and correlates of NIHL among traffic policemen in the city of Colombo. METHODS: A cross sectional study was carried out among traffic po icemen in the city of Colombo, 350 participants were selected by cluster sampling. Pure-tone ; udionietry test was performed to assess the level of NIHL. Hearing levels of participants were classified using a classification obtained by modifying the Clark's classification. Correlates of NIHL were assessed using an Interviewer Administered Questionnair (IAQ). RESULTS: High frequency hearing of, 169 (total 287} participants (5->.9%) was normal. Seventy nine participants (27.5%) had minor NIHL and 39 participants (13.6%) lad major NIHL. In bivariate analysis 23 variables showed statistically significant association with mild and major NIHL while multi-variate analysis showed only age had statistically significant association with major NIHL with odds-ratio(OR) of 1.088 and only 'duration of work as a policeman" had statistically significant association with any NIHL (major or minor) with OR of 1.007. Conclusions: Prevalence of NIHL among traffic policcrien working in the city of Colombo was 41.1 %(95% CI=35.5%-46.9%). A third of those having r IHL had major NIHL. Traffic policemen should undergo periodic hearing assessment. The police department should explore the feasibility of reducing the number of HOLTS per day spent on the road by traffic policemen. Traffic policemen with NIHL must be transfe'-red to a different division immediately.