Temporal and spatial variations in road traffic noise for different frequency components in metropolitan Taichung, Taiwan.
Road traffic noise exposure has been associated with auditory and non-auditory health effects, but few studies report noise characteristics. This study determines 24-h noise levels and analyzes their frequency components to investigate associations between seasons, meteorology, land-use types, and traffic. We set up 50 monitoring stations covering ten different land-use types and conducted measurements at three times of the year to obtain 24-h-average A-weighted equivalent noise levels (LAeq,24h) and frequency analyses from 2013 to 2014 in Taichung, Taiwan. Information on land-use types, road parameters, traffic flow rates, and meteorological variables was also collected for analysis with the annual averages of road traffic noise and its frequency components. The annual average LAeq,24hin Taichung was 66.4 ± 4.7 A-weighed decibels (dBA). Significant differences in LAeq,24hand frequency components were observed between land-use types (all p-values < 0.001), but not between seasons, with the highest two noise levels of 71.2 ± 1.0 dBA and 70.0 ± 2.6 dBA measured in stream-channel and commercial areas, with the highest component being 61.4 ± 5.3 dBA at 1000 Hz. Road width, traffic flow rates, and land-use types were significantly associated with annual average LAeq,24h(all p-values < 0.050). Noise levels at 125 Hz had the highest correlation with total traffic (Spearman's coefficient = 0.795) and the highest prediction in the multiple linear regression (R2= 0.803; adjusted R2= 0.765). These findings reveal the spatial variation in road traffic noise exposure in Taichung. The highest correlation and predictive capacity was observed between this variation and noise levels at 125 Hz. We recommend that governmental agencies should take actions to reduce noise levels from traffic vehicles.
Department of Occupational Safety and Health, College of Public Health, China Medical University, Taichung, Taiwan.
Ven-Shing
VS
Wang
Department of Occupational Safety and Health, College of Public Health, China Medical University, Taichung, Taiwan.
Ei-Wen
EW
Lo
Department of Occupational Safety and Health, College of Public Health, China Medical University, Taichung, Taiwan.
Chih-Hsiang
CH
Liang
Department of Occupational Safety and Health, College of Public Health, China Medical University, Taichung, Taiwan.
Keh-Ping
KP
Chao
Department of Pharmacy, College of Pharmacy, China Medical University, Taichung, Taiwan.
Bo-Ying
BY
Bao
Department of Occupational Safety and Health, College of Public Health, China Medical University, Taichung, Taiwan. Electronic address: tychang@mail.cmu.edu.tw.
Ta-Yuan
TY
Chang
D002947:Cities; D004781:Environmental Exposure / Q000009:adverse effects / Q000706:statistics & numerical data*; D004784:Environmental Monitoring; D040362:Geographic Information Systems; D006801:Humans; D018986:Motor Vehicles; D009624:Noise, Transportation / Q000009:adverse effects / Q000706:statistics & numerical data*; D062211:Spatio-Temporal Analysis; D013624:Taiwan / Q000453:epidemiology; D014504:Urban Health / Q000706:statistics & numerical data
Frequency analysis; Land-use type; Multiple linear regression; Road traffic noise; Traffic flow rate