Department of Otolaryngology-Head and Neck Surgery, University of Toronto, Toronto, Canada.
Department of Otolaryngology-Head and Neck Surgery, Hospital for Sick Children, Toronto, Canada.
J Otolaryngol Head Neck Surg. 2017 Nov 23;46(1):62. doi: 10.1186/s40463-017-0239-6.
With an increasing proportion of the population living in cities, mass transportation has been rapidly expanding to facilitate the demand, yet there is a concern that mass transit has the potential to result in excessive exposure to noise, and subsequently noise-induced hearing loss.
Noise dosimetry was used to measure time-integrated noise levels in a representative sample of the Toronto Mass Transit system (subway, streetcar, and buses) both aboard moving transit vehicles and on boarding platforms from April - August 2016. 210 measurements were conducted with multiple measurements approximating 2 min on platforms, 4 min within a vehicle in motion, and 10 min while in a car, on a bike or on foot. Descriptive statistics for each type of transportation, and measurement location (platform vs. vehicle) was computed, with measurement locations compared using 1-way analysis of variance.
On average, there are 1.69 million riders per day, who are serviced by 69 subway stations, and 154 streetcar or subway routes. Average noise level was greater in the subway and bus than in the streetcar (79.8 +/- 4.0 dBA, 78.1 +/- 4.9 dBA, vs 71.5 +/-1.8 dBA, p < 0.0001). Furthermore, average noise measured on subway platforms were higher than within vehicles (80.9 +/- 3.9 dBA vs 76.8 +/- 2.6 dBA, p < 0.0001). Peak noise exposures on subway, bus and streetcar routes had an average of 109.8 +/- 4.9 dBA and range of 90.4-123.4 dBA, 112.3 +/- 6.0 dBA and 89.4-128.1 dBA, and 108.6 +/- 8.1 dBA and 103.5-125.2 dBA respectively. Peak noise exposures exceeded 115 dBA on 19.9%, 85.0%, and 20.0% of measurements in the subway, bus and streetcar respectively.
Although the mean average noise levels on the Toronto transit system are within the recommended level of safe noise exposure, cumulative intermittent bursts of impulse noise (peak noise exposures) particularly on bus routes have the potential to place individuals at risk for noise induced hearing loss.
随着城市人口比例的增加，大众运输系统迅速发展以满足需求，但人们担心大众运输系统有可能导致过度暴露于噪音中，从而导致噪声性听力损失。
使用噪声剂量学测量了 2016 年 4 月至 8 月多伦多大众运输系统（地铁、街车和公共汽车）中代表性样本在移动运输车辆上以及在登机平台上的时间积分噪声水平。在平台上进行了多次测量，每次测量约 2 分钟，在行驶中的车辆内进行了 4 分钟测量，在车内、自行车或步行时进行了 10 分钟测量。计算了每种交通工具和测量位置（平台与车辆）的描述性统计数据，并使用单向方差分析比较了测量位置。
平均而言，每天有 169 万名乘客，由 69 个地铁站和 154 个街车或地铁线路提供服务。地铁和公共汽车中的平均噪声水平高于街车（79.8 +/- 4.0 dBA，78.1 +/- 4.9 dBA，而 71.5 +/- 1.8 dBA，p < 0.0001）。此外，地铁平台上测量的平均噪声高于车内（80.9 +/- 3.9 dBA 与 76.8 +/- 2.6 dBA，p < 0.0001）。地铁、公共汽车和街车路线的峰值噪声暴露平均值分别为 109.8 +/- 4.9 dBA 和范围为 90.4-123.4 dBA、112.3 +/- 6.0 dBA 和 89.4-128.1 dBA、108.6 +/- 8.1 dBA 和 103.5-125.2 dBA。在地铁、公共汽车和街车中，分别有 19.9%、85.0%和 20.0%的测量值超过 115 dBA。
尽管多伦多运输系统的平均噪声水平处于推荐的安全噪声暴露水平内，但特别是在公共汽车线路上，间歇性脉冲噪声（峰值噪声暴露）的累积可能会使个人面临噪声性听力损失的风险。
