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How Loud is too Loud?

The Board of Health’s 2017 report How Loud is too Loud – Health Impacts of Noise on Environmental Health describes the increasing concern about the impacts of environmental noise on health, especially in urban areas.

The World Health Organization standard is for a level of 55 dB daytime while Toronto has environmental levels up to an average of 64.1 daytime. And ML&S has proposed up to 85dB for amplified sound and currently grants noise exemption permits at this level. Modified motorcycles can be much louder.

The Public Health Noise Management Action Plan will be developed in conjunction with the new Noise Bylaw and should help reduce permitted levels in this Bylaw.

Executive Summary

There is increasing concern about the impacts of environmental noise on health, especially in urban areas. The growing body of evidence indicates that exposure to excessive environmental noise does not only impact quality of life and cause hearing loss but also has other health impacts, such as cardiovascular effects, cognitive impacts, sleep disturbance and mental health effects.

Health studies usually report on average noise exposure for a specific period (daytime, nighttime or 24 hrs) and measured as A-weighted decibel levels (dBA). Toronto Public Health (TPH) conducted a noise monitoring study in the early fall of 2016. The average 24-hour equivalent noise levels in Toronto were 62.9 dBA. Average daily levels at individual locations ranged from a low of 50.4 to a high of 78.3 dBA, with mean levels of 64.1 dBA daytime (7:00 a.m. to 11:00 p.m.) and 57.5 dBA nighttime (11:00 p.m. to 7:00 a.m.). Nearly 60 percent of noise in Toronto can be attributed to traffic noise and it is estimated that dissemination areas in the lowest income quintile are almost 11 times more likely to have 50 percent of their residents exposed to night noise levels over 55 dBA, than residents in the highest income quintile. The results of the study show that levels of noise in Toronto are similar to levels found in other large cities such as Montreal and Toronto; as well, similar to other cities there is a disparity between income and exposure to noise.

Non-auditory health impacts of environmental noise were reviewed by the World Health Organization (WHO) in 2009 and 2011. The reports show that cognitive impacts, sleep disturbance mental health and cardiovascular effects could occur at noise levels commonly experienced in urban environments. Toronto Public Health has reviewed the evidence that has accumulated since the WHO evaluation. Newer evidence confirms that health impacts can occur at levels between 42 and 60 dBA outdoors, which is below the 70 dBA benchmark that TPH had previously been considered protective of health. The available evidence suggests that environmental noise in Toronto occurs at levels that could be detrimental to health.

The World Health Organization (2009) established health-protective guidelines of 55 dBA outdoors (Leq 16 hours) for daytime and evening exposures and night-noise exposure guidelines of 40 dBA (outdoors Leq night 8 hours, to keep an indoor average of 30 dBA). Given that 40 dBA is often difficult to achieve in urban centres, the WHO indicated an interim nighttime limit of 55 dBA. The Ontario Ministry of Environment and Climate Change has recommendations for road-related noise thresholds: for sensitive land uses, such as residential uses, mitigation measures are required if outdoor levels at the centre of a window or door opening exceed 55 dBA daytime or 50 dBA nighttime.

Reducing the exposure of environmental noise to residents is multi-pronged and includes periodic assessment of the noise environment through monitoring and modelling, policy interventions (for example, traffic management, building code standards, equipment performance standards, and noise bylaws), and education and engagement of the public. Maintaining a quality outdoor noise environment will contribute to better health and wellbeing. Not only will such an environment promote a more active lifestyle (walking, cycling and active recreation), which can reduce noise levels from transportation, it will also contribute to a reduction in the risk of chronic disease, making Toronto a healthier city for all.

Table of Contents

  • Executive Summary 4

  • Glossary 7

  • Environmental Noise and Health 8

  • Noise-induced Hearing Loss 9

  • Non-Auditory Health Impacts of Environmental Noise 9

  • Cardiovascular Effects 10

  • Cognitive Impairment 11

  • Sleep Disturbance 11

  • Mental Health 11

  • Pulmonary 12

  • Emerging Health Evidence 12

  • Discussion 13

  • Noise Levels Recommended for Health 14

  • Noise Levels in Toronto 15

  • Noise Monitoring 15

  • Noise Modelling 16

  • Results 17

  • Populations Affected 20

  • Mitigation and Regulation 21

  • Noise Regulation in Ontario 21

  • Mitigation Best Practice 21

  • Conclusions 23

  • References 24

  • Appendix 31

Download and read the full report: Toronto Public Health. How Loud is Too Loud?

Reference: Toronto Public Health. How Loud is Too Loud? Health Impacts of Environmental Noise in Toronto. Technical Report. April 2017

Authors: Kelly Drew, Ronald Macfarlane, Tor Oiamo, Meghan Mullaly, Desislava Stefanova, Monica Campbell

We gratefully acknowledge the contributions made by a wide variety of people who helped shape the contents and key ideas presented in this report, including:

  • Tor Oiamo, Desislava Stefanova (Ryerson University)

  • Reg Ayre, Kate Bassil, Taryn Ridsdale and Andi Camden (Toronto Public Health)

  • Renata Moraes (Transportation Services)

  • Annemarie Baynton (Energy and Environment)

  • Christian Giles (City Planning)

  • Elaina MacIntyre (Public Health Ontario)

  • Eleanor McAteer (Engineering and Construction Services)

  • Ross Lashbrook (Ministry of Environment and Climate Change)

  • Vanessa Fletcher, Hamish Goodwin, Mark Sgara, Jessica Walters (formerly) (Municipal Licensing and Standards)

Cover Photo: istock, Saturated

Distribution: Copies of this document are available on the Toronto Public Health Web site:, or by: Phone: 416-338-7600 TTY: 416-392-0658 email:

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