Noise Exposure - How to Limit Hazards on Construction Sites

Noise exposure is one of the leading workplace-related hazards, and construction sites are no exception. Excessive noise is ever-present on worksites, stemming from a myriad of equipment, such as jackhammers, chainsaws, and heavy machinery. If noise isn’t managed, it can lead to severe health-related repercussions on workers. To ensure their safety, the CNESST (Commission des normes, de l’équité, de la santé et de la sécurité du travail) established strict regulations, effective since June 16, 2023.

What are the effects of prolonged noise exposure on the health of workers, and what are potential preventative measures? What new regulations were implemented? This article explores the consequences of excessive noise and mandatory measures set forth to ensure occupational safety.

What Are the Effects of Noise Exposure?

Excessive noise can lead to permanent hearing damage, even after brief exposure. According to the World Health Organization (WHO) and the Occupational Safety and Health Administration (OSHA), noise exposure exceeding 85 dBA for more than 8 hours per day poses a significant risk of hearing loss. In most Canadian provinces, the regulation states a strict 85 dBA limit measured over an 8-hour shift. 

The Leading Risks of Noise Exposure

Hearing Loss

Hearing loss is one of the leading consequences of prolonged noise exposure. It can either be progressive or sudden, depending on the noise intensity and the duration of exposure. Once hearing loss occurs, note that, in most cases, it’s irreversible. Equipment like jackhammers, which generate sound levels exceeding 100 dBA, pose a high risk of occupational hearing loss. The INSPQ (Institut national de santé publique du Québec) published several reports underlining the increasing number of occupational hearing loss cases reported in Quebec, especially in the construction and industrial sectors. 

Tinnitus

Tinnitus is another consequence of frequent noise exposure. The constant ringing or humming can affect the quality of life and lead to sleep-related difficulties, anxiety, and even depression. Workers regularly exposed to loud noises often report chronic tinnitus, even after short periods of exposure.

Cardiovascular Diseases

A study by the WHO proved that excessive noise exposure can also have adverse effects on one’s cardiovascular system. Noise leads to increased stress and elevated blood pressure, which can lead to long-term heart disease, such as hypertension and heart attacks.

Loud Noises: Other Effects on Overall Health

Aside from immediate hearing damage, excessive noise can lead to generalized disorders, such as stress, chronic fatigue, and trouble concentrating. Workers exposed to elevated noise levels may be at a greater risk of accidents since they’re less likely to hear verbal warnings or instructions.

NIOSH: Acceptable Daily Levels and Exposure Time

Pursuant to the Règlement sur la santé et la sécurité du travail (RSST), the Code de sécurité pour les travaux de construction (CSTC), and the National Institiute for Occupational Safety and Health (NIOSH), Canadian employers are now more than ever required to comply with stricter noise exposure limits. The daily exposure limit went from 90 dBA to 85 dBA and impact noises shouldn’t exceed 140 dBC. 

Current Regulations in Canada: Limits Established by Occupational Safety and Health Organizations

Source: NIOSH 2024, and CNESST, RSST, and CSTC 2023

What Is the Occupational Noise Exposure Limit in Ontario and Quebec?

Impulse noises, which include impact noises like those of a jackhammer, are particularly harmful. Said sort of tool generates sudden spikes in noise levels, which can exceed the tolerated thresholds by a few milliseconds. As such, the CNESST and CCOHS (Canadian Centre for Occupational Health and Safety) now mandate that such noises not exceed 140 dBC.

How to Measure Noise Exposure and Decibels

Regular noise monitoring is a key step in assessing and monitoring occupational exposure. There are several methods used to effectively measure sound levels on construction sites.

What Tools Can You Use to Measure Noise on Worksites?

Sound Level Meter

Mainly used for accurate readings, a sound level meter measures the noise level at a precise moment in time. It’s often used during construction site sound audits to assess immediate exposure for workers. However, it’s not the best tool to measure exposure over a full day’s worth of work.

Dosimeter

On the other hand, a dosimeter is worn by workers throughout their shifts. It measures continuous noise exposure to get a more accurate reading regarding daily exposure. The Réseau de la santé publique en santé au travail (RSPSAT) recommends using a dosimeter for all accurate noise level evaluations.

How Often Should Workplace Noise Levels Be Measured?

Noise levels should be measured regularly, especially on worksites where they tend to fluctuate. According to the CNESST’s guide about reducing occupational noise levels, businesses should reevaluate noise levels at least once a year, or at the very least every time new equipment makes its way onto a worksite.

What Is Accumulative Exposure?

Accumulative exposure considers all noises workers are exposed to throughout a shift. Not only does it include tool-generated noises, but it also factors in material vibrations and surrounding noises. The CNESST has an online calculator that assesses accumulative exposure against noise levels and time exposure.

What Is the Best Way to Manage Excessive Occupational Noise Levels?

To protect workers, it’s essential to implement noise level reduction measures. They can include source-based solutions, work organization adjustments, and preventative measures.

Preventative Measures

Personal Protective Equipment

Hearing protection like earplugs or noise-cancelling headsets must be provided to workers exposed to dangerous noise levels. However, PPE shouldn’t be used solely as a last resort. As underlined by Isabelle Dugré, ASP Construction's Prevention Advisor, "Reducing noise levels at the source is always the priority but, in some cases, hearing protection is mandatory to provide adequate safety." (Quote translated by RenoQuotes in English)

Worker Training and Awareness

Employers have the obligation of training their staff to recognize noise-related hazards. They must also ensure workers know how to adjust their hearing protection correctly and understand the risks associated with ineffective usage.

Implement a Noise Management Policy

A proactive approach to limit noise exposure comes from implementing a clear and concise in-house policy. Such a policy should include several aspects to ensure noise levels are constantly monitored and workers are protected at all times:

Regular noise level monitoring program: Companies must establish a regular noise level assessment calendar to ensure the established limits are respected.

Yearly noise audits, done by qualified professionals: Such audits can identify all potentially dangerous noise sources and adjust work practices if necessary.

Continuous training programs raising awareness among workers about the dangers of noise: Worker training and awareness must be ongoing, ensuring they understand the associated risks, and know how to use personal protective gear adequately.

Establish noise reduction goals in equipment maintenance and purchase plans: When acquiring new tools or planning regular maintenance, it’s essential to consider the equipment’s noise level and prioritize low-noise tools and machinery.

Ongoing Monitoring and Evaluation of Implemented Measures

After having implemented noise reduction measures, it’s essential to continue monitoring their efficiency. Carrying out regular noise level assessments and equipment inspections ensures remedial efforts are still implemented and working efficiently. The Réseau de la santé publique en santé au travail (RSPSAT) recommends renewing evaluations at least once a year or every time significant worksite equipment is changed. Doing so guarantees ongoing occupational improvement, working toward the betterment of employee protection against noise exposure.

Noise (dBA) Reduction Solutions

Source-Based Reduction

One of the most effective noise reduction strategies is limiting it at the source. For example, purchasing low-noise equipment and tools, such as power tools instead of thermal ones, significantly reduces noise levels. Moreover, installing noise barriers around loud machines can limit the amount of noise pollution on construction sites.

Cloistering Noises at the Source

In some cases, setting up soundproofing barriers around the loudest equipment and tools is quite feasible. These partitions act as physical barriers, significantly reducing noise levels experienced by workers nearby. This method is particularly effective for constant noises generated by stationary equipment or machinery.

Schedule Team Tasks to Limit Exposure Time

Last but not least, scheduling teams in such a way as to limit noise exposure can prove quite practical. For example, rotating workers between noise-generating tasks and less noise-exposed ones is feasible to comply with exposure limits while ensuring on-site productivity.

The Importance of Proactive Management, Ensuring Occupational Health and Safety

Occupational noise exposure represents a serious hazard to worker health and safety. Employers, with the support of regulations implemented by several provincial organizations (RSST, CSTC, OHSA), are required to take all appropriate measures to lessen occupational risks by implementing noise reduction strategies at the source, providing all workers with personal protective equipment. Thanks to proactive management and the use of reliable measurement tools, the impact of noise can be limited, ensuring safer workplaces.

For more information about occupational health and safety, check out our articles:

• Is Registering with the CNESST Mandatory?

• New Regulation Respecting Construction Worksite Safety

• The Role of a Health and Safety Representative