Monitoring Environmental Hazards Involved in Tunnel Construction
Growing Risks of Occupational Hazards Faced by Tunnel Workers
As population density increases in Australian cities and suburbs, tunnel infrastructure has become more important than ever to alleviate congestion and enhance connectivity across the continent. Tunnels are a practical way of allowing fast and direct travel across dense cities for both public and private transportation. Australia is heavily increasing reliance on tunnel infrastructure, with tunnel projects ongoing in most major cities such as the Melbourne Metro Tunnel and the Western Sydney Metro Tunnel. Many other cities around the world have relied on tunnels for efficient train systems such as the London Underground and the New York Subway.
The scale and complexity of these projects necessitate the utmost vigilance when it comes to occupational health and safety. Workers involved in tunnel construction face unique challenges which differ from those faced in above-ground projects, including exposure to hazardous materials, confined spaces, machinery operations, and tunnel collapses.
In this article, we explore key hazards linked to tunnel construction in Australia, regulations that govern this sector and monitoring solutions to ensure worker safety.
Australian Safety Laws and Regulations for Tunnel Construction Sites
Due to the danger and hazards associated with tunnel construction, everyone involved in projects, particularly employers, should be aware of the legal and regulatory framework which applies.
The Model Work Health and Safety Laws
Since the introduction of the Model Work Health and Safety (MWHS) laws in 2011, this is the source of most matters of workplace safety regulation in Australia. The laws aim to maximise consistency between states in workplace safety standards and have been implemented across six states so far. As of the 31st of March 2022, WA has enforced a modified version of the laws leaving Victoria as the only state that has not implemented the model laws at all. For this reason, it is essential that personnel responsible for occupational health and safety make themselves aware of the specific application of the laws in their own jurisdiction. The MWHS operates through a combination of the MWHS Act, MWHS Regulations and Codes of Practice.
In states and territories that have implemented the MWHS Act, any person conducting a business or undertaking (PCBU), officer (such as a business owner or some senior employees) and even workers themselves should be aware of their obligations under the act. The MWHS Act provides broad obligations to ensure the health and safety of workers and to avoid putting the health and safety of others at risk. The WHS regulations provide more specific detail on the way work should be carried out to meet the obligations within the MWHS Act, including procedural and administrative requirements like licensing and record keeping. Due to the inherently hazardous nature of tunnel construction, worksites must meet high safety standards.
Codes of Practice Relating to Tunnel Construction
Codes of Practice provide practical guidance on monitoring and control measures which can be implemented to meet the requirements imposed by the WHS laws. There is currently no specific Code of Practice for tunnelling work. Therefore, for WHS best practice in tunnel construction projects, a range of Codes of Practice should be taken into account, depending on what hazards are involved in the project. The following resource list is not exclusive and in some jurisdictions additional rules and regulations may operate, depending on how the state has chosen to implement the WHS laws. For example, in NSW the Code of Practice for Tunnels Under Construction (2006) remains in operation post implementation.
Guide for Tunnelling Work – This guide provides information on common hazards and that are faced when undertaking tunnelling construction projects and suggests control methods.
Code of Practice: Excavation Work – All tunnelling projects involve excavation work. This code identifies hazards which may arise during excavation and guidance on managing them.
Code of Practice: Asbestos removal – Some tunnelling projects may involve exposure to or removal of asbestos. In this case, this code should be referred to for guidance on best practice for managing this risk.
Code of Practice: Confined Spaces – Unlike most above-ground construction, tunnel projects underground always require work to be done in confined spaces which poses unique risks.
Code of Practice: Management of WHS Risks – Whilst not specific to tunnel projects, this provides guidance to those who have duties under the WHS Act and Regulations to manage workplace health and safety risks.
When referring to the codes, it is important to note that when ‘must’, ‘requires’, or ‘mandatory’ are used, the action is compulsory if the code is legally binding in the jurisdiction where the project is being undertaken.
Safety Hazards and Monitoring Associated with Tunnel Construction
Monitoring occupational hazards in tunnel construction projects is essential for safeguarding the health and safety of workers, preventing accidents, complying with regulations, mitigating financial risks, ensuring project continuity, protecting the environment, and maintaining positive relationships with stakeholders.
There are a wide range of monitoring solutions available depending on the hazards which need to be monitored. These hazards can include air quality, hazardous gases, dust and particulate matter, noise and more.
These hazards can include:
Exposure to dust and particulate matter: Tunnel construction often generates substantial dust, particulate matter and even silica from tunnelling activities such as mining and blasting. Inhalation of these particles can lead to respiratory problems, eye irritation, and long-term health issues. Dust control measures, such as water suppression and fit tested respiratory protection, are critical for worker safety. Dust monitoring stations are commonly used to monitoring dust and particulate exposure however specific devices like the Nanozen DustCount 9000 may be needed for the monitoring of specific hazards.
Exposure to harmful gases: Tunnelling work is often done in highly confined spaces with poor natural ventilation which can lead to gases accumulating in high concentrations or sudden gas inrush. These gases can include carbon monoxide (CO), nitrogen dioxide (NO2), sulphur dioxide (SO2), and methane (CH4) and are often produced by machinery, vehicle exhaust, or natural sources. Due to the nature of working in confined spaces, adequate ventilation and personal gas monitoring such as the Industrial Scientific MX6 iBrid Portable Multi Gas Monitor can provide workers with an immediate alarm, warning them to exit the area once a certain gas concentration threshold has been exceeded.
Noise and vibration: Noise is a hazard common to many industrial and construction settings due to the operation of loud machinery. Heavy machinery used in tunnel construction can generate high levels of noise and vibration. Prolonged exposure to noise can result in hearing damage, while vibration can lead to musculoskeletal disorders. Ear protection and vibration-dampening measures are necessary are necessary to mitigate any potential dangers. Depending on the nature of the project, vibration meters and noise dosimeters or sound level meters maybe necessary.
Heat related illnesses: Heat stress may be more likely to occur in confined spaces such as tunnels where there is limited air flow or high humidity. Workers in tunnels are also exposure to additional heat sources from machinery and equipment. Heat stress monitors can assist in the management of heat stress in tunnel constructions by providing real-time data on work conditions, alerting workers to heat stress hazards, and by helping employers identify and assess heat stress risks associated with the site.
Multi-Parameter Continuous Air Quality Monitoring for Tunnelling
Hazards may be monitored in different ways depending on the dangers and risk management approach taken. In some cases, monitoring instrumentation may be chosen due to its ability to continuously monitor several parameters while other cases may require the monitoring of only a single parameter and therefore require spot measurements.
Many multi-parameter monitoring stations on the market can currently monitor a range of hazards including particulate matter, noise, gas, and weather conditions. These are commonly installed in key areas of tunnelling projects to provide continuous monitoring of potential hazards. Air quality statistics obtained from air quality monitoring stations such as the Australian Made certified AirMetER Monitoring Station series provide project managers and safety professionals with a wealth of data that can be used to identify trends, assess the effectiveness of control measures, and adjust as needed to maintain safe working conditions.
Many air quality monitoring stations available in the market offer the option of integrating cloud-based data portals. These play a crucial role in the protection of workers in tunnel projects when using air quality monitoring stations like the AirMetER for a number of reasons:
Remote Accessibility: Cloud-based data portals enable users to remotely access data generated by air quality monitoring stations. This feature proves invaluable for tunneling construction projects, as these stations may be situated in remote or challenging-to-reach locations.
Real-Time Monitoring: Cloud-based data portals provide users with real-time data from air quality monitoring stations. This capability allows for the swift detection and response to air quality issues, which is especially critical in tunneling environments where conditions can change rapidly.
Data Storage and Analysis: Cloud-based data portals can store and analyse data from air quality monitoring stations over time. This data can be used to identify trends and patterns, and to assess the effectiveness of air quality control measures. This is also an important feature for regulatory compliance requirements.
Enhanced Collaboration: Cloud-based data portals can facilitate collaboration between different stakeholders in tunnelling construction projects, such as contractors, engineers, and regulators. This can help to improve the overall management of air quality on tunnelling construction sites.
Continuous multiparameter air quality monitoring is a critical component of tunnel construction projects to safeguard the health and safety of workers, neighbouring communities, protect the environment, comply with regulations, and ensure efficient project management.
The Australian Made AirMetER Monitoring Station Series is proudly manufactured in Australia by Air-Met Scientific. The monitoring station series is available for sale and rental and is locally serviced and supported. Contact your local Air-Met Scientific office for more information.
