The Hidden Health Hazards in Highway Construction and Maintenance

As well as physical injury, road and highway works are high-risk for health, so why are they still commonly under-controlled?

Highway construction is the development and maintenance of infrastructure designed to improve the efficiency of existing roadways, flyovers and bridges. These projects can involve creating new high-speed connections, easing high-volume traffic areas or maximising safety and durability on existing routes. Highway and road construction works are critical for the successful movement of people and goods throughout the UK, a necessity for economic stability.

Although necessary, civil engineering highway construction and maintenance work can put site teams and engineers at risk of injury and illness if not properly managed. Whilst we are all aware of the immediate accident risks, health risks are often deprioritised despite 11,000 estimated lung disease deaths each year being linked to past exposures at work[1].

Exposure to hazards during roadworks and similar activity can reach dangerous levels from continuous work or be cumulative through shorter-duration maintenance tasks. Both can have serious and long-term consequences on an individual’s health if left uncontrolled or if over-reliant on PPE which alone, is unlikely to comply with best practice.

The 5 Most Overlooked Health Hazards in Highway Construction and Maintenance

1. Respirable Dust (including silica dust)

Respirable dust is made up of fine particles small enough to penetrate deep into the lungs, these particles are invisible once airborne and can exceed occupational exposure limits within minutes, even during short tasks or out in the open.

During highway works, the most serious risk to health comes from respirable crystalline silica (RCS) which is generated when concrete, stone or masonry is disturbed. Long-term exposure to RCS is linked to silicosis, chronic obstructive pulmonary disease (COPD), lung cancer, kidney disease and more. Read more about the health risks associated with dust exposure in our whitepaper here >

Roadworks maintenance schemes are often higher risk per hour of silica dust exposure because the allocated time for these tasks is shorter. Shorter turnarounds can lead to a more relaxed approach to hazard control than on more complex projects, meaning engineering controls for construction hazards usually employed on bigger tasks (e.g. wet methods) are skipped in favour of speed. High-risk activities include but are not limited to:

• Concrete and pavement breaking including road slab removal, utility breakout, joint removal
• Cutting and sawing including kerbs, edging, flags, drainage channels, expansion joints
• Planning and milling including asphalt resurfacing (especially dry cutting)
• Dry sweeping and cleaning particularly during reinstatement and maintenance
• Excavation especially in dry conditions, with friable or made-up ground
• Reinstatement works including trimming surfaces prior to surfacing works

Exposure from these activities occurs because the work often involves operators being positioned directly over the dust source, making exposure extremely difficult to avoid. Dust from these tasks can also become airborne and travel beyond the immediate work area, exposing nearby traffic marshals, supervisors, inspectors, and more. Air movement from live traffic compounds the issue further by keeping dust airborne for longer, increasing the likelihood of exposure.

Highway works frequently extend into the night, reducing visibility and masking dust plumes which could otherwise be tackled reactively.

The Solution

Employing the right engineering controls can help control dust, limit harmful exposure and the risks that come with it. If the immediate work area and dust source are small enough, they can be contained using a dust enclosure to minimise the area where airborne dust can travel. When paired with a dust extraction unit or specialist LEV system, dust can be captured and filtered at the source, providing a best practice, compliant and safe solution for the project.

When dust production is on a larger scale and the environment is suitable, dust suppression is also an option. Dust suppression cannons can spray a fine mist where water molecules attach themselves to dust particles and drag them to the ground. As water is heavier than the dust, any which settles on the ground can make it harder for dust to become airborne in the first place. Some dust suppression units also have features such as tow bars, water lines and extendable/retractable arms that allow for targeted suppression and control.

Note: Dust suppression will not always be suitable, for example when cabling is exposed or telephone poles are nearby. Speaking with an advisor or undertaking a site assessment may be the easiest way to determine which engineering controls would work best for your specific project requirements.

2. Exhaust fumes and hot work emissions

Many activities on highway projects rely on diesel-powered plant or involve welding and hot works that produce harmful fumes such as diesel engine exhaust emissions (DEEEs), carbon monoxide (CO), nitrogen oxide (NOx) and more. Exposure to fumes classified as carcinogens has been linked to lung cancer and many other serious health issues, making control and management of the fumes integral to protecting worker health. Download our welding fume whitepaper here >

Common high-exposure tasks for exhaust fumes and hot works during highway and bridge construction include:

• Surfacing and resurfacing such as asphalt laying, bitumen spraying and reheating operations
• Confined or semi-confined works under bridges, retaining walls and cuttings and urban street works
• Maintenance operations including drain cleaning with jetting units or reactive repairs
• Structure and steelworks such as welding, burning or cutting
• Night works that may involve plant idling or reduced airflow

Small changes in working conditions can put operatives at increased risk of exposure when the team themselves may not even realise it. If there is plant idling nearby, still air conditions or even a change in wind direction so site teams end up downwind of emissions all can contribute to increased exposure levels.

The Solution

The right fume control solution will be dependent on the machinery being used and activities carried out. Exhaust fumes can be filtered and emissions reduced using diesel particulate filters (DPFs) on highway construction equipment such as mobile plant, whereas fume extraction from a generator exhaust, welding or hot works would require more heavy-duty, LEV kit.

LEV set-ups would ensure that harmful fumes produced by works carried out are captured and filtered effectively enough to protect those working on site and nearby. Similar to dust control, containing the work area will limit how far the fumes can travel and ensure best practice regardless of dynamic external factors such as wind and time of day.

RVT Group have formulated a methodology to minimise risks and maximise best practice when tackling dust and fume using LEV. The 3Cs methodology focuses on containing the hazard as much as possible using dust tents, noise enclosures or even polythene sheeting for internal works taking place in one stationary location. Once the area is contained, the hazard is then captured as close to the source as possible using a suitable capture hood. The hazard is then controlled using appropriate ducting and filter units to remove as much of the harmful particulate as possible before diverting the cleaned air back into the atmosphere.

3. Noise exposure from repetitive works

Highway projects often create high-intensity and impulsive noise which can be especially difficult to manage. Unlike dust and most fumes, there is no visible cue and, if operatives accumulate to their working environment can easily overlook the need for noise control.

Hearing damage is cumulative, irreversible and often unrecognised until it’s permanent and when there is increased evidence to show links between hearing difficulties and long-term illnesses such as dementia, prioritising noise control has never been more important. Read our news article on the link between hearing loss and dementia >

Typical noisy activities found during highway projects include:

• Breaking and demolition using road breakers and pneumatic tools such as jackhammers
• Cutting and drilling with concrete saws, core drills and other similar tools
• Compaction operations using rollers and vibrating plates
• Surfacing works involving pavers, planers and tippers
• Bridge and structure works including steel decking, handrails and fixing

Noise becomes even more difficult to manage during nightfall as limits may be exceeded sooner than expected.

As a lot of the tasks listed above are repetitive with multiple noisy activities carried out at once, exposure can be layered and compounded. Given the busy nature of a highways project and increased chance to encounter moving vehicles, there is additional risk of hearing protection being removed by workers to communicate and keep alert to their surroundings. Noise also carries across a site, meaning an operative who is not necessarily carrying out the noisy activity, may still be exposed without realising.

The Solution

The right type of noise control will depend on multiple factors such as:

• The type of activity taking place
• How mobile those works are e.g. cutting materials can be confined to one small area whilst compaction will need more movement
• How many different types of noisy works are taking place at one time
• The environment they are taking place in e.g. urban or rural
• How large the project site and total work area are

Some highways projects may benefit from acoustic enclosures which act as a hub for noisy works such as cutting, drilling etc. The enclosures can be bigger, stationary areas or smaller with wheels to move around as required. Any projects using generators may also benefit from specialist enclosures designed to reduce the continuous, low frequency noise output of a generator.

Larger projects with neighbouring communities may benefit more from acoustic barriers such as curtains or quilts which can hang on fencelines or scaffolding, helping to increase the acoustic shadow and minimise gaps where noise can escape.

4. Hand-arm and whole-body vibration

A lot of handheld tools and equipment on highway projects will expose operatives to vibration semi-regularly. Vibration is different to dust, noise and fume because symptoms often appear years later. Repetitive vibration exposure can damage nerves, blood vessels and joints which is why it is governed by the Control of Vibration at Work Regulations 2005.

Types of highway works that expose workers to vibrations include:

• Hand-arm vibration (HAV) caused by breakers and drills, impact wrenches, compaction equipment, grinders, saws and more
• Whole-body vibration (WBV) caused by ride-on-rollers, dumpers, paving machines, excavators on uneven ground and more.

A lot of this equipment is used regularly, and it can become easy to forget the knock-on-effect that prolonged exposure can have, especially when accurately measuring exposure levels and establishing a baseline is difficult to begin with.

As operatives can quickly get used to working with vibrating equipment, workers often underestimate exposure duration and when there is a time pressure or strict deadline to work towards, task rotation breaks can be deprioritised. When PPE offers very limited meaningful HAV protection, it’s easy to see how vibration exposure could go unchecked.

The Solution

Proactive planning is key to effective vibration management. Scheduling regular breaks and rotations for operatives can minimise long-term harm cause by high-vibration activity without impacting deadlines or time-pressures.

When work is reactive and there is less time to plan in measures like this, using low vibration tools, plant and other machinery can help to reduce the impact of works on operatives and nearby buildings. Pairing this equipment with ongoing vibration monitoring will help identify when vibration is nearing dangerous levels or pre-determined limits. It’s safe to assume that if vibration levels are exceeding those established for the surrounding environment, that the operative carrying out the work will also be exposed to harmful levels.

Note: Vibration monitoring is good supplementary information alongside regular breaks, shift rotations and alternative tools but should not be used as the default decision driver when it comes to looking after those on site.

5. Secondary Exposure

All the health hazards listed above carry an exposure risk to those elsewhere on the project such as site supervisors, inspectors and engineers. Some projects can also expose members of the public, neighbouring communities and adjacent properties (especially in urban areas) to health hazards. Examples of highway works that create secondary exposure include:

• Urban maintenance work
• Footway and carriageway repairs
• Bus-stop and crossing upgrades
• Utility reinstatement
• Narrow lane closures

Managing exposure outside of the project directly can be even more difficult to manage than protecting the workforce on-site. Wind and traffic turbulence can carry contaminants beyond the immediate work area and public who will not have access to PPE operatives are using.

To limit secondary exposure, hazards should be captured as close to the source as possible through engineering controls; where this isn’t feasible, projects must monitor hazards so reactive measures can be implemented promptly. This is particularly important during temporary works, where conditions change rapidly.

The Solution

Environmental monitoring for hazards such as dust, noise and vibration can provide real-time data insights into activity taking place on site. Monitors can be used to establish accurate baselines before work begins so highways work taking place in more polluted environments such as near motorways or in city-centres can accurately define what noise, dust and vibrations are actually a result of project works.

Monitoring can also alert those on site when nearing pre-set limits so reactive measures can be put in place or work paused when necessary to manage secondary exposure. This does not just protect health of those on site and nearby but can help keep a highways project compliant with regulations. If the project faces scrutiny from inspections or complaints, monitors can provide accurate records of hazardous output from the project. These records can also be used to inform future decisions.

PPE as the last line of defence

Operatives are expected to use appropriate PPE for specific tasks however, relying on PPE alone is not best practice, particularly where engineering controls have not been properly considered. HSE is clear that PPE should be the last line of defence, you can refer to the hierarchy of controls below or read about it in more detail in our whitepaper >

This is especially relevant on highway projects, where PPE use can be inconsistent, poorly fitted, or quickly degraded. These environments often involve multiple concurrent hazards and tightly sequenced activities, meaning tasks are delivered in shorter, time‑pressured bursts. While good planning and regular breaks can support safer working, these shorter durations can also lead to a more informal approach to PPE, highlighting the importance of prioritising effective engineering control measures rather than relying on PPE alone.

If hazards such as dust, fume and noise are left unassessed and uncontrolled, a highways project could be putting site teams at risk, breaching compliance limits and face several costly repercussions as a result. From fines, unnecessary delays and complaints right through to stoppages and work needing to be redone, all can impact company reputation and even the awarding of contracts in future projects.

Proactive engineering controls help keep productivity high and risk low, protecting your workforce, keeping your project compliant and helping you stay on track. See an example of how we have supported highways projects in the past >

Discuss hazard control solutions for your highways project with a dedicated technical consultant for Infrastructure projects >

[1] https://www.hse.gov.uk/statistics/causdis/overview.htm