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Why you should be monitoring NO2 on construction and demolition sites

Air Quality & Dust

Construction sites can generate many types of pollution. If you asked somebody to describe what they thought were the most common types of waste, they would point to things like noise, vibration, and dust pollution.

However, one of the most common problems people experience on demolition and construction sites is the presence of nitrogen dioxide and fine dust particles, known to many as particulate matter.

With roughly 7% of all NO2 production in London generated by Non-Road Mobile Machinery (NRMM), it’s never been more important to engage in proper dust monitoring and keeping an eye on MO2 levels.

How do construction sites make NO2?

So, the burning of fossil fuels creates oxides of nitrogen. This is what we call NO2, but what we’re actually interested in is NOx. This is a combination of nitric oxide and nitrogen dioxide. NO2 is primarily the concerning element due to the health impact that it has.

However, nitric oxide can convert to NO2 in the air, so if we’re going to manage the concentrations of NO2 properly, we need to control NOx emissions!

What are the health effects of NO2?

So, it is important to recognise that there are short-term consequences of NO2 and long-term consequences. Short-term impacts can include airway inflammation in healthy people and increased respiratory distress in asthmatics.

Studies have also shown that there is a connection between short-term exposure to NO2 and increased admission to hospitals for respiratory illness.

Furthermore, NOx can mix with ammonia, moisture and other compounds in the air to form smaller particles that can easily enter the sensitive parts of the body.

Recent research conducted on the subject shows that children who were exposed to air pollution in London had a poor lung capacity and were at risk of developing lifelong breathing problems.

Thoughts on NO2 measurement

Dust monitoring is a good way of gauging how much NO2 is present in the air.

There are special devices which have an actively pumped airflow which allows them to sample NO2 in the atmosphere to get a proper understanding of how many key pollutants exist on the site.

The data is then stored and uploaded to the cloud, which can be accessed by anybody.

There are also passive systems to consider that collect and store information over the course of a month.

We usually measure NO2 concentrations as something over an hour period, and we use it frequently for construction projects during working hours in this way.

Final thoughts

It’s important to measure NO2 concentrations to gauge how harmful the exposure is to the workers on the construction site. Long-term exposure to this chemical can be dangerous, which is why it is important to keep an eye on it.

It’s often recommended that construction sites get real-time figures on NO2 production, as well as having the passive data gathering for a month. The two working in tandem can help to make a comprehensive analysis and be good for dust monitoring.

The ultimate off-grid power solution: solar power hub

Construction Resources

There is much discussion about clean energy on construction sites with construction managers keen to adopt newer, cleaner solutions. The default power source to date after mains, has been diesel generators but using these produces considerable CO2 which is a known greenhouse gas, NO2 and Particulate Matter which contributes to poor air quality in urban areas. Climate changing greenhouse gases and poor urban air quality are driving the shift from diesel to alternatives.

Campbell Associates supply environmental monitoring solutions for construction sites and are working with partners to reduce our carbon footprint and improve urban air quality with cleaner power options. Our latest innovation is the specially designed Solar Power Hub, model number CA-5546-SP.

Campbell Associates Solar Power Hub

The Solar Power Hub has a high-capacity Lithium Polymer (LiPO4) battery which is suitable for use with a continual draw from 12v environmental monitoring devices. Most batteries are optimised for high wattage use and short duration’s, which makes them unsuitable for powering environmental monitors.

The lithium polymer battery contained in the Solar Power Hub offers significantly reduced size and weight compared to lead acid batteries. It is also far more stable and robust than lithium-Ion batteries, which quickly lose efficiency over time if used outside optimum temperatures (10°C to 30°C), which are common for outdoor conditions where these systems are needed.

This battery is charged by the latest bi-facial 240-watt solar panel technology, and this is optimised for charging and powering the device in use, via a smart battery controller. The Solar Power Hub also includes an LCD display with the current battery status, and this can also be seen via Bluetooth on a smart phone app – The app includes solar charging data in real time at no extra charge.

Campbell Associates Solar Power Hub

The batteries themselves will power the monitoring system for many days/ weeks if Solar is not available and it can be charged overnight with the supplied external DC charger.

The system has rugged wheels and a handle so it can be deployed with ease. Once at the desired location the Solar panel is fixed with the supplied bracket and the wheels and handle can be removed for security purposes.

Benefits vs diesel:

• Reduction in greenhouse gas/CO2 emissions by up to 100% at point of use.

• Improves local air quality – Reduction in NOx and Particulate Matter emissions by 100%

• Zero noise emission

• Near zero running costs

The disadvantages vs diesel:

• Power produced by solar is not sufficient for power intensive applications.

• Requires panel to receive solar energy. Panel needs to point towards and have access to the sun for the duration of the project to charge the battery. (Battery can be charged by the supplied DC charger if required.)

Campbell Associates Solar Power Hub with SiteSens Dust Monitor

Summary:

Solar offers emission free, low-cost power for construction & demolition sites when matched with the intended devices in operation. To power other devices from the Solar Power hub or for systems with hydrogen backup please contact Campbell Associates to discuss your requirements. This system is available for hire with or without the solar panel option.

RAAC in UK schools: the urgency of rebuilding with environmental monitoring

Air Quality & Dust

In recent years, the presence of Reinforced Autoclaved Aerated Concrete (RAAC) in UK schools has raised significant concerns. RAAC, a lightweight form of concrete used extensively from the 1950s to the 1980s, has been found to deteriorate over time, posing structural risks.

As the UK government and educational authorities embark on rebuilding and refurbishing affected schools, incorporating robust environmental monitoring becomes crucial.

The RAAC Crisis in UK Schools

RAAC was initially favoured for its cost-effectiveness and ease of use. However, over decades, the material’s limitations have become apparent. RAAC is prone to moisture ingress, which can significantly weaken its structural integrity. In schools, where the safety of students and staff is paramount, the presence of RAAC has prompted urgent action.

The UK government has recognised the severity of the RAAC issue and launched initiatives to address it. This includes funding for inspections, temporary accommodations, and ultimately, rebuilding or refurbishing affected structures. While immediate safety measures are critical, the long-term solution lies in comprehensive rebuilding programs.

The Role of Environmental Monitoring in Rebuilding

As schools undergo rebuilding, environmental monitoring becomes an essential component of the process. Environmental monitoring involves the continuous assessment of environmental parameters to ensure that construction activities do not adversely affect the health and well-being of students, staff, and the surrounding community.

Key Aspects of Environmental Monitoring:

Noise and Dust Monitor powered by solar energy

Air Quality Monitoring:

  •  Dust and Particulate Matter: Construction activities can generate significant dust, affecting air quality. Using our dust monitors will ensure that dust levels remain within safe limits.
  • Volatile Organic Compounds (VOCs): The use of certain construction materials can release VOCs, which need to be monitored to prevent respiratory issues.

Construction Noise: High noise levels from construction can disrupt the learning environment and impact health. Monitoring helps in implementing noise control measures.

Noise monitor powered by battery

Implementing environmental monitoring during the rebuilding process offers numerous benefits:

  • Health and Safety: Protects the health of students, staff, and the local community by ensuring a safe construction environment.
  • Compliance: Helps schools comply with environmental regulations and standards.
  • Community Confidence: Demonstrates a commitment to environmental responsibility, building trust with the community.
  • Sustainable Practices: Promotes sustainable construction practices, contributing to long-term environmental stewardship.

The presence of RAAC in UK schools necessitates urgent rebuilding efforts to ensure the safety of students and staff. As these rebuilding projects commence, incorporating comprehensive environmental monitoring is not just a regulatory requirement but a moral obligation. By prioritising environmental monitoring, schools can ensure a safe, healthy, and sustainable learning environment for future generations.

The challenge posed by RAAC in UK schools is significant, but with proactive measures and a commitment to environmental monitoring, it is an opportunity to rebuild better and safer educational spaces.

Our range of noise, vibration, dust and air quality monitors are able to assist contractors in maintaining safe practice on projects.

Comparison of power supply options for noise and dust monitors

Construction Resources

To power the 4 SiteSens – DM30N Noise and Dust Monitors on-site, we evaluated three power supply options: mains electricity, a diesel generator, and a solar power system with battery backup. Below is a comparison based on cost, noise emissions, and environmental impact.

Power SourceConsumed Power (kWh/year)Running Cost (£/year)Noise Emissions at 7m (dB)CO2 Emissions (kg/year)
Mains Supply877£219.15015
Diesel Generator (2.5kVA)877£2,350.36724,291
Solar PowerHub877£000

 

1. Power Usage and Costs:

  • Mains Supply:
    • Annual consumption: 877 kWh.
    • Cost: £219.15/year at £0.25 per kWh.
  • Diesel Generator (2.5kVA):
    • Annual consumption: 877 kWh.
    • Cost: £2,350.36/year at £2.68 per kWh.
  • Solar PowerHub (240W Solar Panel, 460Ah Battery):
    • Annual consumption: 877 kWh.
    • Cost: £0/year.

2. Noise Emissions:

  • Mains Supply: No noise emissions at 7 metres.
  • Diesel Generator: 72 dB(A) noise level at 7 metres, potentially disruptive to site operations and nearby communities.
  • Solar PowerHub: No noise emissions, providing a silent energy solution.

3. Environmental Impact (CO2 Emissions):

  • Mains Supply:
    • Carbon emissions: 15 kg CO2/year from the national grid.
    • No site emissions.
  • Diesel Generator:
    • Carbon emissions: 4,291 kg CO2/year.
    • Significant on-site emissions contribute to the carbon footprint.
  • Solar PowerHub:
    • Carbon emissions: 0 kg CO2/year.
    • No site emissions, offering a fully renewable solution.

Conclusion:

  • Cost: Solar power is the most cost-effective solution with no ongoing energy costs, while diesel is by far the most expensive.
  • Noise: Both solar and mains supply provide silent operations, but diesel generators create significant noise pollution.
  • Environmental Impact: Solar power and battery systems offer a zero-emission solution, making them the best choice for sustainability. Mains supply has minimal emissions, whereas diesel generators produce high CO2 emissions.

Based on the analysis, the solar power and battery system emerges as the most cost-effective, environmentally sustainable, and quiet solution for powering the DM30N monitors on-site.

However, opting for a mains power supply could also offer advantages, as it would eliminate the need for hiring and maintaining a power generator on-site.

Monitoring weather including wind & gusts on construction sites

Construction Resources

Wind and Construction Sites

What is the issue?

Higher wind speeds can significantly increase hazards on construction sites. Wind can affect equipment stability, especially for cranes and scaffolding, and can lead to flying debris, making it more dangerous for workers. It’s crucial for construction teams to monitor weather conditions and implement safety protocols, such as securing materials and possibly halting work during high winds to ensure everyone’s safety.

High winds pose several insurance risks for construction sites, including:

Property Damage: Strong winds can damage equipment, materials, and structures, leading to costly claims. This includes damage from flying debris or toppled scaffolding.

Injury Claims: Increased risk of accidents due to falling objects or unstable equipment can result in worker injuries, leading to liability claims and workers’ compensation costs.

Project Delays & Contractual Risks: Wind-related interruptions can extend project timelines, leading to additional costs and potential penalties.  It is recommended to have a record of weather conditions to assist with disputes and any additional liabilities

What are the limits and recommendations

The Health and Safety executive states:Do not consider going on any roof in poor weather conditions such as rain, ice, frost or strong winds (particularly gusting) or if slippery conditions exist on the roof.  Winds in excess of 23mph (Force 5) will affect a persons balance.

The National Federation of roofing contractors has very useful and practical guidance in their Roofing and Cladding in Windy Conditions document.   https://www.nfrc.co.uk/knowledge-hub/NFRC-publications Their recommendations are 23mph as per the HSE guidelines and 17mph where operatives are handling larger materials which will impact the wind load on them.

Crane operations: The safe wind speed for different types of cranes varies. For example, the maximum in-service wind speed for tower cranes is typically 45 mph, while it’s 31 mph for crawler cranes and 22 mph for mobile cranes.

In general, as stated in ISO 4302:2016 Cranes – Wind load assessment, the maximum wind speed for all cranes types installed in the open should be 20 m/s (45 mph), and it’s 31 mph for crawler cranes and 22 mph for mobile cranes. It can be higher or lower, the rule of thumb is to always check the crane manual and follow crane manufacturer’s guidelines accordingly.

Wind load, Average Wind and Gusts

Normally it is average wind speed, which is reported, however it is usually wind gusts (that are often not considered), which is do the most damage and are most hazedous on construction sites.  Here’s a breakdown of the concepts:

Wind load refers to the pressure exerted by wind on structures and objects.

Static Wind Load is calculated based on the average wind speed and it considers factors such as an objects shape and surface area.

Dynamic Wind Load (Gust Load) accounts for sudden increases in wind speed, known as gusts. Gust loads can significantly impact the safety of individuals and stability of structures.

Higher wind speeds increases the wind load with the square of the wind speed (i.e, doubling the wind speed quadruples the wind load).

Gust windspeed can be 1.5 times higher than average windspeed on flat open areas and 2 times higher in urban areas where you have effects of wind funnelling between buildings. 

For the above reasons wind gusts should be measured accurately and recorded.

How to measure to wind gusts

To measure wind, we use an anemometer which come in two types.  We have traditional the mechanical cup design and ultrasonic anemometers.

 

Sensors:

Cup anemometers work by measuring their rotating speed and using the cup size to calculate the wind velocity.

Ultrasonic wind sensors use transducers to emit and receive ultrasonic sound waves, and then calculate the wind speed from the time it takes for the sound waves to travel between the transducers.

Cup anemometers have the advantage of being lower cost but are prone to wear and damage because of mechanical parts.

Ultrasonic anemometers have no moving parts and require less maintenance.

Quality of data

When averaged over time, ultrasonic and mechanical measurement accuracies are comparable. Mechanical sensors, however, will not always reflect turbulence and gusts due to the physical limitations of its moving parts. If there is a sudden gust of wind it will take several seconds to register and report the change especially where the wind direction is changing.

An ultrasonic sensor, however, will immediately measure a change in wind direction or a high gust. (This is what spurred the National Weather Service to update its 883 Automated Surface Observation Systems from mechanical to ultrasonic sensors).  For these reasons we use ultrasonic sensors.

How we record gusts and average

Wind speed, wind direction and gusts are reported over a 2-minute interval in compliance with World Meteorological Organisation (WMO) recommendations.

Wind speed is averaged over 2 minutes; gusts are the peak value of wind speed over the 2-minute period and reset at the start of the next 2-minute interval. The peak value is calculated from a 3 second moving average in compliance with (WMO) recommendations.

To complement the sensors we have developed a market leading module in the DL40 which is a LPWAN cellular communications device. Specifically, it connects to  LTE-M or NB-IoT networks depending on which is available or which network provides the better connection.  Data is available 24-7 via the supplied Sonitus Cloud Portal.

The system is powered by 230v/ 100v or 12V DC (includes long life 12v battery packs and Solar)

Cloud Data reporting.

The cloud displays wind speed and gusts as standard and with the GMX600 version it will also report temperature, humidity and precipitation. Real time alerts can also be set to advise site management immediately via SMS or email if wind speeds exceed thresholds.

 

Risks of aspergillus in construction & demolition & how to mitigate them

Air Quality & Dust

Aspergillus is a micro-organism that can be found during demolition and construction works and is a health risk to humans. Aspergillus is a fungus that can cause significant health problems when breathed in during certain construction work.

It is typically 2 – 3.5 μm in size, small enough to enter the airways.

Aspergillus is a mould commonly found in many indoor environments such as old & dilapidated building. Construction/demolition activities on sites such as these can release the fungal spores into the air increasing the exposure. It is possible that Aspergillus can also be found outdoors in damp and garden environments.

It is critical on construction and demolition projects that we control the risks and exposure to workers on site while they work. There are prevent measures which can be carried out to control the exposure to Aspegillus.

First, carry out risk assessments and controls to ensure workers & visitors are protected and a plan is in place.

Secondly, we must ensure the particle doesn’t become airborne by using dust control along with real-time dust monitors to monitor the levels of air particles and sizes throughout the project.

Thirdly, install proper ventilation systems which are maintained, and contamination free.

Workers with damaged lungs or a weakened immune system can get several diseases (called Aspergillosis or farmer’s lung) if they inhale these spores. The symptoms of ASPGILLOSIS are a cough, shortness of breath and wheezing. More symptoms can be found on the NHS website.

Dust particles of 2 – 10  μm can be measured using dust detection analysers. Campbell Associates offer several solutions for this.

Such as our Aeroqual Ranger using a PMX dust monitor module which will measure TSP, PM10, PM4, PM2.5 & PM1. This handheld device allows the operator to walk around the site and establish the level of dust particles in each cubic metre of air as the unit μg/m3.

If continuous monitoring should be carried out then we would deploy our MCERTS Certified (by the Environment Agency) PM10 & PM2.5 dust monitor.

The DustSens DM30 monitor provides real-time data alerts and mean average readings into a cloud platform. SMS & Email alerts are setup when exceedances have been hit, alerting workers on site to take action.

What can I do to stop mould growth in the first place? 

The EniSens DL40 is a low power, automated data logger for measuring temperature and relative humidity. 

Mold thrives in humid, warm environments, typically when relative humidity is over 60% and temperatures are between 20-30°C (68-86°F). By using a logger, you can monitor the conditions and take steps to keep the humidity and temperature within ranges less favourable for mold.

Using a logger enables us to monitor patterns and detect spikes in humidity and temperature, especially in mold-prone areas. By setting threshold limits, such as 60% relative humidity, we can send email or SMS alerts to workers or environmental managers when levels exceed safe limits.

This allows site supervisors to take corrective actions, like increasing dehumidification or improving ventilation, to prevent mold growth. When water suppression is used to control dust levels, it may raise relative humidity and lead to damp areas where mold could develop later.

Particulate matter – why do we monitor it?

Air Quality & Dust

Our health is incredibly important to us; without it we have nothing. If we can prevent ourselves from becoming unwell, wouldn’t we all take that opportunity? With increasing construction works around the country the importance of air quality and it’s health implications has become a prominent feature in the media. You might have heard of PM10, but what exactly is it and how does that affect our air quality?

PARTICULATE MATTER – ALL THE ANSWERS!

Air pollution or air quality is a very wide concept and can mean various things but are all related to our heath. When we talk about particulate air pollution we talk about an air-suspended mixture of both solid and liquid particles and these are all related to size and the possible harm they can do to the human body.

The size of the particles defines three classifications:

  1. ultrafine particles: <0.1µm in diameter;
  2. Fine: 0.1 to 2.5µm in diameter;
  3. Coarse: between 10µm and 2.5µm in diameter.

Local councils in general will only be interested in PM10. When monitoring PM10 all particles smaller than 10 µm are logged – which includes fine and ultrafine particles. These particles include dust, pollen and mould spores (PM10) and combustion particles, organic compounds and metals (PM2.5). The table below sums it all up and shows where particulate matter comes from.

The World Health Organisation (WHO) believes particles are affecting more people worldwide than any other pollutant. Damage to the respiratory and cardiovascular are one of the primary health effects. The small particles can easily penetrate in to the deepest parts of our lungs as well as access the gas exchange regions of the lung via diffusion.

As a result of the damaging health effects from PM10 the WHO recommend the exposure limit below – which is commonly the limit values that local councils use in their Code of Practice:

PM10: 50 ug/m3 24 hour mean

To control this limit on site, local councils demand higher limits in shorter time periods to make sure daily exposure limits won’t be exceeded. Often, they will ask for a 200 or 250 ug/m3 per 15-minute RED alert.

These guidelines can be hard to follow because of the many activities going on in all our mayor cities. The limits are therefore hard to meet in a whole but the understanding and seriousness of the issue is a great step forward. Monitoring certain activities that have a higher risk of producing these particles, like construction & demolition, will eventually lead to a cleaner and more sustainable environment.

Local governments don’t always acknowledge higher particle sizes are a threat because there is no direct health risk involved. As the table above points out these particles are visible to the human eye and therefore will end up in the nuisance category. This size is called Total Suspended Particles (TSP) which is everything above 10µm but can still affect health.

HOW CAN CAMPBELL ASSOCIATES ASSIST YOU?

When it comes to monitoring particulate matter (PM), Campbell Associates provides a complete and reliable solution designed to give you peace of mind. Our range of dust and air quality monitors, which form part of our NVD suite, are engineered to accurately measure PM levels, including PM₁₀ and PM₂.₅.

This crucial data is sent in real-time to our web-based platform, Sonitus Cloud, enabling you to view live readings, access historical data, and receive instant alerts if levels exceed set limits. With our monitors, you not only ensure compliance with environmental regulations but also gain actionable insights to protect your site, your workers, and the surrounding community from the harmful effects of airborne particles.