PM monitoring challenges – and how to overcome them

Particulate matter (PM) – including PM10 and PM2.5 – is a dangerous component of air pollution. In fact, fine PM2.5  is considered the most harmful air pollutant to human health. In this article, we explain what PM is and the many instances in which it should be monitored. We highlight three ways PM monitoring can be a challenge, and demonstrate how the bettair® PM-only node can be the ideal solution.

What is PM?

Particulate matter consists of tiny particles and liquid droplets suspended in the air. It includes a huge variety of different substances and is classified according to size. PM10 refers to particles that are 10 micrometres or smaller, and PM2.5 refers to those up to 2.5 micrometres in size.

Why monitor PM?

Particulate matter is dangerous because it is breathable. Once inhaled, larger PM10 particles are mainly deposited in the nose and throat, whereas smaller PM2.5 particles can be drawn deep into the lungs. Public Health England write that there is extensive evidence that long-term exposure to PM increases the likelihood of illness and death from cardiovascular and respiratory diseases. In addition, the International Agency for Research on Cancer (IARC) has classified PM – a major component of outdoor air pollution – as carcinogenic.

Who needs to monitor PM?

PM is a complex pollutant and originates from a number of sources – both natural and anthropogenic. Natural sources include wind-blown soil and dust, sea spray, and ash from wild fires. The main man-made sources are combustion of fuels (in vehicles, industry, and homes) and other common processes such as tyre and brake wear. So, who should monitor it?

• UK government – The UK government has long-term targets to reduce PM5 levels (The Environmental Targets (Fine Particulate Matter) (England) Regulations 2023). They also have limits for air pollution (including PM) that must not be exceeded presently (The Air Quality Standards Regulations 2010). These targets are legally-binding.
• Local authorities – Local authorities will be instrumental in helping the UK government meet the above targets and standards. Under The Air Quality (England) Regulations 2000, they are themselves responsible for regularly reviewing and assessing air quality in their respective areas. Local Air Quality Management (LAQM) is then the process of making improvements and meeting air quality objectives. Wales, Scotland, and Northern Ireland have the same standards in their own legislation.
• Facility, environment and H&S managers – Industrial set-ups that burn fuels, process, handle, or transport dusty materials, as well as construction sites, waste management facilities, and transport hubs should strongly consider monitoring PM – for the health and safety of workers, as well as people in the wider area (PM can travel large distances). PM monitoring may already be required by an environmental permit or local council conditions. Recent research has also found that agriculture is a significant source of particulate pollution found within cities. Ammonia emissions from manure management or fertiliser use combine with other pollutant materials in the air to form PM.
• Centres supporting vulnerable people – Children, the elderly, and those with pre-existing cardiovascular or respiratory conditions are especially vulnerable to particulate matter pollution. We wrote about the effects of air pollution on children in another blog. Because of these vulnerabilities, nurseries, schools, hospitals, clinics, and nursing homes should also consider monitoring PM. Data can then be used to make decisions that better the health of the individuals in their care.
• Researchers and innovators – By monitoring PM, academics and innovators can evaluate the effectiveness of new technologies, policies, and strategies, developing knowledge that will benefit public and environmental health.

PM monitoring challenges

Here, we’ve identified three challenges you might face in monitoring particulate matter, and we introduce the bettair® PM-only node as Enviro Technology’s solution.

Challenge 1: Achieving high spatial resolution

PM’s complex source profile comprising industrial facilities, transport, domestic heating, and rural agriculture means that the pollutant can have a complex spatial distribution.

The UK’s main air quality measuring is done by the Automatic Urban and Rural Network (AURN). Consisting of 195 monitoring sites, with the exception of large cities like London and Manchester, this is an average of just a couple per urban centre. Measurements are often combined with the results of modelling assessments. Leonardo Santiago, CTO and Co-founder of bettair Cities, told a science news service: “With the number of stations that a city usually has, it’s not enough for them to create an actual map. They normally use mathematical models to estimate what is happening, but they don’t see the reality”.

Where they can, local authorities use AURN data but often have to supplement it with their own collection and/or more basic predictive models.

The bettair® PM-only device can enable managers and decision-makers to better characterise particulate matter pollution geographically. Measuring PM10, PM2.5, and even smaller PM1, the bettair® PM-only node is light and compact. It just needs to be connected to power, or can be supplied with a solar panel for energy self-sufficiency. It’s easy to attach to streetlights or other urban fixtures, and to re-locate – it can even be used on vehicles, too. Re-position one node or install a network to map PM pollution and identify critical hotspots in your area of concern.

Challenge 2: Understanding the data

Particulate matter is a particularly complex air pollutant and managers and decision-makers are not necessarily experts in interpreting air quality data. Advantageously, the bettair® node was developed alongside a dedicated, user-friendly software: the bettair® Platform. Here, you can view the values of the nodes, in real-time, as well as representative maps, statistics, and trends over time. The software also incorporates data from the Air Quality Index (AQI).

Users can access all of this information by logging into the bettair® online dashboard or you can connect the data to your own system using bettair®’s Application Programming Interface (API). A bettair® app is also currently under development to make reviewing node data even easier and more immediate.

Challenge 3: Budget constraints

There are a number of factors that make the bettair® PM-only node cost-effective for authorities and organisations managing tight budgets or not wishing to invest substantially in ambient air quality monitoring. These include the fact that:

• The nodes have an accuracy comparable to large, traditional, and expensive monitoring stations. A major reason for this is bettair®’s novel and advanced post-processing algorithm. When processing the data, this algorithm takes into account the sensor’s age, performance, and surrounding environmental conditions to ensure that results accurately reflect air quality at the site.
• The sensors do not require in-situ collaboration or maintenance. Calibration prior to delivery, as well as bettair®’s exclusive data processing software, mean the nodes consistently provide accurate data for the duration of their lifetime, without calibration or maintenance costs. After two years, replace the sensors and data will have the same reliability as a new node.
• The data management and visualisation software (the bettair® Platform, discussed above) is included free of charge with purchase of a node. The subscription automatically renews when a sensor replacement is purchased, too.

Get in touch

To start addressing particulate matter pollution in your area or at your site, get in touch with Paul Norman.

Read more about particulate matter in our other blogs:

• PM data was used to create eye-catching visualisations of air quality changes over time in the Air Quality Stripes.
• Students responded to PM pollution in these three campaigns.
• We discuss the many ways in which air pollution – including PM – affects children and young adults.