Asbestos was once a popular material in construction, but its fibres can pose serious health risks when they become airborne. Breathing in these tiny particles can lead to conditions like asbestosis, lung cancer, and mesothelioma. That’s why it’s so important to accurately detect and measure airborne asbestos fibres to keep people safe. In this article, we’ll take a closer look at how this is done.
Why It’s Important to Detect Airborne Asbestos Fibres
When materials containing asbestos are disturbed, they release microscopic fibres into the air. These fibres are so small that you can’t see them, and they can linger in the air for a long time. This makes them easy to inhale, which can be dangerous. Detecting and measuring asbestos levels helps assess risks and ensures safety regulations are being followed, creating a safer environment for everyone involved.
How Airborne Asbestos is Detected and Measured
There are several ways to find and measure asbestos in the air. Each method has its strengths and weaknesses, and is used for specific purposes. Here are the most common techniques used:
1. Phase Contrast Microscopy (PCM)
PCM is the most commonly used method. Air samples are collected on a filter and then examined under a special microscope. Here’s why PCM is popular:
It’s affordable and fairly quick.
It detects fibres longer than 5 micrometres with a length-to-width ratio greater than 3:1.
However, it can’t distinguish asbestos fibres from other types of fibres.
2. Transmission Electron Microscopy (TEM)
TEM is more advanced and accurate than PCM. It not only looks at the shape of fibres but also analyses their composition and structure. TEM is:
Highly precise, especially for identifying smaller fibres.
Ideal for detailed analysis.
More expensive and time-consuming, so it’s not used for every situation.
3. Scanning Electron Microscopy (SEM)
SEM combines the imaging of PCM with the advanced analysis of TEM. It:
Helps distinguish asbestos from non-asbestos fibres.
Is less common because it’s costly and complex to operate.
4. Gravimetric Analysis
This method measures the total dust in an air sample. While it doesn’t specifically target asbestos, it’s useful when paired with other techniques like PCM or TEM to determine asbestos levels.
How Air Sampling Works
Air sampling is the first step in detecting asbestos. Here’s how it’s done:
Set up a pump that draws air through a filter at a controlled rate.
Pick sampling spots, focusing on areas where asbestos might have been disturbed or where people spend a lot of time.
Use the right filters, like mixed cellulose ester (MCE) filters, to capture fibres.
Send the samples to a lab for analysis using the chosen method.
Asbestos Safety Regulations
Countries have strict rules about how much asbestos can be in the air. In the UK, the Control of Asbestos Regulations 2012 sets these limits:
The maximum allowed is 0.1 fibres per cubic centimetre (f/cm³) of air, averaged over four hours.
Monitoring and clearance testing must be done after asbestos removal to ensure fibre levels are safe.
Getting Accurate Results
For reliable results, it’s important to:
Calibrate equipment regularly to keep sampling accurate.
Handle samples carefully to avoid contamination.
Use accredited laboratories that follow strict standards, like ISO 17025.
Final Thoughts
Detecting and measuring asbestos fibres in the air is crucial for managing risks and keeping people safe. Whether it’s PCM, TEM, or SEM, each method has a role to play in ensuring accurate assessments. By following best practices and adhering to safety regulations, professionals can create safer environments for everyone.
If you need expert help with asbestos detection and removal, reach out to Safe:Environment. Your safety is our top priority.
