Common Contaminants – Asbestos
6th March 2020
The dangers of asbestos are universally known. Whilst asbestos containing material (ACM) is most commonly associated with older materials found in the home, a school or work place, few ever consider the soils beneath their feet. Northpoint provide a brief overview, concentrating on the assessment of asbestos in soil.
What is Asbestos?
Asbestos in its natural state is a geological fibrous mineral. Its former uses in the UK ranged from electronical insultations, fireproofing, adhesives, plastics, brake pads, rope, linings, to talc and paper.
Asbestos comes in a variety of forms. The most common of these include:
- White (chrysotile)
- Brown (amosite)
- Blue (crocidolite)
Asbestos has been used in the UK mostly throughout the 20th Century. It is amazing to think that this material has only recently been phased out in the UK. Northpoint note that ACM use is still common in other parts of the world.
For more information on the asbestos timeline, please follow this link.
Why is it a Hazardous Material?
Sadly, those exposed to asbestos may develop mesothelioma and asbestosis. Consequently, this originates where people breathe into their lungs the fibres which in turn may manifest into raspatory related diseases.
Why would I find Asbestos in soil?
Asbestos in soil comes directly from human activity.
Asbestos fibres are microscopic, and easily airborne in their free -fibre state.
As an example, vehicle brakes used asbestos throughout most of the last century. It is still common to find residual asbestos debris in soils adjacent to highways. The majority of asbestos in soil is normally placed or deposited due to an associated process. ACM is common in old cement, tiles, paper, rags, insulation boarding. Fragments of these products are frequently found in soil during site investigation inspections and sampling. This is more common if a site is brownfield, or has a history of previous development. For example, historical demolition activities prior to significant regulations in the 1980s.
Quite often, asbestos waste from older construction projects was simply discarded. As a result, fragments entered the soil. Furthermore, we have recorded asbestos beneath slabs, driveways and roads. It was common practice to tip unwanted ACMs.
Is Asbestos in Soil Dangerous?
Firstly, asbestos presence in its own right can be hazardous if a person can come into contact with it. As a result, the purpose of a soil investigation is to establish what type of asbestos is present (i.e free-fibres or contained). Most noteworthy, if contained within a fragment of concrete or tile, there is less potential for fibres to migrate in the air and cause harm.
The soil investigation should allow for an adequate survey and risk assessment. Consequently, where Northpoint conducts a survey and risk assessment, we consider a number of factors. We consider the moisture content of the soil. Moisture, particularly for free fibre asbestos makes the asbestos “stick” to soil, so the release potential is far less. There is a significantly higher chance of asbestos release if a soil is dry and exposed.
We also take into consideration how construction works and future users (workers, gardeners, maintenance, residents) may come into contact with asbestos in soil.
From our assessments, we note that where asbestos is located beneath a new building, the risks are low. The new building will “cap” and permanently block any hazardous fibres in the ground.
Lastly, we use the data to prepare an exposure assessment to confirm the overall level of risk.
How to find out more
There is a wealth of freely available information regarding asbestos and asbestos in soils. If you have any concerns regarding the soils at your property or proposed build, feel free to get in touch with our soil’s experts.