Just when you thought that your asbestos awareness of the deadly fibre material was up to speed, reports of asbestos found in the UK’s road network may indeed stop you short once more.

Local residents living in streets close to major works in the repair of a viaduct near West Bromwich are concerned over the discovery of asbestos, despite assurances of its safe removal. Highways England say that the asbestos is considered to be “stable and low risk”. But how many people know that the problem of asbestos hidden in Britain’s road infrastructure could be more widespread than they might imagine?

As part of their maintenance operations, a recent Highways Agency initiative in the south east of England has involved asbestos management surveys and testing of more than 300 structures that could potentially contain asbestos, just within the M25 network alone.

Asbestos cement used in many other construction applications

At the height of Britain’s industrial use of asbestos fibres as material strengthener and insulating material between the 1950s and early 1980s, around 170,000 tons of asbestos was annually imported. The mineral fibres were used to produce building and construction products, which were installed into almost every type of public, private and commercial building, in particular, materials made with asbestos cement. Residential premises, including local authority housing and council estates, could contain at least 10 – 30 per cent asbestos in materials, such as cement panel ceilings, tiles and textured coatings.

However, asbestos cement materials were widely used at the time in many other construction applications, which was likely to include the building of Britain’s motorways. The first motorway infrastructure to be opened was the 8.25 miles in length M1 Preston By-pass (now part of the M6) in December 1958. This was followed by succeeding stages of the MI, Britain’s first full-length motorway, opened in late 1959.

Over the next thirty years, the motorway network rapidly expanded, reaching a high point in the mid to late 1970s, which exactly coincided with the UK’s peak asbestos use. The first asbestos ban (brown and blue fibre types) was introduced in the mid 1980s followed by the final ban on all asbestos use at the end of 1999.

Asbestos removed from motorway gully pots

Highways England say that early on in their survey of the viaduct, they identified that asbestos had been used during its construction in the late 1960s. The asbestos used in construction of the M5 motorway viaduct structures is “bound” within cement materials. Along the M5 corridor, asbestos containing materials had previously been removed from 70 gully pots, which had been used as packing material under the gully lids.

Under the recent Highways England initiative, detailed surveys were carried out on a wide number of structures including, bridges, culverts and retaining walls. Asbestos containing materials, known to exist within the highway boundary, can range from road and drainage to road tunnels and depot buildings. Some of the older drainage runs on the highways are constructed with pipes made of flexible ‘pitch fibre’ or asbestos fibre impregnated with sticky black pitch / bitumen tar.

Highways England has “Duty to Manage” obligations

There are now more than 320 motorways crisscrossing the UK, with a half a dozen more at least under construction. However, some of the motorway extensions of the late 1970s, 80s and even into the 90s could have included asbestos materials. As a result, the highways maintenance industry recognise that one of the biggest risks associated with renewal schemes, repair and maintenance is the hidden dangers of the fibre reinforced cement.

Asbestos cement is hard, grey-coloured and looks like ordinary cement, which can be difficult to tell the difference. Often asbestos cement products exposed to weathering over many years are likely to be in a fragile condition, and likely to fragment and release the deadly fibres into the air. Inhaled fibres permanently lodged in the lung linings can cause tissue inflammation, which can also eventually lead to asbestosis disease or turn cells cancerous, forming the fatal tumours of mesothelioma cancer.

Under the Control of Asbestos Regulations (2012), highways are considered exactly the same as any building structure, and Highways England has “Duty to Manage” obligations. Consequently, the agency aims to implement the requirements of Regulation 4, as agreed with the Health and Safety Executive (HSE). Over a period of 20 years, a minimum target of 5 per cent each year of the strategic road network has been set for detailed asbestos surveys and removal to be carried out.