Occupational exposure tends to be the most common cause of mesothelioma. However, it should not be forgotten that asbestos fibres were used in the manufacturing of thousands of everyday consumer products in the UK. From time to time, a shocking discovery is made, which reminds us of the often unexpected, hidden workplace risks from both past and even present day exposures.

It was recently reported that a commonly available modelling clay used in school classrooms across the UK and Europe throughout the 1960s and 70s may have been responsible for the death of an Italian teacher in her late 70s. In 2015, it was reported that the talc used as a binding agent in children’s crayons, which is  currently produced in China, was found to contain asbestos fibres.

Found almost anywhere in working life

During Britain’s peak asbestos using period, more than 1.3 million tons of asbestos was imported into the UK during the 1950s, which peaked at 1.6 million tonnes in the 1960s and continued around 1.5 million in the 1970s. Until the final import ban on white asbestos in 1999, more than five million tons had been used in British industry as a key insulation and fireproofing product, and could be found almost anywhere in British working and domestic life.

Until the late 1970s and early 80s, most exposures occurred in shipbuilding yards, railway/vehicle assembly plants, manufacturing industries, and during building and construction. The mineral fibre was mixed with cement to be most commonly used in both household and workplace insulation, from interior walls, ceilings and floors to lining boilers and lagging hot water pipes, and exterior roofing.

Not always straightforward to pinpoint the source of an exposure

Today, there is a greater asbestos awareness to the widespread use of the mineral fibres. Nearly every week there is a report of dust leakage found in rooms, storage areas and corridors in all types of public buildings, from schools, hospitals and town hall offices to libraries, leisure centres and council housing.

However, it is not always straightforward to pinpoint the source of an exposure to asbestos in buildings where the potentially fatal fibres are not found. In the current case, the retired school teacher diagnosed with mesothelioma – a disease caused solely by exposure to asbestos – had never worked in a school building where asbestos was present. The case had been classified as an “unknown asbestos exposure” but further investigation found that nearly every day for ten years the teacher had used a particular type of clay in her classroom.

Asbestos fibres added as a material strengthener

Between 1963 and 1975, an estimated 55 million packs of DAS air-drying modelling clay were sold and used in schools across the UK and Europe. As with many products, it was revealed that asbestos fibres were added as a material strengthener. The team investigating the case emphasise that the handling of this type of modelling clay should be considered as a “certain” asbestos exposure.

The investigators also restate the need to always conduct a thorough, detailed examination of all circumstances and whenever the exposure source cannot be immediately identified. It is not unusual for a Coroner to record the death of a victim of mesothelioma, caused by asbestos exposure, simply as an “industrial disease”.

Asbestos in schools continues to be a real health risk

The acute problem of asbestos in schools continues to be a real health risk across many regions of the country. In areas of Manchester and Wales, it has been estimated that up to 90 per cent of schools contain hazardous asbestos materials. One report also claims that 93 per cent of schools in Edinburgh built before 2000 contain asbestos in the walls, ceilings or floors.

The call for a permanent solution to rid Britain’s schools of the potential health risks of asbestos has also led to a growing list of government reports. In 2012, evidence given to the Education Select Committee estimated that, “in Britain between 200 and 300 people will die each year of mesothelioma because of their asbestos exposure experienced as a child at school in the 1960 and 1970s. Over a twenty year period that means that between 4,000 and 6,000 former pupils could die.”

There is still a long-standing myth that low-level exposure is harmless. However, occupational, low-level asbestos exposure, which has continued over a period of time – as shown by the daily use of the modelling clay – does increase the potential to develop mesothelioma. HM Government Office for Science has previously said that “ …it is not possible to determine a threshold level, below which, exposure to chrysotile (white asbestos) could be regarded as ‘safe’ for human health”.