The prevalence of asbestos fibres in products manufactured in Britain throughout the middle decades of the twentieth century has left a fatal legacy in the twenty first century among the unfortunate victims of mesothelioma. Not only is it now widely thought that an increasing number of unexplained industrial diseases were caused by contact with the insulation material but better asbestos awareness has highlighted the true extent of environmental exposure.

As imports began to accelerate from the 1950s onwards the fibres from a number of different asbestos types were used as a cheap source of material strengthener as well as insulation in around 3,000 products produced for almost every type of industrial and commercial application. Numerous household items known to contain asbestos fibres included gloves, curtains, wallpaper, clothes irons, hair dryers, fuse boxes, potting mixtures and talcum powder.

Other asbestos fibre types

While three asbestos minerals – chrysotile (white), amosite (brown) and crocidolite (blue) – were most commonly used, other asbestos fibre types were also employed, notably actinolite, anthophyllite and tremolite. Anthophyllite possessed high chemical resistance for robust thermal and electrical insulation, and also used for producing adhesives, plastics, insulation and filling reinforcement materials. Tremolite and actinolite were found only in natural materials, such as talcum powder, and used in a variety of commercially available products.

Talcum powder is made from a soft magnesium silicate mineral similar to asbestos, which is crushed, dried and milled to produce powder used in cosmetic products, and may also share chemical similarities to asbestos. The potential health risks associated with breathing in talcum powder have long been known and investigated.

The small fibres, which may not be removed in the powder making process are considered carcinogenic and may increase the risk of lung fibrosis, known as talcosis. The fibres are also thought to be a causal factor in the development of ovarian cancers, urinary tract disorders, gynaecological tumours as well as mesothelioma.

Identifiable fibres

Research into the possible harmful effects of talcum powder and the link with mesothelioma continue to this day. A new study published in 2014 found “identifiable” anthophyllite and tremolite asbestos fibres from one specific and historical brand of talcum powder in the lungs and lymph node tissues of a woman who used the product and later died from pleural mesothelioma.

Current analytical methods for the identification and quantifying of asbestos fibres in talcum products include various light-microscopy technologies, which are severely limited by the ultimate resolution of the light-optical system. As a result, small particles may be unresolved. In addition, talc fibres often possess different optical properties, which can further hinder clear analysis.

Nevertheless, the presence of asbestos fibres were still found. By weight, tremolite may be determined at levels as low as 0.10 per cent, chrysotile 0.25 per cent, and anthophyllite at 2.0 per cent in talcum powder. Today, only fibre-free grade talc of the highest quality and purity is used in cosmetics although some low-grade industrial talcs may contain a high number impurities, including fibres.

While previous research which involved around 2,000 women found an increased risk of between 20 per cent and 30 per cent for ovarian cancer in women who used talcum powder, overall lifetime risk would be about 1.8 per cent, and therefore, considered negligible.