Asbestos: Geology of a sinister mineral

Asbestos is a natural mineral. It is extracted from rocks that formed deep within mountain ranges and in subduction zones, brought to the surface after millions of years of uplift and erosion. This product of nature turned out to be miraculous. It is fireproof, indestructible, eternal. Eternit, the well-known Belgian asbestos-based product, was widely used in infrastructure and in a myriad of other applications. The possibilities seemed endless. Until the devastating downside of asbestos came to light. First, we'll touch on the health damage and the culture of silence, to continue with a journey into the natural origins of asbestos.

Text: Kathelijne Bonne.

Processing asbestos both in mines and factories releases massive clouds of asbestos dust, each tiny dust particle made up of ultra-fine microscopic fibres. Inhaling asbestos fibres damages the lungs and leads to serious diseases. Asbestosis ('dust lung'), lung cancer and deadly pleural mesothelioma were diagnosed in asbestos workers and in residents living near factories, up to decades after inhalation. Haunting testimonies of people still receiving diagnoses today, more than 25 years after asbestos was banned in Belgium (1998), are published by Stoff ("Dust"), an association that gives a voice to asbestos victims in the Waasland region, the place where I'm from and the hardest hit area in Belgium.

The risks were known early on, since before World War II, but were ignored for a long time despite warnings from generations of respiratory physicians. The factory Scheerders Van Kerckhove (SVK) turned my birthplace the town of Sint-Niklaas (Waasland) into one of the epicentres of the large-scale asbestos industry. The younger generation can only imagine the dust was stirred up. The abuses have cast a dark shadow over the industrial history of Belgium, a still-present stain that is not due to asbestos itself, but to those who hushed up the toxicity and failed to protect or support the victims.

Asbestos capital of the world

The impact of asbestos came to my attention through my grandfather Dr Paul Deschepper, pulmonologist, now 97, who warned about the health risks as early as 1972 (1). My uncle Dr Koen Deschepper, pulmonologist and oncologist, continues the profession and is involved in several international studies to develop new treatments for 'asbestos cancer' (malignant pleural mesothelioma). Belgium ranks fourth worldwide in terms of deaths (*), after the UK, Australia and Italy. Sint-Niklaas in particular has an even much higher mortality rate than the already high Belgian average. Koen Deschepper was not exaggerating when he called Sint-Niklaas the asbestos capital of the world in several media outlets (2)(3).

(*) One can doubt whether every country in the world discloses correct disease and death figures.

Mineralogy of asbestos

Asbestos is not one well-defined mineral but an umbrella term for fibrous, 'asbestiform' types of given silicate minerals, often metamorphic (*), such as serpentines and amphiboles. The shape of the fibres can be either curly or straight and needle-like, and reflects the way the atoms are arranged in the crystal lattice, which can be in long strands or chains.

(*) metamorphic rock forms from another rock that transforms under high pressure and/or temperature.

The origin of asbestos can go back very far, sometimes as far as the Precambrian, which is the timespan before 539 million years ago. Outcrops of asbestos can be found in large and ancient complex structures (deformation belts): the places where two tectonic plates collided and formed mountains, now long eroded. Some of those mountain ranges were part of the supercontinent Gondwana (including Australia and South Africa). When tectonic plates collide, two things can happen: subduction and obduction. During subduction, one plate plunges beneath the other, but sometimes a piece of plate is squeezed on top of the other (obduction). In the latter case, deep rocks from the Earth's mantle can also be thrusted onto the Earth's surface. In both cases, the rock undergoes immense pressure; it melts and recrystallises to form a 'new' range of metamorphic minerals. Asbestos is one of the metamorphic minerals created in this way. Then, ages of erosion are still needed before asbestos-containing rocks are finally exposed on the Earth's surface. 

Amiantos in Cyprus

Cyprus is the place par excellence where rocks from the deep Earth's crust and mantle have been 'obducted'. The world-famous (that is to geologists) Troodos Ophiolite shows a whole range of deep oceanic and mantle rocks and it is one of the finest places to study obduction and very special 'ultramafic' rocks. Europe's largest asbestos mine was located near the town of Amiantos. It closed in 1988. However, the town's name lives on, as in Spanish and other Roman languages asbestos is called 'amianto'.

There are several types of asbestos, but the best known are chrysotile (white asbestos), amosite (brown asbestos), and crocidolite (blue asbestos). These minerals have been mined at a large scale and chrysotile is still being mined were rules are lax. Other asbestiform minerals do exist, such as tremolite (see photos above), anthophyllite, actinolite, richterite, winchite and fluoro-edenite.

Chrysotile from Canada and Russia

Chrysotile or white asbestos is the most common and widely used form of asbestos. It belongs to the serpentine mineral group and has curly fibres. Hydrothermal water rich in minerals circulates through fissures and fractures in serpentine rock and converts the minerals into fibrous forms. The largest chrysotile deposits are in Canada, in Precambrian rocks in Quebec and Ontario. The Urals in Russia have massive chrysotile outcrops as well, therefore the brand name of Uralita in Spain.

Canada was one of the largest producers until the end of the 20th century, but due to health risks, production stopped in 2012. The gaping hole of the once thriving Jeffrey mines near the Canadian town of Asbestos, renamed Val-des-Sources in 2020, still bears witness to the former industry but also to the suffering that seeped out from there and spread tentacles to many other places around the world, including Sint-Niklaas.

Amosite and Crocidolite from South Africa and Australia

Amosite or brown asbestos and crocidolite (Greek, krokè: thread) or blue asbestos belong to the mineral group of amphiboles. Amphiboles are a group of silicate minerals with a straight chain structure that makes them tough and undegradable. Amosite is mainly mined in South Africa.

Crocidolite was mined in mines in South Africa and Australia, and is by far the most dangerous form of asbestos because of its fine needle-like fibers that can be easily inhaled and cause severe lung damage. It was banned in Belgium in the late 1960s. Crocidolite was mined from 1937 to 1966, among other places, in Wittenoom, Australia, a place that is still haunted. 2,000 out of 20,000 people died of asbestos cancer and it is still considered unsafe.

Natural risks?

If asbestos is not 'disturbed' in its natural form, as a rock, there is no immediate danger. But if it is processed, damaged or otherwise treated, the fibers are inevitably released, e.g. when natural asbestos deposits and old abandoned mining sites undergo erosion. But the risks are almost always associated with human activity that accelerates erosion, and with processing.

To this day, asbestos can be found all over the world in houses and infrastructure (in Belgium if built before 2000), inert, inconspicuous, sometimes visible (corrugated sheets) and much more often hidden from view (e.g. as insulation and in the most unimaginable products, like make-up). Asbestos is now banned in many countries, but mining and processing are still in full swing in China, Kazakstan, India, Brazil and Russia, among others. The largest still-active asbestos mines in the world are located in the Urals were mining, processing and misleading is ongoing. The thick fog that shrouded the health risks of asbestos is far from clearing. And as deafening as the corona pandemic seemed, many asbestos epidemics rage on silently and mercilessly.

Will Sint-Niklaas be overshadowd by new asbestos capitals rising elsewhere in the world? However, I doubt the details (and reliable disease and death figures) will trickle down to us any time soon. Those who get rich from the asbestos industry make sure no one talks. In western countries, remediation is now a massive business and asbestos is safely disposed of in designated sites. But asbestos remains indestructible. Something tells me that asbestos dust can slip through cracks, in any sense, as long as there are corrupt helping hands.

-----

Read more about the complex dynamics between natural resources and our human fragility, e.g., lapis lazuli and the taliban, soil under fire in Ukraine, soil erosion and desertification, salinisation, ecocide in Spain, the earthquake in Turkey (2022) and why so many people are living on dangerous plate margins and the eruption of disposable plastic in the Gulf of Naples. Or read something less disturbing, e.g. about the supercontinent Gondwana, its climates, mountains and life.

Kathelijne: I am intrigued by how earth, life, air, ocean and societies interact on geological and human timescales.

Why I started GondwanaTalks.

Recent posts:

Do you like this article? Subscribe to my short newsletter (every couple of weeks, no large files or annoying gifs), to let you know I published something new.