Asbestos: still a very topical problem

What is asbestos and where is it found?

Asbestos is a fibrous mineral of the silicate family, which are minerals found in great abundance in the Earth's crust. Naturally occurring in rocks, the silicates are extracted and then transformed by a mechanical process into mineral fibres, to enable their use in industry.

 There are many natural asbestos outcrops around the world. The main French ones are in the Western Alps, Haute-Corse (Corsica) and New Caledonia. The French Bureau of Geological and Mining Research (BRGM) has produced maps that identify areas likely to contain asbestos fibres in rocks and natural soil.

Why was asbestos used and in which sectors?

Asbestos has been mined since ancient times but this began to develop after 1860, with the discovery of large deposits and driven by the textile industry. Industrial and commercial exploitation then grew steadily until 1975, due to the mineral's special physical and chemical properties. Asbestos fibres are resistant to fire, chemical attack, friction and tensile stress, and have low thermal and electrical conductivity. These properties, combined with the low cost of its extraction, led to the massive use of asbestos fibres in many forms and many fields throughout the 20th century, in France and abroad.

The two mineralogical varieties of asbestos mined and traded were:

• serpentines, from which chrysotile or white asbestos is extracted;
• amphiboles, from which anthophyllite, actinolite, tremolite and the two most commonly used types (amosite or brown asbestos, and crocidolite or blue asbestos) are extracted.

Thousands of products for industrial and domestic use were therefore manufactured for the thermal insulation of heating equipment, false ceilings and joints, or the manufacture of building components such as corrugated sheets, facade elements, ventilation ducts, piping, etc.

In France, asbestos use reached its peak in the 1970s, at around 150,000 tonnes per year. It was then gradually restricted until it was completely prohibited in 1997, which also coincided with a ban on the manufacture and import of asbestos products. However, despite this, asbestos-containing materials remain, particularly in buildings but also in some road surfaces, whose recycling was possible until 2013.

 What are the sources of exposure to asbestos?

Exposure mainly comes from:

• Work on manufactured products and materials containing asbestos;
• Asbestos waste treatment and disposal activities;
• Work on natural materials containing asbestos.

Which population groups have the highest exposure to asbestos?

Workers

 Workers are the population most exposed to asbestos. There are two main types of occupational exposure to asbestos:

• Continuous and discontinuous active exposure:  
  • continuous exposure concerns workers who have been involved in the extraction, processing and primary use of asbestos. In these situations, the concentrations of asbestos to which the workers were exposed were not necessarily stable, but the exposure to these concentrations was relatively long-term. 
  • discontinuous exposure is encountered in workers whose jobs involved working on asbestos-containing materials. This is mainly the case for all professionals carrying out maintenance or servicing work on products and materials containing asbestos, such as asbestos-cement pipes or asbestos vinyl floor tiles.

• Passive occupational exposure.  This type of exposure concerns people who work either in the vicinity of someone working on asbestos-containing materials, or in premises where asbestos-containing materials are degrading in the structure of buildings.

Following the ban on asbestos in 1997, there is no longer any extraction, transformation or primary use of asbestos in France. However, many asbestos-containing materials are still in place in partitions, fire doors, false ceilings, pipes, floor tiles, etc. and therefore remain sources of asbestos exposure. 

• For more details, the INRS has produced a guide listing the occupational situations involving exposure to asbestos during work with materials or equipment liable to release asbestos fibres.

Today, the main occupations concerned by the risks of inhaling asbestos dust are:

• Workers in asbestos removal companies;
• Employees in the building and public works industry;
• Professionals in the construction sector tasked with demolition or remediation;
• Professionals in the building and public works industry tasked with finishing works, maintenance or servicing (plumbers, electricians, heating engineers, painters, etc.);
• Employees working in waste treatment;
• Employees working on asbestos-bearing land.

The concentrations measured during occupational exposure are generally much higher than those found in the general population.

The rest of the population

Non-occupational exposure to asbestos is more difficult to assess, due to the low fibre concentrations most often encountered, and the lack of data on exposure frequencies and durations and the type of fibres.

Exposure to asbestos in the general population can be of the following types:

• para-occupational (people exposed to asbestos dust brought home by workers);
• passive environmental (due to asbestos pollution inside public and private buildings);
• domestic (due to household objects containing asbestos: insulation panels, ironing boards, toasters, etc. or to work on asbestos materials);
• environmental (due to the proximity of natural asbestos outcrops or asbestos mines and processing plants).

Exposure levels in the general population are highly variable due to this diversity of exposure situations.

What are the health effects of asbestos?

The morphology and size of the fibres are two key criteria determining the pathogenicity of asbestos. Other factors also play a role in the toxic properties of asbestos fibres, mainly their chemical composition and surface reactivity.

Because asbestos fibres mainly enter the body through inhalation, the health risks primarily concern diseases of the respiratory system.

However, people can also be exposed to asbestos by ingestion, in particular through drinking water contaminated by the deterioration of asbestos-cement pipes or by natural sources. Studies have therefore examined the effects of asbestos on the digestive organs. On the other hand, there are no data on dermal exposure.

Cancer

All varieties of asbestos have been classified in Category 1A (known to have carcinogenic potential for humans) by the European Union and in Group 1 (carcinogenic to humans) by the International Agency for Research on Cancer (IARC).

The main types of cancer linked to asbestos exposure are: 

• lung cancer, the leading cause of death in subjects exposed to asbestos, a risk that is aggravated by combined exposure to tobacco smoke;
• mesothelioma, a cancer that mainly affects the pleura (membrane surrounding the lungs) but also the peritoneum (membranes surrounding the viscera) and the pericardium (membrane surrounding the heart). Today, asbestos is the only proven risk factor for mesothelioma. Other factors, such as ionising radiation and certain viruses, are now also suspected of causing its development.

Lung cancer and mesothelioma are progressive diseases and can have a latency period of 20 to 40 years or more.

A proven link between asbestos exposure and ovarian and laryngeal cancer was also established by the IARC in 2012.

Other types of cancer are suspected (colorectal, pharyngeal and stomach cancers), although the level of evidence in humans is not yet sufficient.

Other diseases

Inhalation of asbestos fibres can lead to other non-cancerous pleural and pulmonary diseases such as:

• asbestosis, a disease typical of prolonged exposure to asbestos. Asbestosis results from a reaction of the lung tissue to the inhaled fibres. This reaction results in sclerosis of the tissue, also known as pulmonary fibrosis, which reduces breathing capacity and can, in severe cases, lead to respiratory failure. The risk and severity of asbestosis depends on the duration and level of exposure to asbestos;
• pleural plaques: damage or fibrosis of a limited area of pleural tissue. These are non-cancerous, generally asymptomatic lesions considered to be a marker of past asbestos exposure;
• pleurisy and pleural fibrosis (or thickening), which can cause chest pain, coughing and breathing difficulties.

How many people in France are affected?

In 2007, the INRS estimated that between 1 and 2 million workers were potentially exposed to asbestos during maintenance or servicing activities, including 900,000 in the building sector. 

According to the latest health insurance data from 2014, the number of recognised asbestos-related occupational diseases reached a peak in 2007 (6292 cases).

Asbestos-related diseases are now the second most common cause of occupational diseases and the leading cause of work-related deaths (excluding occupational accidents).

According to a report by the High Council for Public Health published in 2014, by 2050, the number of deaths from lung cancer due to asbestos may be 50,000 to 75,000, along with a further 18,000 to 25,000 deaths from mesothelioma. This figure is an underestimate as it does not include deaths from laryngeal or ovarian cancer related to asbestos exposure.

In 2005, the Ministry of Health estimated that the financial impact of compensation paid to victims was 1.3 to 1.9 billion euros per year. According to the same authors, the cumulative cost over twenty years of caring for asbestos victims is between 26.8 and 37.2 billion euros.

What are the regulations in force in France and Europe?

Although the dangers of asbestos have been known since the early 20th century in France, its use was only regulated from 1977 and then banned twenty years later, in 1997. At the European level, Entry 6 of Annex XVII of Regulation (EC) No 1907/2006 prohibited as of 1 January 2005 the manufacture, placing on the market and use of asbestos fibres and of articles and mixtures to which they have been intentionally added.

Since then, several intergovernmental action plans have been drawn up to improve the prevention of asbestos-related risks and support the development of measures in favour of renovation and energy efficiency, with a view to preventing accidents and disease.

What protective measures are in place? 

For workers 

The regulations on the prevention of asbestos-related occupational risks have been completely revised since 2012.

Protection of workers from the risk of exposure to asbestos is governed by specific regulatory provisions that supplement the general preventive measures in the workplace. In order to limit the risks for their employees, French regulations therefore oblige employers to implement the following:

• measurements of dust levels: the average concentration of asbestos fibres, over eight working hours, must not exceed ten fibres per litre;
• information and training of employees;
• measures relating to work organisation, exposure monitoring, waste treatment and environmental protection on work sites.

In general, young and temporary workers are prohibited from carrying out activities liable to cause the emission of asbestos fibres.

For the general public

Passive exposure from buildings (homes, offices, establishments open to the public, etc.) is caused by the dispersion of fibres in the air from simple occupation or during work on asbestos-containing materials and components, especially during sanding, drilling, cutting, rubbing, etc. In France, owners, tenants and occupants of buildings for which construction permits were issued before 1997 are subject to specific regulations aimed at identifying, monitoring and, if necessary, acting on materials containing asbestos. Occupants of buildings containing asbestos must be informed.

The portal notre-environnement.gouv.fr presents the main points of these regulations, and the main reference texts can be found on the website of the Ministry of Health.