Naturally Occurring Asbestos in France: a Technical and Regulatory Review

ERELL LÉOCAT* Iffendic, Bretagne 35750, France

Key Terms: Naturally Occurring Asbestos, Elongated Mineral Particle, Transmission Electron Microscopy, Regulation, France

ABSTRACT

Naturally occurring asbestos (NOA) has been a wellknown issue within rock quarries for a long time. In France, the subject has recently become more controversial, particularly since 2013. In fact, some mineral fibers with the chemical composition of regulated asbestos (i.e., actinolite) have been discovered in roadbase aggregates and associated air filter samples. The main problem concerns the determination of the asbestiform versus non-asbestiform character of such mineral particles. The in-force standard based on the morphological identification of a fiber does not allow one to make this distinction. Presently, in France, the asbestos analysis of building material is based on a “yes” or “no” result. This method has limitations for analyzing NOA, as NOA may be present in lower concentrations in natural materials, especially in road-base aggregates. The health effects of the non-asbestiform particles, also called “cleavage fragments,” with fiber morphology are not well established. The French government mandated the National Agency for Food, Environmental and Occupational Health and Safety to conduct a review on the “state of the art” concerning the cleavage fragment issue. The conclusions of the report highlight the fact that elongate mineral particles (EMPs) are up for debate and address remaining questions concerning this subject. The next fundamental step is to secure agreement on the terminology of EMPs with the aim of comparing the studies in different disciplines.

INTRODUCTION

There are many issues in France related to the identification of asbestos, especially naturally occurring asbestos (NOA). Some of the issues can be explained by the non-concordance of terms used by the different stakeholders (Table 1). The legislation refers to “asbestos,” that is, a commercial term referring to

*Corresponding author email: leocat.erell@gmail.com

six mineral species extracted from specific rocks and deposits because of their asbestiform qualities. It is well known that these deposits may contain in trace amounts non-asbestiform varieties of these same mineral species (Langer, 1975; Van Orden et al., 2008). Identifying commercial asbestos in building material is easier, as this material is mainly composed of asbestiform fibers with typical shape and morphology, in particular curved and thin fibers with a length over width ratio of 20:1 or more (U.S. EPA, 1993), and interfering mineral fibers are easily distinguishable. Most of the standards dedicated to the analysis of building material and identification of commercial asbestos refer to the “fiber” term, especially to inhaled fibers, defined by a diameter of <3 µm. However, the dimension and morphology criteria of a fiber might be differently defined in these documents. These criteria lead to include mineral particles with various origins such as asbestiform minerals, other fibrous minerals, and cleavage fragments with fiber dimension. Under physical strengths, some single minerals can break along the weakness plane, called the “cleavage plane,” leading to particles called “cleavage fragments” that may have various shapes such as irregular particles with non-parallel sides, particles with fiber dimension, and particles with dimension of asbestiform fiber. In this context, the identification of asbestos in natural material is not obvious, and the determination of the nature of fibrous material remains challenging.

The term “elongate mineral particle” (EMP) is a recently used term for particles with an aspect ratio of >3:1 and with approximately parallel sides, without a distinction in terms of the particle’s origin (ANSES, 2017). Within this dimensional and morphological definition are numerous particles with various origins, including fibrils originated from asbestiform bundles, single minerals with a fiber habit, cleavage fragments with asbestiform dimensions, cleavage fragments with fiber morphology, and cleavage fragments with nonparallel sides.

REGULATORY REVIEW

Asbestos has been forbidden in France since 1997 (Décret, 1996). Only the six following mineral fibers,

classified as “asbestos,” are regulated in France: chrysotile, amosite (asbestos grunerite), crocidolite (asbestos riebeckite), asbestos tremolite, asbestos actinolite, and asbestos anthophyllite. The following fibers are not regulated: the non-asbestiform homologues of the six regulated asbestos and the four mineral fibers recognized as carcinogens for the human by the U.S. EPA (2014) for the winchite and the richterite and by the International Agency for Research on Cancer (IARC; 2014) for the erionite and the fluoro-edenite.

For Asbestos Survey in Bulk Material

The decree (Décret, 2012) requires completion of an asbestos survey before work, demolition, and sale related to any construction older than 1997. If asbestos is present in a material, some specific processes must be followed depending of the nature of the material and the work equipment used to remove it, but not on the content of the asbestos.

Consolidated by a regulatory document (UFETAM, 2013), this survey must be done on bituminous pavement, as chrysotile has been added in some bituminous coating materials. Actinolite has been identified in some cases, but the distinction between asbestiform fibers and cleavage fragments was not obviously performed. This mineral occurs naturally in most of the rocks used for road coated aggregates. NOA became a significant issue within the construction business (Léocat et al., 2018). Consequently, the Work Ministry published a directive on the regulated asbestos and cleavage fragments (Note DGT, 2014). This document gives information on the management of this issue in transportation and building domains. Under a request of the French government, the National Agency for Food, Environmental and Occupational Health and Safety led to the development of a report on the health effects of cleavage fragments (ANSES, 2015). The conclusion of this report is that the toxicity of these particles cannot be excluded, as any scientific studies could argue that there is no hazard. Consequently, the agency recommends following the precaution principle and using the same dispositions for the cleavage fragments as for asbestos. It also recommends extending the regulation to the non-asbestiform homologues of the six asbestos minerals and to the four human carcinogenic minerals. The French Work Ministry published a second directive (Note DGT, 2018) on the dust-creating work activities during disturbance of building materials containing aggregates. In the case of presence of non-asbestiform fibers, the worker protective dispositions to be applied are those related to dust hazards and not those related to asbestos.

A recent decree (Décret, 2017) outlines the obligation to perform an asbestos survey before work in seven domains, according to the respective standards:

1. Building (NF X46-020, 2017); 2. Other buildings (NF X46-102, in progress) engineering structures, transportation infrastructures, and other networks; 3. In-place rocks and soils (NF P94-001, in progress). This domain is concerned with NOA and refers to quarries, earthworks, etc.; 4. Railway equipment and other transportation equipment (NF F01-020, in progress); 5. Boat, ship, and other sea equipment (NF X46-101, 2019); and

Case Material Type of Analyzed Mineral Particles

1 Building material Intentionally added asbestos 2 Contaminated soil (with debris of building material) Intentionally added asbestos 3 Rocks (e.g., soils, aggregates) Naturally occuring asbestos 4 Non-fibrous elongate mineral particles,* fibers from cleavage fragments, and fibers from asbestiform habit 5 Building materials containing natural material (roads, Naturally occuring asbestos 6 cement, concrete, coating) Non-fibrous elongate mineral particles,* fibers from cleavage fragments, and fibers from asbestiform habit

6. Aircraft (NF L80-001, in progress). 7. Facilities, structures, and equipment of the industrial domains (NF X46-100, 2019).

For Asbestos Testing Laboratories

The in-force standard (NF X43-050, 1996) is mandated for transmission electron microscopy (TEM) asbestos analysis of air filter sampling. This standard gives the definition of a fiber as a mineral particle with parallel or stepped sides. Moreover, a fiber has a length to width ratio of over 3 μm and a minimal length of 0.5 µm; that is the technical limit. It defines “asbestos” as silicate minerals belonging to the amphibole and serpentine groups that have crystallized with asbestiform facies. This term “asbestiform” refers to a specific habit of a mineral for which the fibers and fibrils present a high tensile strength and a high flexibility. However, this document does not explain what an asbestiform mineral is from an analytical point of view. In fact, no dimensional and morphological criteria are attributed to the asbestiform habit. This standard also says that fibers analyzed in air samples need to have a diameter of under 3 µm. The asbestos regulatory rulings for the ambient air in buildings (Arrêté, 2011) and for the worker exposure limit (Arrêté, 2018) specify that the analyzed fibers in air samples are the fibers defined by the World Health Organization (WHO, 1998). This fiber called “WHO fiber” has a length of >5 µm. As no specific standard refers to bulk materials, the NF X43-050 (1996) standard is used for the analysis of this material and mainly for the identification of fibers. Qualitative analysis of short and long fibers should be performed to detect asbestos and should conclude by a “yes” or “no” result. The detected fibers must have a width under 3 μm, a length over 0.5 μm, and an aspect ratio of 3:1. The French Association for Accreditation, the government body overseeing asbestos testing laboratories, published a document for laboratories that were applying to be accredited for asbestos analysis in bulk material (COFRAC, Lab INF 44, 2018) (Table 2). This document defines six areas of accreditation depending on the material type and the nature of the fibers (industrial asbestos, NOA, cleavage fragments) Three methods can be used, as follows:

1. PLM (polarized light microscopy); 2. SEM (scanning electron microscopy); 3. TEM.

The following six cases are distinguished: In cases 1 and 2, the industrial asbestos is identified, respectively, in building material and in soils contaminated with asbestos-containing material. The term “intentionally added asbestos” refers to the asbestos added to building material. In case 2, the intentionally added asbestos refers to the one incorporated in building material that may contaminate the ground. In cases 3 and 5, the laboratory can identify the six regulated asbestos types in rocks and industrial materials containing natural material, but it is not allowed to report on non-asbestiform fibers. In cases 4 and 6, respectively, in rocks and in building material containing rocks fragments, the laboratory has the ability to identify three different particles: ◦ cleavage fragments; ◦ asbestiform fibers; and ◦ non-fibrous EMPs.

In this document, the term “non-fibrous” refers to particles having non-parallel and/or non-stepped sides and an aspect length:diameter ratio of >3. With an absence of standard testing materials, a guide (COFRAC, Lab GTA 44, 2018) has been published for testing laboratories that want to be accredited for asbestos identification in bulk materials. It explains, among other things, what the requirements are for validating the detection limit of 0.1 percent asbestos in bulk materials. The detection limit is based on the fact

that asbestos additions in building materials were performed only in amounts greater than 0.1 percent (Directive européenne, 1999). The laboratory should have a referent person who has knowledge in mineralogy to support NOA identification. This guide also says that TEM analysis allows for identification of asbestos using the following three criteria:

1. Morphology to distinguish the fibers from the whole particles; 2. Chemistry to get the chemical composition of the fiber; and 3. Diffraction to identify the crystalline structure and distinguish the mineral fibers from the other fibers.

This guide says that SEM analysis allows only classification of asbestos because identification of crystalline structure by diffraction analysis is not possible. However, the SEM three-dimensional images allow for distinguishing cleavage fragments from fibers from a morphological point of view. This document also requires using the Locock (2014) spreadsheet based on the International Mineralogical Association (IMA) classification to identify the five amphibole mineral species belonging to asbestos, which are actinolite, tremolite, anthophyllite, grunerite, and riebeckite species.

TECHNICAL REVIEW

After the first report, the French government mandated that the ANSES agency conduct a review on the emission source of EMPs of interest (EMPi; ANSES, 2017). These particles correspond to the asbestiform and non-asbestiform particles of the six regulated minerals and the four human carcinogen minerals. In this report, the agency proposes a protocol for identifying minerals in materials that are susceptible to liberate EMPi and a protocol to measure EMPi in the air. The aims are to explore the potential exposure of the professional population and the public to EMPi in some construction work activities (for example, the gravel quarries) and to study the emissivity of materials containing EMPi.

Following these recommendations, BRGM (French Geological Survey), the Institut National de la Recherche Scientifique (INRS), and the Particle, Fiber, Asbestos Laboratory (LAFP) worked on the asbestos emissivity of aggregates submitted to attrition tests during the PIMAC project (BRGM, 2018). The French government asked the Professional Organization for Accident Prevention in the Building and Public Works Sector to coordinate a project on the EMPi with health, work, and environment ministries and the French scientific organizations. Based on the recommendations of the ANSES report (2017), the project yielded the EMPi measurement campaign in construction activities.

The different French scientific organizations have carried on various works on the subject for the last few decades. Among other tasks, BRGM works on mapping of rocks that contain or may contain NOA in natural outcrops and in quarries (BRGM, 2005, 2013). Based on the potential of containing NOA, the rocks are classified into five groups. Recent works weigh in on the metrological issue of NOA identification (Lahondère et al., 2018; Misseri and Lahondère, 2018). The INRS published a guide on NOA management during work on soils and rocks for engineering construction and transportation infrastructure terrain (INRS, 2013).

DISCUSSION AND CONCLUSIONS

The NOA issue has been apparent for a long time, and some scientific organizations, such as BRGM, are currently working on the subject. The presence of NOA became a big issue when it affected the domain of public works and buildings. Research projects and work are mainly concentrated on the emissivity of natural materials or building materials containing natural materials and to a lesser degree on the toxicity of these EMPs. Further essential work will concern a clear and univocal definition of EMPs and a nomenclature of the amphibole mineral species with asbestiform habit to support international agreement. In fact, an integrated NOA knowledge database may lead to improved understanding of the issues.

ACKNOWLEDGMENTS

I would like to thank all the individuals who encouraged me in my work in the field of asbestos and NOA. My thanks go to the reviewers Francesco Turci, Mark Bailey, and Florence Cagnard, who patiently read a first version of this article to greatly improve it.

REFERENCES

ANSES (Agence Nationale de Sécurité Sanitaire de l’Alimentation, de l’Environnement et du Travail [French National Agency for Food, Environmental and Occupational Health and Safety]), 2015, Effets sanitaires et à l’identification des fragments de clivage d’amphiboles issus des matériaux de carrière: Avis de l’Anses, Saisine 2014-SA-0196, 13 p. ANSES, 2017, Particules minérales allongées. Identification des sources d’émission et proposition de protocoles de caractérisation et de mesures: Avis de l’Anses, Saisine 2016-SA-0034, 13 p.

Arrêté du 19 août 2011 relatif aux modalités de réalisation des mesures d’empoussièrement dans l’air des immeubles bâtis: Journal Officiel de la République Française (JORF [Gazette of the French Republic]) 0202. Arrêté du 30 mai 2018 modifiant l’arrêté du 14 août 2012 relatif aux conditions de mesurage des niveaux d’empoussièrement, aux conditions de contrôle du respect de la valeur limite d’exposition professionnelle aux fibres d’amiante et aux conditions d’accréditation des organismes procédant à ces mesurages: JORF0148. BRGM (Bureau de Recherches Géologiques et Minières [French Geological Survey]), 2005, Recensement et classement des sites naturels amiantifères et des formations géologiques potentiellement amiantifères en France: BRGM/RP-53599-FR, 59 p. BRGM, 2013, Exposition aux fibres asbestiformes dans les industries extractives: Identification des sites potentiellement concernés en France métropolitaine: BRGM/RP-61977-FR, 163 p. BRGM, 2018, PIMAC: capacité de libération et d’émission de particules amiantifères des granulats de carrières: Electronic document, available at https://www.brgm.fr/projet/pimaccapacite-liberation-emission-particules- amiantiferesgranulats-carrieres COFRAC (Comité Français d’Accréditation [French Association for Accreditation]), 2018, Guide technique d’accréditation: Recherche d’amiante dans les échantillons massifs: Lab GTA 44, 17 p. COFRAC, 2018, Nomenclature et expression des lignes de portée d’accréditation pour la recherche d’amiante dans les échantillons massifs: Lab INF 44, 6 p. Décret 96-1133 du 24 décembre 1996, relatif à l’interdiction de l’amiante, pris en application du code du travail et du code de la consummation: Premier ministre. Décret 2012-639 du 4 mai 2012, relatif aux risques d’exposition à l’amiante: JORF0106. Décret 2017-899 du 9 Mai 2017, relatif au repérage de l’amiante avant certaines opérations: JORF0109. Directive européenne, 1999, Directive 1999/45/CE du Parlement européen et du Conseil du 31 mai 1999 concernant le rapprochement des dispositions législatives, réglementaires et administratives des États membres relatives à la classification, à l’emballage et à l’étiquetage des préparations dangereuses: Journal Officiel de l’Union européenne L 200 du 30/07/1999, pp. 0001–0068. IARC (International Agency for Research on Cancer), 2014, Carcinogenicity of fluoro-edenite, silicon carbide fibres and whiskers, and carbon nanotubes: Lancet, Vol. 15, pp. 1427–1428. INRS (Institut National de la Recherche Scientifique [National Center for Scientific Research]), 2013, Travaux en terrain amiantifère. Opérations de génie civil de bâtiment et de travaux publics: INRS ED 6142, 121 p. Lahondère, D.; Cagnard, F.; Wille, G.; and Duron, J., 2018, TEM and FESEM characterization of asbestiform and non-asbestiform actinolite fibers in hydrothermally altered dolerites (France): Environmental Earth Sciences, Vol. 77, p. 385. Langer, A. M.; Mackler, A.D.; and Pooley, F. D., 1974, Distinguishing between Amphibole Asbestos Fibers and Elongate Cleavage Fragments of their Non-Asbestos Analogues: Environmental Health Perspectives, Vol. 9, p. 63–80. Léocat, E.; Rielland, C.; and Letessier, P., 2018, Analysis and identification of elongate mineral particles in road coated aggregates: Toxicology Applied Pharmacology, Vol. 361, pp. 149–154. Locock, 2014, An Excel spreadsheet to classify chemical analyses of amphiboles following the IMA 2012 recommendations: Computer Geosciences, Vol. 62, pp. 1–11. Note DGT (Direction générale du travail), 2014, Cadre juridique applicable aux travaux réalisés sur des matériaux de BTP contenant des fibres d’amiante et/ou des fragments de clivage issus de matériaux naturels: Ministère du Travail, de l’Emploi, de la Formation professionnelle et du Dialogue social, Paris, France. Note DGT, 2018, Amiante – Cadre juridique applicable aux travaux réalisés sur des matériaux de BTP contenant des fibres d’amiante et/ou des fragments de clivage issus de matériaux naturels: Ministère du Travail, de l’Emploi, de la Formation professionnelle et du Dialogue social, Paris, France. Misseri, M. and Lahondère, M., 2018, Characterisation of chemically related asbestos amphiboles of actinolite: Proposal for a specific differentiation in the diagram (Si apfu versus Mg/Mg+Fe 2+ ): International Journal Metrology Quality Engineering, Vol. 9. NF X43-050, 1996, Qualité de l’air – Détermination de la concentration en fibres d’amiante par microscopie électronique à transmission – Méthode indirecte: Association Française de Normalisation (AFNOR), Paris, France. NF X46-020, 2017, Repérage amiante – Repérage des matériaux et produits contenant de l’amiante dans les immeubles bâtis: AFNOR, Paris, France. NF X46-100, 2019, Repérage amiante – Repérage des matériaux et produits contenant de l’amiante dans les installations, structures ou équipements concourant à la réalisation ou à la mise en œuvre d’une activité: AFNOR, Paris, France. NF F01-020, 2019, Repérages avant travaux de l’amiante dans le matériel roulant ferroviaire: AFNOR, Paris, France. NF L80-001, in progress, Repérage avant travaux de l’amiante dans les aéronefs: AFNOR, Paris, France. NF P94-001, in progress, Repérage avant travaux – repérage amiante environnemental dans les sols et roches en place: AFNOR, Paris, France. NF X46-101, in progress, Repérage amiante – Repérage des matériaux et produits contenant de l’amiante dans les navires, bateaux et autres constructions flottantes: AFNOR, Paris, France. NF X46-102, in progress, Repérage des matériaux et produits contenant de l’amiante dans les ouvrages de génie civil, infrastructures de transport et réseaux divers: AFNOR, Paris, France. UFETAM (Union Fédérale de l’Environnement, des Territoires, des Autoroutes et de la Mer [Federal Union of the Environment, Territories, Highways and the Sea]), 2013, Gestion des risques sanitaires liés à l’amiante dans le cas de travaux sur les enrobés amiantés du réseau routier national non concédé: Circulaire du 15 Mai 2013, 8 p. U.S. EPA (U.S. Environmental Protection Agency), 1993, Method for the Determination of Asbestos in Bulk Building Materials: EPA/600/R-93/116, 98 p. U.S. EPA, 2014, Toxicological Review of Libby Amphibole Asbestos. In Support of Summary Information on the Integrated Risk Information (IRIS): EPA/635/R-11/002F, 685 p. Van Orden, D. R.; Allison, K. A.; and Lee, R. J., 2018, Differentiating amphibole asbestos from non-asbestos in a complex mineral environment: Indoor Built Environment, Vol. 17, No. 1, pp. 58–68. World Health Organization, 1998, Détermination de la concentration des fibres en suspension dans l’air. Méthode recommandée: la microscopie optique en contraste de phase (comptage sur membrane filtrante), Geneva, Switzerland, 64 p.