Additional information on Asbestos in Québec

(INSPQ, 1213, 1380, 1409)

Draft regulation to amend the Regulation respecting occupational health and safety and the Safety code for the construction industry NEW 

  • On December 27th, 2012, the Gazette officielle du Québec  (Québec Gazette) published a draft regulation adding new safety regulations related to 1) asbestos management particularly with regard to the tracking by the employer, of sprayed asbestos and asbestos-containing heat insulation coating; 2) verification by the employer who is about to undertake  dust emitting work, of the presence of asbestos containing materials and 3) the recording and dissemination of information regarding the location and the status of those materials (Source: www2.publicationsduquebec.gouv.qc.ca/dynamicSearch/telecharge.php?type=1&file=58697.PDF).

Recommendations and follow-up in view of acquired knowledge on asbestos from 2003 to 2009 NEW 

  • That the ministère de la Santé et des Services sociaux (ministry of health and social services) asks the Commission de la santé et de la sécurité du travail du Québec (Québec workers’ compensation board) to lower the current standard for asbestos exposure in the workplace (in particular the Regulation respecting occupational health and safety), and that  no regulation currently in force be relaxed (particularly the Safety code for the construction industry and the asbestos standards of the Regulation respecting occupational health and safety).
  • That the ministère de la Santé et des Services sociaux encourages the Commission de la santé et de la sécurité du travail du Québec to continue its work on the adoption of a regulation requiring public buildings owners to identify premises with asbestos-containing materials; to set up a program for the safe management of asbestos; and to report on the progress of its work.  
  • That the ministère de la Santé et des Services sociaux  
    • requests the implementation of a surveillance program to measure ambient air concentrations of asbestos in mining towns in Québec, under the authority of the ministère du Développement durable, de l’Environnement, de la Faune et des Parcs (ministry of Sustainable Development, Environment, Wildlife and Parks);
    • requests an evaluation of asbestos background concentrations in urban and  rural environments;
    • requests that transmission electron microscopy be used to analyse asbestos samples;
    • asks the concerned authorities to establish proper exposure control measures in Québec mining towns, such as prohibiting access to asbestos tailings; stopping use of asbestos wastes as ballast/backfill or abrasives; and covering tailings with uncontaminated materials.
  • The Institut national de santé publique du Québec (Québec’s public health institute) suggests to the ministère de la Santé et des Services sociaux that it verify, with relevant public health authorities, and report on the status of the precautionary approach to the safe management of asbestos in different premises: schools, daycare centers, cegeps and universities (under the authority of the ministère de l’Éducation, du Loisir et du Sport -ministry of Education, Recreation and Sports), health care facilities (under the authority of the agences de la santé et des services sociaux - health and social services agencies) and municipal buildings (under the authority of the municipalities and the ministère des Affaires municipales, des Régions et de l’Occupation du territoire - ministry of municipal affairs, regions and occupation of territory).

Asbestos exposure limits in Québec 

  • Québec's occupational asbestos exposure limits have remained unchanged since 1990. The time-weighted average (TWA) and the short-term exposure limit (STEL) for chrysotile, tremolite, anthophyllite and actinolite are respectively 1 fibre/ml (f/ml) and 5 f/ml. The TWA and the STEL for crocidolite and amosite are respectively 0.2 f/ml and 1 f/ml.
  • The exposure limit of 1 f/ml is ten times higher than the one in force in Ontario, the United States and France, where it is 0.1 f/ml.
  • The exposure limit of 1 f/ml is 100 times higher than the one in the Netherlands and in Switzerland.
  • In France, the decree 2012-639 that came into force in July 2012, stipulates that the current occupational asbestos exposure limit of 0.1 f/ml will decrease to 0.01 f/ml in June, 2015 (Source: www.travailler-mieux.gouv.fr/IMG/pdf/Decret_amiante_4_mai_2012.pdf, accessed February 25, 2013).
  • There is no environmental limit for asbestos exposure.

Asbestos exposure in the general population of Québec 

  • In 2004, in Montréal and the city of Québec, total outdoor air fibre concentrations obtained from 117 samples collected by the ministère du Développement durable, de l'Environnement et des Parcs (MDDEP - ministry of Sustainable Development, Environment, Wildlife and Parks) and analyzed by phase contrast optical microscopy (PCOM) ranged from < 0.0015 to 0.0054 fibre/ml (f/ml) while transmission electron microscopy (TEM) analyses of five samples identified no asbestos fibres.
  • In the city of Asbestos, the average annual fibre concentrations in the ambient air, reported between 1988 and 2005 by the Jeffrey mine, varied between 0.003 and 0.007 f/ml depending on the sampling site (unspecified analysis method).
  • In the city of Thetford Mines, in 2004, the total outdoor air fibre concentrations obtained from 125 samples collected by the MDDEP and analyzed by PCOM varied between < 0.0015 and 0.056 f/ml. Asbestos fibre concentrations measured in seven samples analyzed by TEM ranged from < 0.0006 f/ml to 0.0082 f/ml with an average of 0.0043 f/ml.
    • The average asbestos fibre concentration measured by the MDDEP in outdoor air in Thetford Mines in 2004 (0.0043 f/ml) was 215 times higher than that obtained in the outdoor air around buildings in the United States that were the subject of litigations concerning the removal of asbestos-containing materials. The same is true for the average concentration of 0.004 f/ml measured by TEM in Asbestos in 1997 by the Association des mines d'amiante du Québec (Québec asbestos mining association).
  • Contrary to the sampling that was carried out in 2000 by the ministère de l'Environnement du Québec (Québec's ministry of Environment), no asbestos fibres were detected in 2005 in the ambient air of Thetford Mines close to the yards and alleys filled with asbestos tailings.
  • Asbestos fibre concentrations measured in the indoor air of 26 residences in the city of Thetford Mines in 2003 and 2004 by the Association des victimes de l'amiante du Québec (Québec's asbestos victims association) ranged from < 0.000553 to 0.010 PCMe fibre/ml (phase contrast microscopy equivalent) with an average of 0.0018 PCMe fibre/ml.
    • This average concentration is 1.7 to 1.4 times lower than that observed at the end of the 1990s in 17 schools in Québec (0.0031 PCMe fibre/ml) and in two apartments affected by the dust from the collapse of the World Trade Center in 2001 (0.0026 PCMe fibre/ml).
    • It is 16 to 45 times higher than concentrations observed in the indoor air of buildings in the United States that were the subject of litigations concerning the removal of asbestos-containing materials from 1980 to the early 2000s (0.00004 to 0.00011 PCMe fibre/ml).
  • No data is available on exposure in the general population to asbestos fibres from asbestos-containing asphalt present on Québec roads.

Asbestos exposure in the workplace in Québec 

Mining sector 

  • We have found no publication later than the year 2000 on the exposure levels of mine workers in the regions of Thetford Mines and Asbestos.

Industrial sector 

  • Between 2005 and 2009, none of the nine factories in Québec that used chrysotile asbestos in their manufacturing process or in which workers handled asbestos-containing products, did so in a safe manner.
  • In four of the nine factories in which asbestos exposure was evaluated, 22 workers were exposed to levels ≥ 0.1 fibre/ml (f/ml). Of these, two workers who worked in the same factory were exposed to levels above the time-weighted average of 1 f/ml, and this, despite wetting the materials during sample collections.
  • In 2010, the ministère des Transports du Québec (Québec's ministry of Transport) identified 28 plants equipped to produce asbestos-containing asphalt across Québec, of which, only 20 were still open and only four of those were in operation. Workers' exposure measurements were performed in only one of these plants and the levels were below 0.1 f/ml.

Construction industry 

  • Of the 2,475 samples of asbestos-containing materials collected at high risk construction sites, 75 % contained chrysotile only, 15 % contained chrysotile in the presence of other types of fibre and 10 % contained amphiboles only.
    • The samples containing chrysotile usually came from ceilings, walls, pipe elbows and floors.
    • The samples containing amosite were chiefly found around pipes and elbows.
  • Of the 3,000 air samples collected at high risk construction sites, 43 % had concentrations ≥ 1 f/ml (the chrysotile asbestos occupational exposure limit), 13 % had concentrations higher than 5 f/ml and 5 % had concentrations higher than 10 f/ml with a maximum value of 96 f/ml. However, only 3 % of the samples were taken in the breathing zone of workers; 52 % were in the breathing zone of bystanders and 42 % were at fixed stations. These conditions can have the effect of underestimating the number of exceedances of the reference values.
  • Of the 2,616 air samples collected in changing rooms on asbestos removal worksites, 77 % had fibre concentrations ≥ 0.01 f/ml (the criterion for dismantling enclosures on high risk construction sites) compared to 14 % in adjacent areas. However 46 % of the samples in the changing rooms and 74 % in the adjacent areas did not comply with the prescribed optimal sampling conditions.
  • During asbestos-removal work, asbestos fibre emissions seem to be more intense during waste recovery, removal of materials and demolition activities compared to during cleaning, sealing and inspection tasks.
  • Of the 23,099 samples of asbestos-containing materials indexed in 1,550 buildings located across Québec, 10,538 contained chrysotile. Of these 10,538 samples, 95 % contained chrysotile only and 5 % contained a mix of chrysotile and amphiboles (amosite and crocidolite).
    • Chrysotile-containing materials were chiefly pipe insulation, sprayed asbestos, floor coverings, and asbestos-cement plates.
    • Materials containing amosite and crocidolite were chiefly pipe insulation.
  • In 2004, the ministère des Transports du Québec measured total fibre concentrations in ambient air along a roadway with asbestos-containing asphalt in the Chaudière-Appalaches region. Prior to the removal of this material, the total fibre concentrations varied between < 0.001 and < 0.004 f/ml (sic) in phase contrast optical microscopy (PCOM). Measurements taken at mobile stations (n=17) during the removal operations revealed concentrations that ranged from 0.09 to < 0.90 f/ml by PCOM analysis. Actinolite was present in three of the five samples analyzed by transmission electron microscopy.

Asbestos fibres in the lung tissue of Québec workers NEW 

  • The lung fibres burden of 123 Québec workers with an asbestosis, a mesothelioma or an asbestos-related lung cancer who had a mineralogical analysis between 1988 and 2007 was described.
    • More then 85 % of the workers had chrysotile in their lung tissues; 76 % had tremolite, 64 % amosite and 43 % crocidolite.
    • In general, chrysotile and tremolite fibres were in higher concentrations than amosite and crocidolite fibres.
    • Chrysotile fibres of all lengths were observed in the lungs of some of the workers more than 30 years after the end of their exposure. Their lung chrysotile fibres burden was higher than in the reference population.
    • The total fibres distribution was as follows: 80 % short and thin fibres and 20 % WHO fibres. However, since the relationship between asbestos exposure and disease onset was established solely on the basis of WHO fibre counts in epidemiological studies, the potency of short and thin fibres should be questioned.
    • Among workers exposed in mines and diagnosed with an asbestos-related disease, tremolite and chrysotile fiber concentrations were the highest; amosite concentrations were highest among workers in the maintenance and repair of asbestos-containing products or structures, while amosite and tremolite predominated among construction workers.

Effects of asbestos on the health of the general population of Québec 

Pleural mesothelioma 

  • In Québec, 1,530 new cases of pleural mesothelioma cases (1,210 men and 320 women) were registered in the Fichier des tumeurs du Québec (Québec Tumour Registry) between 1982 and 2002. The average annual age-adjusted incidence rates were 1.98 per 100,000 person-years among men and 0.41 per 100,000 person-years among women.
  • From 1982 to 2002, a significant increase in the annual age-adjusted incidence rates for pleural mesothelioma was observed among men. This increase corresponds to an average annual growth rate of 3.6 %, which is lower than the value calculated for the period from 1982 to 1996. No significant time trend was observed among women.
  • From 1981 to 2003, 1,059 pleural cancer deaths were registered in the Fichier des décès (death registry), of which 769 were men and 290 were women.
  • At the regional level, the standardized incidence rates of pleural mesothelioma are significantly higher among men and women in the Chaudière-Appalaches region, and among men in the Montérégie and Lanaudière regions. These rates are significantly lower among men in the Bas-Saint-Laurent and Outaouais regions. The geographic distribution of the significant excesses of incidence rates coincides with the geographic distribution of excess mortalities from pleural cancer.
  • At the Canadian level, mesothelioma incidence rates among men and women in Québec were the highest in Canada for the period from 1993 to 1997.
  • Internationally, comparisons made for the period from 1993 to 1997 reveal that only the combined standardized incidence ratios for pleural, peritoneal and pericardial mesotheliomas taken together among men in New Zealand, the Netherlands, several regions in the United Kingdom and Australia, were higher than the Québec rate. Among women, significant mesothelioma excesses compared to Québec were observed only in western Australia and in Scotland.
  • A review of mesothelioma cases registered in the Fichier des tumeurs du Québec in 2001 and 2002 showed that 73 % to 77 % of the cases were considered as certain or probable mesothelioma by a panel of three physicians (one chest physician, one radiologist and one pathologist) after a review of the summaries of the charts containing the appropriate content. These proportions were advantageously comparable with the scientific literature. The corollary of this result is that approximately 25 % of the cases may not be mesothelioma. The study did not allow verifying the presence of mesothelioma cases registered under another diagnosis in the Fichier des tumeurs du Québec.

Peritoneal mesothelioma 

  • In Québec, 170 new cases of peritoneal mesothelioma (98 men and 72 women) were registered in the Fichier des tumeurs du Québec from 1982 to 2002. The average annual age-adjusted incidence rates were 0.15 per 100,000 person-years among men and 0.09 per 100,000 person-years among women. Annual incidence rates showed no significant trend and no region in Québec showed significant excess or deficit for this mesothelioma.

Asbestosis 

  • From 1992 to 2004, 2,072 persons (1,993 men and 79 women) hospitalized with first mention of asbestosis as the primary or secondary diagnosis were registered in the system for the maintenance et exploitation des données pour l'étude de la clientèle hospitalière (maintenance and use of data for the study of the hospital clientele, known as the MED-ECHO system).
  • The average annual hospitalization rates with first mention of asbestosis were 4.80 per 100,000 person-years among men and 0.14 per 100,000 person-years among women. No significant time trend of annual rates was observed among men or among women.
  • From 1981 to 2003, 195 asbestosis deaths were registered in the Fichier des décès, 191 men and four women.
  • Significant excess hospitalizations for asbestosis were observed among men and women in the Chaudière-Appalaches region and among men in Estrie and Lanaudière regions. Significant excess mortalities from asbestosis were observed only among men in Chaudière-Appalaches and Estrie.

Evaluation of the lung cancer and mesothelioma risk in the general population of Thetford Mines 

  • An assessment of the lung cancer and mesothelioma risk among residents in the city of Thetford Mines was conducted using two approaches. The lifetime mortality risk from these two cancers, estimated using the approach based on the ministère de la Santé et des Services sociaux (ministry of health and social services) guidelines was 72, 110 or 125 per 100,000 persons residing in Thetford Mines and with continuous lifetime exposure to asbestos.
  • The lifetime mortality risk for these same cancers estimated using the approach based on the Berman and Crump model was 8.2 per 100,000 persons exposed.
  • By way of comparison, the risks associated with asbestos fibre concentrations in the indoor and outdoor air of buildings with asbestos-containing materials in the United States ranged from 0.46 to 7.1 per 100,000 persons depending on the approach used.
  • This risk assessment carries uncertainties related to the determination of the unit risks and to the concentrations used to determine the average lifetime exposure dose. It should therefore be interpreted with caution.

Effects of asbestos on the health of Québec's workers 

New cases of asbestos-related diseases among workers 

  • Between 1998 and 2003, 1,348 workers had 1,512 asbestos-related diseases recognized as occupational lung diseases by the Comité spécial des maladies professionnelles pulmonaires (CSMPP- special committee on occupational pulmonary diseases) following a claim filed with the Commission de la santé et de la sécurité du travail du Québec (Québec workers' compensation board). Of these workers, 57.3 % had asbestosis, 27.9 %, mesothelioma and 27.0 %, lung cancer.
  • The workers affected by these diseases were distributed among the following occupational exposure settings:
    • 29.1 % in mines
    • 28.4 % during maintenance and repair of asbestos-containing products or structures
    • 21.0 % in construction
    • 11.3 % in asbestos processing plants
    • 10.2 % in other workplaces.
  • Since construction workers and maintenance and repair workers generally perform the same jobs, the two sectors were combined. The percentage of workers from these two sectors suffering from an asbestos-related disease (49.4 %) surpasses the percentage of mine workers.
  • Most of the workers with mesothelioma came from the combined sectors of construction and maintenance and repair (59.5 %) while workers with lung cancer came chiefly from the mining sector (56.5 %).
  • During the study period, there was an increase in the number of workers diagnosed with an asbestos-related disease in the construction and maintenance and repair sectors and in the "Other workplaces" category. The number of cases reported in the mining and processing sectors remained relatively stable.

Asbestos-related deaths among workers 

  • Between 2005 and 2011, asbestos was responsible for 77 to 89 % of all deaths caused by occupational diseases that were submitted to the Board of Directors of the Commission de la santé et de la sécurité du travail du Québec and for which the decision to compensate was rendered.

Screening for asbestosis in the construction industry 

  • In 2006, 925 workers from seven construction trades in three regions of Québec (Montérégie, Laval, Lanaudière) had a screening X-ray for asbestosis. Of the 772 X-rays available at the time of the study, six (0.8 %) presented abnormalities compatible with asbestosis. As well, 142 (18.4 %) showed pleural plaques and pleural thickenings.

Occupational mesotheliomas and asbestoses in the general population of Québec 

  • The mesothelioma cases recognized as occupational diseases by the CSMPP between 1975 and 2003, following a claim filed with the Commission de la santé et de la sécurité du travail du Québec, represent 21.4 % of all the pleural mesothelioma cases registered in the Fichier des tumeurs du Québec (Québec tumour registry) between 1975 and 2002.
  • The asbestosis cases recognized by the CSMPP between 1967 and 2003 represent 35.0 % of the individuals hospitalized with first mention of asbestosis and registered in the MED-ECHO system between 1988 and 2003.

Notifiable diseases related to asbestos exposures NEW 

  • Since 2003, physicians must report mesothelioma, asbestosis and asbestos-related lung cancer cases confirmed to be of  occupational origin by the CSMPP.
  • Between 2006 and 2010, 160 asbestosis cases, 28 lung cancer cases and 53 mesothelioma cases were notified on average each year.
  • Only two asbestosis and 16 mesothelioma cases did not have an occupational origin. This can be explained by the fact that most of the notifying physicians were members of the CSMPP.
  • Among cases with an occupational origin, a little more than half of the cases were exposed to insulating materials (38 %) and to dusts (15 %).
  • A little less than half of the cases were exposed in an unspecified activity sector. The other workers were mainly exposed in the mines, quarries and oil wells sectors, and in the buildings and public works sector. A little more than half of the cases were buildings and public works employees (39 %) and mine workers (13 %) (Source: Surveillance des maladies à déclaration obligatoire au Québec. Maladies d’origine chimique ou physique. Rapport des maladies et intoxications d’origine chimique déclarées au Québec de 2005 à 2010).
  • From 2006 to 2012, no new asbestos-related diseases were reported among mine workers of the Estrie region hired since 1975 (Source: Simard R. Unpublished data. Data from the MADO registry of the Estrie region. September 2012). In the Chaudière-Appalaches region, eight new cases involved workers hired since 1975 (Source: Bernier V, Deshaies P. Maladies de l’amiante dans la municipalité régionale de comté des Appalaches. Rapport d’analyse des enquêtes de maladie à déclaration obligatoire colligées entre 2006 et 2012 en réponse à une demande de journaliste. Agence de la santé et des services sociaux de Chaudière-Appalaches. Janvier 2013.