CANJEM

This Website presents a summary of the CANJEM occupational exposure information system.

CANJEM is a job exposure matrix, i.e. for a given occupation and time period, it provides information on the probability, frequency and intensity of exposure from a list of 258 occupational risk factors.

CANJEM was built from past individual expert evaluations of occupational exposures in a series of four case control studies of various cancers conducted since the mid-1980s up to 2010 in the greater Montreal area. During these studies over 30 000 jobs from 1920 to 2005 held by close to 10 000 subjects were evaluated by experts who assigned exposures based on descriptions of tasks, processes, work environment, and exposure control measures.

CANJEM provides information on work activities using standard classifications of occupation and industry. Versions of CANJEM based on occupation include the following systems: Canadian Classification and Dictionary of Occupations (CCDO 1971), National Occupational Classification (Canada, 2011), International Standard Classification of Occupations (ISCO 1968), and Standard Occupational Classification (USA, 2010). Versions of CANJEM based on industry include the following systems: Standard Industrial Classification (Canada, 1980), North American Industry Classification System (2012), and International Standard Industrial Classification of all Economic Activities (UN, 1968). Searching for specific codes from these classifications can be done on a sister website: www.caps-canada.ca.

The full CANJEM system is being finalized. This Website provides a snapshot of what will be available to potential users. For each of the 258 agents that will be present in CANJEM (click on the agent hierarchy on the left), this Website provides their basic definitions and descriptive statistics, as well as the top 5 occupations and industries regarding probability and intensity of exposure.

Interested users are encouraged to contact our group to develop collaborations.

In the full CANJEM, the following figures show an example of the additional information that will be provided for the occupation Motor vehicle mechanic during the period 1985-2005. Explanations for the CANJEM exposure metrics can be found here. Other sections below provide further information on the development of CANJEM.

The CANJEM system is currently being finalized. This website aims at informing users about the CANJEM project, as well as providing preliminary reports about the 258 agents included in CANJEM.

The list on the left of the screen is a hierarchical classification of the 258 agents according to their physic-chemical properties and uses. At the bottom of the hierarchy, categories in light green are actual CANJEM agents, and clicking on them provides preliminary information available in CANJEM.

The information includes the definition of the agent, the number of jobs in the CANJEM database that were deemed exposed to this agent by the experts as well as descriptive statistics of two simple JEMs including no time period and based either on the 4-digit Canadian Classification and Dictionary of Occupations (CCDO 1971), or on the Canadian Standard Industrial Classification (Canada, 1980).

For each classification, one table presents the top 5 categories with the highest probability of exposure (see definition), and another presents the top 5 categories with highest frequency weighted intensity of exposure (see definition).

The current and final CANJEM database contains 31673 jobs from 8760 subjects, covering the years from 1920 to 2005.

The table below present the top 20 agents in terms of number of jobs exposed.

Content

• Introduction
• Description of the Study populations that are the basis for CANJEM
• Description of the exposure assessment performed by our group
  • Outline of the expert assessment approach
  • Validity of the individual expert assessments
  • Example of exposure assessment for a job
• Development of CANJEM
  • CANJEM dimensions
  • CANJEM exposure metrics
  • Computing of exposure metrics within cells
• Availability
• References

Introduction

Since the mid 80s, our research group has performed several community-based case-control studies of cancer and occupation. Throughout these studies, occupational exposure to close to 300 chemicals was assessed for more than 30 000 individual jobs using an expert-based approach. This approach, based on the evaluation by industrial hygienists of tasks and work environment descriptions collected from interviews, has been regarded as the best, albeit most costly, exposure assessment method for this type of study. The exposure assessments performed during the course of our studies have contributed to a considerable extent to the current body of knowledge on the relationships between occupational exposures and cancer. We intend to further exploit our data by translating the extensive exposure database accumulated into a job-exposure matrix, called CANJEM, that is useable outside the scope of our studies, by other epidemiologists or public health specialists in Canada and internationally.

Description of the Study populations that are the basis for CANJEM

The first Montreal cancer case-control study, hereafter referred to as the Multisite study, is a study of male Canadian citizens aged 35-70 years, living in Montreal during 1979-1985. Cancer cases were ascertained from the 18 largest hospitals in the Montreal metropolitan area, while population-based controls were selected from population based electoral lists and a small group through random-digit dialling. Over 20 cancer sites were considered eligible for recruitment.

The second Montreal study, hereafter referred to as the Lung study, was undertaken from 1996 to 2004 and was also a population-based case-control study aiming to elucidate occupational and non-occupational risk factors for cancer. By contrast with the Multisite study, it focused on lung cancer only and included both men and women aged 35-75 years. In this study, there were 1205 cases and 1541 population controls interviewed.

The third Montreal study involved in this project is hereafter referred to as the Brain cancer study. In 2000, the International Agency for Research on Cancer (IARC) undertook to coordinate an international epidemiologic study of the possible relationship between the use of cellular telephones and brain cancer (INTERPHONE study). That study involved 20 centers located in 13 different countries, including Canada. The Canadian branch of that study included three centers: Ottawa, Montreal and Vancouver. The Ottawa and Montreal sections, managed by our group, involved the implementation of our exposure assessment approach. 218 cases, men and women aged 30-59 of glioma, meningioma, acoustic neurinoma or malignant parotid gland tumours, and 414 controls were successfully interviewed.

The fourth study was a hospital-based breast cancer case-control study. Cases were recruited between 1996 and 1997 and were aged between 50 and 75 years. Controls were subjects newly diagnosed of cancer (32 different sites), frequency matched by age and selected in the same hospitals and during the same period than cases. 1,069 women were included in this study.

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Description of the exposure assessment performed by our group

Outline of the expert assessment approach

We present here a succinct outline of the exposure assessment method used in the three studies along with basic descriptive statistics of the data generated. The reader is referred to Siemiatycki [1] or Gérin [2] for additional details, including the list of substances and examples of job-specific questionnaires. For each consenting subject, interview included a semi-structured section eliciting a detailed description of each job held by the subject in his working lifetime. For each job held, a trained interviewer asked the subject about the company, its products, the nature of the worksite, the subject’s main and subsidiary tasks, and any additional information (e.g., equipment maintenance, use of protective equipment, activities of coworkers) that could provide clues about work exposures and their intensity. Occupations and industries were coded, respectively, according to the 1971 Canadian Classification and Dictionary of Occupations and the 1970 and 1980 versions of the Standard Industry Classification. For some occupations, supplementary questionnaires were used to assist interviewers with detailed technical probing. A team of chemists and industrial hygienists examined each completed questionnaire and translated each job into a list of potential exposures using a checklist of ~300 agents. This list was originally devised to include substances prevalent in the workplace and for which scientific and technical literature was available. The agents include specific chemicals (e.g. benzene), chemical groups or functions (e.g. aromatic amines), mixtures of relatively fixed composition (e.g. gasoline) or variable composition (e.g. paints), complex materials (e.g. cement), as well as general categories (e.g. solvents). They are classified into categories according to their usual physical state: dusts, gases, fumes and smoke, and liquids and their vapors. The sources of information available to the hygienists included scientific and technical literature, trade directories, contact with experts and consultants from the industry or the occupational health and safety network, as well as worksite visits.

When taking together all studies, the team of coders spent 50 person-years on the exposure assessment, including helping to develop the methodology, monitoring the quality of the interviewing, conducting background research on exposures in different occupations, coding the individual participants’ files, and recoding after the initial complete round of coding was finished. The final exposure codes attributed to a participant were based on consensus among the coders. Coders were blind with regard to the subject’s disease status. For each substance considered present in each job, the coders noted three dimensions of information, their degree of confidence (‘reliability’) that the exposure had actually occurred (possible, probable, definite), the frequency of exposure in a normal workweek (<5%, 5% to 30%, >30% of the time for the Multisite study, and a percentage value for the Lung, Brain and Breast studies), and the relative level of concentration of the agent (low, medium, high). Concentration levels were established with reference to certain benchmark occupations in which the substance is found. Specifically, we identified some hypothetical workplace situations a priori which would correspond to low, medium and high exposure for each substance, and the experts rated each real job against these benchmarks. As an illustration, examples of settings for crystalline silica would include: low concentration - mining and brickworks; medium concentration - foundries, concrete work and masonry; high concentration - sandblasting and pottery works. The exposure assessment was based not only on the worker’s occupation and industry, but also on individual characteristics of the workplace and tasks as reported by the subject. Non-exposure was interpreted as exposure up to the level that can be found in the general, non-occupational environment.

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Validity of the individual expert assessments

The expert assessment method used in our studies is considered to be the best available method of retrospectively assessing occupational exposures in community-based studies [3,4]. Moreover, the few assessments of reliability and validity [5-7] have been encouraging. Weighted kappa for repeatability has been reported as high as 80% when the raters worked as a panel and around 70% when they worked independently [7]. Intra-rater reliability in the same study was also around 70%. Finally, Fritschi et al. reported a validation study where the Montreal experts assessed exposure to 19 substances for 47 jobs for which some measurements were available [8]. They found that the experts were able to correctly identify between 70% and 90% of the substances known to have been present. This study is the closest to external validation performed to date on the Montreal expert data.

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Example of exposure assessment for a job

The following example is of a job of working on the production line from 1952 to 1953 at an appliance facility.

The occupation coded in CCDO 1971 was ‘electrical appliance set-up man’ (electrical equipment).

The industry, coded in Canadian SIC 1980 was ‘Major appliance industry’

The following are the notes from the interviewer for that job, loosely translated from French :

Big plant (occupied a whole city block) ~ 100 guys on the production line Subject was adding the main control and ‘butter compartment’ Subject used only drill and air powered screwdrivers, no visible dust Did not use oil, grease or any other chemical

Following these descriptions, the experts assigned the following exposures:

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Development of CANJEM

CANJEM is the synthesis of the expert evaluation of ~30 000 jobs held by subjects of the 4 studies described above. For each job, a decision was made on the presence, frequency and intensity of exposure to ~300 agents. This sums up almost to 10 M decisions.

It was decided the best way to implement this synthesis in order to share this information with others was to create a series of job exposure matrices (JEMs). A JEM can be viewed as a tool linking a particular exposure situation to exposure estimates. The exposure situation can be described by one or several axes. The simplest kind of JEM may have 2 axes: occupation and agent. For each combination of values of the axes describing an exposure situation (e.g. welder and lead fumes), the JEM will provide exposure estimates (e.g. in the crudest form: exposed or not exposed). There can be more than 2 axes for a JEM; for instance exposures are known to change over time, and time period can form an additional JEM axis. A particular combination of values of the JEM dimensions, or axes, is called a JEM cell. Each JEM cell corresponds to a particular exposure situation, and thus has its own exposure estimates. Depending on the type of information, exposure estimates provided by a JEM can take several forms; e.g. from simple exposed/not exposed dichotomy to a quantitative exposure level in concentration unit.

The sections below summarize the dimensions of the CANJEM system, the exposure metrics derived for each cell of the JEM, and the statistical approach used to compute these metrics.

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CANJEM dimensions

The first dimension of CANJEM is ‘risk factor’. The initial list of occupational risk factors in the Multisite study included 294 agents. This list was updated during the following studies. Some agents were added while some were eliminated. CANJEM includes 258 agents that were coded in all studies and which could be pooled across the studies.

The second dimension of CANJEM is ‘activity’, i.e. which tasks were performed by the worker within which industrial environment. CANJEM is available either as occupation based or industry based, i.e. the activity is defined by the worker’s occupation, or by the industry in which it was performed. In order to facilitate linking CANJEM to other systems, occupation in CANJEM is described using 4 different standard classification systems: Canadian Classification and Dictionary of Occupations (CCDO 1971), National Occupational Classification (Canada, 2011), International Standard Classification of Occupations (ISCO 1968), and Standard Occupational Classification (USA, 2010). In a similar manner, industry is described in 3 different standard classification systems: Standard Industrial Classification (Canada, 1980), North American Industry Classification System (2012), and International Standard Industrial Classification of all Economic Activities (UN, 1968). CANJEM versions exist with the ‘activity’ axis being any of these 7 standard classifications.

The third dimension of CANJEM is time. In order to provide flexibility to users, and since splitting the data into separate time periods can impact the number of occupations or industry with sufficient information, CANJEM will be available based on 3 different time period classifications : no time period (1920-2005), 2 time periods (1920-1969 and 1970-2005), and 4 time periods (1920-1949, 1950-1969, 1970-1984 and 1985-2005).

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CANJEM exposure metrics

For each cell, several exposure metrics were calculated:

Probability of exposure was measured as the proportion of jobs coded as being exposed within a cell, i.e. if the exposure occurred for a minimum of 2 h/week at a low exposure level or higher.

Distribution of Exposure intensity across individual exposed jobs; 3 proportions for low, medium and high summing to 100% are provided

Distribution of Exposure assignment reliability across individual exposed jobs; 3 proportions for low, medium and high summing to 100% are provided

Distribution of Exposure frequency across individual exposed jobs; 4 proportions for [0-2h], ]2h-12h], ]12h-39h] and >40h per week, summing to 100%, are provided

To facilitate quantification of exposure in the cells of the JEMs, we created an index that combines the intensity averaged over a 40-hour workweek, referred to as frequency-weighted intensity (FWI; i.e. FWI = exposure intensity*frequency of exposure in hours worked per week/40 hours). To operationalise this computation, we attributed numerical values to the three exposure intensity values from the expert assessment (i.e. low, medium, high). The experts considered that medium and high levels corresponded approximately to relative absolute values of 5 times and 25 times the low level. This varied from agent to agent, but these weights (i.e. 1, 5, 25) were thought to represent the best overall estimate of the ratios for the three intensity categories across agents. Intensity of exposure for a JEM cell was defined as the median FWI across all exposed jobs within a cell.

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Computing of exposure metrics within cells

The metrics described above were computed using Bayesian hierarchical models, using the hierarchy of the occupation/industry classifications, to draw information from similar groups in order to improve estimates for cells with few observations. This framework was also used to provide measures of uncertainty around the estimates reported in the cell, as well as to adjust for potential differences in exposure assessment between the studies from which CANJEM was built upon.

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Availability

CANJEM will be available for free from the Web to allow users to find information on specific occupations, industry or chemicals in the form of summary reports or cell by cell.

Regarding bulk access to the various CANJEM matrices, since it was funded by Canadian institutions, the aim of our group is to provide access to Canadian research teams for minimal fees depending on the amount of work involved for our group. For other research teams, financial participation would depend on each particular situation. Any collected money this money will serve to help maintain and refine CANJEM, and to provide technical and scientific support to users.

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References

1. Siemiatycki J. Exposure assessment in community-based studies of occupational cancer. Occup Hyg 1996;3:41-58.http://www.csa.com/partners/viewrecord.php?requester=gs&collection=ENV&recid=3913624 (accessed 9 Feb2011).
2. Gérin M. Recent approaches to retrospective exposure assessment in occupational cancer epidemiology. Recent Results Cancer Res 1985;120:39-49.
3. Teschke K, Olshan AF, Daniels JL, et al. Occupational exposure assessment in case-control studies: opportunities for improvement. Occup Environ Med 2002;59:575-93; discussion 594.http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1740358&tool=pmcentrez&rendertype=abstract (accessed 29 Jun2011).
4. McGuire V, Nelson LM, Koepsell TD, et al. Assessment of occupational exposures in community-based case-control studies. Annu Rev Public Health 1998;19:35-53. doi:10.1146/annurev.publhealth.19.1.35
5. Goldberg MS, Siemiatycki J, Gérin M. Inter-rater agreement in assessing occupational exposure in a case-control study. Br J Ind Med 1986;43:667-76.
6. Benke G, Sim M, Forbes L, et al. Retrospective assessment of occupational exposure to chemicals in community-based studies: validity and repeatability of industrial hygiene panel ratings. Int J Epidemiol 1997;26:635-42.
7. Siemiatycki J, Fritschi L, Nadon L, et al. Reliability of an expert rating procedure for retrospective assessment of occupational exposures in community-based case-control studies. Am J Ind Med 1997;31:280-6.http://www.ncbi.nlm.nih.gov/pubmed/9055950
8. Fritschi L, Nadon L, Benke G, et al. Validation of expert assessment of occupational exposures. Am J Ind Med 2003;43:519-22.

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Acknowledgments

Lesley Richardson contributed to the design of the studies, and the development and coordination of the data collection methods. Exposure assessment methods were expertly developed and implemented by Michel Gérin, Louise Nadon, Ramzan Lakhani, Denis Bégin, and Benoit Latreille. The studies would not have been possible without the able participation of a large number of research assistants and interviewers, including Marie-Claire Goulet, Jerome Asselin, and Sally Campbell. Dora Rodriguez and Elmira Aliyeva, were responsible for the work on verifying the coding of cross-walks, while Ana Gueorguieva in conjunction with Mendher Merzoug prepared the databases and analyses required in the preparation of the final matrix.

Grant Support

The actual development of the CANJEM was funded by the Société de recherche sur le cancer (SRC) through the GrePEC initiative. The original studies were funded by a number of agencies, including the National Health Research and Development Programme, Health Canada, the National Cancer Institute of Canada, the Medical Research Council of Canada, the Canadian Institutes for Health Research and the National Institutes of Health (NIH). JS was the recipient of a Canada Research Chair and holds the Guzzo-SRC Research Chair in Environment and Cancer. Dr Parent had a salary award from the Fonds de la recherche en santé du Québec.

Definition of the agent

Abrasives dust

Dust generated from abrasives during the manufacturing of abrasives or during abrading, smoothing, or polishing of metals, wood, stones, concrete, jewelry, etc. The abrasive could be of a single composition such as silica, or aggregate material containing alumina or silicon carbide, with binders such as vitrified glass, resins or rubber.

In the current CANJEM database, 1365 jobs are exposed at low concentration, 1220 at medium, and 311 at high, for a total of 9.1 percent exposed.

JEM based on occupation (4-digit CCDO 1971)

The matrix based on occupation contains 361 cells, covering 98 percent of the CANJEM population. 176 cells have a non null probability of exposure, with 71 lower than 5% and 105 greater than 5%. The median and range of probability values among cells with >5% probability is 20% [5.1-96].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 occupations with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 occupations with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week

JEM based on industry (Canadian SIC 1980)

The matrix based on industry contains 495 cells, covering 96 percent of the CANJEM population. 305 cells have a non null probability of exposure, with 100 lower than 5% and 205 greater than 5%. The median and range of probability values among cells with >5% probability is 12% [5-87].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 industries with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 industries with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week.

Definition of the agent

Cristalline silica

The crystalline forms of free silica are quartz, cristobalite and tridymite. Many sands, clays and rocks are largely composed of small silica crystals; exposure to silica occurred mainly because of sand used in construction, in sand blasting, in foundry molds, clay, glass and stone processing, pottery and brick making. Exposure also occurred to workers involved in mining, quarrying, and rock and soil drilling.

In the current CANJEM database, 1646 jobs are exposed at low concentration, 705 at medium, and 156 at high, for a total of 7.9 percent exposed.

JEM based on occupation (4-digit CCDO 1971)

The matrix based on occupation contains 361 cells, covering 98 percent of the CANJEM population. 182 cells have a non null probability of exposure, with 74 lower than 5% and 108 greater than 5%. The median and range of probability values among cells with >5% probability is 18% [5-100].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 occupations with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 occupations with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week

JEM based on industry (Canadian SIC 1980)

The matrix based on industry contains 495 cells, covering 96 percent of the CANJEM population. 248 cells have a non null probability of exposure, with 82 lower than 5% and 166 greater than 5%. The median and range of probability values among cells with >5% probability is 14% [5-94].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 industries with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 industries with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week.

Definition of the agent

Alumina

Oxide of aluminium, Al2O3 and its various polymorphs and hydrated species. Corundum (both natural and synthetic), the crystalline form of alumina, has been widely used as an abrasive while the trihydrate is used as an extender pigment in paints, plastics, cosmetics, etc.

In the current CANJEM database, 1308 jobs are exposed at low concentration, 315 at medium, and 24 at high, for a total of 5.2 percent exposed.

JEM based on occupation (4-digit CCDO 1971)

The matrix based on occupation contains 361 cells, covering 98 percent of the CANJEM population. 134 cells have a non null probability of exposure, with 54 lower than 5% and 80 greater than 5%. The median and range of probability values among cells with >5% probability is 17% [5.3-72].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 occupations with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 occupations with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week

JEM based on industry (Canadian SIC 1980)

The matrix based on industry contains 495 cells, covering 96 percent of the CANJEM population. 223 cells have a non null probability of exposure, with 85 lower than 5% and 138 greater than 5%. The median and range of probability values among cells with >5% probability is 12% [5-83].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 industries with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 industries with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week.

Definition of the agent

Silicon carbide

A bluish-black, crystalline, artificial mineral characterized by extreme hardness, a high melting point and chemical inertness. It has been used mainly as an abrasive in the form of granules or powder for shaping, cleaning or polishing surfaces. Other applications include refractories and wear-resistant surfaces.

In the current CANJEM database, 623 jobs are exposed at low concentration, 187 at medium, and 6 at high, for a total of 2.6 percent exposed.

JEM based on occupation (4-digit CCDO 1971)

The matrix based on occupation contains 361 cells, covering 98 percent of the CANJEM population. 98 cells have a non null probability of exposure, with 44 lower than 5% and 54 greater than 5%. The median and range of probability values among cells with >5% probability is 11% [5-57].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 occupations with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 occupations with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week

JEM based on industry (Canadian SIC 1980)

The matrix based on industry contains 495 cells, covering 96 percent of the CANJEM population. 161 cells have a non null probability of exposure, with 71 lower than 5% and 90 greater than 5%. The median and range of probability values among cells with >5% probability is 10% [5-50].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 industries with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 industries with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week.

Definition of the agent

Inorganic insulation dust

Dust arising from the placement or removal of any inorganic heat insulating materials including asbestos (chrysotile or amphibole), mineral wool, glass fibers and vermiculite/perlite.

In the current CANJEM database, 672 jobs are exposed at low concentration, 564 at medium, and 21 at high, for a total of 4 percent exposed.

JEM based on occupation (4-digit CCDO 1971)

The matrix based on occupation contains 361 cells, covering 98 percent of the CANJEM population. 117 cells have a non null probability of exposure, with 65 lower than 5% and 52 greater than 5%. The median and range of probability values among cells with >5% probability is 15% [5-92].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 occupations with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 occupations with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week

JEM based on industry (Canadian SIC 1980)

The matrix based on industry contains 495 cells, covering 96 percent of the CANJEM population. 193 cells have a non null probability of exposure, with 109 lower than 5% and 84 greater than 5%. The median and range of probability values among cells with >5% probability is 11% [5-86].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 industries with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 industries with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week.

Definition of the agent

Chrysotile asbestos

Naturally occuring fibrous hydrated silicates. Asbestos fibers can be divided on the basis of mineralogical features into two groups: serpentines and amphiboles. Chrysotile fibres are curly serpentine fibers made up of tiny individual fibrils which take the shape of a spirally wound tube. Chrysotile asbestos is the type most used for textiles, friction materials (e.g. brake and clutch linings) and floor tiles.

In the current CANJEM database, 1329 jobs are exposed at low concentration, 606 at medium, and 58 at high, for a total of 6.3 percent exposed.

JEM based on occupation (4-digit CCDO 1971)

The matrix based on occupation contains 361 cells, covering 98 percent of the CANJEM population. 171 cells have a non null probability of exposure, with 73 lower than 5% and 98 greater than 5%. The median and range of probability values among cells with >5% probability is 15% [5.1-93].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 occupations with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 occupations with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week

JEM based on industry (Canadian SIC 1980)

The matrix based on industry contains 495 cells, covering 96 percent of the CANJEM population. 260 cells have a non null probability of exposure, with 94 lower than 5% and 166 greater than 5%. The median and range of probability values among cells with >5% probability is 12% [5-85].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 industries with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 industries with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week.

Definition of the agent

Amphibole asbestos

Naturally occuring fibrous hydrated silicates. Asbestos fibers can be divided on the basis of mineralogical features into two groups: serpentines and amphiboles. The amphibole fibers are straight and needle-like silicate structures generally more brittle than chrysotile asbestos fibers.

In the current CANJEM database, 526 jobs are exposed at low concentration, 245 at medium, and 22 at high, for a total of 2.5 percent exposed.

JEM based on occupation (4-digit CCDO 1971)

The matrix based on occupation contains 361 cells, covering 98 percent of the CANJEM population. 100 cells have a non null probability of exposure, with 44 lower than 5% and 56 greater than 5%. The median and range of probability values among cells with >5% probability is 12% [5-91].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 occupations with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 occupations with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week

JEM based on industry (Canadian SIC 1980)

The matrix based on industry contains 495 cells, covering 96 percent of the CANJEM population. 169 cells have a non null probability of exposure, with 93 lower than 5% and 76 greater than 5%. The median and range of probability values among cells with >5% probability is 8.8% [5-79].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 industries with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 industries with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week.

Definition of the agent

Glass fibres

Manufactured from the raw ingredients of glass but with processes designed to create fibrous material. These filament fibers have been used mainly as insulators, as plastic reinforcing materials and in special textiles.

In the current CANJEM database, 322 jobs are exposed at low concentration, 256 at medium, and 8 at high, for a total of 1.9 percent exposed.

JEM based on occupation (4-digit CCDO 1971)

The matrix based on occupation contains 361 cells, covering 98 percent of the CANJEM population. 80 cells have a non null probability of exposure, with 50 lower than 5% and 30 greater than 5%. The median and range of probability values among cells with >5% probability is 11% [5-60].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 occupations with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 occupations with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week

JEM based on industry (Canadian SIC 1980)

The matrix based on industry contains 495 cells, covering 96 percent of the CANJEM population. 102 cells have a non null probability of exposure, with 60 lower than 5% and 42 greater than 5%. The median and range of probability values among cells with >5% probability is 9.8% [5-67].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 industries with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 industries with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week.

Definition of the agent

Mineral wool fibers

Mineral wool is a glassy fibrous silicate material made by melting and fiberizing slags (slag wool) or natural rocks (rock wool). Mineral wool has been used since the 1930s, mainly as a thermal and acoustical insulator.

In the current CANJEM database, 370 jobs are exposed at low concentration, 323 at medium, and 1 at high, for a total of 2.2 percent exposed.

JEM based on occupation (4-digit CCDO 1971)

The matrix based on occupation contains 361 cells, covering 98 percent of the CANJEM population. 70 cells have a non null probability of exposure, with 38 lower than 5% and 32 greater than 5%. The median and range of probability values among cells with >5% probability is 12% [5-65].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 occupations with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 occupations with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week

JEM based on industry (Canadian SIC 1980)

The matrix based on industry contains 495 cells, covering 96 percent of the CANJEM population. 108 cells have a non null probability of exposure, with 67 lower than 5% and 41 greater than 5%. The median and range of probability values among cells with >5% probability is 11% [5-68].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 industries with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 industries with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week.

Definition of the agent

Metallic dust

Any metal dusts generated, regardless of the specific metals involved or whether they are known or unknown. Most metals will have undergone a certain amount of surface oxidation but exposure to specific metal oxides (e.g., lead oxides; iron oxides) was coded only when the main exposure was to the oxide itself and not to the metal dust.

In the current CANJEM database, 1934 jobs are exposed at low concentration, 1364 at medium, and 216 at high, for a total of 11 percent exposed.

JEM based on occupation (4-digit CCDO 1971)

The matrix based on occupation contains 361 cells, covering 98 percent of the CANJEM population. 187 cells have a non null probability of exposure, with 59 lower than 5% and 128 greater than 5%. The median and range of probability values among cells with >5% probability is 23% [5-100].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 occupations with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 occupations with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week

JEM based on industry (Canadian SIC 1980)

The matrix based on industry contains 495 cells, covering 96 percent of the CANJEM population. 279 cells have a non null probability of exposure, with 73 lower than 5% and 206 greater than 5%. The median and range of probability values among cells with >5% probability is 15% [5-93].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 industries with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 industries with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week.

Definition of the agent

Bronze dust

Dust generated when objects made of bronze are cut, abraded, machined, polished, etc. The term bronze is generally applied to any copper alloy where tin is the other major alloying element, although small amounts of other elements are added to modify the characteristics of the bronzes. The product obtained by adding tin to copper is more fusible than copper and thus better suited for casting.

In the current CANJEM database, 46 jobs are exposed at low concentration, 85 at medium, and 12 at high, for a total of 0.45 percent exposed.

JEM based on occupation (4-digit CCDO 1971)

The matrix based on occupation contains 361 cells, covering 98 percent of the CANJEM population. 42 cells have a non null probability of exposure, with 28 lower than 5% and 14 greater than 5%. The median and range of probability values among cells with >5% probability is 7.7% [5-24].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 occupations with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 occupations with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week

JEM based on industry (Canadian SIC 1980)

The matrix based on industry contains 495 cells, covering 96 percent of the CANJEM population. 63 cells have a non null probability of exposure, with 44 lower than 5% and 19 greater than 5%. The median and range of probability values among cells with >5% probability is 6.7% [5.3-24].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 industries with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 industries with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week.

Definition of the agent

Brass dust

Dust generated when objects made of brass are cut, abraded, machined, polished, etc. Brasses are the most widely used alloys of copper. They are fundamentally binary alloys of copper with zinc but often their properties are modified by addition of other elements in small amounts. Brasses are stronger than copper and are used in structural applications. Uses include bullet jackets, imitation gold jewelry, plumbing hardware, pipes, radiator cases and condenser tubing.

In the current CANJEM database, 76 jobs are exposed at low concentration, 102 at medium, and 18 at high, for a total of 0.62 percent exposed.

JEM based on occupation (4-digit CCDO 1971)

The matrix based on occupation contains 361 cells, covering 98 percent of the CANJEM population. 52 cells have a non null probability of exposure, with 34 lower than 5% and 18 greater than 5%. The median and range of probability values among cells with >5% probability is 8% [5-18].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 occupations with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 occupations with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week

JEM based on industry (Canadian SIC 1980)

The matrix based on industry contains 495 cells, covering 96 percent of the CANJEM population. 67 cells have a non null probability of exposure, with 41 lower than 5% and 26 greater than 5%. The median and range of probability values among cells with >5% probability is 11% [5.3-33].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 industries with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 industries with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week.

Definition of the agent

Stainless steel dust

Dust generated when objects made of this metal are cut, abraded, machined, polished, etc. Stainless steel is available in many different compositions but the most common one, usually known as 18-8 stainless steel, is 18% chromium and 8% nickel. Many other elements such as titanium, molybdenum, niobium, silicon and others are also added in small quantities to customize the steel for special purposes.

In the current CANJEM database, 237 jobs are exposed at low concentration, 288 at medium, and 35 at high, for a total of 1.8 percent exposed.

JEM based on occupation (4-digit CCDO 1971)

The matrix based on occupation contains 361 cells, covering 98 percent of the CANJEM population. 86 cells have a non null probability of exposure, with 49 lower than 5% and 37 greater than 5%. The median and range of probability values among cells with >5% probability is 15% [5-52].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 occupations with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 occupations with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week

JEM based on industry (Canadian SIC 1980)

The matrix based on industry contains 495 cells, covering 96 percent of the CANJEM population. 128 cells have a non null probability of exposure, with 60 lower than 5% and 68 greater than 5%. The median and range of probability values among cells with >5% probability is 11% [5-47].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 industries with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 industries with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week.

Definition of the agent

Mild steel dust

Dust generated when objects made of this metal are cut, abraded, machined, polished, etc. Mild steel is essentially a combination of iron and carbon (less than 2% carbon). All steels contain manganese (usually at least 0.3%) and small amounts of other metals, which provide the strength and hardness that is required by the construction and manufacturing industries.

In the current CANJEM database, 1153 jobs are exposed at low concentration, 894 at medium, and 93 at high, for a total of 6.8 percent exposed.

JEM based on occupation (4-digit CCDO 1971)

The matrix based on occupation contains 361 cells, covering 98 percent of the CANJEM population. 145 cells have a non null probability of exposure, with 58 lower than 5% and 87 greater than 5%. The median and range of probability values among cells with >5% probability is 20% [5-80].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 occupations with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 occupations with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week

JEM based on industry (Canadian SIC 1980)

The matrix based on industry contains 495 cells, covering 96 percent of the CANJEM population. 236 cells have a non null probability of exposure, with 84 lower than 5% and 152 greater than 5%. The median and range of probability values among cells with >5% probability is 12% [5-79].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 industries with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 industries with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week.

Definition of the agent

Inorganic pigments

Insoluble white or colored powders of very fine particle size (0.01 to 1.0 microns) which imparts color and/or other properties (e.g. anti-corrosive properties) to other materials either when mixed intimately with them (dispersion or suspension) or when applied over their surfaces in a thin layer. Inorganic pigments can be subdivided into white (which includes titanium dioxide) , and other colors (iron oxides, lead chromate, etc.) both of which can be of natural or synthetic origin. Organic pigments were coded separately.

In the current CANJEM database, 817 jobs are exposed at low concentration, 209 at medium, and 33 at high, for a total of 3.3 percent exposed.

JEM based on occupation (4-digit CCDO 1971)

The matrix based on occupation contains 361 cells, covering 98 percent of the CANJEM population. 160 cells have a non null probability of exposure, with 95 lower than 5% and 65 greater than 5%. The median and range of probability values among cells with >5% probability is 10% [5-72].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 occupations with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 occupations with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week

JEM based on industry (Canadian SIC 1980)

The matrix based on industry contains 495 cells, covering 96 percent of the CANJEM population. 206 cells have a non null probability of exposure, with 109 lower than 5% and 97 greater than 5%. The median and range of probability values among cells with >5% probability is 8.9% [5-87].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 industries with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 industries with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week.

Definition of the agent

Titanium dioxide

This extremely dense, powerful opaque white inorganic pigment has great hiding power. It is absolutely inert and therefore permanent. The best quality is produced from ilmenite. It has been used as a pigment in paints, paper, plastics, floor coverings, inks, rubber, ceramics, roofing granules, textiles and as a fluxing agent in welding electrodes.

In the current CANJEM database, 247 jobs are exposed at low concentration, 55 at medium, and 7 at high, for a total of 0.98 percent exposed.

JEM based on occupation (4-digit CCDO 1971)

The matrix based on occupation contains 361 cells, covering 98 percent of the CANJEM population. 60 cells have a non null probability of exposure, with 42 lower than 5% and 18 greater than 5%. The median and range of probability values among cells with >5% probability is 11% [5.3-46].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 occupations with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 occupations with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week

JEM based on industry (Canadian SIC 1980)

The matrix based on industry contains 495 cells, covering 96 percent of the CANJEM population. 78 cells have a non null probability of exposure, with 54 lower than 5% and 24 greater than 5%. The median and range of probability values among cells with >5% probability is 8.8% [5.1-62].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 industries with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 industries with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week.

Definition of the agent

Iron oxides

All oxides of iron (e.g., Fe3O4, Fe2O3, FeO.Fe2O3). The most important uses of these compounds have been in pigments for plastics, leather, bricks, textiles, paper and concrete products. Exposure to iron oxides is widespread; this also includes exposure to rust.

In the current CANJEM database, 551 jobs are exposed at low concentration, 371 at medium, and 44 at high, for a total of 3 percent exposed.

JEM based on occupation (4-digit CCDO 1971)

The matrix based on occupation contains 361 cells, covering 98 percent of the CANJEM population. 115 cells have a non null probability of exposure, with 55 lower than 5% and 60 greater than 5%. The median and range of probability values among cells with >5% probability is 14% [5.1-45].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 occupations with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 occupations with the highest intensity of exposure (FWI)

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median FWI is the median frequency weighted intensity,Median.frequency is the median number of hours exposed per week

JEM based on industry (Canadian SIC 1980)

The matrix based on industry contains 495 cells, covering 96 percent of the CANJEM population. 159 cells have a non null probability of exposure, with 62 lower than 5% and 97 greater than 5%. The median and range of probability values among cells with >5% probability is 10% [5.3-75].

The following tables present the 5 top occupations with the highest probability of exposure and weighted intensity of exposure, respectively.

Top 5 industries with the highest probability of exposure

ntot is the number of jobs in the cell, nsub the number of subjects, nexp is the number of individual jobs exposed, nexp.s is the number of sibjects exposed, p is probability of exposure in %, p.C1 the proportion of jobs with low concentration, p.C2 the proportion of jobs with medium concentration,p.C3 the proportion of jobs with high concentration, Median.frequency is the median number of hours exposed per week

Top 5 industries with the highest intensity of exposure (FWI)