Results show that approximately 3,600 Canadians are exposed to 1,4-dioxane in their workplaces; 56% of these workers are male. The largest exposed industry groups are pharmaceutical and medicine manufacturing, followed by professional, scientific and technical services, public administration and basic chemical manufacturing.
When exposure is examined by occupation, the largest exposed group is chemical technologists and technicians (1,400 workers exposed), followed by chemists (900 workers exposed), chemical plant operators (400 workers exposed) and labourers in chemical products processing and utilities (200 workers exposed).
Data Sources & Methods
Data used in developing the occupational estimates for 1,4-dioxane were collected from several sources:
- The Canadian Workplace Exposure Database (CWED) contains over 300 measurements for 1,4-dioxane exposure. These measurements were collected during the years 1981 to 2004 in Ontario and British Columbia workplaces.
- Canadian and US scientific peer reviewed publications that addressed 1,4-dioxane exposure in Canada and the United States.
- Grey literature including technical reports from governments and international bodies.
Prevalence Estimate Method
CAREX defines exposure to 1,4-dioxane as inhalation and dermal contact at work to levels above those encountered in the general environment.
To determine the number of workers potentially exposed to 1,4-dioxane at work, CAREX occupational exposure experts used methods previously established in other peer-reviewed CAREX projects in Europe. A series of steps were taken to assign exposure proportions to occupations and industries at risk of exposure to 1,4-dioxane.
- Occupations and industries at risk of possible exposure to 1,4-dioxane were identified using any combination of data sources described above.
- The total number of workers in each identified occupation and industry intersection was obtained from Statistics Canada 2006 census data.
- A percentage of workers exposed was assigned to that occupation and industry intersection. Percentages were determined by consultation with existing evidence in the data sources, previously established methods from the Europe CAREX estimates and the expert judgement of CAREX occupational hygienists.
- The number of workers in the identified group is multiplied by the assigned percentage to calculate the prevalence estimate of workers exposed to 1,4-dioxane.