Results show that approximately 15,000 Canadians are exposed to chloroform in their workplaces; 49% of these workers are male. The largest exposed industries are "other amusement and recreation industries" (which includes workers at chlorinated swimming pools), "services to building and dwellings" (which includes specialized cleaners for swimming pools), and "sewage and other systems."
When exposure is examined by occupation, the largest exposed groups are program leaders and instructors in recreation, sport and fitness or lifeguards (11,000 exposed), specialized cleaners (900 exposed), chemical technologists and technicians (600 exposed) and water and waste plant operators (500 exposed).
Data Sources & Methods
Data used in developing the occupational estimates for chloroform were collected from several sources:
- The Canadian Workplace Exposure Database (CWED) contains less than 50 measurements for chloroform exposure. These measurements were collected during the years 1982 to 2001 in British Columbia workplaces.
- Canadian and US scientific peer reviewed publications that addressed chloroform exposure in Canada and the United States.
- Grey literature including technical reports from governments and international bodies.
Prevalence Estimate Method
CAREX defines exposure to chloroform as inhalation exposure at work to levels which significantly exceed ambient background levels.
To determine the number of workers potentially exposed to chloroform 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 chloroform.
- Occupations and industries at risk of possible exposure to chloroform 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 chloroform.