Results show that approximately 500 Canadians are exposed to nitrobenzene in their workplaces; 75% of these workers are male. Industries with the greatest numbers of exposed workers are basic chemical manufacturing, petroleum and coal products manufacturing, and paint, coating and adhesive manufacturing, where nitrobenzene may be used as a solvent or in the synthesis of various organic compounds.
When exposure is examined by occupation, the largest exposed groups are chemists (100 workers exposed), chemical plant operators (100 workers exposed), and gas and chemical process operators (100 workers exposed).
Data Sources & Methods
Data used in developing the occupational estimates for nitrobenzene were collected from several sources:
- Canadian and US scientific peer reviewed publications that addressed nitrobenzene exposure in Canada and the United States.
- Grey literature including technical reports from governments and international bodies.
Prevalence Estimate Method
CAREX defines exposure to nitrobenzene as inhalation exposure at work above levels encountered in the general environment.
To determine the number of workers potentially exposed to nitrobenzene 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 nitrobenzene.
- Occupations and industries at risk of possible exposure to nitrobenzene 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 nitrobenzene.