Diesel exhaust exposure in Ontario fire halls

Firefighters are at risk of exposure to many different carcinogens when firefighting and studies have found an increased risk of cancer. However, they spend a small percentage of their time actively fighting fires and more time at the fire hall.  This suggests that there may be other hazards contributing to the increased cancer risk such as shift work, stress, and diesel engine exhaust from firetrucks or other diesel equipment operating within the hall. Diesel engine exhaust has been classified as a definite human carcinogen (Group 1) by the International Agency for Research on Cancer (IARC).

This project consisted of multiple parts:

• Stationary 24-hour area air samples were collected to measure levels of diesel particulate matter in the vehicle bays, common areas and living quarters of fire halls.
• Through structured interviews with firefighters, work histories and the amount of time firefighters spend in the fire halls were assessed. Diesel exhaust exposure policies were also collected and reviewed.
• Determinants of exposure such as fire hall design, number of diesel engine apparatus present in the vehicle bay within the hall, and types of ventilation present in the vehicle bay were assessed.
• The volumetric flowrate of local exhaust ventilation at each fire hall was assessed and compared to the recommended ventilation flowrate.

A total of 69 air samples were taken in 12 fire halls from six fire services departments in Ontario. The samples were analyzed for elemental carbon (a marker for diesel engine exhaust). Of these samples, 11 (16%) had detectable elemental carbon concentrations, ranging from 0.6 to 2.7 μg/m³. Ten of the 11 samples with detectable levels of elemental carbon were taken in the vehicle bays. Assessment of local exhaust ventilation (LEV) revealed that LEV units were operating at an average of 54% of the recommended flowrate.

Because there is no occupational exposure limit that applies to diesel exhaust exposure levels in fire halls with which to compare the measured levels to, it is recommended that fire departments continue minimizing exposure within the fire halls using a combination of engineering and administrative controls, including a consistent maintenance schedule for LEV units.

For complete results, click here to read the study report (2017).

This project was funded by the Ontario Ministry of Labour.