In June 2012, the International Agency for Research on Cancer (IARC), an arm of the World Health Organisation, reclassified diesel engine exhaust to be a Group 1 agent – substances that are carcinogenic to humans. Prior to this, diesel particulate matter (DPM) had been classified as ‘probably carcinogenic’.
The change in classification is based on the IARC working group’s conclusions that there is sufficient evidence to link exposure to diesel exhaust to an increased risk of lung cancer.
By using personal monitors to measure DPM exposures, operations can understand the risk profile of their workers. CMTS is NATA-accredited for the sampling and analysis of DPM (NIOSH 5040 method).
Underground mining risks
As most mines use diesel vehicles and equipment, workers may be potentially exposed to diesel exhaust fumes in areas such as:
- underground parts of a mine
- where multiple vehicles are used in a single air split
- confined areas
- enclosed environments
- where ventilation is limited or where there is mechanical ventilation
- areas identified by the mine or risk assessment
It can be understood that risk potentially exists whenever workers are in an environment where diesel powered equipment operates.
Under the NSW Work Health and Safety (WHS) Act 2011, mine operators must ensure the health and safety of their workers. As part of the WHS Regulations, air monitoring must be conducted to detect airborne contaminant levels in the workplace.
In addition, the CMHS Regulation sets out limits for workplace and diesel exhaust monitoring, and requires exposure to be minimised to as low as reasonably practicable.
Recommended exposure standards
Mine Design Guideline 29 (MDG 29), ‘Management of Diesel Engine Pollutants in Underground Environments’, recommends that workers should not be exposed to levels of DPM – in the form of Elemental Carbon (EC) at greater than 0.1mg/m3.
What should mining operations do?
- All mines should have a documented strategy to control diesel emissions as part of their mine health and safety management system (a Diesel Emissions Plan).
- Follow the hierarchy of risk control: eliminate; isolate; engineering controls; administrate.
- Aim to minimise diesel emissions to the lowest level reasonably practicable (recommended maximum workplace exposure of 0.1mg/m3 E.C.).
- Implement a program for regularly testing all areas and tasks of potential risk.
Recommendations to minimise risks
As with all airborne contaminants, the best method of reducing exposures is to follow the hierarchy of risk controls and aim to eliminate exposures, or as a minimum, reduce exposure following this principle.
Some practical examples of controls include:
- maintain or enhance ventilation quantities and qualities
- limit use of diesel powered equipment in ventilation districts
- review operator standing positions in relation to exhaust
- correct use of diesel powered machines
- have machines serviced regularly and to well defined standards
- compliance with OEMs specifications and approvals
- ‘Tag Board’ compliance
- operators’ understanding of machine limitations and their need to ensure correct on-road servicing, as well as road condition management.
How CMTS-Occupational Hygiene can help
We have the ability and expertise to measure workers’ exposure to DPM, and can also help operations to comply with legislation and the recommendations set out in MDG29.
Our team of specialists is available to assist operations in areas such as:
- developing sampling programmes
- reviewing data
- offering advice on best practice controls
- developing and conducting workplace education
- providing information from external sources
- assisting in risk assessments.