Health Case Studies
As discussed in last year's HSEC Report, our Illawarra Coal operation, located near Wollongong in New South Wales, Australia, has been undertaking extensive research into diesel exhaust particulate, following studies that showed that exposure to diesel particulate has the potential to cause serious health effects. The work on programs to minimise the exposure of our employees to diesel exhaust has continued, and an effective program now exists.
Background
Since the publication in 1988 of research data by the US National Institute of Occupational Safety and Health (NIOSH) regarding the potential carcinogenic effects of diesel particulate, the scientific community has been evaluating available data and undertaking new studies into the health effects of this contaminant. Recently a consensus has emerged, and diesel exhaust exposure is now considered carcinogenic by many world regulatory bodies.
Strategy to Minimise Employee Exposure to Diesel Particulate
Experience has demonstrated that no single solution presents for the control of exposure to diesel particulate. Rather, the use of measures at all levels of the control hierarchy, including improved fuels, mine ventilation, better engine maintenance, better operating techniques and, in some instances, exhaust filters, are required to effectively manage this issue.
In June 2004, the BHP Billiton HSEC Forum unanimously endorsed a strategy to minimise employee exposure to diesel particulate. The Diesel Exhaust Initiative within the Company has focused on taking to sites the immediately deliverable improvements learned from Illawarra Coal and our contacts in the Canadian metalliferous mining industry. These include:
- methods for the site mechanical maintenance team to best manage engines to minimise both gaseous and particulate emissions
- processes for matching vehicle emissions to the mine ventilation to minimise exposure
- the use of the correct fuels and lubricants to achieve cleaner, more complete combustion and reduce emissions
- techniques to measure and assess worker exposure.
The Manager Rehabilitation Infrastructure at Illawarra Coal, Hank Pinkster, says, 'Illawarra Coal's involvement with diesel particulate was originally as a research project to gather information on an emerging issue, but now we see the control of diesel emissions as part of our Zero Harm program. There are positive benefits not only in terms of workforce health but also in productivity'.
By the end of June 2005, all our underground mine sites had been visited by an expert team. Key members of this team were Brian Davies, who has been involved in the research at Illawarra Coal from its outset and has recently been awarded a PhD for this work, and Sean McGinn, an expert in the control of diesel emissions in the Canadian metalliferous mining industry. During these visits, the team presented information on diesel particulate; provided educational material to site management, operators, safety professionals and maintenance people; conducted testing of engines; and assisted in the development of diesel exhaust management plans.
A key part of the Diesel Exhaust Initiative has been the association with the Mine Operations Network, which works within the Company's Operating Excellence Framework. The network has regular workshops and field days at which the diesel emissions specialists from Illawarra Coal and Canada have presented information on diesel emission management techniques. Activities include measurement of emissions and practical demonstrations of the effects of simple maintenance techniques, such as replacement of air filters and engine timing.
Following a presentation at a seminar on sustainable development hosted by the Tasmanian Minerals Council, the Council's Executive Director, Terry Long, said, 'The talk was illuminating. Site people were very interested. You've given people here both an interest in the subject and directions to lots of information. I'm sure we'll be hearing more about diesel particulates in coming years'.
Developments in Exhaust Sampling Equipment
Methods for the collection and analysis of diesel particulate are available to accurately determine personal exposure of workers. Equipment to measure the gaseous components of diesel exhaust has been available for some time; however, currently available equipment to directly measure particulate emissions is cumbersome and expensive. The diesel particulate analyser used by Illawarra Coal is set up in a mobile trailer that is not suitable for underground use.
In the United States, the NIOSH has developed a prototype hand-held instrument, which can measure the particulate concentration in the raw exhaust in less than a minute. In order to progress the prototype to commercial production, data is needed to validate and calibrate the prototype against existing instruments. To this end, prototypes have been loaned to the Company and the necessary data is being collected during the site visits.
Arrangements are in place between NIOSH and SKC Inc, a leading manufacturer of air sampling equipment, to produce a commercial instrument. This will allow maintenance mechanics to test and tune engines to minimise particulate emissions as a routine part of vehicle maintenance. Immediate in-service testing of engines will allow out-of-tune engines to be identified, taken from service and re-tuned.
Diesel Emissions Management Manual
The collective knowledge has been compiled in a Diesel Emissions Management Manual. The manual is a collaborative effort between experts from Illawarra Coal and the Canadian metalliferous mining industry and other specialists. The content covers health effects, monitoring methods, engine selection, fuel quality, mine ventilation, maintenance, exhaust filtration and allied emission controls, operator practices, education, and personal protective equipment and includes a list of suppliers.
The manual is available in hard copy and on our internal Mining Operation Network Community of Practice intranet site. It has attracted a high level of interest and has been made available to regulators in Australia and South Africa and to other mining companies and organisations in Australia, South Africa and North America.
