Many factors can contribute to the reduction of lung disease caused by work place exposure to respirable dust including the use of dust reduction technologies, personal protection equipment, and the implementation of technologies which are able to remove respirable dust from human occupied enclosures such as machine cabs and stationary control rooms.
According to the American Thoracic Society, occupational exposures account for 10-20% of symptoms or functional impairment consistent with COPD. Exposures can include organic and inorganic dusts, chemical agents and fumes. Data collected in the National Health and Nutrition Examination Survey estimated that overall 19.2% of COPD cases could be attributed to work and 31.1% of the cases in nonsmokers.
Occupations which involve the moving of dirt, crushing of rock, processing of minerals, paper manufacturing, agricultural work, transportation of commodities, etc., all create opportunities for high quantities of respirable dust exposure. Reduction of risk factors is necessary to see a reduction in the number of workers suffering from Chronic Bronchitis, COPD, and other Lower Respiratory illnesses.
Separating Fact from Fiction
There are many divergent opinions as to whether or not a cab capable of consistently protecting the operator at a high level can be cost-effectively produced. The fact is highly effective machine cabs are already being cost effectively manufactured and retrofitted around the world accelerating the push to near zero exposure levels. Testing and validation of the hypothesis has been going on for many years. The National Institute of Occupational health and Safety NIOSH in the USA has been aggressively researching in this area for more than 20 years and have published extensively on this topic.
Other governments and private companies have worked together to develop solutions to the real world problems typical of operating in harsh environments.
In 2009 the Queensland Government Department of Employment, Economic Development, and Innovation in partnership with a provider of innovative technology, LSM Technologies Ltd, completed a study (RESPA® Trial 2009) on a sandstone cutting machine in Queensland, Australia. The executive summary states:
“Exposure to respirable crystalline silica (RCS) particularly in dimension stone (sandstone mines) is of concern. Studies in the United Kingdom, United States of America along with a trend in reduction of occupational exposure limits (OEL) supports this view. Monitoring undertaken inside an excavator (with saw attachment) cabin has demonstrated that there is reduced exposure to both airborne particulate matter and RCS after installing a RESPA® pre-cleaner, filter and pressurization (PFP) unit. The technology proved to be very effective at reducing the RCS exposure in the operator enclosure such that the operator was not required to wear a personal protection dust mask while operating the machine with the doors and windows closed.”
The World Health Organization has clearly stated that there is no acceptable exposure level to asbestos. In many parts of Australia there are high ambient levels of asbestos fibers due to the high concentration of asbestos in Australian soils. Efforts to reduce asbestos exposure within operator enclosures have produced some remarkable results. In one mine site the zero tolerance for asbestos exposure has produced a multiyear retrofit program that has produced fleets of vehicles that consistently show zero asbestos fiber contamination.
While developing environmental enclosures capable of producing near zero exposure to toxic respirable dust is technologically challenging, it has been demonstrated to be feasible. The biggest challenge to reducing the overall dust exposure levels for all environmental enclosures rests in education. The International Society of Environmental Enclosure Engineers (ISEEE) recognizes that for broad progress to be made cab engineering education has to include a comprehensive understanding of how to engineer controls into the cab that consistently work together to protect the occupant from respirable dust. ISEEE has developed both an extensive education program for cab engineers as well as the ISEEE Best Practice Guide for Developing Highly Effective Environmental Enclosures for this purpose.
In addition to education, the consumer has to request better performing environmental enclosures. ISEEE has developed a performance level program that educates the consumer quickly on which performance level is required for their specific working environment. The Original Equipment Manufacturer (OEM) is educated on how to achieve the performance level specified by the customer through the ISEEE Performance Level Guide for Original Equipment Manufacturers.
The last and most critical component of a successful cab development program is the field test procedure, which demonstrates the effectiveness of the operator enclosure under real world operating conditions. The objective is to produce environmental enclosures that protect the operator continuously. The performance test validates the engineer controls and assigns the performance level of the cab for use by the manufacturer and end user. This simple method allows the buyer to request a cab that is set up specifically for their working environment and allows the manufacturer to interpret their request and produce the required performance level in their cab.
The “Push to Near Zero Exposure Levels” is a push to gain alignment between all of the participants involved in the development, manufacturing, purchasing, and maintaining of an environmental enclosure. To do so requires clarity in: consumer education, the use of engineering controls, simple and accurate testing and validation, and a common vocabulary between all of the market players.
The ISEEE objective of “Preserving Lives and Capital” is possible and is being achieved by willing, educated market participants who are doing the right things to improve operator enclosures because it is in their best interest and the interest of the market do so.