Workplace exposures
In 2005 the increase in the amount of workplace sampling, particularly for dust and noise but also for levels of whole body vibration in large equipment, continued. This increased sampling is a result of operations implementing the occupational health standards.
Generally, this increased sampling has resulted in a rise in the number of workers reported as exposed to levels greater than 50 per cent of the legal standard for dust or to noise above 85 dB(A). In 2004, it was estimated that an additional 4,100 Group employees were covered by workplace sampling programmes; in 2005 a further 845 have been added
Noise
One of our occupational health targets is aimed at reducing the number of employees exposed to more than 85 dB(A) through engineered controls of the noise source. Reducing noise exposures below 85 dB(A) averaged over eight hours remains a major engineering challenge as many of the powerful pieces of equipment used in mining, such as fans, crushers and heavy mobile equipment, exceed 85 dB(A). In 2005, the rate of new cases of occupational illness was 4,115 (per 10,000 employees), compared to 3,938 in 2004, mainly due to improved monitoring and reporting.
Given the long lead time for many engineering controls to reduce noise exposures, the use of equipment such as ear muffs and ear plugs to reduce the noise dose to the worker will continue to be needed for many tasks.
Additionally, we have set a target of zero exposure of employees to a noise dose of more than 82 decibels (averaged over eight hours), after allowing for the use of hearing protection. In 2005, 40 employees were exposed to noise exceeding 82 decibels, a decrease from the 149 exposures in 2004. Abatement measures will be investigated further and implemented in 2006.
Dust
Legal dust standards are in place in most countries and are developed to protect the health of the great majority of workers from harm if they are exposed to dust over their working lifetime. However, a lower value, often set at 50 per cent of the exposure limit is used as a trigger point at which dust control measures should be considered. Rio Tinto uses this 50 per cent trigger as an indicator of dust exposures in the workplace.
Radiation
Legal standards within a country generally require workers' exposures to radiation to be below 100mSv over five years with a 50mSv limit in any one year. Rio Tinto has adopted a stricter standard of 20 mSv in any one year.
No employees or contractors have been exposed to radiation levels above 20 mSv for over five years. Three employees were exposed to levels between 20 mSv and 10 mSv in 2005. These exposures occurred in the drum filling area at Rössing.
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