Since 2002, the reported number of employees (per 10,000) exposed to noise levels above 85 decibels (averaged over 8 hours) or more than 50 per cent of the legal dust limit has increased. This is most likely a result of increased monitoring of workplace conditions, as required by our occupational health standards.

Noise
There was a 17 per cent increase in the number of employees (per 10,000) exposed to noise levels of more than 85 decibels (averaged over eight hours) from 2002. Eighty five decibels is an indication of high exposure and is based on the usual noise standard in most countries.

Exposures do not take into account the benefit of wearing personal protective equipment such as ear plugs. We have a target that no employee is exposed to an average daily noise dose of more than 82 decibels (averaged over eight hours) by the end of 2004, after allowing for the use of hearing protection such as ear muffs or plugs.

However, while it is difficult to reduce noise levels in the workplace, particularly around noisy pieces of mining equipment, work to reduce exposures continues and we are targeting a 20 per cent reduction in the number of employees (per 10,000) exposed to a noise dose of more than 85 decibels (averaged over eight hours) between 2004 and 2008. This target does not allow for the use of hearing protection.

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, to protect the most sensitive workers, it is common to set a lower value, and often this is 50 per cent of the limit in the dust standard. Rio Tinto has adopted this as an indicator of dust exposures in the workplace.

There was a 13 per cent increase in the number of employees (per 10,000) exposed to more than 50 per cent of the dust standard compared to 2002. As discussed previously, this is most likely a result of more employees being covered by workplace monitoring as operations implement the occupational health standards.

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 decided to use a lower standard, ie. 20 mSv in any one year.

No employees or contractors have been exposed to radiation levels above 20 mSv for over five years and since 2001, none have been exposed to levels above 10 mSv.