Key challenges

Lead

Exposure to lead has a long history of adverse health effects. Xstrata mines lead at Mount Isa, north Queensland, in addition to a zinc-lead bulk concentrate at McArthur River Mine in the Northern Territory. At Mount Isa, production in the underground lead mine ceased in 2005 and was replaced by production from the George Fisher Mine and open cut Black Star zinc-lead mines. Lead mined and smelted at Mount Isa is refined and processed at Northfleet in the UK. We regularly monitor the lead in blood levels of employees at the Northfleet lead refinery in the UK and in all lead production areas at Mount Isa and McArthur River Mine in Australia.

We collect and analyse blood samples to determine lead concentration, which is measured in micrograms per decilitre (µg/dL). Alterations in blood levels indicate a change in exposure, or behaviour, which is immediately addressed with the exposed person in confidence. Biological and workplace monitoring is conducted in accordance with recognised international occupational hygiene monitoring standards. Employees with blood lead concentration levels of 40 µg/dL or greater, or have achieved three consecutive results of 35 µg/dL or greater, must be removed from the workplace until concentrations are below 30 µg/dL. In the lead smelter, the limit is 45 µg/dL or greater, or three consecutive results of 40 µg/dL or greater.

At Mount Isa, where our copper, zinc and lead operations are in close proximity to one another, a lead management programme is in place. For copper employees, this focuses mainly on road maintenance crews and equipment maintenance teams who work around the lead operations. A review of Mount Isa's lead management system commenced in late 2005 and will be completed in early 2006, with the aim of reducing blood lead levels further amongst lead employees and contractors.

Xstrata has also continued its free blood lead monitoring programme for Mount Isa residents. The test is available on request from the Queensland Medical Laboratories located in the town centre and funded by Xstrata. The results of the blood lead test are confidential and are forwarded to a general practitioner nominated by the community member being tested. The general practitioner explains the test results to their patient and any actions required.

At Northfleet in the UK, we have removed employees at progressively lower levels of blood lead concentration and have achieved continued improvements in average blood lead levels. The average boundary lead-in-air concentration in 2005 was below 0.5 µg/m3 at Northfleet although one monitoring location (closest to the refinery) had a higher average level. Since the start of 2006, the average level for this monitoring location has fallen to 0.58 µg/m3. Blood lead concentration levels in the UK are regulated by the Control of Lead at Work (CLAW) Act which has set the limit at 60 µg/dL, although several EU countries have reduced their limit to 40 µg/dL. In 2005, we removed all employees with blood lead levels in excess of 40 µg/dL until their blood lead levels were below 35 µg/dL. Our aim in 2006 is to work towards removing employees with blood lead levels of greater than or equal to 35 µg/dL and will continue to reduce this level further to greater than or equal to 30 µg/dL in future years.

The Northfleet refinery has also participated in the supply of information and data to assist the progress of the Voluntary Risk Assessment for Lead. This research is being carried out in the European Union by the Lead Development Association International.