Australian news, and some related international items

Workers exposed to radioactive polonium at BHP uranium mine

“These high readings should trigger further investigation and individual testing for polonium in the body,

Roxby’s radioactive risk,  The Independent Weekly. HENDRIK GOUT04 Jun, 2010 Mining giant BHP Billiton is risking the lives of its staff and employees at Olympic Dam in South Australia by exposing them to unsafe levels of radiation, according to a company whistleblower.

Documents received by The Independent Weekly say BHP Billiton has been warned about the risks, and has chosen to take no action.

The documents show BHP Billiton uses manipulated averages and distorted sampling to ensure its “official” figures slip under the maximum exposure levels set by government.

But experts have warned exposure levels currently regarded as the international limit should be lowered, following the poisoning of Alexander Litvinenko in London four years ago………………

BHPB is aware of the danger of polonium-210 at its Olympic Dam mine. As it says, “In uranium mining, one of the risks to occupational health is exposure to airborne particles of polonium-210, which is part of the natural uranium decay process.”

BHPB makes the claim that to counter this at Olympic Dam, “a smelter ventilation project is resulting in substantial reductions in exposure to Po210 while allowing production to be maintained at a sustainable rate.”

Not so, say other experts.

The 2005 “smelter ventilation project” supposedly integrated occupational hygiene monitoring with process controls and improved ventilation.

Since then, the company claims, airborne concentrations of Po210 have remained under the regulatory limit for radiation exposures……

BHPB radiation officer Frank Harris won a company health and safety award for this project and the uranium projects manager Dean DellaValle declared it “Mission Complete.”

Subsequent reports show the exposure levels have steadily increased and are well above BHPB’s own target.

To understand the danger, imagine what it’s like working at Olympic Dam……That danger is inhaling even a single particle of polonium-210.

“Po210 is a volatile radionuclide, an atom with an unstable nucleus. When material containing low concentrations of Po210 is heated, the Po210 is released into the fume. Inhalation can contribute to occupational radiation exposure,” BHPB says with considerable understatement.

Because inhalation “occupational radiation exposure” can be a euphemism for “a work-related deadly dose”…….

Radiation like this is measured in sieverts, an international unit of subatomic particles which can detach electrons from atoms or molecules. At Olympic Dam, as in every other uranium processing facility, there are maximum levels – world-wide standards – which must not be exceeded.

The regulatory maximum limit for radiation exposure is 20 millisieverts a year, but the internationally recommended exposure for polonium-210 is far lower – just six mSv.

Data available to The Independent Weekly shows that at Olympic Dam, workers might be exposed to doses far higher than this. BHPB works on airborne radiation dust readings averaged throughout at least an entire shift. “…..system is used at Olympic Dam. Air samples are taken over long periods and then averaged out. Polonium-210 is released in bursts, and any single burst could be deadly even if the average meets the standard. Even on reported “average” figures as used by the company, there is evidence of trouble……..
“These high readings should trigger further investigation and individual testing for polonium in the body, instead of claiming that the workers would have been wearing a respirator,” said a mine employee.

BHPB does not undertake continuous personal monitoring of exposed workers. There are no blood tests or urine sampling for radiation poisoning.

“BHPB cannot guarantee workers have not been exposed,” Greens MLC Mark Parnell said after seeing the data. “BHPB has random urine sampling for recreational drug use of workers, yet it refuses to do random urine sampling of polonium exposure because it fears the results.”….

“The EIS fails to demonstrate that worker exposure to radiation in the smelter operations will be below international standards,” Mr Parnell told Mineral Resources Development minister Paul Holloway in response to the EIS.

“In the Olympic Dam smelter there are high emissions during furnace tapping when workers are present. This occurs around 30 per cent of the 24-hour cycle. Monitoring is done for a few shifts per month and not correlated to tapping times or process events.

Roxby’s radioactive risk – Local News – News – General – The Independent Weekly

June 4, 2010 - Posted by | health, South Australia | , , , , , , ,

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