Workers at a ferromanganese smelter near Durban were not checked for signs of overexposure to manganese dust and fumes until 2006, an inquiry heard on Friday.

Dr Joao Do Vale, who did occupational health work for the Assmang ferromanganese smelter at its Cato Ridge plant, was testifying at the labour department's inquiry into several cases of manganese poisoning.

He told the inquiry that prior to 2006 the medical screening of employees did not include a "specific protocol... to detect manganese in the employees."

Blood tests for manganese in employees only began in 2006.

Not specific

"The initial [medical screening] system wasn't specifically targeted for manganese," he said, adding that there were no checks done to see if there were high levels of other toxic substances in employees blood.

He said blood tests for all employees began in 2006 after the airing of an SABC Special Assignment broadcast in April 2005 that showed the debilitating effects of the disease.

The hearings form part of an investigation launched by the labour department in November 2006 when five workers were reported to be suffering from manganese poisoning.

Manganism is acquired by overexposure to airborne manganese and is a disease that affects the sufferer's central nervous system, leaving them with symptoms similar to Parkinson's disease and multiple sclerosis (MS). The disease was first recognised among miners in Scotland back in 1835.

Do Vale said Assmang requested surveillance for manganism in July 2005 and that by January 2006 his practice had found two employees that had failed the manganism screening. In October 2006, another three employees had failed the screening process.

By the end of 2006 all of the company's estimated 700 employees had been screened by Do Vale's practice and among those, 80 had been referred to a neurologist in Pietermaritzburg for further testing.

Do Vale said that if an employee failed two neuropsychological tests or at least showed one unexplained symptom he would be referred to the neurologist.

He said that of the 80, he was aware that about half were referred to a second neurologist — one of whom was Dr Susan Tager, neurologist who specialises in movement disorders and who gave testimony earlier this week.

Some of those employees who had high levels of manganese in their blood were moved to areas of low exposure within the plant. If the employees could not be accommodated in another part of the plant, they would be sent home and blood tests would be taken every four weeks until their manganese levels had decreased.

An analysis of the blood results had revealed that two workers working at the same section of the plant would have very different levels of manganese.

Erratic results

"The results of the blood tests were erratic. People exposed to the same (fumes and dusts) were not coming back (with) the same (manganese levels in their blood)."

Do Vale said that he had been through the Assmang plant and that "it did not strike me as a healthy place to work."

He told the inquiry that he had not been informed by Assmang that occupational hygienists had told the company that manganese dust levels at the Cato Ridge plant were too high. He said he had never seen a risk assessment of workers exposure to manganese.

The inquiry continues on Monday.

Sapa