Responding to public concerns arising from media coverage of the notorious Free State asbestos roof audit, Professor David Rees, Emeritus Professor of Public Health at Wits University, said there is no evidence that asbestos cement (AC) roofs are causing asbestos related diseases (ARDs).

Rees, who recently retired from the National Institute for Occupational Health, was speaking at the Annual General Meeting of the Asbestos Relief and Kgalagadi Relief Trusts on 10 November 2020.

He said the replacement of AC roofs was a relatively low priority when considering the many other public health risks facing South Africans, including food security, clean water, reliable energy, and communicable disease. There was no urgent need for the mass removal of asbestos cement roofs.

Commenting on media coverage of the Free State asbestos roof audit where an occupant of a house with an AC roof reportedly said, “I can’t breathe”, he said it was highly unlikely the roof sheets would affect the day to day health of residents.

It was possible to contract pleural plaques (typically medically unimportant) and mesothelioma, a serious and potentially fatal disease, from relatively low levels of exposure to respirable asbestos fibres. But it was unlikely that this would arise from the weathering of AC roofs.

Dangerous respirable asbestos fibres would, however, be released by aggressive work practices such as cutting, sanding, or cleaning a roof with a high-pressure water jet.

While there was no scientific evidence that anybody had contracted an ARD because they lived in a house with an AC roof, more research was needed, “maybe a mesothelioma register that includes an exposure history taken from all subjects reported to the register.”

He called for “sober and sensible communication” about the relative health risks of asbestos fibres, whether they be found in former mining areas, occupational settings, or residential areas.

“A balanced message is key. We can’t dismiss the potential risk but if people are getting mesothelioma from this source of exposure the numbers will be small. We don’t want to create unnecessary anxiety for occupants who are then powerless to do anything about it. It would be more productive to reassure people about these roofs but also urge them to take proper precautions, or employ suitably trained contractors, when they remove or work with these materials.”



Professor Rees said however that AC roofs on millions of homes in South Africa – and in thousands of schools and other buildings – would eventually deteriorate and have to be replaced.

It was therefore necessary for government to develop a long-term asbestos abatement plan. Among the necessary measures he identified were the safe removal and disposal of the roof sheets.

In Australia homeowners had access to a smart phone app that helped them assess the risk of AC building materials and what to do if they were in poor condition. Options included removal or coating.

The medical advisor to the trusts, Dr Jim teWaterNaude, said he was concerned about homeowners cutting or sanding AC products and thus releasing respirable asbestos fibres. Few homeowners could afford to employ asbestos abatement specialists for a simple roof repair or building extension.

The chairman of the Kgalagadi Relief Trust, Brian Gibson, commented that high levels of windblown fibre in former asbestos mining areas, and communities living on or near unrehabilitated asbestos mine dumps, was indeed a public health priority.

He observed that the 1998 Asbestos Summit convened by government, business, and labour, had submitted a priority plan to the Cabinet for dealing with South Africa’s asbestos legacy. The replacement of AC building materials had not been a priority.

Professor Rees suggested that a further national discussion about asbestos would be an opportunity to educate the public about the environmental risks in former mining areas and how to deal with asbestos cement building materials in the decades ahead.


Media Statement Issued by the Asbestos Relief Trust and the Kgalagadi Relief Trust: The trusts provide additional compensation to victims of asbestos exposure at and in the vicinity of former asbestos mines covered by the respective trust deeds.

For further information contact Brian Gibson on 083 2535988 or