Decades after South Africa banned asbestos mining, former miners continue to die from the long-term effects of exposure to one of the country’s deadliest industries, according to new research from the University of Cape Town (UCT) that sheds light on the enduring human cost of the asbestos economy.
The study, published in the American Journal of Industrial Medicine, examined mortality trends among 11 343 former asbestos miners and found that overall mortality was 4% higher than in the general population.
Among women, however, mortality was 17% higher than expected, a finding the researchers said reflected the often-overlooked realities of women’s labour in the asbestos industry.
South Africa once dominated the global asbestos market, producing nearly all the world’s amosite asbestos and about 97% of crocidolite, among the most dangerous forms of the mineral. At its peak in the late 1970s, asbestos mining employed tens of thousands of workers across the Northern Cape, Limpopo and Mpumalanga.
Although asbestos mining and use were banned in 2008 because of its cancer-causing effects, the authors said the health consequences continued decades after mines closed, particularly in historically poor mining communities where access to healthcare remained limited.
Asbestos exposure is linked to serious diseases such as asbestosis, lung cancer, mesothelioma and other respiratory and some non-respiratory cancers, with international studies showing consistently higher death rates among exposed workers, including miners.
In South Africa, however, the authors noted that the full scale of illness and mortality among former asbestos miners was not well quantified due to limited data. Asbestos-related diseases were widely underdiagnosed, under-treated and often uncompensated, leaving many former workers with long-term health and financial burdens.
The study formed the basis of an MMed dissertation by Dr Yumna Williams-Mohamed, a registrar in occupational medicine at UCT, supervised by professor Rodney Ehrlich, Dr Jim teWater Naude and associate professor Shahieda Adams.
Using records from the Asbestos and Kgalagadi Relief Trusts collected between 2004 and 2023, the researchers analysed occupational histories, chest X-rays, spirometry tests and compensation records of former miners seeking medical evaluation for asbestos-related disease.
The findings point not only to the persistence of asbestos-related illness but also to deep structural failures in surveillance, compensation and occupational healthcare in post-apartheid South Africa.
“Asbestos-related disease remains underdiagnosed and undertreated, with most individuals only identified when they present to health services with advanced disease,” said Williams-Mohamed.
Under the Occupational Diseases in Mines and Works Act, former miners are entitled to periodic medical examinations.
But the study noted that there was no national system mandating active surveillance of former asbestos workers, meaning many people with progressive disease were diagnosed years later, only after symptoms became severe.
The researchers warned that the true burden of asbestos-related mortality was probably substantially underestimated.
The authors said some of the most severely affected miners might never have been captured in the data because many workers died before the establishment of compensation trusts in the early 2000s or before entering the trusts’ database.
High labour turnover, incomplete employment records and the historic use of migrant labour further complicated efforts to quantify the full scale of illness and death.
The study highlights the harsh socioeconomic conditions in former asbestos mining regions. Many communities historically linked to asbestos production continue to experience high unemployment, poor access to healthcare and poverty. The conditions compound the long-term health effects of exposure.
Women emerged as one of the most vulnerable groups in the study. The team found that nearly all female workers were employed in aboveground processing jobs, including cobbing — manually breaking asbestos rock — where airborne fibre exposure was particularly intense. Women also often faced secondary exposure through washing contaminated clothing at home.
“This is reflective of gender-specific job tasks, aboveground asbestos work and inadequate protective measures in historical mining settings,” Williams-Mohamed said.
The severity of lung abnormalities on chest radiographs was one of the strongest predictors of mortality. As disease severity worsened, the risk of death increased significantly, the study found.
Similarly, severely impaired lung function was strongly associated with higher mortality. Former miners with very low forced expiratory volume in one second faced a 60% increased risk of death, while those with severely reduced forced vital capacity had a 26% increased risk.
The study also identified smoking and low body weight as important risk factors. Former smokers faced a 43% increased mortality risk, while underweight participants had a 46% increased risk of dying.
The authors observed that standardised mortality ratios declined over the 20-year study period. “While this may suggest some improvement, we caution that interpretation is limited by incomplete data,” said Williams-Mohamed. “Nevertheless, the trend reflects how mortality patterns may be shifting and highlights the importance of continued surveillance.”
For the team of authors, their findings strengthen the case for targeted surveillance programmes capable of identifying high-risk former miners earlier, before irreversible lung damage develops.
It proposes a risk-stratified approach in which workers with advanced radiological abnormalities or impaired lung function receive more intensive monitoring, including frequent imaging and respiratory testing.
They also called for improved diagnostic capacity, better training for healthcare workers and stronger smoking cessation support.
Beyond its clinical findings, the study raises broader questions about environmental justice and the long afterlife of hazardous industries in the country.
Although mining has ceased, asbestos-containing materials remain in buildings and infrastructure across the country, meaning environmental exposure persists in some communities.
For many former miners and their families, the consequences of asbestos exposure continue long after employment ended.
“The effects of hazardous occupational exposure do not end when a mine closes,” Williams-Mohamed said. “Former workers may continue to experience illness, disability and premature mortality for years or decades.”
A new University of Cape Town study has found elevated mortality among former asbestos miners in South Africa, highlighting the long-term health consequences of asbestos exposure decades after mining ended
