Three minerals, three epidemics
All three of the major commercial forms of asbestos – Cape crocidolite (blue asbestos),
amosite (brown asbestos) and chrysotile (white asbestos) occur in South Africa. Amosite,
together with Cape and Transvaal crocidolite, belongs to the amphibole family of asbestos
minerals, whereas chrysotile is a serpentine asbestos
In their monograph on asbestos mining and disease in South Africa, Felix et al.1
have traced the history of the mining of each of the these forms of asbestos, and demonstrated
their links with local epidemics of asbestos-related diseases, and through
exportation of massive amounts of these minerals, with disease in workers and communities
around the globe.
The South African asbestos trade began in the early nineteenth century following
the discovery and mining of crocidolite near Prieska in the Northern Cape in 1806. This
town is at the southern end of a region with numerous asbestos occurrences, extending
some 50 km in width and 400 km in length northwards to South Africa’s border with
Botswana, where the now defunct Pomfret, the largest of the crocidolite mines, is situated.
Initially, and well into the first half of the twentieth century, crocidolite mining
was outcrop and small digging operations run by tributers and farmers. Mining and
milling were highly labour-intensive. Fibre was cobbed from rock by hand-held hammers,
sieved by hand, sorted by a combination of a hand and mechanised method, and
transported in Hessian sacks to its destination. Women and child labour was extensively
employed in sorting and cobbing.
Trans-national companies became predominant in the mining of asbestos for
international markets, a process that began with the establishment of the United Kingdom
based Cape Asbestos Company that began mining and milling operations at
Prieska in 1893. By 1919 more than 3000 tons of Cape crocidolite fibre were being
produced per year. By the 1930s trans-national corporations dominated the asbestos
mining scene in South Africa.
Amosite – a name derived from the acronym for Asbestos Mines of South Africa –
occurs in the Lydenburg district, with the major deposit being at Penge where mining was
carried out from 1914 to 1992. Numerous deposits occur north-west of Penge in a 45 km
arc and during the mid-twentieth century were mined for amosite and Transvaal crocidolite
in numerous small operations using crude technologies that caused extensive environmental
pollution and exposed the labour force to high levels of asbestos dust.
Chrysotile mining in the Barberton district of Mpumalanga Province began at a
number of sites after 1915. Exploitation of the major deposit at Msauli began in 1937.
Msauli is currently South Africa’s only operational asbestos mine, now employing less
than 350 people.
A recent review of South African asbestos production, exports and destinations
from 1959–932 confirms that sales of crocidolite and amosite reached their peaks
in 1977 when South Africa exported a total of 380 000 tons of asbestos (Fig. 5.1),
making it the third biggest supplier in the world in that year.
Mesothelioma and asbestos – the beginnings
The association between asbestos and mesothelioma was first correctly made in people
from the Northern Cape Province crocidolite fields, an association that was subsequently
confirmed and accepted worldwide.4,5 Considering that crocidolite had already been exploited
for 150 years and that thousands of people had been exposed, many at an early
age and under crude conditions, it is perhaps surprising that it had not been considered
earlier. It appears that there were sufficient cases for Sleggs, Wagner and Marchand to
assemble their series of 33 cases of this usually rare tumour in only four years!
In reviewing developments subsequent to the discovery of this association, Felix et al.
recount that at the 1959 Pneumoconiosis Conference held in Johannesburg a resolution
was adopted to further investigate the relationship between asbestos exposure and mesothelioma,
and in 1961 the Pneumoconiosis Research Unit (PRU) of the governmentsponsored
Council for Scientific and Industrial Research (CSIR) embarked on a field survey
in the northern Cape and at Penge. The first year of the study cost 12 000 rand. Asbestos
mining companies contributed 8000 rand and the South African Cancer Association
contributed 4000. It must have soon been clear to the researchers that they were dealing
with a serious instance of environmental pollution. Flynn6 recounts that Webster was charged
with the unpleasant task of informing the asbestos industry of the environmental disaster
in the Northern Cape and that crocidolite was the carcinogenic factor. This information
apparently evoked a negative response which included a campaign to denigrate the scientists
involved, accusing them of “trying to destroy a valuable export industry for selfaggrandisement”.
6 Funding of the project by the industry and the Cancer Association was
not renewed for a second year of the study, and consequently the field-work was never
completed. However, the CSIR contributed 10 000 rand to finalise the research report on
the work completed, but subject to an undertaking by the Research Advisory Committee
of the PRU that “such a ‘report’ would not be published or made available outside the unit
[PRU], other than to sponsors and the various members of the working committees that
had been concerned with the conduct of the ‘survey
Mesothelioma: reporting of cases and trends,
1955–92
After the 1959 Pneumoconiosis Conference in Johannesburg, the National Research
Institute of Occupational Diseases (NIROD – subsequently the National Centre for
Occupational Health [NCOH]) in association with the Asbestos Tumour Reference
Panel – a panel of expert histopathologists established in 1965 – continued to record
and check each diagnosis of mesothelioma reported to it. In 1973 Webster published
the group’s experience of the first 232 cases.9 Later, Zwi et al. released results of a case
series of mesothelioma compiled from a variety of sources, provided an estimate of
mesothelioma incidence and described characteristics of 1347 cases identified in South
Africa between 1976 and 1984.10 Other case series have also been reported.11–13
In 1986, a South African National Cancer Registry (SANCR) was established within
the South African Institute for Medical Research (SAIMR). The SANCR essentially
incorporated the work of the Asbestos Tumour Reference Panel (ATRP) and centralised
reporting of cancer diagnoses made by pathologists at all major public and private institutions
in South Africa.14 Between 1986 and 1992, 1158 cases were reported to the SANCR
Asbestos exposure and mesothelioma
Four case series have been published that detail the source of exposure in 505 cases of
histologically proven mesothelioma in South Africa (Table 5.2).9,11–13 Most of the cases
where exposure was not known or where it was believed that there was no exposure
are from the first case series. If these 61 cases are excluded, of the remaining 444, in
118 or 26.6% the exposure was confirmed as being environmental only, whilst in the
remainder a source of occupational exposure was identified with a slight majority of
cases being reported from secondary industry.
Occupational mesothelioma
Mining-related exposures in asbestos mines or mills contribute the largest proportion of
cases (145 cases or 44.5%) of those mesotheliomas where exposure is known. Mesothelioma
has been described in relation to both crocidolite and amosite exposure, but given
mesothelioma
Prior to 1993, compensation for miners developing occupational diseases, including mesothelioma,
was racially discriminatory. The Occupational Diseases in Mines and Works
Amendment Act of 1993 abolished racial discrimination in the amounts paid, but awards
are modest – usually about 70 000 rand given as a lump sum. The funding of future
awards is of some concern as payments are made from the miners’ Compensation Fund,
maintained by current mining employers pro rata for the number of miners that they
employ and their level of risk. If a mine has ceased operation the Act can require the
state to make up the cost to the Fund of that mine’s compensation. Since the asbestos
mining industry is essentially defunct, all compensation costs of former miners in South
Africa have come either from general revenues or from current mining employers.
Environmental mesothelioma
Evidence from mesothelioma case studies
In the vast majority of the cases of mesothelioma in South Africa where there was
known to have only been environmental exposure to asbestos, this exposure has occurred
in the Northern Cape in proximity to mines, mills and dumps.
A high proportion of cases of environmental origin (26.6%) is unique to South
Africa. The only comparable example is Australia, the only other country to have mined
crocidolite in significant amounts. Ferguson et al.27 found that in 726 cases of mesothelioma
registered in Western Australia during 1980–85, 43 cases or 6% had environmental
exposure only, and only in six cases (<1%) was environmental asbestos exposure
due to residence in an asbestos mining region (Wittenoom)
Compensation for patients with environmental
mesothelioma
There is currently no form of financial compensation in South Africa for people who develop
mesothelioma from environmental exposure. It has at various times in the past been
mooted that the Department of Health should establish such a fund, but nothing has been
forthcoming. It also appears that there has been no successful civil legal action for personal
injury damages in this context. As we discuss below, this situation may be changing.
Preventing occupational mesothelioma
Since 1987 the use of asbestos in South African secondary industry has followed Asbestos
Regulations framed in terms of the Occupational Health and Safety Act.27 Among the
provisions are a Permissible Exposure Limit (PEL) of 1 f/mL and an Action Exposure
Limit (AEL) of 0.5 f/mL for all types of asbestos. More importantly and in line with
trends elsewhere, there has been major substitution of most of the former uses of
asbestos, particularly amphibole asbestos.
Most of the occupations listed in Table 5.2 are of historical interest only and are
of little importance as current prevention strategies. For example, steam locomotives
are being replaced. The asbestos cement industry used significant amounts of crocidolite
in its products until the mid-1980s when substitution with chrysotile began.
In the future the main occupational asbestos hazard in industry will be the removal
of asbestos, particularly in situations where it has been used as insulation on
boilers, steam pipes and in buildings. It is not clear that this risk is adequately controlled
by the current Asbestos Regulations and it is important that contractors are
monitored to prevent unacceptable practices and methods of removal such as using
untrained, daily paid workers to do this kind of work.
Although amphibole asbestos is no longer mined in South Africa, it is sobering to read
Felix et al.’s account1 of regulation of the health effects of asbestos mining by the Department
of Minerals. Standards applied in South Africa have lagged behind those applied in Europe
and North America. Sluis-Cremer17 estimated that in surface workings in 1945, dust counts
at crocidolite mines were 30–160 f/mL, and were 8–30 f/mL in 1970. In the 1970s, at a time
when European countries were beginning to ban the importation of crocidolite, the PEL for
asbestos surface workings was 10 f/mL. In 1984 the current uniform surface and underground
mining standard of 2 f/mL was introduced.1 In 2001 the Department is proposing
that this limit be reduced to 1 f/mL for all types of asbestos.
Preventing environmental mesothelioma
The focus for the prevention of environmental mesothelioma has to be twofold: the rehabilitation
of the areas polluted by asbestos during mining and milling of the mineral and
the education of the affected communities about the asbestos hazard. The extent of the
problem of environmental pollution by asbestos in the affected regions is enormous. Living
for the most part in complete ignorance of the health threat posed by asbestos, many
communities have been seriously polluted with asbestos. Although initial remedial efforts
by local and Provincial governments were slow and sporadic, a more concerted effort has
been made by the Department of Minerals in recent years. The government has spent 44
million rand on this process, and estimates that a further 52 million is needed to complete
this task. Companies have contributed less than 5% of the rehabilitation costs
Treating mesothelioma
People who develop this cancer have a poor prognosis and, internationally, experience
with treating mesothelioma has been discouraging. It is not clear that any treatment
available to us confers benefit above that provided by simple palliation. This grim
outlook seems to have discouraged clinical interest in this condition in South Africa.
Specialised oncology therapies are only available in major centres and none of these
are particularly close to the asbestos fields. Individual clinicians have over time developed
considerable experience in the palliation of this cancer, but little of this experience
has been published.36
The nihilism that surrounds the clinical management of mesothelioma has other
consequences. In high-prevalence areas a typical case of mesothelioma (a painful pleural
effusion that does not respond to anti-tuberculous therapy) is often not subjected to
pleural biopsy unless drainage and pleurodesis becomes nescessary. Pleural biopsy is
viewed as conferring no benefit other than confirming the diagnosis and carries a not
insubstantial risk of tumour recurrence at the biopsy site – a troublesome complication
that requires radiotherapy and distant referral.
Future prospects for mesothelioma
The future prospects for mesothelioma in South Africa are not encouraging. It could
be expected that the occurrence of mesothelioma will peak some 20 to 30 years after
the peak of crocidolite exploitation. This peak production was in 1977 and we may
well be approaching this point in the epidemic. It can be expected that the epidemic
will continue at least for the lifetime of those large numbers of people exposed to
crocidolite in mining and industry up until the late 1980s. In view of the lack of timely,
effective environmental rehabilitation in most affected communities it can be expected
that mesothelioma will still be a spectre in the lives of children being born into these
communities even today.
The asbestos tragedy has been described as “one of the most colossal blunders of
the twentieth century” by Bill Sells,2 a former executive of Johns-Manville, once a
major US manufacturer of asbestos products. Sells wrote in 1994, “In my opinion the
blunder that cost thousands of lives and destroyed an industry was a management
blunder, and the blunder was denial,” instead of the “responsibility . . . and product
stewardship” demanded of so serious a situation.
Although asbestos in other countries could be considered a colossal blunder of
management denial it is perhaps easier to understand the South African citizenry as
the naive victims of a superbly conducted confidence trick carried out in the names of
jobs, development and prosperity. Even now the con victim is scratching his head,
looking at the dud cheque and saying to himself, “How did they do it?”
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