Asbestos Review Program
The thousands of West Australians living everyday with the fear that they may die from an asbestos-related disease, such as mesothelioma, have had one constant source of comfort. They have been assured that some of the State’s best doctors have been carrying out the most comprehensive research and monitoring program of asbestos workers and their families of its kind in the world.
The employment records of the now infamous Australian Blue Asbestos Company (CSR), which operated out of Wittenoom between 1943 to 1966, have been used by a team of epidemiologists headed by Professor Bill Musk, clinical professor of Medicine and Population Health from the University of Western Australia, to study the effect of asbestos on health.Tracking down Wittenoom workers
Since 1975, work has been taking place to track down the thousands of people (6500 men and 500 women) who had been employed in the Wittenoom mine over the quarter of a century in which it operated. That was a task in itself given many of the workers had arrived in Wittenoom from other parts of the world in the search for work, particularly Italians and Eastern Europeans.Over the 20 years in which the project has been running in its various forms, 1500 to 2000 people who were either employed in the mine or lived in the asbestos town have been part of the study at any point in time.In the latter years of the program, people exposed to asbestos from other industries, including construction, manufacturing and maritime, have been welcomed into the study.
Researching asbestos exposure
The focus of the research component of the program has been to work out the exposure of each worker to asbestos and their risk of developing an asbestos-related disease.
According to Professor Musk, “Dust measurements were taken in Wittenoom over the years and we got the idea of what the exposure was of different people in different jobs”.
As a result, as Professor Musk explains, “We have been able to allocate to everybody an estimate of what their exposure to blue asbestos was.”
In the early 1990s medical researchers were interested in whether Vitamin A had a role to play in cancer prevention. According to Professor Musk,“At the time, there was evidence, that vitamin A could reduce the risk of all sorts of cancers. Vegetarians have lower risks of all sorts of cancers and it was thought that beta-carotene, one form of Vitamin A, was the active ingredient.”The participants in the program were split into two groups for the purpose of comparing the effects of the two different forms of Vitamin A as prevention measures against the development of asbestos-related diseases.As Professor Musk recalls, “We suggested to people that they might want to try Vitamin A but, knowing that people could easily get their own supplies of the vitamin if they thought they were being given a placebo in the trial, we compromised and gave half the group beta carotene and the other half retinol.”Retinol is the form Vitamin A takes once it has been broken down in the liver. Patients were administered 30mg of betacarotene or 25,000 international units of retinol and they were regularly monitored at the Perth Chest Clinic.After the first five years of the Vitamin A trial, in 1996, there were 13 cases of mesothelioma in the beta-carotene group and just three cases in the retinol group.At the end of the next five years, in 2001, there were still fewer cases of mesothelioma in the people who were on retinol than expected.
But after 15 years, there was no difference in the rates of mesothelioma between the groups and there were also concerns raised by research in other parts of the world about side effects from high doses of betacarotene.
“So in 2007, we concluded that Vitamin A was not a prevention tool in relation to asbestos-related cancers and we stopped giving it to people on the program,” Professor Musk said.
The Asbestos Review Program
At the end of the Vitamin A trial, a revised program was initiated called the Asbestos Review Program. The revised program has focused on monitoring the health status of people exposed to asbestos and providing health promotion resources to all participants, particularly in relation to smoking, diet and exercise and recommended screening programs.
All of the participants in the existing program continued to attend the Asbestos Review Program at the Perth Chest Clinic once a year for a range of tests, health advice and support. Because of the constant medical monitoring of these patients, other medical problems can be detected and referrals made for necessary treatment. The program is now housed at the Department of Respiratory Medicine at Sir Charles Gairdner Hospital.
Professor Musk said the ARP program had shown that the amount of asbestos a person was exposed to and the passage of time are the major indicators of the likelihood of developing an asbestos-related disease.
The annual testing of the 1400 participants currently in the program includes:
- A lung function assessment for all patients who attend the Clinic.
- A more comprehensive gas transfer test for those participants who worked in the Wittenoom asbestos mine,
- Weight and height is measured.
- An annual digital chest x-ray, reviewed by Professor Musk, is taken and changes are compared with previous years.
- A blood sample to monitor blood levels for Vitamin A is taken.
- Participants’ results are referred by the Clinic to the participant’s GP and the participant.
- Health promotion advice is provided if requested.
Read about participant Ted Lawrence’s experiences.
Research outcomes
Besides the positive effects the program has had on the health of those involved, it has also resulted in a massive body of information about asbestos exposure and the development of various asbestos-related disease.“We were able to show there is going to be increasing numbers of mesothelioma and lung cancer as a result of asbestos exposure as time goes on,” he said. This information assists policy makers and the medical profession in their ability to manage these cases as they are diagnosed and to have the resources needed to assist them.Professor Musk and his team have been able to determine that by 2020, the cases of mesothelioma in Western Australia will continue to increase as time since exposure increases and is a major determinant of risk.The program has also been able to show that there is no level of exposure to asbestos below which there is no risk of developing malignant mesothelioma, that quitting smoking results in a reducing risk of lung cancer and that lung function in asbestos workers is adversely affected by both past asbestos exposure and smoking, even in those who have no evidence of asbestosis on chest x-ray.