|HEALTH, SAFETY & ENVIRONMENT|
OCCUPATIONAL HEALTH IN THE OIL INDUSTRY
THE HEALTH WATCH STUDY
Since 1980, the Australian Institute of Petroleum has sponsored the development and operation of an independent epidemiology program called Health Watch.
Health Watch is a university-based research program which studies people who have worked in the Australian petroleum industry to find out what happens to them in terms of their health. Health Watch has followed about 19,000 past and present employees during their time in the industry and after they leave or retire. Along the way, Health Watch records any occurrence of cancer and, eventually, the cause of death.
By comparing this information for different jobs within the petroleum industry and with the general Australian population, Health Watch tries to provide useful information about risks in jobs in the petroleum industry and risks in lifestyle. The information from the Health Watch study is important in identifying factors that may be a risk to health and ways in which these risks may be controlled.
The Health Watch Study has always been conducted independently, first at the University of Melbourne and then, from 1998, at the University of Adelaide. In 2005 the study was transferred to the Monash Centre for Occupational and Environmental Health, a leading international centre for epidemiological programs and collaborative research at Monash University.
Participation in the study
Health Watch covers those petroleum industry employees from all major oil and gas companies who voluntarily joined the program at their work sites across Australia. Although participation in Health Watch is voluntary, the employee participation rate has been outstanding – clearly demonstrating the value of the Study to employees. About 95% of the industry's employees who were approached to participate have joined Health Watch (including employees from refineries, distribution terminals, and production sites onshore and offshore). The very high participation rate amazes overseas researchers. The study has historically enjoyed very strong support from employees, unions and companies and is also very well regarded internationally.
Employees in the industry were enrolled in the study by participating in one or more of four industry surveys over the 1980s and 1990s, using a detailed job and health questionnaire. This process obtains information on job tasks, on lifestyle factors (eg. smoking and alcohol) and on health status. An employee is taken into the cohort analysis following a survey interview or after having served five years in the industry, whichever is later, and remains in the Health Watch cohort for life. Employees who have left the employment of participating companies are contacted periodically for an update of their employment and health status.
Design of the Study
The main output of the study is analysis of mortality and cancer incidence. These are carried out by comparing the rates of deaths and cancers in the Health Watch cohort with the rates in the age and sex matched general Australian population.
Death registrations and cancer registrations in the general population are obtained from the Australian Institute of Health and Welfare (AIHW), which compiles the National Death Index (NDI) and the National Cancer Statistics Clearing House (NCSCH) on behalf of all State Death and Cancer Registries. Deaths and cancers in the Health Watch cohort are obtained by matching the Health Watch data with Registries data.
Results are published in periodic Health Watch reports (of which the latest report is the 13th) and in scientific medical journals. A summary of the latest Report findings have been sent to individual Health Watch members (see infosheet below).
WHAT HEALTH WATCH HAS FOUND SO FAR
Overall, the Study clearly shows that petroleum industry employees have better health than the general Australian community and are less likely to die of the diseases commonly causing death - including cancer, heart and respiratory conditions.
The cancer rate
The overall cancer rate of employees in the petroleum industry is no different to the average cancer rate for the general Australian population.
Deaths from cancer
The overall death rates from cancer are significantly lower than the average death rates from cancer for the Australian population.
Leukaemia has been a cancer of special concern in this industry because of its association with benzene exposure. Earlier Health Watch reports indicated a higher than expected number of leukaemia cases. However, the latest report shows the risk of leukaemia – of all types – is no greater than in the general population and has fallen compared to previous reports. This is true even of acute non-lymphatic luekaemia, which has been associated with exposure to benzene.
The industry has taken significant steps to reduce exposure to petroleum products in general and to benzene in particular. The known association between benzene and certain leukaemias has seen the Governments around the world set occupational exposure standards for benzene and petroleum companies have taken steps to make sure that they comply with them.
There have been 23 cases of mesothelioma diagnosed among Health Watch members, the majority before 2000. These cancers are likely to have been a result of exposure to asbestos that took place in the 1950s and 1960s (including asbestos exposure before entering the petroleum industry). It can take 30–40 years between exposure to asbestos and mesothelioma diagnosis. Similar to benzene exposures, a greater awareness of the hazards of asbestos mean that working in the petroleum industry in more recent times, is unlikely to result in asbestos exposure. This is highlighted in the recent Health Watch report by the significantly low lung cancer rates in the petroleum industry compared to the general population. This means there can be few, if any, asbestos related lung cancers.
Health Watch results show a higher rate of melanomas being diagnosed in workers in the petroleum industry. It appears that workers in the petroleum industry are likely to have melanomas diagnosed sooner than in the general population. This increased rate of reporting can cause an increased melanoma incidence rate. However early diagnosis and treatment can increase the survival rate. Not surprisingly therefore, the death rate from melanoma in the petroleum industry is less than the Australian average.
The death rates for heart disease, stroke, respiratory and digestive diseases and other causes (eg. accidents) are significantly lower than the comparable Australian rates.
Effects of lifestyle
Health Watch results show that smoking has a powerful effect on the risk of early death, and that quitting smoking noticeably reduces the risks. The death rate from all causes increases significantly the more cigarettes smoked. For those who have low to moderate alcohol consumption, the overall death rate appears to be lower compared with those who don't drink at all. Those who drink more than five glasses of alcohol daily have a higher death rate.
BENZENE – OCCUPATIONAL VERSUS COMMUNITY EXPOSURE
The Health Watch study only looks at those who work in the petroleum industry. Benzene exposure in the nonsmoking Australian community is much lower than the occupational exposure level and petroleum companies have been working to steadily reduce the benzene content in petrol.
THE FUTURE OF THE HEALTH WATCH STUDY
AIP is committed to supporting Health Watch because it is highly valued by the petroleum companies and their employees and is an internationally respected study. The Study also provides a robust scientific basis for the community to understand the health impacts of exposure to petroleum products. For these reasons, AIP and its member companies have decided to significantly expand the Health Watch Study from 2008.
FOR FURTHER DETAILS ABOUT HEALTH WATCH
Health Watch Frequently Asked Questions (FAQs)
The answers to many frequently asked questions in relation to Health Watch are available from the following link:
The latest Health Watch reports give the findings in more detail. Available below are the 13th, 12th and 11th Health Watch Reports and the Health Watch Case Control Report (called the Lympho-haematopoietic Cancer and Exposure to Benzene in the Australian Petroleum Industry, Technical Report and Appendices).