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 tracks over 20,000 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 typically 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) during major recruitment drives in the 1980s. 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 five industry surveys since the 1980s (including a recent survey over 2010–12), 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.

The Australian Institute of Health and Welfare (AIHW) compiles data for the National Death Index (NDI) and the Australian Cancer Database (ACD) on behalf of all State Death and Cancer Registries. Deaths and cancers for past and present employees in Health Watch are obtained by matching the Health Watch data (obtained when Monash conducts a survey of employees) with the data from the Registries.

Results are published in periodic Health Watch reports (of which the latest report is the 14th) 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

Overall, the Study clearly shows that petroleum industry employees have better health than the general Australian community are less likely to die from cancer and from heart, respiratory and digestive diseases than the general population.

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

Compared with the general Australian population, the death rate in the Health Watch cohort is about 30% lower for men and women compared to the national rates, and lower for men in all major disease categories: heart disease (25% lower), cancer (20% lower), respiratory disease (30% lower), diseases of the digestive system (40% lower) and external causes such as accidents (40% lower).

Leukaemia

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, more recent reports including the latest report show the risk of leukaemia is no greater than in the general population. This is true even of acute non-lymphatic leukaemia (ANLL), which has been associated with exposure to benzene, where ANLL cases in Health Watch are lower than the number of cases expected in the general population.

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.

Asbestos-related Cancers

There have been 39 cases of mesothelioma diagnosed among Health Watch members. This cancer is strongly associated with asbestos exposure. According to Monash University, it is likely that several of these cancers are related to asbestos exposure in refineries before the 1970s, although it is possible that some could be from asbestos exposure outside 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 (20% lower than national rates). This means there can be few, if any, asbestos related lung cancers.

Other cancers & Health Watch results

Compared to the general Australian population, Health Watch results (particularly for men) also show:

• lower rates of cancer of the liver, lip, oral cavity and pharynx;
• the same chance as the general population of developing cancer, which includes for men kidney cancer, bladder cancer (which previously had an elevated risk), and cancers of the colon, stomach and pancreas;
• 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;
• prostate cancer is the most common cancer in men in the Health Watch cohort (730 cases) and there are more than the expected number of cases of prostate cancer in Health Watch compared to the national rates; however, deaths from prostate cancer in the Health Watch cohort are at the same rate as that of the general population; according to Monash University, “these findings may suggest that members of the cohort are screened for prostate cancer at a greater rate than the general population and may indicate a screening bias whereby more cases are detected earlier, but at a stage when treatment is likely to have a more successful outcome”;
• a similarly low chance of dying or of getting cancer or heart disease no matter where Health Watch members worked including upstream production sites, refineries, terminals and airports.

The Health Watch findings in relation to all cancers, particularly those currently in excess, will continue to be closely monitored.

Other diseases

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. Combining all causes of death, it is estimated that smoking has played a part in about 883, or 39% of the 2,265 deaths among Health Watch members.

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. Heavy drinking (more than 7 drinks per day), however, remains associated with 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 expanded the Health Watch Study over 2010–12.

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:

Health Watch Frequently Asked Questions	Download PDF

Latest Health Watch Reports

The latest Health Watch reports give the findings in more detail. Available below are the 14th, 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).

14th Health Watch Report – Full Report	Download PDF
14th Health Watch Report – Summary	Download PDF
14th Health Watch Report – Employee Infosheet	Download PDF
13th Health Watch Report	Download PDF
12th Health Watch Report	Download PDF
11th Health Watch Report	Download PDF
Health Watch Case Control Report	Download PDF