10 March 2020
By Dr Wendy Winnall - Scientific writer for PCFA.
Australian professional and volunteer firefighters do a brave and difficult job. Their recent efforts during the 2019-2020 bushfire season have saved many lives. But there is evidence that firefighters have an increased risk of some cancers. Are our firefighters more likely to get prostate cancer?
Firefighting in Australia
There are many different kinds of firefighters in Australia. Professional metropolitan firefighters usually attend fires in major cities. Bushfires are often fought by volunteer firefighters from state-based organisations. There are thousands of professional and volunteer firefighters in Australia.
Firefighters are potentially exposed to a range of chemicals during the course of their work. This includes mixtures of smoke, toxic gases, fumes and compounds formed due to high temperatures. These contain many known and potential carcinogens – cancer-causing substances. Whilst firefighters often wear protective and breathing gear to reduce their exposure, there is still some risk. If firefighters are exposed to cancer-causing substances as part of their jobs, then it’s possible that they have increased risks of some cancers.
The recent 2019-2020 bushfire season has seen many thousands of firefighters potentially exposed to smoke from burning bushland and buildings. It’s certainly too early to measure any increases in cancer for these people. However, there have been many long-term studies of firefighters around the world that have addressed their risk of cancer.
Cancer risks for firefighters
A comprehensive study of firefighters in Florida was recently published. The senior author of the study is Prof Erin Kobetz from the Sylvester Comprehensive Cancer Center in Miami, Florida. The research team used information from firefighter employment records and the Florida Cancer Data System registry to conduct their study. They accessed records from 109,009 people employed in fighting fires in the state of Florida. These records were used to search the cancer database containing 3.3 million reports of cancer diagnoses in Florida from 1981 to 2014.
By comparing the two sets of data, 3,760 cases of cancer in male firefighters and 168 cases in female firefighters were detected. The study found that male firefighters had an increased risk of some cancers: melanoma (skin cancer), thyroid cancer, late-stage colon cancer, testicular and prostate cancer. For prostate cancer, there was a 1.36-fold increase in risk of diagnosis. This means that for every 100 non-firefighters diagnosed, there were 136 firefighters diagnosed with prostate cancer over the same age groups.
Numerous other studies have estimated the risk of prostate cancer in male firefighters. A Swedish study found a small increase in the risk of prostate cancer for firefighters. But this only occurred in men who had been in the job for 30 years or more. A systematic review of 50 high-quality studies from around the world estimated a lower risk than for Florida. This study found a 1.15-fold increased risk of prostate cancer diagnosis – meaning that for every 100 non-firefighters with prostate cancer there were 115 male firefighters diagnosed.
Prostate cancer in Australian firefighters
Firefighting in Australia is conducted under unique circumstances. People fighting bushfires in Australia are exposed to smoke from the unique flora present in Australian bushland. Assuming this smoke exposure is contributing to the risk of cancer, then the risks for Australia firefighters needs to be studied here.
A large project was conducted by researchers at Monash University in Victoria. The Australian Firefighters’ health study was completed in 2014. The aims of this study were to measure cancer rates and causes of death for Australian firefighters. This study found that for Australian male firefighters:
- Professional full-time male firefighters (17,394 people) had 1,208 new cases of cancer and 780 deaths
- Part-time paid firefighters (12,663 people) had 485 new cases of cancer and 286 deaths
- Volunteer firefighters (163,159) had 4,647 deaths and 7,057 new cases of cancer.
The researchers used Australian population data to calculate the expected numbers of deaths and
cancers for each firefighter group based on age groups. There were many different findings from this study:
Overall death rates
The death rate for all major causes of death was relatively low for male paid and volunteer firefighters. Firefighters were generally a healthy group of people. This is likely to be a result of what’s called the healthy worker effect. It’s common to see that people who work are healthier than the general population (of the same age groups). Firefighters need to be fit and healthy to do their jobs, so it's not surprising that these people are healthier than the general population.
Firefighters also had a lower risk of dying of cancer than their non-firefighting Australian counterparts. However the risk of dying from cancer was not very much reduced compared to other diseases.
This does not mean that fighting fires was protecting people from dying from diseases such as cancer and cardiovascular disease. It’s more likely that people who choose, and are able to do the job, are healthier to start with, and they maintained their health and fitness to perform this difficult job.
Prostate cancer in Australian male firefighters
Despite relatively low cancer death rates for fire fighters, the number of new cases was increased for some cancers. For most types of cancer, the risk was not higher. In fact, for many cancers, firefighters had a lower risk. This is consistent with the healthy worker effect described above.
Professional full-time firefighters had a significantly increased risk of prostate cancer diagnosis. This was particularly so for men who were employed for more than 20 years. The risk for full-time firefighters was 1.23-fold higher than non-firefighters of the same ages. Part-time paid firefighters also had an increased risk of being diagnosed with prostate cancer.
For volunteer firefighters, there was no overall trend for increases in cases of cancer. But this story was different when just prostate cancer was investigated. These men had an increased risk of prostate cancer compared to the general population if they had served for over 10 years. The increased risk was 1.12-fold – a small but statistically significant increase.
What’s causing the increase in prostate cancer?
Unfortunately we don’t have sufficient scientific evidence to pinpoint the actual causes of this increase in prostate cancer for Australian firefighters.
The answer to this question is likely to be complicated. There are many possible causes of any cancer. Firefighters are exposed to a wide range of potentially carcinogenic compounds. We don’t yet know which of these is most problematic.
Another factor that complicates the results of such studies is that the increased risk of prostate cancer is more likely for men who worked for 10 years or 20 years as firefighters. Equipment and processes to reduce the risk of chemical exposure have improved over the past 20 years. So the risk factors causing these past cases of prostate cancer may not be the same for men who are fighting fires today.
It’s important to understand these causes in order to protect firefighters from prostate cancer. An increased investment in research would help identify the most dangerous exposures for Australia’s brave firefighters and help to reduce their risk in the future.
If you are, or have been, a firefighter in Australia and are concerned about your risk of cancer, you may find more information by contacting your employer, your state’s workplace safety organisation or your union. Compensation may be available for firefighters diagnosed with prostate cancer.
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