By Dr Anthony Horton
Earlier this week, the Australian Federal Government announced a plan to phase out unleaded petrol within 2 years. The basis of this plan is unleaded fuel sold in Australia has the highest sulphur concentration of 35 OECD countries – according to the current Australian fuel quality standards, the sulphur concentration of unleaded fuel is 500 parts per million (ppm). As part of their announcement, the Government launched two Regulations and a discussion paper covering fuel quality, vehicle efficiency and vehicle emissions in Australia. Having reviewed these documents, the omission of the health impacts of benzene emissions from petrol leaves me to conclude that the Government’s planned phase out of unleaded petrol is a bit on the nose.
In the Regulations and discussion paper there is a clear focus on the economic impact(s) of increasing the fuel efficiency of vehicles sold in Australia and of tightening Australia’s fuel quality standards. Economic impact(s) are certainly an important consideration – cost benefit analysis has been part of standard business operations for decades. Drilling down into the economic positions presented in these documents however, I find it particularly interesting that the economic impact in terms of health outcomes is discussed in terms of particles, oxides of Nitrogen (NOx) and Sulfur (SOx) and ground level ozone. This is interesting because while particles, NO2 and SO2 and ozone are important emissions from vehicles, a thorough economic assessment of the health outcomes should also include benzene. Benzene has replaced lead in petrol and is an aromatic compound – one of the first chemicals you may smell when filling up your petrol tank.
As someone who has worked in air pollution monitoring and management for more than 15 years and completed a PhD examining the excess lifetime leukaemia risk of exposure to benzene in petrol, I find the omission of benzene from the health outcome discussion disappointing. Like many chemicals, benzene has acute and chronic exposure symptoms and has been known to be carcinogenic (extremely harmful to humans) since the 19th century. The acute (short term) exposure health effects range from dizziness and euphoria to vomiting and loss of consciousness. The chronic (long term) exposure heath effect is leukaemia – based on exposure to very high concentrations over many years in occupational settings. As a result of the link between occupational exposure to benzene and leukemia, benzene has been phased out in many industries in which it was used (e.g. chemical manufacture).
As part of my PhD I conducted a study of personal exposure to benzene in petrol and recruited participants who were not exposed to benzene as a result of their occupation or from smoking. In addition to monitoring participants’ personal exposure, I monitored benzene concentrations at petrol bowsers, along freeways and in multi-storey carparks. Suffice it to say the highest concentrations were found at the bowsers which may surprise some people given that refuelling may only take 1 minute or so (depending on the capacity of the fuel tank). I suspect that many people fill up their vehicle fuel tank without giving much thought to the emissions that are around them.
The last stage of my research was a risk assessment which sought to determine what added cancer risk refuelling once per week posed over a lifetime. I used a World Health Organisation (WHO) risk assessment methodology which based the risk on a lifetime of 70 years. I found that the excess lifetime risk of refuelling once per week was approximately double that of commuting in Perth. Throughout most of North America and Europe, laws have existed for decades which mandate equipment being attached to the bowser hose that is essentially a vacuum. When you insert the nozzle from the bowser into your vehicle fuel tank, the vacuum forms a seal around the nozzle and tank so that your exposure is greatly minimised (if there is any exposure at all). To date, only one Australian state (New South Wales) has introduced a rollout of vapour recovery at petrol bowsers.
A previous article I wrote last year ‘Australian Government review of vehicle emissions has a now familiar aroma of disappointment’ discussed the Federal Government’s announcement of a working group charged with the responsibility of examining the implementation of Euro 6 vehicle emission standards for light duty vehicles (cars and vans), fuel quality standards, fuel efficiency measures for light duty vehicles (focusing on CO2) and vehicle emissions testing. In my article I expressed concern that the Government was ignoring the exposure of petrol station customers to benzene at the point of sale and in this week’s announcement regarding the planned phase out of unleaded petrol, it appears that the Federal Government has again missed an opportunity to reduce air pollution emissions and improve the health outcomes of Australian motorists by failing to acknowledge that any review and discussion of fuel quality and vehicle emissions in Australia must include benzene.
About the author: Anthony Horton holds a PhD in Environmental Science, a Bachelor of Environmental Science with Honours and a Diploma of Carbon Management. He has a track record of delivering customised solutions in Academia, Government, the Mining Industry and Consulting based on the latest wisdom and his scientific background and experience in Climate/Atmospheric Science and Air Quality. Anthony’s work has been published in internationally recognised scientific journals and presented at international and national conferences, and he is currently on the Editorial Board of the Journal Nature Environment and Pollution Technology. Anthony also blogs on his own site, The Climate Change Guy.