HSE Chemicals in the Environment Series
Written by Dr Richard Thwaites, FRACI CChem
Published 7 July 2020
If the meeting had been held in a Hall, the “House Full” sign would have been put up at the doors. Nearly 200 people registered for the event, but unfortunately not everybody could be accommodated on the night: a recording of the meeting was made and will be available to anybody who wants to follow up this really important and informative seminar. (For information please contact the National Office)
Dr Bradley Clarke is a Senior Lecturer at the University of Melbourne, and Messrs. Jaye Marchiandi and Drew Szabo are a couple of his research students. Brad’s research group focuses on assessing the risk to public health and the environment from persistent organic pollutants (POPs), including per and poly fluoralkyl substances (PFASs), brominated flame retardants (BFRs) and microplastics. Brad is the lead researcher of the Australian Laboratory for Emerging Contaminants (ALEC) which is an industry aligned collaboration that applies cutting edge analytical techniques to solve problems of chemical contamination.
Brad provided some alarming statistics about the prevalence of synthetic organic compounds in all forms of animal life. Every human baby born today contains synthetic chemicals which were unknown to humanity and were not even discovered or invented 50 years ago! Brad said that the CAS registry comprised over 147 million unique organic substances, the properties and effects on the environment of many of which are quite unknown.
The main focus of Brad’s presentation was the chemical warehouse fire in West Footscray in August 2018 which lasted several days. Although the fire fighters used fluorine free fire-fighting foam, run-off to an adjacent waterway (Stony Creek) contained fluorine containing chemicals, among many other species, indicating that many unknown chemicals had been stored illegally in the warehouse.
Brad noted that PFOS and PFOA also known collectively as PFAS had been around since the 1950s, and had been incorporated into numerous household products such as non-stick cookware, fabric protection, etc. as well as into industrial products and fire-fighting foams. They are now ubiquitous, and because of their long-term stability, persistence, and ability to bioaccumulate they are difficult to eradicate. They are of concern because of their potential ill-effects on health, various examples of which Jaye mentioned in his later presentation. Industry has developed various alternatives to the original C8 per and poly fluorinated molecules, with varying chain lengths, in an attempt to retain the performance benefits without the potential health problems, but they all still contain fluorine atoms.
The research program that Brad described covered sampling of Stony Creek after the fire both upstream and downstream from where run-off from the fire occurred, and applying new sophisticated analytical techniques such as time of flight mass spectrometry to identify the range of contaminants originating from the fire. PFAS concentrations of impacted surface waters ranged from 525 to 4110 nanograms per litre, compared with 88 to 105 ng/l upstream from the fire.
In his presentation, Jaye Marchiandi presented his soon to be published work on “Exposomics”, a term which was new to many in the audience. He talked about the effects of PFAS on health and disease. For example, from the early days of the development of PFOA, the du Pont Company discharged factory effluent which contained PFOA into ground water: soon clusters of health problems started to emerge. Lots of new fluorinated compounds have since been developed. The question will arise will exposure to any of these result in similar (or different) health outcomes.
Drew Szabo reported on his work, analysing for per and polyfluoroalkyl substances (PFASs) in the livers of fledgling shearwaters (aka mutton birds) found on Lord Howe Island. PFAS was used in fire-fighting foams at the airport for training purposes, which could well have been the source of any PFAS which might be found in sea birds. He worryingly also found that 70% of the birds also had plastic and other debris (with no or even negative nutritional value) in their intestines.
The seminar, chaired by Dr Ian Thomas, included an excellent interactive question and answer session. Ian referred to the allegedly serious proposal to modify the atmosphere of the planet Mars by introducing sulfur hexafluoride and octafluoropropane to create an artificial “greenhouse warming” effect to in theory make it habitable for human life. He commented that it seemed absurd that humans (not content with what we are doing here on earth) would mess up another planet before we had even been there!
The seminar told us a lot about the latest most up to date analytical techniques to detect and identify persistent organic contaminants. It is good to know that analytical techniques are getting so sophisticated that even nanogram quantities of contaminants which may cause subsequent health problems (to humans, other animals, birdlife and fish) can be detected. To know what to do about the information, and to eliminate the problems without eliminating the benefits of the chemicals concerned is the challenge of the future.