Last month, some of Australia’s most iconic beaches were shut down by a plague of mysterious black balls.
While authorities initially thought these bizarre spheres were toxic tar balls, scientists have now revealed that their origins are far more disgusting.
Researchers from the University of New South Wales say that the balls are actually a foul mixture of raw sewage, cooking fat, soap scum, and drugs.
Chemical analysis shows that the orbs contain traces of veterinary medicine, steroids, and drugs including THC from cannabis and even methamphetamine.
Scientists who worked on the project say these chemicals are strong indicators that the balls contain a significant amount of human faeces.
This suggests that Sydney‘s black balls were not formed by an oil spill as many thought, but are actually chunks of a ‘fatberg’ typically found in city sewers.
Associate professor Jonathan Beves, who led the investigation, says: ‘Our analyses show that the material is not natural and cannot be attributed solely to an oil spill.
‘It is most consistent with human generated waste.’
Scientists have revealed the disgusting origins of the mysterious back balls plaguing Sydney’s beaches (pictured)
Chemical analysis shows that the balls (pictured) are likely to be solidified chunks of a fatberg formed when human waste mixes with oils and soap scum in the sewers
The mystery began on October 16 when hundreds of the strange spheres washed up on Coogee Beach, followed by more beaches including Clovelly and Maroubra.
Amid fears that they might be toxic, city authorities closed a total of eight beaches including Bondi and ordered a massive clean-up operation.
It was initially thought that the balls were a type of tar formed when leaking oil from a ship or off-shore rig mixed with cold water and debris.
Residents were warned not to touch the balls and some experts cautioned that they might be carcinogenic.
Each ball has a crusty exterior formed by accumulated sand and minerals surrounding a soft, sticky core.
‘They smell absolutely disgusting, they smell worse than anything you’ve ever smelt,’ lead investigator Professor Beves told 9News.
Using a barrage of different tests, the scientists have slowly been able to pick apart the chemical makeup of the strange balls.
Although preliminary investigations suggested that the balls resembled crude oil, Professor Beves explains that reality was far more complex.
The balls first appeared on October 16, triggering authorities to close down eight beaches including Coogee (pictured) and Bondi as well as ordering a massive cleanup operation
Initial tests suggested that the black balls could be a form of tar ball formed when crude oil comes into contact with cold water
Scientists found traces of veterinary medicine, steroids, and illicit drugs such as methamphetamine. This suggests that the balls contain some amount of human faeces
The balls are likely to be chunks of a fatberg which formed in the sewers when faeces mixes with oils and soap scum to form a solid lump
Most of the black goop making up the orbs was found to be carbon, but only 30 per cent of that came from fossil fuels like oil.
The remaining 70 per cent, the scientists found, was modern carbon from human sources.
Rather than being made up of solidified tar, the balls were actually a sticky mixture of cooking oils and soap scum.
However, further investigation revealed that this modern carbon contained hundreds of different chemical traces.
Professor Beves says: ‘We found the sticky spheres contained hundreds of different components, including molecules that derive from cooking oil and soap scum, PFAS chemicals, steroidal compounds, antihypertensive medications, pesticides, and veterinary drugs.
‘This combination suggests a mix of substances derived from both fossil fuels and plant or animal sources.’
When Professor Beves first examined the balls using Nuclear Magnetic Resonance (NMR) testing, his team found they contained some elements derived from petrolium.
However, the presence of medicines and drugs suggested that the black balls might have had a far more disgusting origin than a leaky oil tanker.
Initial tests showed that the balls glowed under UV light, this hinted that they may have some organic compounds mixed in with the petroleum-derived oils
All eight affected beaches have now been reopened, but the origins of the sewage leak are still unknown. Pictured: the Coogee Beach cleanup operation
Professor William Donald, who worked on the analysis, says: ‘Detecting markers of human faecal waste – like coprostanol – alongside recreational drugs like THC and industrial PFAS ‘forever chemicals’ pointed us to sewage and other sources of urban effluent as the most consistent origins.’
When soap, fat, and human waste mix in the sewage system, high levels of calcium can trigger these organic chemicals to clump into insoluble masses called fatbergs.
These are typically found in the sewers of large cities and require constant effort to break up and unblock.
This suggests that a sewage leak is the most likely origin of these mysterious black orbs.
However, the exact source of the contamination still remains a mystery.
Writing in The Conversation, Professors Beves and Donald, say: ‘The black ball incident does highlight the broader issue of pollution along Sydney’s coastline.
‘Even after all we did, we cannot yet draw definitive conclusions regarding the primary source of the blobs.
‘This uncertainty reflects the broader challenges faced by scientists and environmental agencies in tracking and addressing pollution in coastal areas.’