Expert Comment: Fatberg Autopsy

Posted on 30 April 2018

Dr John Wilkinson (Environment) was part of a team of experts who took part in Channel 4’s Fatberg Autopsy: Secrets of the Sewers. Here he tells us about what they found when they analysed samples of the giant block of fat removed from sewers under central London.

The filming of Fatberg Autopsy. Credit: Dr John Wilkinson

“We came up with a method to analyse the components of the fatberg using ultrasonic solvent extraction and then mass spectrometry. Specifically, we looked at the quantities of 40 different pharmaceuticals, three plasticisers, four perfluorinated surfactants as well as benzoylecgonine (the main urinary metabolite of cocaine).

Contaminants

“Surprisingly, there were relatively low concentrations of these chemicals in the fatberg itself; however we did find high concentrations of pharmaceuticals and many of the other contaminants in the sewage flowing around the fatberg.

“Most interesting to me was the high concentration of the antibiotic ciprofloxacin in the London sewage water sample. We’ve done quite a bit of work here in York and nearby areas looking at this pharmaceutical and found concentrations generally about 10 times lower in untreated sewage. I suspect that the part of the sewer where the London samples came from was receiving waste water from a hospital.

Environment

“It’s unlikely that residues of these pharmaceuticals in sewage, or indeed in fatbergs, directly affect human health. The chemicals in these samples would have made their way to a sewage treatment plant in London where they will have been predominately degraded then discharged into the Thames. The way in which such contaminants may affect organisms in the aquatic environment though is a question that’s still being studied.”