Is there life after industry? – Prof Michael Johnson

Prof Johnson had conducted a fundamental review of natural environmental services at the University of Liverpool in partnership with Merseyside County Council. He had held a lectureship at Liverpool, & had then been offered a chair at Imperial College, London. However, the Rio Tinto Company had endowed a personal chair for him at the University of Liverpool, following which he sometime later moved into the private sector as a consultant to the mining industry.

He had studied the estuaries & coastal waters, & particularly pollution of the Mersey Basin. High levels of toxic metals (Hg & Cu) had been found in the fish in these waters, with peak levels of Hg in ~ 1980 thru 2015. Discharge from local chemical industry was found to be the source of this pollution. There were also toxic organic pollutants (e.g. pesticides & PCBs) found in estuary fish. By comparison, the Dee estuary was much less polluted.

Air quality

An early (1970s) form of bio-monitoring had established the existence of fluoride around Al refineries, which was very hazardous to neighbouring livestock. However, modern refineries were designed with environmental controls. It had been found that daffodils were very sensitive to the presence of HF, SiF4 & H2SiF6.. Fluorosis had been studied in the wood mouse (Apodemus sylvaticus), which was a good surrogate for livestock but having a feeding range of ~ 100m. F combines with P in the bones to form apatite, leading to rot of the teeth & bones. A good remediation of this problem was to buy the neighbouring farm from the farmer & sell it back to him at a nominal price under the condition that he conduct arable rather than livestock farming.

Water Pollution

A case study at the Santiago Cru mine in Spain showed that fish had died in the River Ulla in Galicia. Acid main drainage was only part of the problem. Detective work had shown that very high Al concentrations in low pH water, when mixed with high pH water resulted in microscopic precipitation of Al(OH)3. These particles blocked the gills of fish. The Rio Tinto river had been found to have a pH of as low as 1.8 at times, which could erode concrete. However, a modern treatment plant in Portugal was capable of producing potable water.

Waste Management

Work for British Nuclear Fuels a Sellafield, Cumbria had seen a transition from indiscriminate dumping at Drigg to containerised placement of low-level waste in a licensed depository. This site had now become a wildlife haven free from human interference. Radioactive liquid discharge from Sellafield into the Irish Sea had reduced rapidly from 1970 thru 2012 owing to better controls, as evidenced by the levels of Cs137 in fish.

Dramatic improvement in Hg catalyst pollution from an HF plant had been achieved by an innovative use of anhydrite waste (normally CaSO4.1/2H2O) by layering the anhydrite with polluted material with more anhydrite, etc. When mixed with rain, and encased in a gypsum CaSO4.2H2O (Plaster of Paris) sarcophagus, significant improvement was obtained.

Land pollution

The Grasberg mine in W Papua had had problems with waste containment owing to seismic activity. The Aykwa river estuary had effectively become a low level tailings site, which was unfortunately on the border of the Lorentz National Park, a UNESCO World Heritage Site. Rio Tinto Minera had also become an example of how a fully denuded landscape could result from pollution by SO2 forming H2SO4. At Aznalcollar (Los Frailes, Spain), a tailings wall had breached owing to a foundation failure of clays in the separation dam. The tailings were very high in levels of Cd, Hg, etc., hence very toxic. This had caused huge damage in the Donana National Park (another UNESCO World Heritage Site). A massive remediation programme was undertaken involving rapid removal of toxic debris, & reconstruction of the damaged environment to produce a wildlife ecosystem. This had demonstrated how adaptable flora & fauna were, and might flourish as a result of hybrid vigour.