Concerns that radioactive contamination could be responsible for the deaths of six people who worked in a university building where pioneering atomic experiments took place at the start of the 20th century have been quelled after an independent inquiry found no link.
Former university staff called for a review of the Rutherford Building — where nuclear physicist Ernest Rutherford conducted experiments on atomic structure in the early 1900s — in a report published in June last year. It followed the authors’ chance discovery in 2001 that the building where they worked had been found in 1999 to be radioactively contaminated.
Over the course of the independent investigation it became apparent that at least three cases of pancreatic cancer and two cases of brain cancer had occurred among people who had worked in the Rutherford Building, as well as a possible case of motor neurone disease. In the last two years alone, four people who occupied the building have died. These followed the death from cancer of a lab assistant in 1984, and lecturer, Dr John Clark, who died from a brain tumour in 1992.
Presenting the findings of his inquiry on 30 September, Professor David Coggon, from the University of Southampton, concluded that the deaths were not a result of contamination. He said: “Despite some uncertainties about exact levels of contamination in the past, I think we can be pretty confident that any risks to health have been small, and that the cases of cancer that have occurred among former occupants of the Rutherford Building are not a consequence of the contamination.”
For long-term occupants, lung cancer posed the greatest potential health risk from contamination by radioactive chemicals, according to the professor. Yet, even allowing for uncertainties in the assessment of historical exposures to radiation, the risk is expected to be small. Excess risks of pancreatic cancer and brain cancer will have been substantially less than those for lung cancer — calculated at less than one excess death per 10,000 people.
Potential risks of cancer from ionising radiation in future occupants of the Building, and in maintenance workers carrying out structural repairs were calculated to be lower than those in long-term past occupants.
Referring specifically to the cluster of cases of pancreatic cancer, Professor Coggon said that the most plausible explanation for the deaths is “chance coincidence”.
Given the low potential for risk identified by the report, no form of health screening or other health intervention has been recommended for people who may have been exposed to hazardous contaminants in the building. However, it does suggest more exploration of the chemical form and origin of the mercury contamination in waste removed from the building during refurbishment work carried out between 2004 and 2006, and limited additional monitoring of mercury levels in air.
The report also states that, prior to the carrying out of any future intrusive maintenance work that could cause significant disturbance to floor or wall materials, a radiological risk assessment should be conducted.
