Professor Coggon's recommendations
Professor Coggon's review has two recommendations for the University.
"Further work has since been initiated to address the residual contamination by mercury. After completion of this work, repeat environmental monitoring for mercury should be carried out in the rooms concerned and in those adjacent to them (since changes in under-floor airflow associated with the remedial work might alter levels of mercury in adjacent rooms). In addition, it would be prudent to carry out further monitoring of mercury levels in air in those rooms, which in the most recent HSL survey, had airborne concentrations of mercury in excess of 4 μg/m3. The purpose would be to check that the measured values were not unrepresentatively low, with higher levels at other times of year. Thus, this additional monitoring (both post- remediation and in those rooms with measured concentrations above 4 μg/m3) should be carried out on four occasions at three-monthly intervals over the course of a year."
Further mercury monitoring has been commissioned from HSL, been undertaken and will continue as part of the long term maintenance programme for the building. Results of this monitoring will be updated here.
- HSL report on mercury monitoring (June and December 2009)
- HSL report on mercury monitoring (March 2010)
- HSL report on mercury monitoring (November 2010)
- HSL report on mercury monitoring (February/March 2011)
- HSL report on mercury monitoring (May/June 2011)
To support the ongoing monitoring programme, the University's Health and Safety Committee has agreed the following threshold levels:
"It would, however, be prudent to explore further the chemical form and origin of the mercury contamination of the waste removed from the Rutherford Building during the refurbishment carried out during 2004-06. In particular, it would help to establish whether the non-metallic mercury that is present in the waste is likely to have resulted from a chemical reaction of split mercury that collected under the floorboards, or to have been a contaminant of cotton insulation material when it was originally installed."
Work has been undertaken by our own chemists in the School of Earth & Atmospheric Sciences to analyse mercuric compounds contaminating the sub-floor floc, which had previously been removed from the building. The results are inconclusive and do not appear to confirm the observations made in the original analysis referenced in Professor Coggon's report. We are currently engaged with HSL in order to establish what, if any, further analysis should be undertaken.