Cataract formation following chronic radiation exposure (JS)

PI: Jim Smith, University of Portsmouth.

The formation of cataract in humans due to occupational or accidental exposure to acute ionising radiation is well documented. However, little is known about the effect of long-term chronic exposure through the life span of organisms exposed in the natural environment.  A recent study of voles at Chernobyl (Lehmann et al. Scientific Reports 6; 2016), apparently found significant increases in cataract incidence at cumulative doses as low as 10 mSv. This generated significant media coverage and, if true, would represent a major challenge to current radiation protection regulation. Key flaws in this study, however, were the method of field sample preservation/preparation, and the subjective nature of the lens opacity measurement.

The purpose of the proposed study is to further develop methods for stabilisation and preparation of fish lens samples to measure any ultrastructural changes to the constituent crystallin proteins within the lens fibre cells caused by environmental radiation damage. We will also collect fish lenses from lakes contaminated by the Fukushima accident to complement samples we have from Chernobyl. To analyse these unique samples, we plan to use the low angle X-ray diffraction beamline (I22) at the Diamond Synchrotron. This will provide highly sensitive data giving objective and quantitative results.