Radioactivity - Footnotes
1) Radon and gamma values are specific to Scotland. Other values are assumed to be the same as the UK average as published in the Health Protection Agency - Radiation Protection Division's publication: HPA-RPD-001 - Ionising Radiation Exposure of the UK Population: 2005 Review.
2) Because of rounding, percentages do not add up to 100.
3) From 1996 onwards, the concentrations reported were lower than the limit for detection. Note that figures pre-1996 were produced by the HPA who took milk samples from a number of milk depots throughout the country, in proportion to the quantity of milk handled by each depot in order to generate the data. Post-1996 the figures were produced by SEPA who collected samples and analysed them for sites remote from nuclear sites. As a result, the 1996-2010 figures are not strictly comparable with previous years, although they still represent average concentrations in milk in Scotland.
4) Unlike 137Cs, which was widely dispersed in the environment, 90Sr was mostly deposited near Chernobyl.