Chernobyl-derived radiocesium in heather honey and its dependence on deposition patterns

Gamma-ray spectra were measured from Scottish heather honey samples gathered from hive locations with associated airborne gamma-ray survey data. The honeys all contained radiocesium, with activity concentrations ranging from 43-680 Bq kg(-1) 137Cs, and 134Cs/137Cs ratios consistent with Chernobyl deposition. Activity concentrations in honey were highly correlated with ground deposition within 2.5 km of the hive location over two successive years. Both isotope ratios and the quantitative relationships between environmental and food levels suggest that weapons testing fallout is significantly less available than recent deposition. The implications for design of future monitoring programs and radiological consequences are discussed. The whole-body retention of 137Cs in honey ingested by a volunteer was consistent with the ICRP's metabolic model for cesium.