210Po, 210Pb, 226Ra in Aquatic Ecosystems and Polders, Anthropogenic Sources, Distribution and Enhanced Radiation Doses in the Netherlands

Abstract

Surveys of Dutch waters show that the Oosterschelde estuary and regular fresh waters have the lowest levels of 210Po, 210Pb and 226Ra. Elsewhere effluents from phosphates and iron ore processing industries cause nearby enhancements. At a distance of 50–100 km enhancements of 210Po in edible parts of mussels and shrimps are of the order of 100 Bq.kg-1 dry weight. Estimates indicate that high consumption rates of fishery produce from specific waters may result in dose enhancements of 0.1–0.3 mSv.y-1. Which probably affect a group of less than 1000 anglers and an unknown number of frequent mussel and shrimp consumers. Harbour sludge, with probably enhanced activity levels due to the phosphogypsum effluents, has been used as landfill in polders around Rotterdam. Here enhanced doses of 0.3–1 mSv.y-1 may occur from consumption of local livestock produce and from inhalation of enhanced indoor radon. Further research is indicated to obtain information on effluent emissions, their associated environmental enhancements and risks.