ISSUES OF NATURAL RADIOACTIVITY IN PHOSPHATES

The fertilization of phosphorus (P) fertilizers is essential in agricu ltural production, but phosphates contain in dependence on their origi n different amounts of trace elements. The problem of cadmium (Cd) loa ds and other heavy metals is well known. However, only a limited numbe r of investigations examined the contamination of phosphates with the two heaviest metals, uranium (U) and thorium (Th), which are radioacti ve. Also potassium (K) is lightly radioactive. Measurements are done o n the radioactivity content of phosphates, P fertilizers and soils. Th e radiation doses to workers and public as well as possible contaminat ion of soils from phosphate rock or fertilizer caused by these element s or their daughter products is of interest with regard to radiation p rotection. The use of P fertilizers is necessary for a sustainable agr iculture, but it involves radioactive contamination of soils. The cons equences of the use of P fertilizers is discussed, also with regard to existing and proposed legislation.