gamma-Ray spectrometric and alpha-counting method comparison for the determination of Pb-210 in estuarine sediments

An intercomparison of methodology and of dating results, from alpha -counti ng and from the more recent gamma -spectrometry method, has been made for m arine sediment cores from several locations. The former method involves con siderable chemical manipulation, whereas the latter is more straightforward and enables direct interpretation of the results, Similar precisions (simi lar to 12%) were found for both methods. With the constant flux model, the methods gave calculated sedimentation rates between 4.3 and 7.8 cm a(-1) fo r replicate cores near a ferry pier in Hong Kong Harbor. The gamma -spectro metry method is thus a reliable, more rapid method for routine monitoring a nd investigation of the harbor dynamics and history of pollution.