中文摘要：

运用1：20万地球化学数据和现场伽马能谱数据，评价了珠海市区的放射性水平情况。从区域地球化学数据中得到珠海市区内天然放射性核素238 U、232 Th、40 K的比活度为29．64～229．71 Bq/kg，64．55～397．88 Bq/kg和127．81～1361．55 Bq/kg。研究表明该地区内的天然放射性核素含量普遍较高，其中花岗岩地区的放射性核素含量较高，第四系沉积物放射性水平较低，可能受到南屏-唐家断裂带和南屏断裂带的影响，地区中部的238 U、232 Th、40 K含量比其他区域都要高。因此，利用地球化学数据取得土壤放射性核素的含量，推算放射性核素的比活度，圈定测区的异常区域，分析研究该区域内的核辐射环境水平，是一种有效可行的评价方法。

英文摘要：

Based on 1：200000 geochemical data and gamma spectroscopy ,the article made an evaluation of radi-oactivity in Zhuhai .From the regional geochemical data ,the specific activities of 238 U、232 Th and 40 K in the city are 29.64~229.71 Bq/kg,64.55~397.88 Bq/kg and 127.81~1 361.55 Bq/kg respectively.The study show that the natural radionuclide content is relatively high in the place ,and the radionuclides of granite areas are more higher than Quaternary sediments .On the other hand ,238 U、232 Th and 40 K levels in regional central are higher than other regions because of Nanping -Tang fault and Nanping fault .Therefore ,using soil geochemical data to obtain the specific activities of radionuclides and delineate the abnormal area ,and then surveying the re-gion’s level of nuclear radiation environment based on gamma spectrometry is a feasible and effective methods .