Present study is an attempt to identify the source of monazite deposits and understand the dynamics of natural radionuclides in the coastal environs of Alappuzha and Thiruvananthapuram districts, south west coast of India. The source of monaztite bearing black sands was identified by combining the activity concentration of the natural radionuclides, lithology and drainage systems of Alappuzha and Thiruvananthapuram districts. The activity concentrations of naturally occurring radionuclides (40K, 226Ra, and 232Th) in sand samples collected from the study area were determined using high efficiency NaI(Tl) detector. The radiological parameters viz. radium equivalent activity (Raeq), absorbed dose rate (D), annual effective dose (indoor and outdoor), annual gonadal dose equivalent, and excess lifetime cancer risk were also determined from the activity concentration and compared with the values reported for the other regions of the world. The results of these systematic investigations are presented and discussed in detail in the manuscript.

中文翻译：

---

印度西南海岸喀拉拉邦选定沿海地区独居石矿床来源和天然放射性核素动态的地理空间分析

目前的研究试图确定独居石矿床的来源，并了解印度西南海岸阿拉普扎和蒂鲁文南特布勒姆地区沿海环境中天然放射性核素的动态。结合阿拉普扎和蒂鲁文南特布勒姆地区天然放射性核素的活度浓度、岩性和排水系统，确定了含黑砂的独居石的来源。使用高效 NaI(Tl) 检测器测定从研究区收集的沙样中天然存在的放射性核素（40K、226Ra 和 232Th）的活度浓度。放射学参数即。镭当量活度（Raeq），吸收剂量率（D），年有效剂量（室内和室外），年性腺剂量当量，还根据活动浓度确定了终生癌症风险，并与世界其他地区报告的值进行了比较。这些系统研究的结果在手稿中详细介绍和讨论。