The present study aims at measuring the activity concentrations of ^210Po and ^210Pb in the potable water of Eloor, a major industrial belt in the Ernakulam district of Kerala, India with an aim of evaluating resultan...The present study aims at measuring the activity concentrations of ^210Po and ^210Pb in the potable water of Eloor, a major industrial belt in the Ernakulam district of Kerala, India with an aim of evaluating resultant ingestion dose to critical population. The industrial units located in Eloor discharge their treated effluents into the river Periyar and the surrounding environs. The two major industries of interest with respect to NORMs are the fertilizer plant, processing rock phosphate and the monazite processing plant, which had been in operation for the last 50 years. For sampling, Eloor region was divided into four zones and a total of 55 water samples from different locations were collected and analysed as per standard analytical procedure manual of BARC. The ^210Po concentration ranged between 0.3 to 4.7 mBq.L^-1 and ^210Pb ranged from 0.6 to 4.3 mBq.L^-1. All values are well below the limit of 0.1 Bq.Ll recommended by World Health Organization. Statistical analysis shows a good co-relation between ^210Po and ^210Pb in the water samples analyzed and the mean activity concentration is found to be relatively high in the western region of Eloor compared to other regions. The annual effective dose equivalent to man from ^210Po and ^210Pb through drinking water intake were estimated and found to be 1.13 μSv.y^-1 and 0.99 μSv.y^-1 respectively, which is well below the reference level of committed effective dose （100 μSv.y^-1） recommended by WHO.展开更多
大气^(210)Po、^(210)Bi和^(210)Pb的沉降通量是海洋中核素示踪颗粒物动力学过程(颗粒有机碳输出、颗粒物输运)的基础参数,为揭示我国近海地区^(210)Po、^(210)Bi和^(210)Pb活度浓度的时空变化规律并估算其沉降入海通量,本文于2016年9...大气^(210)Po、^(210)Bi和^(210)Pb的沉降通量是海洋中核素示踪颗粒物动力学过程(颗粒有机碳输出、颗粒物输运)的基础参数,为揭示我国近海地区^(210)Po、^(210)Bi和^(210)Pb活度浓度的时空变化规律并估算其沉降入海通量,本文于2016年9月至翌年2月和2021年9-11月分别对上海及厦门地区近地表大气气溶胶中^(210)Po、^(210)Pb和^(210)Bi的活度浓度进行了连续观测;基于^(210)Po-^(210)Pb活度比(^(210)Po/^(210)Pb)和^(210)Bi-^(210)Pb活度比(^(210)Bi/^(210)Pb)两种示踪法计算了气溶胶颗粒物的滞留时间,并利用一维简单气溶胶沉降速率模型估算了3种核素以大气沉降方式输入东海的通量。结果显示,2016年上海秋、冬两季^(210)Po、^(210)Bi、^(210)Pb 3种核素活度浓度的变化范围分别为0.11~1.27 m Bq/m^(3)、0.45~1.83 m Bq/m^(3)和1.12~6.10 m Bq/m^(3);2021年秋季厦门^(210)Po、^(210)Bi、^(210)Pb 3种核素活度浓度的变化范围分别为0.05~0.85 m Bq/m^(3)、0.83~2.52 m Bq/m^(3)和0.17~1.32 m Bq/m^(3),上海近地表气溶胶中3种核素的活度浓度秋季平均值比厦门地区高。利用^(210)Po/^(210)Pb和^(210)Bi/^(210)Pb计算得到上海和厦门近地面大气的气溶胶滞留时间存在显著差异,基于^(210)Po/^(210)Pb计算上海气溶胶滞留时间均值为(94±54)d,基于^(210)Bi/^(210)Pb计算上海气溶胶滞留时间均值为(6.4±4.8)d,造成这种差异的原因很可能是两种示踪法本身具有的系统性差异。本文基于一维简易气溶胶沉降速率模型估算了上海地区的^(210)Pb、^(210)Bi和^(210)Po的大气沉降入东海的通量,其在秋季期间的变化范围分别为0.1~26.35 Bq/(m^(2)·d)、0.04~7.91 Bq/(m^(2)·d)和0.01~5.49 Bq/(m^(2)·d)。基于模型估算的^(210)Po、^(210)Bi和^(210)Pb沉降通量与研究区域的实际观测值接近一致,表明利用一维简易气溶胶沉降速率模型间接估算法在替代观测站直测核素的沉降入海通量方面具有一定可行性。展开更多
文摘The present study aims at measuring the activity concentrations of ^210Po and ^210Pb in the potable water of Eloor, a major industrial belt in the Ernakulam district of Kerala, India with an aim of evaluating resultant ingestion dose to critical population. The industrial units located in Eloor discharge their treated effluents into the river Periyar and the surrounding environs. The two major industries of interest with respect to NORMs are the fertilizer plant, processing rock phosphate and the monazite processing plant, which had been in operation for the last 50 years. For sampling, Eloor region was divided into four zones and a total of 55 water samples from different locations were collected and analysed as per standard analytical procedure manual of BARC. The ^210Po concentration ranged between 0.3 to 4.7 mBq.L^-1 and ^210Pb ranged from 0.6 to 4.3 mBq.L^-1. All values are well below the limit of 0.1 Bq.Ll recommended by World Health Organization. Statistical analysis shows a good co-relation between ^210Po and ^210Pb in the water samples analyzed and the mean activity concentration is found to be relatively high in the western region of Eloor compared to other regions. The annual effective dose equivalent to man from ^210Po and ^210Pb through drinking water intake were estimated and found to be 1.13 μSv.y^-1 and 0.99 μSv.y^-1 respectively, which is well below the reference level of committed effective dose （100 μSv.y^-1） recommended by WHO.
文摘大气^(210)Po、^(210)Bi和^(210)Pb的沉降通量是海洋中核素示踪颗粒物动力学过程(颗粒有机碳输出、颗粒物输运)的基础参数,为揭示我国近海地区^(210)Po、^(210)Bi和^(210)Pb活度浓度的时空变化规律并估算其沉降入海通量,本文于2016年9月至翌年2月和2021年9-11月分别对上海及厦门地区近地表大气气溶胶中^(210)Po、^(210)Pb和^(210)Bi的活度浓度进行了连续观测;基于^(210)Po-^(210)Pb活度比(^(210)Po/^(210)Pb)和^(210)Bi-^(210)Pb活度比(^(210)Bi/^(210)Pb)两种示踪法计算了气溶胶颗粒物的滞留时间,并利用一维简单气溶胶沉降速率模型估算了3种核素以大气沉降方式输入东海的通量。结果显示,2016年上海秋、冬两季^(210)Po、^(210)Bi、^(210)Pb 3种核素活度浓度的变化范围分别为0.11~1.27 m Bq/m^(3)、0.45~1.83 m Bq/m^(3)和1.12~6.10 m Bq/m^(3);2021年秋季厦门^(210)Po、^(210)Bi、^(210)Pb 3种核素活度浓度的变化范围分别为0.05~0.85 m Bq/m^(3)、0.83~2.52 m Bq/m^(3)和0.17~1.32 m Bq/m^(3),上海近地表气溶胶中3种核素的活度浓度秋季平均值比厦门地区高。利用^(210)Po/^(210)Pb和^(210)Bi/^(210)Pb计算得到上海和厦门近地面大气的气溶胶滞留时间存在显著差异,基于^(210)Po/^(210)Pb计算上海气溶胶滞留时间均值为(94±54)d,基于^(210)Bi/^(210)Pb计算上海气溶胶滞留时间均值为(6.4±4.8)d,造成这种差异的原因很可能是两种示踪法本身具有的系统性差异。本文基于一维简易气溶胶沉降速率模型估算了上海地区的^(210)Pb、^(210)Bi和^(210)Po的大气沉降入东海的通量,其在秋季期间的变化范围分别为0.1~26.35 Bq/(m^(2)·d)、0.04~7.91 Bq/(m^(2)·d)和0.01~5.49 Bq/(m^(2)·d)。基于模型估算的^(210)Po、^(210)Bi和^(210)Pb沉降通量与研究区域的实际观测值接近一致,表明利用一维简易气溶胶沉降速率模型间接估算法在替代观测站直测核素的沉降入海通量方面具有一定可行性。
