天文台之夜观后感(2300字)

发表于:2017.10.21来自:www.ttfanwen.com字数:2300 手机看范文

天文台之夜观后感

公元前2600年,古埃及为了观测天狼星,建立了迄今为止已知世界上最早的天文台;前20xx年,巴比伦也建立了天文台。中国在大约2500年前,也开始有天文台,当称为清台、灵台、观象台。古代许多国家的天文台常常不但是天文观测的场所,也是运用占星学的场所,也因此天文台一般都为统治者所控制。15-16世纪,欧洲的一些天文家开始建立自己的天文台,其中很著名的就是丹麦的天文学家第谷1576年 在哥本哈根建立的天文台,它配备了当时最先进的天文仪器。天文望远镜发明后,天文台得到了发展。1667年法国建立了巴黎天文台;1675年英国建立了格林尼治天文台。20世纪,天体物理学的发展进一步促进了天文台的发展,许多天文台装备了大口径的反射望远镜。截止至20xx年,世界上大约有400个大型的天文台。 天文台的分类主要有三种,光学天文台:主要装备各光学天文仪器,如光学天文望远镜、太阳镜等,从事方位天文学或天体物理学方面的研究!

射电天文台: 一般主要由巨型甚至超巨型的无线接受设备和基站等构成,装射电天文台备射电望远镜,观察的范围更大,受干扰小,从事射电天文学的研究! 空间天文台:主要有一些用于空间观测的人造卫星组成,配备非常先进的光学观测。天文台的创建拉近了我们与宇宙的距离,让我们更加近距离的了解我们的地球和这个宇宙中的其他行星。

天文台之夜这门课让我更多的了解了行星。比如如何判断恒星的真实年龄,恒星的大小不是判断恒星年龄的依据,目前判断恒星年龄的方法很不成熟,一般判断的都是大概的年龄.科学家有利用天文地震首次直接测算恒星年龄,这种方法比较先进。

20xx年05月17日新浪科技:据澳大利亚广播公司(ABC)15日报道,利用恒星的震动,科学家首次可以 对恒星的年龄进行直接测量.他们打开了一扇星体实验室的大门,这将增进我们对在地球上很难进 行研究的恒星活动的了解.

澳大利亚悉尼大学的天文物理学家提姆·伯丁副教授和他的研究小组将在8月号的《天文物理杂志》上发表他们的研究成果.包括太阳在内的绝大多数恒星不断

发出的脉冲是其外层的大气进行剧烈混合的结果.通过对从表面发出的光线的多普勒频移的研究他向我们描述了在我们银河系附近的一颗 恒星是如何发出脉冲的.他建立了计算机模型来说明脉冲的过程是如何的复杂.伯丁说:“它并不是简单地内外震动.它的震动在同一时间存在多种不同模式.”伯丁利用地质学家使用地震学研究地球内部的同样方式,利用天文地震学来找出更多关于恒星的信息.使用这种方式他颇有兴趣地试图弄清楚他是否可以确定已知的恒星的化学成分、质量以及年龄.脉冲频率说明这颗恒星远比太阳要轻.比较重元素轻30倍,但比氢元素和氦元素要重.这些反过来会告诉他这颗恒星的年龄,因为一颗恒星的质量直接与它 的年龄有关.

伯丁说,和你可能所认为的相反,重恒星并没有轻恒星的寿命长.重恒星较大的重力和较高的温度使得它们燃烧燃料的速度远比轻恒星要快.恒星的震动告诉伯丁他正在观察的恒星的质量较小,已经非常古老,寿命大约为90亿年,确认了之前对这颗恒星质量的测定.他说,之前只能使用间接对恒星质量的测量来估算恒星的年龄.伯丁说:“这是首次对恒星年龄的直接测算.”

除了能够直接测算恒星的年龄外,天文地震学还可使我们研究恒星中的各种活动,例如,对流是如 何活动的以及随着恒星的年龄不断增长燃烧产生怎样的变化.他说:“我们可以研究在极端条件下的自然规律,物理规律.”在地球上这种极端条件科学家是如何也不能创造出的.伯丁希望能为建立遍布全世界的一个天文望远镜筹集资金以便能够对天文地震学所需要的恒星的脉冲继续进行研究 .

20xx年5月19日消息,据媒体报道,科学家发现宇宙存在着大量的暗物质,宇宙中暗物质占到了大约27%,暗物质被认为是一种神秘的宇宙物质,研究发现暗物质只通过引力与周围物质发生相互作用,不参与其他电磁作用。

科学家发现银河系中央存在神秘类型的伽玛射线“光束”,推测其有可能来自暗物质的作用,科学家一直在争论由暗物质形成的伽玛射线“光束”。研究人员使用美国宇航局费米伽马射线太空望远镜对伽玛射线“光束”进行探测,试图确定暗物质是否会产生神秘的“光束”。暗物质理论认为暗物质可能是一类被称为大质量弱相互作用粒子(WIMP),暗物质粒子质量可能比普通的粒子更大,而且不参与电磁力作用,运动的速度较为缓慢。大质量弱相互作用的粒子被认为拥有自身的“反粒子”,如果两个WIMP粒子碰撞,就是发生湮灭,并发出伽玛光子。

科学家称已经探测到暗物质粒子,费米望远镜正在对银河系中央天区进行扫描。科学家们希望确定银河系中央附近是否存在其他类型的伽玛射线,这些“光束”可能处于130GeV左右的能量区间上。19xx年勒梅特首次提出了现代宇宙大爆炸理论:整个宇宙最初聚集在一个“原始原子”中,后来发生了大爆炸,碎片向四面八方散开,形成了我们的宇宙。从此之后,大爆炸理论成为众多科学家争论的焦点。

宇宙大爆炸仅仅是一种学说,是根据天文观测研究后得到的一种设想。 大约在150亿年前,宇宙所有的物质都高度密集在一点,有着极高的温度,因而发生了巨大的爆炸。大爆炸以后,物质开始向外大膨胀,就形成了今天我们看到的宇宙。大爆炸的整个过程是复杂的,现在只能从理论研究的基础上描绘过去远古的宇宙发展史。在这150亿年中先后诞生了星系团、星系、我们的银河系、恒星、太阳系、行星、卫星等。现在我们看见的和看不见的一切天体和宇宙物质,形成了当今的宇宙形态,人类就是在这一宇宙演变中诞生的。 天文台之夜这门课让我更多的了解了关于行星这方面的知识,大大增加了我对这个宇宙的兴趣。




第二篇:香港天文台 81600字

??????????

HONG KONG OBSERVATORY

??????????23??

Technical Report No. 23

????????輻??????????

2003

SUMMARY OF

ENVIRONMENTAL RADIATION MONITORING

IN HONG KONG

2003

李????????????????

S.W. Li and K.C. Yeung

?????????行????????

? Hong Kong Special Administrative Region Government

??零零??年????????

Published July 2004

??????????????

??????龍??????134A??

Prepared by:

Hong Kong Observatory 134A Nathan Road Kowloon, Hong Kong

??????????????????

??????????????料??流?????????? 行????????????????????????理 ????????????????????料?????????????????????? ???????????????????????? 不??????????????????????????????????????

律??????????????料????????????????????????????????????????????????

?????? ??不????????律?????????????????????????????? ?? ???????????????????????????????? ????不 ?????????????????????????????????????? ??????????????????

??不??????????????????????

This publication is prepared and disseminated in the interest of promoting information exchange. The Government of the Hong Kong Special Administrative Region (including its servants andagents) makes no warranty, statement or representation, express or implied, with respect tothe accuracy, completeness, or usefulness of the information contained herein, and in so far aspermitted by law, shall not have any legal liability or responsibility (including liability for negligence) for any loss, damage, or injury (including death) which may result, whether directly or indirectly, from the supply or use of such information.

Mention of product of manufacturer does not necessarily constitute or imply endorsement orrecommendation.

Permission to reproduce any part of this publication should be obtained through the Hong Kong Observatory.

????

????輻??????????????零零??年??????????????????年度????????????????????????行??????????年????????????????年??????錄了??????????????????????量????????????????????年????????????????????了??????????????????

??

????零零??年??????????輻??????????錄????????輻??????????????????????????????????????????????若??????????不??????????????????????量????量??????????????????????????137??????????90??????239??????????度??度????????????????嶺??????????????????????????????度????????????????????????????????????來????????????????????零年????????????????????

??

??零零??年????量??????????????????嶺????????????????來????????????輻??????????????????????????????????????????????????????數量??????????量????????????

ABSTRACT

As the Environmental Radiation Monitoring Programme entered its seventeenth year in 2003, the monitoring work by the Hong Kong Observatory has become well established. From this year onward, the annual report incorporates only salient features of the programme, including summaries of measurement method and results, highlights of new work, changes and measures introduced during the year.

The ambient radiation levels in Hong Kong in 2003 as measured by the Observatory radiation monitoring networks were within the normal background ranges. As in the past years, traces of artificial radionuclides, namely caesium-137, tritium, strontium-90 and plutonium-239, were detected in various environmental and food samples. The activity concentrations were all within their respective ranges of values before the Guangdong Nuclear Power Station and Lingao Nuclear Power Station came into operation. This could be attributed to atmospheric nuclear tests from 1945 to 1980.

Based on the results, it is concluded that there was no measurable increase in 2003 in ambient radiation levels and artificial radionuclides in the Hong Kong environment and foodstuffs consumed by Hong Kong people, compared with those before the operation of the nuclear power stations.

5

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??????????????????六??年??????????????????輻????????????參????????????????????IAEA??????????????????WMO??????????????????輻????????????????????????????????????????????????????????????年????了??????????????輻??????????????????????????????????????????輻????????????????年??????????年????????????見??????????????1992??????????????年????????????????????????????????????年年????????????????1994-2003????

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????輻??????????????????????????????輻????????????????BRMP????????????????年??????????年??????行????????????????年??????????????????????????見????1??????????????????輻????????????????????????????????????????????????輻????????來????????????輻????????????????????????ERMP-II????????????年??????????????????BRMP??????????????????????????????????????????量????????????????ERMP-II????????????行??????????????????????????????????????????????????????????????????????????零零??年??????????????????????嶺??????????????來??????????

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??了??????????????????????????????輻????????????????1980年????????????????????量????量??????累????????????輻????量??ERMP-II ??????????量??????????????????????????????????????????????2????????????????Harshaw 8807??????????????LiF:Mg,Ti??????????量??????????數????????精??度??????????????????????????????量????????????量????????????更??????讀??????

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11

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????????六年??????????????????????????????????????????1??????????硫??????ZnS??????????????????????度??????????????????????????????????????利??????????????濾????????????濾??????不????????????????????????????????濾??????????硫????????????量????????????????????????????度????????濾????????????????利??????????????????????????????????????????????????????????量度????????更??????濾????????–131??度??????????????????度數??????????????????????????????????????????????????????????????????????–131????度數??????????????????????????

??零零??年??????????EG&G Berthold????????????????????????????老??????????????????????了??列????????????????Genie 2000??????????????????Canberra Industries InSpector 2000 ??????????????????????????????????理????令????????????????????????料????更????????

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??–14????量????BRMP????????????????????????????????????????????????????量??????????ERMP????量??????????????????Wong et al. ??2003??????????????–14????度????????????????????????????嶺??????????????????????????????????????????UNSCEAR??2000??????????????????????????????????????數量????????????????????????????嶺??????????????類????????????????????–14??????不??????????????????????????????????????–14??度????量??????????零零??年??????????年??????????????????????????????????????

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??????????????????????????????零零??年??????????????????2????????????????????????????????????????????????????????????????????????????????林????????????????龍???? ????????????????????朗??????朗????????????????????????????????????????????????????????????樂????????了??????????????????5????????????????????????朗??????????????????????????????????????樂????????????????????????????????????????朗????????BRMP??????量????????????樂??????????零零??年????????????六??????????????????

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15

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16

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????零零??年????????????????????????行了????????輻????量????????????量率??????????0.031??0.033??????見??6??????

??

??????????????????????????量率??????????????????????????行????????????????零零??年??????????????????????零零零年????????????度??????行了??????????????量????????????????????????????????六??????????????????????????????????數??????????????????

??零零??年????????????????????????行了??????????????????????????量率??量????7????量????????????????????輻??????????????????????????????量率????????????0.049??0.142????????????????????0.096??????????????????????????量率????????????0.115????0.242??????????????????????0.174??????????????????????????率

1.81????????????????零零??年????量??????????Wong et al. 1999??????

????????????2001-2003??????

??

????輻????????

??

??????????零零??年??????行了????????輻????????????????????????????????????????????????????????????行????硏????????????????????????????????錄??????????????????????

??

17

????Flückiger & Bülikofer??2003????????????????????????????????????????????????????????????????????令??????????????????粒????????????????輻????????降??Ziegler 1998??????????????????????????????????????????????????????量????????????????錄??????????????數率??Flückiger & Bülikofer??2003????

??

????????????????????????六??????????行??????輻????????????????????錄??????數率??????????????零零??年????????????????數率????降????度??????????????????????????????????????????????????????????????????8????????????????數率??????廓????????

????????????????

??

????零零??年??????????????了??????????????????????????????7??????9??10????列??????????????????????????????90??????239????量????????????列????????????????????????量??????????便參??????11??不??????????????列了??零零??年??????????類??????量????????

??

????????????137

??

??????????????若??????????零零??年????????泥??????????????量????????????????????????137????????????????????豬????????????????????????????????????????BRMP??ERMP-II??Wong et al. 2003??????????????????????????????137??????????????????137????度????BRMP????????????????

??

????????????????????????????????137????????????????????????????零年??????????????????降????????UNSCEAR 2000????????

????????????

??

??????????????若??????????零零??年????????????????????????????量??????????????????????????????????????????????????????????????????????????????????????????????類????????????????????????????????度????BRMP??????????????????????????????????

18

??????????????????????????????UNSCEAR 2000??????

??

????????????90

??

????????零零??年??????????????泥??????????????量??????90??????????????????????????????????????????????????????????????????????類??????????????????????BRMP??ERMP-II????????????????????????90????零零??年????????????度????BRMP??????????????????90??????來????????????????UNSCEAR 2000??????

??

????????????239

??

??????????????若??????????零零??年????????泥??????????????量??????239????????????????????????????????????????????????????????????????239????度????BRMP??????????????????????????????????????239????來??????????????????降????UNSCEAR 2000????????

??

3.2????論??

??

??零零??年??????????不??????錄??????????????量率????BRMP????????????????????????????????????????????度??度????????BRMP????????????????????????????????????嶺??????????????????????零零??年??????????輻????????????????????????????????????????????????????量????????????

??

19

??????

??????????????????理??????????????????????????????????????????????????????????????????????????????????????????????量????讀??????數??????????行????????????????????????輻????????????????????????????????????????????輻????????????????????????????????????????????????????????????????????????????????????????????量??????????????????

20

參????????

1. Flückiger, E. and R. Bütikofer 2. Hong Kong Observatory

3. Hong Kong Observatory

4. Hong Kong Observatory

5. United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) 6. Wong, M.C., H.T. Poon, H.Y. Mok

and Y.S. Li

7. Wong, M.C., Y.K. Chan, H.T. Poon, W.M. Leung, H.Y. Mok and C.K. So 8. Ziegler, J.F.

2003 1992

1994 to 19951996 to 2003

2000 2003

1999

1998

International Foundation HFSJG

Activity Report 2003, pp. 109-112. Environmental Radiation Monitoring in Hong Kong: Background Radiation Monitoring Programme 1987-1991. Environmental Radiation Monitoring in Hong Kong: Radioactivity Bulletin 1992 - 1994.

Environmental Radiation Monitoring in Hong Kong: Annual Report 1995 - 2002.

Sources and Effects of Ionizing

Radiation, Volume I: Sources. Environmental Radiation Monitoring in Hong Kong – 1987 to 2002, Technical Note No. 106, Hong Kong Observatory.Environmental Gamma Absorbed Dose Rate in Air in Hong Kong 1999, Technical Report No. 17, Hong Kong Observatory.

Terrestrial Cosmic Ray Intensities, IBM Journal of Research and Development, 42, pp. 117-139.

21

CONTENTS

page

FIGURES 22 TABLES 23

1. INTRODUCTION

2. SAMPLING, MEASUREMENT AND QUALITY ASSURANCE

2.1 Direct measurement of ambient radiation level

2.2 Collection of food and environmental samples

2.3 Measurement of food and environmental samples in laboratory

2.4 Quality assurance

3. RESULTS AND CONCLUSION

3.1 Results

3.2 Conclusion

ACKNOWLEDGEMENT

REFERENCES

24 25 25 27 29 30 31 31 34 35 36

22

FIGURES Page

Locations for real-time direct measurement of ambient gamma radiation 37 Thermoluminescent dosimeter network and locations for collection of

environmental samples 38 1. 2.

3. The Government Flying Service’s new Super Puma L2 helicopter housing

the Aerial Monitoring System

4. The Observatory survey vehicle shown with a mechanical arm holding a

Portable Gamma Spectroscopic Analysis Module in position

5. Location of Kwan Lok San Tsuen, a site for underground water to replace

the discontinued site at Yuen Long Estate

6. Background gamma radiation level over the eastern part of Hong Kong,

as measured by the Aerial Monitoring System at about 500 meters above

mean sea level

7. Mean environmental gamma absorbed dose rates in open-field and

built-up areas

8. Vertical profile of atmospheric radioactivity over Hong Kong

on 31 October 2003

39 39 40 41 42 43

23

TABLES Page

Summary of the sampling and analysis programme in 2003 44 Summary of food samples collected in 2003 48 Summary of key measurement parameters 50 1. 2. 3.

4. Ambient gamma dose rate recorded by the radiation monitoring network

and thermoluminescent dosimeter network in 2003

5. Radiation measurement results of the Automatic Gamma Spectrometry

System at Ping Chau in 2003

6. Measurement results of gamma dose rate due to cosmic radiation

7. Measurement results of gamma activities in food and environmental

samples in 2003

8. Measurement results of tritium activities in food and environmental

samples in 2003

9. Measurement results of strontium-90 activities in food and environmental

samples in 2003

10. Measurement results of plutonium-239 activities in food and environmental

samples in 2003

11. Overall summary of measurement results in 2003

52 53 54 54 55 58 60 61

24

1. INTRODUCTION

Since 1961, the Hong Kong Observatory (HKO) has been monitoring environmental radiation levels in Hong Kong and participating in international programmes on environmental radiation monitoring organised by the International Atomic Energy Agency (IAEA) and the World Meteorological Organization (WMO). In response to the construction of the nuclear power stations at Daya Bay in Guangdong, the HKO embarked in 1983 on a comprehensive Environmental Radiation Monitoring Programme (ERMP) to monitor the radiation levels in Hong Kong before and after the power plants commenced operation. The monitoring results for the years 1987 to 1991 can be found in HKO (1992). Those from 1992 onwards are published in annual reports of the programme (HKO 1994-2003).

After years of implementation, the monitoring programme has become well established. Starting from 2003, the annual report (including this report) only includes the most salient features of the programme, including summaries of measurement methods and results, highlights of new work, changes and measures introduced during the year. Readers may refer to the previous reports for details of the sampling, measurement and quality assurance work.

The first phase of the ERMP, known as the Background Radiation Monitoring Programme (BRMP), was conducted from 1987 to 1991 to establish the baseline radiation levels in Hong Kong prior to the operation of the Guangdong Nuclear Power Station (GNPS) in 1994 (see Figure 1 for location). These baseline levels would enable the detection of changes arising from the operation of GNPS if any. The second phase of the ERMP (ERMP-II) commencing in 1992 contains all the essential features of the BRMP, with adjustments in sampling and measurement to take advantage of the experience gained. ERMP-II is an on-going programme to determine long term changes in environmental radioactivity in Hong Kong if any, particularly those arising from the operation of the GNPS and the Lingao Nuclear Power Station (LNPS) also at Daya Bay (see Figure 1 for location), which came into operation in mid-2002.

Chapter 2 in this report describes the sampling schedule, the instruments and methods used for measuring ambient radiation levels, as well as radioactivity in food and environmental samples. A summary of the quality assurance system is also given. Measurement results and conclusion are presented in Chapter 3.

25

2. SAMPLING, MEASUREMENT AND QUALITY ASSURANCE

Under the ERMP, three major exposure pathways are monitored, namely the atmospheric pathway, the terrestrial pathway and the aquatic pathway. In respect of measurement, the ERMP consists of two major components. The first component is the direct measurement of the ambient gamma radiation level in Hong Kong. The second is the detection of any artificial radioactive material, arising from the operation of GNPS and LNPS, in the environment of Hong Kong and in the foodstuff consumed by Hong Kong people. The locations for real-time direct measurement of ambient gamma radiation are shown in Figure 1. The locations for other direct measurement of ambient gamma radiation and collection of environmental samples in 2003 are shown in Figure

2. A summary of the sampling programme of the ERMP in 2003 is given in Table 1.

2.1 Direct measurement of ambient radiation level

Radiation Monitoring Network

Since the commencement of ERMP-II, the ambient gamma dose rate has been monitored by a radiation monitoring network (RMN) consisting of 10 fixed stations (Figure 1). The dose rate is measured at each station continuously by a high pressure ionization chamber (HPIC) (Reuter-Stokes Model RSS-131 environmental radiation monitor) and data are transmitted to the Observatory Headquarters once every minute.

Thermoluminescent Dosimeter Network

To achieve a wide spatial coverage of ambient radiation monitoring economically, a thermoluminescent dosimeter (TLD) network has been in operation since the late 1980s to measure ambient gamma doses accumulated over a long period. In ERMP-II, the network comprises 27 monitoring points over the territory (Figure 2). The TLDs are of the lithium fluoride (LiF:Mg,Ti) type (Harshaw Type 8807). A batch of five TLDs is placed at each site to ensure statistical accuracy. The TLDs are replaced and read once every quarter.

Aerial Monitoring System

The Aerial Monitoring System (AMS), in operation since 1998 and mounted on board a helicopter of the Government Flying Service, has the capability to determine the existence and extent of any radioactive plume over Hong Kong when operating in

26

the plume tracking mode. After passage of the plume, the system can be used to identify surface areas contaminated by deposited radionuclides using the ground contamination measurement mode. The system has two assemblies of sodium iodide (NaI) detectors, one for each of the two operation modes. The gamma spectra, spectroscopic analysis results and location information are displayed on board the helicopter in real time and archived at regular intervals.

The AMS operates on the Government Flying Service’s new helicopter Super Puma L2 (Figure 3) which in 2003 replaced the Sikorsky S76A+ helicopter. In connection with the change of helicopter, special flights commenced in 2003 to update background data for the plume tracking mode, as well as to obtain data to update system parameters for the ground contamination measurement mode. A study of the AMS readings taken with the old and new helicopter is underway and the results will be reported separately.

Automatic Gamma Spectrometry System

The Automatic Gamma Spectrometry System (AGSS) was installed at Ping Chau, Mirs Bay, in 1996 (Figure 1). It consists of a zinc sulphide (ZnS) coated plastic scintillator, a high purity germanium detector and a NaI detector. It continuously collects airborne particulates on a rotating filter drum and gaseous iodine in a carbon cartridge. The ZnS scintillator directly above the filter drum measures the alpha and beta activities of the particulates collected. Inside the filter drum, the germanium detector measures gamma rays emitted by the particulates and gamma spectrometry analysis is carried out automatically. The NaI detector measures the iodine-131 concentration in the carbon cartridge which is replaced automatically at weekly intervals. Data of alpha and beta activities, as well as results of gamma spectrometry analysis are transmitted to a central station at the Observatory Headquarters at 15-minute intervals, while the iodine-131 activity data is sent back every 10 minutes.

A new system, manufactured by EG&G Berthold, became operational in July 2003 to replace the original aged system. The replacement system has the following new features: a Canberra Industries InSpector 2000 multi-channel analyser coupled with Genie 2000 software for gamma spectrometry analysis; and a specially designed front-end processor to enable more reliable data transfer between the field unit at Ping Chau and the Observatory Headquarters.

Mobile Radiation Monitoring Station

The Mobile Radiation Monitoring Station (MRMS) was converted from a

27

commercial van. It is equipped with portable and specially designed instruments for use in routine and emergency radiological surveys.

In 2003, a mechanical arm was installed on the MRMS to enable automatic positioning of the Portable Gamma Spectroscopic Analysis Module over specific survey points for measurement (Figure 4). Together with an external gamma probe and an air inlet on the vehicle roof, environmental samples and survey data can now be obtained without the survey team members going outside the vehicle, resulting in better protection to personnel during radiological surveys.

Upper-air Radioactivity Soundings

The radioactivity in the upper atmosphere is measured by means of balloon-borne radiosondes (Vaisala Model RS80) since 1994. Each radiosonde carries a radioactivity sensor (Vaisala Model NSS14A) which comprises two Geiger-Müller tubes, one measuring only gamma radiation (‘gamma-only tube’) while the other both gamma and high energy beta radiation (‘gamma-plus-beta tube’, > 0.25 MeV). The ground station is a Vaisala DigiCORA MW11 upper-air sounding system which receives and processes data from the radiosonde.

2.2 Collection of food and environmental samples

Food Samples

Both terrestrial and aquatic foodstuffs typical of the diet of the local population are collected at main distribution points, wholesale markets and from enlisted suppliers. Particular attention has been given to food produced locally and in Shenzhen. Food samples collected in 2003 are listed in Table 2.

Atmospheric Samples

As in past years, atmospheric samples, including airborne particulates, wet deposition (precipitation), total deposition (wet plus dry deposition), gaseous iodine and water vapour, are collected under the ERMP. Airborne particulates and wet deposition are collected at King’s Park, Sha Tau Kok and Yuen Ng Fan (Figure 2) at weekly intervals. Airborne particulates are captured by a filter paper installed inside a high volume air sampler (General Metal Works Model UV-2H-1). Wet deposition is collected by a carboy fitted with a top funnel. During the dry season, three sets of carboys and funnels are used at each location to ensure that sufficient amount of water

28

is collected for measurement.

Total deposition, gaseous iodine and water vapour are collected only at King’s Park. The sampler for total deposition is a stainless-steel pan partially filled with distilled water to collect samples at weekly intervals. Gaseous iodine is sampled using a radioiodine sampler (Hi-Q Environmental Products Model CMP-14CV) with a silver impregnated zeolite cartridge. The cartridge is collected and replaced weekly. Water vapour is collected using a gaseous effluent sampler (Science Applications International Corporation Model ACT-100) with a drierite cartridge intermittently for a total time of 36 hours within a randomly selected week each month.

Carbon-14 has been measured under the programme since the BRMP. The objective was to establish the long-term trend of the radionuclide in Hong Kong for dose assessment purpose. A review of the ERMP results (Wong et al. 2003) found that the activity of carbon-14 in Hong Kong was in line with the global trend and there was no measurable increase in its inventory in Hong Kong since the operation of GNPS and LNPS. This agreed with UNSCEAR (2000) which pointed out that compared with the natural production of carbon-14, pressurized water reactors, the type of nuclear reactors used in GNPS and LNPS, only add an insignificant amount of the radionuclide to the environment during their normal operation. With the objective of measuring the radionuclide met, measurement of carbon-14 activity in food and environmental samples was terminated in 2003 and sampling of carbon dioxide at King’s Park ceased from September 2003 onwards.

Drinking Water, Underground Water and Sea Water

As in past years, treated drinking water is collected from distribution taps at Kowloon and Tuen Mun as well as the treatment works at Shatin, Tuen Mun and Yau Kom Tau (Figure 2). Raw drinking water is collected from the High Island Reservoir, the Plover Cove Reservoir, the Muk Wu B Pumping Station and the treatment works at Shatin, Tuen Mun and Yau Kom Tau (Figure 2). Both raw and treated drinking water are collected once every three months by staff of the Water Supplies Department.

With the assistance of the Housing Department, underground water was collected at five locations in 2003 (Figure 2), namely Siu Hong Court (Tuen Mun), Cheung Hong Estate (Tsing Yi), Wan Tsui Estate (East Hong Kong Island), Wah Fu Estate (Pokfulam) and Fu Shan Estate (East Kowloon). Sampling from Yuen Long Estate (Yuen Long) ceased in 2003 as the estate was demolished for re-development. With the assistance of the Civil Engineering Department, a new site with similar geological features was subsequently identified at the nearby Kwan Lok San Tsuen (Figure 5). At the time of

29

writing, samples collected at the new site are being analyzed. If the measured radiation levels of these samples are consistent with the BRMP values (including those at Yuen Long Estate), Kwan Lok San Tsuen will be included as the sixth underground water sampling site commencing 2004.

As in past years, sea water is sampled at three depths - the upper level (2.5 metres underneath the surface), the middle level and the lower level (2.5 metres above the seabed) at four locations in the eastern part of the coastal waters of Hong Kong (Figure 2), namely waters off Waglan Island, Basalt Island, Tai Long Wan and Port Island. Sampling is carried out annually with the assistance of the Environmental Protection Department. Suspended particulates in sea water at the three depths are collected by filtering the corresponding sea water samples through a membrane filter.

Land Soil and Sediments

Land soil is sampled at 39 designated sites throughout the territory. Sampling at various sites is spread over a cycle of five years. In 2003, land soil samples were collected from Silvermine Bay, Tung Chung, Shek Pik, Tai O, Kat O, Tap Mun, Ping Chau and Pat Nai (Figure 2). At each site, samples were collected from two layers, the upper layer from the surface to 15 cm deep and the lower layer from 15 cm to 30 cm deep.

As in past years, intertidal sediments are sampled quarterly at three locations along the coast of Hong Kong (Figure 2), namely Pak Sha Wan, Tsim Bei Tsui and Sha Tau Kok. Two layers are taken at each sampling point, the upper layer from the surface to 15 cm deep and the lower layer from 15 cm to 30 cm deep. Sampling of seabed sediments is carried out annually with the assistance and facilities of the Civil Engineering Department at four locations in the coastal waters of Hong Kong (Figure 2), namely, Tai Tan Hoi Hap, Lung Ha Wan, Picnic Bay and Western Anchorage.

2.3 Measurement of food and environmental samples in laboratory

All radioactivity measurements of food and environmental samples are carried out at the Radiation Laboratories at King’s Park. A list of the major artificial radionuclides routinely monitored in the ERMP is given in Table 1. Each sample, depending on the sample type and measurement objective, would go through one or more of the following analyses:

30

(a) gamma spectrometry analysis to determine the activity

concentrations of gamma-emitting radionuclides;

(b) liquid scintillation counting to determine the activity

concentration of tritium;

(c) low-level gross beta counting to determine the activity

concentration of strontium-90; and

(d) alpha spectrometry analysis to determine the activity

concentration of plutonium-239.

2.4 Quality assurance

Since 1989, the Observatory has been participating in inter-comparison exercises organized by major international and national organizations, namely the International Atomic Energy Agency (IAEA), the World Health Organization (WHO) and the China Institution for Radiation Protection (CIRP). In August 2003, the Observatory participated in an inter-comparison exercise organized by CIRP on strontium-90 measurement of a water sample. The result obtained by the HKO, 19.76 ± 2.8 Bq/L, was consistent with the reference value (21.82 Bq/L) released by CIRP. Other than inter-comparison exercises, the quality of the measurements in the ERMP is also assured through internal quality assurance procedures.

31

3. RESULTS AND CONCLUSION

3.1 Results

A summary of key measurement parameters, including sample size, counting time and detection limits, are given in Table 3.

Radiation Monitoring Network

The annual average ambient gamma dose rates and ranges of 1-minute averages recorded by the RMN in 2003 are tabulated in Table 4.

Since the operation of the RMN, typical temporal changes in the radiation level recorded at any of the stations range from a few percent in seasonal variations, to about 40% in heavy rain and up to 100% in cases involving tropical cyclones affecting Hong Kong.

The most significant changes in the ambient gamma dose rate in 2003 were recorded during the passage of Typhoon Dujuan on 2 to 3 September. Increases in the dose rate against the respective annual means ranged from 34% at Kwun Tong on 2 September to 98% at Ping Chau on 3 September.

Thermoluminescent Dosimeter Network

The average, standard deviation and range of gamma dose rate measured at each of the TLD stations in 2003 are listed in Table 4. The gamma dose rates recorded at all stations were found to be within the BRMP range.

Aerial Monitoring System

In 2003, measurement flights on the new Government Flying Service helicopter (Super Puma L2) in the plume tracking mode were carried out over the eastern part of the territory at 500 metres above mean sea level to obtain new background data over that area. Figure 6 presents the results obtained. No artificial radionuclides were detected. While the count rates over the sea were relatively constant at around 200 cps, those over the land surface ranged from about 250 for flat terrain, to up to 600 cps when the helicopter came close to the hills.

32

Test flights on the helicopter in the ground contamination measurement mode were also conducted in 2003. After completing these test flights in early 2004, a new set of parameters will be obtained, which will be used in the analysis of data obtained in future ground contamination measurement flights.

Automatic Gamma Spectrometry System

Results obtained by the AGSS in 2003 are given in Table 5. No artificial radionuclides were detected, and all results were within their respective ranges of variation from 1997 to 2002.

Mobile Radiation Monitoring Station

Three measurements of cosmic radiation were carried out at Plover Cove in 2003. The average gamma dose rates due to cosmic radiation were found to range from 0.031 to 0.033 μGy h-1 (Table 6).

A territory-wide survey to monitor the distribution and long-term variations of the environmental gamma absorbed dose rate in air was completed in 2003. In this survey cycle, which began in 2000, a total of 522 measurements spanning all seasons were conducted at each of the 42 open-field and 61 built-up area sites covering the entire territory of Hong Kong. A review of the data collected is underway.

In 2003, 59 and 73 measurements of the environmental gamma absorbed dose rate were conducted in open-field and built-up area sites respectively. The results are summarized in Figure 7. After the deduction of the cosmic contribution, the mean terrestrial environmental gamma dose rates in the open field area sites ranged from 0.049 μGy h-1 to 0.142 μGy h-1 with an average of 0.096 μGy h-1. The mean dose rates in built-up area sites were found to range from 0.115 μGy h-1 to 0.242 μGy h-1 with an average of 0.174 μGy h-1. The ratio of averages for built-up areas against open-field areas is 1.81, which is comparable with previous results obtained from 1999 to 2002 (Wong et al. 1999, HKO 2001-2003).

Upper-air Radioactivity Soundings

A total of five radioactivity soundings were conducted in 2003. Of them, three were specially conducted on 30 October, 31 October and 4 November to investigate the effect on atmospheric radioactivity due to record-breaking solar flare eruptions at the end of October and the beginning of November.

33

According to Flückiger and Bülikofer (2003), a number of major solar flares erupting during the above period triggered disturbances in the earth’s magnetic field. These disturbances deflected galactic charged particles approaching the earth, resulting in decreases in atmospheric radioactivity (Ziegler 1998). The solar flare event erupting on 29 October brought about significant decreases in the count rate as registered by ground-based cosmic ray detectors in many parts of the world on 31 October (Flückiger and Bülikofer 2003).

In the 06 UTC sounding in Hong Kong on 31 October, the count rates of the gamma-only tube were lower than the mean count rates of all soundings conducted from 1994 to 2002. The decrease was statistically significant at the 95% confidence level for the range of altitudes from 3,000 to 21,000 meters. Figure 8 shows the vertical profile of the count rate of the gamma-only tube that day.

Food and Environmental Samples

A total of 388 food and environmental samples were collected in 2003. Samples with measurable activity are tabulated in Tables 7, 8, 9 and 10 showing the results of gamma spectrometry analyses, tritium measurements, strontium-90 measurements and plutonium-239 measurements respectively. Only results pertaining to artificial radionuclides are included. For ease of reference, a summary of measurement results in 2003 for the major sample types according to different pathways is given in Table 11.

a) Caesium-137

As in past years, traces of caesium-137, an artificial gamma-emitting

radionuclide, were detected in some food and soil samples in 2003, including rice, pork, seafood, land soil, seabed sediment, and intertidal sediment. Caesium-137 has been detected in the above sample types for many years, in both BRMP and ERMP-II (Wong at el. 2003). The measured activities in 2003 were all within the corresponding ranges of BRMP values.

The presence of caesium-137 in environmental and food samples could be

attributed to remnants of the fall-out of atmospheric nuclear testing conducted from 1945 until 1980 (UNSCEAR 2000).

b) Tritium

As in past years, very low amounts of tritium were detected in some

atmospheric, water and food samples in 2003, including wet deposition, total

34

deposition, water vapour, drinking water, underground water, sea water, rice, milk, vegetables, poultry, meat, seafood and seaweed. The measured activities in these samples were all within the range of corresponding baseline values of the BRMP. Apart from atmospheric nuclear testing, tritium is also produced naturally by cosmic rays entering the atmosphere (UNSCEAR 2000).

c)

Strontium-90 Traces of strontium-90 were detected in some atmospheric, food and soil

samples in 2003, including air particulates, wet deposition, total deposition, rice, milk, vegetables, poultry, meat, seafood, seaweed and land soil. The radionuclide was also detected in the above types of samples during BRMP and ERMP-II. The measured activities in 2003 were all within the respective BRMP ranges. Again the radionuclide could be attributed to the atmospheric nuclear testing (UNSCEAR 2000).

d) Plutonium-239

As in past years, minute amounts of plutonium-239 were detected in some

food and soil samples in 2003, including seaweed, land soil, seabed sediment and intertidal sediment. The measured activities were all within the respective BRMP ranges. Fallout of atmospheric nuclear testing was again the major source of the radionuclide (UNSCEAR 2000).

3.2 Conclusion

The ambient gamma dose rates recorded over various parts of the territory in 2003 were within the BRMP range. The specific activity concentrations of all artificial radionuclides in the samples collected in 2003 were found to be within the corresponding range of baseline values obtained in BRMP. It is concluded that in 2003 there was no measurable increase in ambient radiation levels and in artificial radionuclides in the Hong Kong environment and foodstuffs consumed by Hong Kong people, compared with those before the operation of GNPS and LNPS.

35

ACKNOWLEDGEMENT

The Hong Kong Observatory wishes to express its gratitude to the Agriculture, Fisheries and Conservation Department, Civil Engineering Department, Environmental Protection Department, Water Supplies Department and Housing Department for their assistance in sample collection; the Government Laboratory for chemical treatment of samples; and the Department of Health for providing and reading the thermoluminescent dosimeters. We would also like to express our appreciation to the Government Flying Service for operation of the Aerial Monitoring System; and the Hong Kong Police Force for providing accommodation at police stations to a number of radiation monitoring stations and the Automatic Gamma Spectrometry System. Special thanks also go to those organisations for their permission on the installation of thermoluminescent dosimeters and the collection of land soil samples within their premises.

36

REFERENCES

1. Flückiger, E. and R. Bütikofer 2. Hong Kong Observatory

2003

International Foundation HFSJG

Activity Report 2003, pp. 109-112.

1992 Environmental Radiation Monitoring in

3. Hong Kong Observatory

4. Hong Kong Observatory

5. United Nations Scientific Committee on the Effects of Atomic

Radiation (UNSCEAR) 6. Wong, M.C., H.T. Poon, H.Y. Mok

and Y.S. Li

7. Wong, M.C., Y.K. Chan, H.T. Poon, W.M. Leung, H.Y. Mok and C.K. So 8. Ziegler, J.F.

1994 to 19951996 to 2003

2000 2003

1999

1998

Hong Kong: Background Radiation Monitoring Programme 1987-1991. Environmental Radiation Monitoring in Hong Kong: Radioactivity Bulletin 1992 - 1994.

Environmental Radiation Monitoring in Hong Kong: Annual Report 1995 - 2002.

Sources and Effects of Ionizing

Radiation, Volume I: Sources. Environmental Radiation Monitoring in Hong Kong – 1987 to 2002, Technical Note No. 106, Hong Kong Observatory.Environmental Gamma Absorbed Dose Rate in Air in Hong Kong 1999, Technical Report No. 17, Hong Kong Observatory.

Terrestrial Cosmic Ray Intensities, IBM Journal of Research and Development, 42, pp. 117-139.

?? 1. ????????????輻??????????量??????

Figure 1. Locations for real-time direct measurement of ambient gamma radiation.

香港天文台

37

?? 2. ????????量??????????????????????????

Figure 2. Thermoluminescent dosimeter network and locations for collection of environmental samples.

香港天文台

38

39

?? 3. ??????行????????????????????L2????????????了????輻??????????????

Figure 3. The Government Flying Service’s new Super Puma L2 helicopter housing the Aerial Monitoring System.

?? 4. ??????????車????????????????便??便??????????????????????量????????

Figure 4. The Observatory survey vehicle shown with a mechanical arm holding a Portable Gamma Spectroscopic Analysis Module in position.

香港天文台

香港天文台

40

? ??????????????????????????

????????????????????????????????G03/2004??

The map is reproduced with permission of The Director of Lands.

? The Government of Hong Kong Special Administrative Region. Licence No. G03/2004.

?? 5. ??樂??????????????????????????????????朗??????????????

????????兩????????????????

Figure 5. Location of Kwan Lok San Tsuen, a site for underground water to replace the discontinued site at Yuen Long Estate. Circles indicate the locations of the two sites.

香港天文台

?? 6. ????輻??????????????????????量????????????輻??????????量??度??????????500???? Figure 6. Background gamma radiation level over the eastern part of Hong Kong, as measured by the Aerial Monitoring System at about 500 meters above mean sea level.

41

0.074 0.0710.106 0.1050.081 0.0780.1030.135 0.1040.066 0.0790.051 0.0570.084 0.0820.097 0.0950.089 0.0800.148 0.166 0.114 0.125 0.138 0.143 0.086 0.0860.115 0.170 0.144 0.1450.152 0.184 0.101 0.102 0.153 0.099 0.105 0.120 0.122 0.075 0.0770.227 0.159 0.069 0.204 0.185 0.171 0.094 0.104 0.121 0.118 0.204 0.183 0.207 0.169 0.178 0.179 0.077 0.085 0.116 0.121 0.077 0.076 0.101 0.098 0.083 0.091 0.182 0.210 0.190 0.171 0.176 0.185 0.199 0.171 0.120 0.111 0.173 0.127 0.133 0.086 0.085 0.110 0.1180.143 0.172 0.188 0.191 0.167 0.136 0.116 0.095 0.171 0.170 0.113 0.120 0.121 0.112 0.109 0.115 0.151 0.175 0.177 0.194 0.148 0.195 0.242 0.159 0.126 0.119 0.083 0.085 0.090 0.140 0.142 0.069 0.071 0.047 0.058 0.147 0.231 0.198 0.216 0.181 0.181 0.146 0.138 0.175 0.193 0.133 0.055 0.049 0.090 0.090420.095 0.1027.量率數列μGy h-1Figure 7. Mean environmental gamma absorbed dose rates in open-field and built-up areas. Values for open-field area sites in bold print; dose rate in μGy h-1.

43

香港天文台

?? 8. ??零零??年????????????????輻????????廓??????

??數率??????2 ??里??????????

Figure 8. Vertical profile of atmospheric radioactivity over Hong Kong on 31 October 2003. Count rates are averages at 2 km intervals.

44

?? 1. ??零零??年??????????????????

Table 1. Summary of the sampling and analysis programme in 2003

????類?? Sample type

???????? Sampling location

????數??

Number of location

10

????類?? Type of analysis ??????γ

??????率Sampling frequency??????

1-minute interval

????????輻????Ambient Gamma Radiation ??????量率 ????Ping Chau, ???? Tap Mun, Gamma dose-rate ???? Kat O, ?????? Sha Tau Kok,

?????? Yuen Ng Fan, ?????? Tai Mei Tuk, ?????? Tsim Bei Tsui, ???? Kwun Tong, ?????? Sai Wan Ho, ?????? King’s Park

累????????量???? Ping Chau, ???? Tap Mun, Cumulative gamma dose ???? Kat O, ?????? Yuen Ng Fan,

??????Clear Water Bay, ????Sai Kung,

?????? Tai Mei Tuk, ??????Wu Kai Sha, ????Cape D’Aguilar,

?????? Sha Tau Kok, ????Shatin, ???? Kwun Tong,

??????Shau Kei Wan, ????Tai Po, ??????King’s Park, ??????Happy Valley, ??????Deep Water Bay, ????So Uk,

????????Chi Fu Fa Yuen, ??嶺Fanling, ????Tsuen Wan, ????Shek Kong, ???? Cheung Chau, ??朗 Yuen Long,

?????? Tai Lam Chung, ?????? Tsim Bei Tsui, ???? Tuen Mun ????????Atmospheric Samples ???????? ?????? King’s Park, Airborne particulate ?????? Sha Tau Kok,

??????Yuen Ng Fan

????????(降??) ?????? King’s Park, Wet deposition ?????? Sha Tau Kok, (precipitation) ??????Yuen Ng Fan ???????? ?????? King’s Park Total deposition ??????

Airborne radioiodine ??????????

Water vapour in air ?????? King’s Park ?????? King’s Park

27 ??????γ ???? quarterly

3

3

1

1 1

???? γ,

??-90 Sr-90, ?-239 Pu-239 ???? γ, ?? H-3,??-90 Sr-90, ?-239 Pu-239 ???? γ, ?? H-3,??-90 Sr-90, ?-239 Pu-239 ???? γ ?? H-3

???? (累??????) weekly (bulked monthly) ???? (累??????) weekly (bulked monthly) ???? (累??????) weekly (bulked monthly) ????weekly ????monthly

45

?? 1. (??) Table 1. (cont’d)

????類?? Sample type

???????? Sampling location

????數??Number of 1 2 2 2 1 1 1

????類?? Type of ???? γ, ?? H-3,??-90 Sr-90 ???? γ, ?? H-3,??-90 Sr-90 ???? γ, ?? H-3,??-90 Sr-90 ???? γ, ?? H-3,??-90 Sr-90 ???? γ, ?? H-3,??-90 Sr-90 ???? γ, ?? H-3,??-90 Sr-90 ???? γ, ?? H-3,??-90 Sr-90 ???? γ, ?? H-3,??-90 Sr-90 ???? γ, ?? H-3,??-90 Sr-90 ???? γ, ?? H-3,??-90 Sr-90 ???? γ, ?? H-3,??-90 Sr-90 ???? γ, ?? H-3,??-90 Sr-90 ???? γ, ?? H-3,??-90 Sr-90 ???? γ, ??-90 Sr-90, ?-239 Pu-239

??????率Sampling ???? quarterly ???? quarterly ???? quarterly ???? quarterly ???? quarterly ???? summer ?????????? autumn and winter

???? spring ???? quarterly ???? quarterly ???? quarterly ???? quarterly ???? quarterly ??5年???? once every 5 years

????????Terrestrial Samples ???? Rice ???? Mainland ????(??????) Pasteurized milk ???? Choi sum ???? Pak choi ???? Banana ???? Lychee ???? Mandarin

???? Shenzhen,

?????? Sha Tau Kok

???? Mainland, ???? Local ???? Mainland, ???? Local ???? Mainland ???? Mainland ???? Mainland

???? Sugar cane ?? Chicken ?? Duck ???? Beef ????Pig’s liver ????Pork

????????????????????Land soil

(upper and lower level)

???? Mainland

???? Mainland, ???? Local ???? Mainland, ???? Local ???? Mainland

???? Mainland, ???? Local ???? Mainland, ???? Local ??????濾????

Silvermine Bay Treatment Works, ????????路

Tung Chung Chung Yan Road, ????????Shek Pik Reservoir, ??????立????

Tai O Public Primary School, ??泥 Pak Nai, ??????????????

Kat O Fisheries Research Sub-Station, ????(??林????)

Tap Mun (King Lam School), ????Ping Chau

1 2 2 1 2 2 8

46

?? 1. (??) Table 1. (cont’d)

????類?? Sample type

???????? Sampling location

????數??Number of location

5

????類?? Type of analysis ??????γ, ??H-3

??????率Sampling frequency ???? quarterly

????????Aquatic Samples ??????(????理) ??龍?????? Drinking water (treated) Kowloon distribution tap,

??????????

Tuen Mun distribution tap, ????濾????

Shatin Treatment Works, ??????濾????

Yau Kom Tau Treatment Works, ????濾????

Tuen Mun Treatment Works

??????(??????理) ????濾????

Drinking water (untreated)Shatin Treatment Works,

??????濾????

Yau Kom Tau Treatment Works, ????B??????

Muk Wu B Pumping Station, ????濾????

Tuen Mun Treatment Works, ????????High Island Reservoir, ??????????

Plover Cove Reservoir

?????? ??????Siu Hong Court, Underground water ????Cheung Hong Estate,

????Wah Fu Estate, ????Wan Tsui Estate, ????Fu Shan Estate

???????????????????????? ???? Port Island, Sea water (upper, middle ??浪?? Tai Long Wan, and lower level) ?????? Basalt Island,

?????? Waglan Island

??????????粒?? ???? Port Island, (??????????????????????浪?? Tai Long Wan, Suspended particulate in ?????? Basalt Island, sea water (upper, middle ?????? Waglan Island and lower level) ???? ???? Shenzhen, Aristichthys nobilis ??朗 Yuen Long (Big-head carp) ????

Nemipterus japonicus (Melon coat) ????

Platycephalus indicus (Bartail flathead) ????

Trichiurus haumela (Hair tail)

?????? Daya Bay, ????????????

West of Hong Kong,

???????? Hong Kong Waters ?????? Daya Bay, ????????????

West of Hong Kong,

???????? Hong Kong Waters ?????? Daya Bay, ????????????

West of Hong Kong,

???????? Hong Kong Waters

6 ??????γ, ??H-3 ???? quarterly

5 ??????γ, ??H-3 ??年 yearly

4 ??????γ, ??H-3 ??年 yearly

4

??????γ,

??-90 Sr-90, ?-239 Pu-239 ??????γ, ??H-3, ??-90 Sr-90, ?-239 Pu-239 ??????γ, ??H-3, ??-90 Sr-90, ?-239 Pu-239 ??????γ, ??H-3, ??-90 Sr-90, ?-239 Pu-239 ??????γ, ??H-3, ??-90 Sr-90, ?-239 Pu-239

??年 yearly

2 ???? quarterly

3 ???? quarterly

3 ???? quarterly

3 ???? quarterly

47

?? 1. (??) Table 1. (cont’d)

????類?? Sample type

???????? Sampling location

????數??Number of location

2

????類?? Type of analysis ??????γ, ??H-3, ??-90 Sr-90, ?-239 Pu-239 ??????γ, ??H-3, ??-90 Sr-90, ?-239 Pu-239 ??????γ, ??H-3, ??-90 Sr-90, ?-239 Pu-239 ??????γ, ??H-3, ??-90 Sr-90, ?-239 Pu-239 ??????γ, ??H-3, ??-90 Sr-90, ?-239 Pu-239 ??????γ, ??H-3, ??-90 Sr-90, ?-239 Pu-239 ??????γ, ??H-3, ??-90 Sr-90, ?-239 Pu-239 ??????γ, ??H-3, ??-90 Sr-90, ?-239 Pu-239 ??????γ, ??H-3, ??-90 Sr-90, Pu-239

??????γ, ??H-3, ??-90 Sr-90, ?-239 Pu-239 ??????γ, ??H-3, ??-90 Sr-90, ?-239 Pu-239 ??????γ,

?-239 Pu-239 ??????γ,

?-239 Pu-239

??????率Sampling frequency ???? quarterly

????????Aquatic Samples ?????? ???????????? Portunus sanguinolentus West of Hong Kong, (Three-spotted crab) ???????? Hong Kong Waters ??????

Metapenaeopsis barbata (Fire prawn) ????

Loligo edulis (Squid) ???? Sepia spp (Cuttlefish) ??

Tapes philippinarum (Calm)

????

Perna viridis

(Green-lipped mussel) ????螺

Babylonia formosae (Gastropod) ??

Ulva lactuca (Sea lettuce)

????

Enteromorpha prolifera (Sea hair) ??????

Porphyra dentate (Red algae)

??葉??????

Sargassum hemiphyllum (Brown algae) ????????????????????????Intertidal sediment (upper and lower level) ?????????? Seabed sediment

????????????

West of Hong Kong,

???????? Hong Kong Waters ?????? Daya Bay, ????????????

West of Hong Kong,

???????? Hong Kong Waters ???????? Hong Kong Waters

2 ???? quarterly

3 ???? quarterly

1 ???? quarterly

???? Cheung Chau, ??露?? Tolo Harbour ???? Cheung Chau, ??露?? Tolo Harbour, ?????? Daya Bay

????????Hong Kong Waters

2 ???? quarterly

3 ???? quarterly

1 ???? quarterly

?????? Po Toi O 1

??????????winter and spring ???? winter

??露?? Tolo Harbour 1

?????? Po Toi Island 1 ???? winter

?????? Po Toi O 1

??????????winter and spring ???? quarterly

??????Pak Sha Wan, ?????? Tsim Bei Tsui, ?????? Sha Tau Kok

???????? Tai Tan Hoi Hap, 龍???? Lung Ha Wan, 索???? Picnic Bay,

?????????? Western Anchorage

3

4 ??年 yearly

48

?? 2. ??零零??年???????????????????? Table 2. Summary of food samples collected in 2003

類??Type ???? Rice

????(??????) Pasteurized milk

???? Choi sum

????Location ????(??????????)

Mainland (Pearl River Delta)

???? Shenzhen ?????? Sha Tau Kok

????(????) Mainland (Shenzhen)

???? Local ????(????) Mainland (Shenzhen)

???? Local ????(????)

Mainland (Guangdong)

???? Mainland ????(????)

Mainland (Guangdong)

????(????)

Mainland (Guangdong)

????(????) Mainland (Shenzhen)

???? Local ????(????) Mainland (Shenzhen)

???? Local ???? Mainland ????(????)

Mainland (Guangdong)

???? Local ????(????)

Mainland (Guangdong)

???? Local ???? Shenzhen ??朗 Yuen Long ?????? Daya Bay ???????????? West of Hong Kong ????????Hong Kong Waters

?????? Daya Bay ???????????? West of Hong Kong ????????Hong Kong Waters

?????? Daya Bay ???????????? West of Hong Kong ???????? Hong Kong Waters

???????????? West of Hong Kong ???????? Hong Kong Waters

??????????數

Total no. of sample collected

4 4 4 4 4 4 4 4 1 2 1 4 4 4 4 4 4 4 4 4 4 4 0 0 3 0 0 3 0 0 3 0 3

???? Pak choi ???? Banana ???? Lychee ???? Mandarin ???? Sugar cane ?? Chicken

?? Duck ???? Beef ????Pig’s Liver

????Pork ???? Aristichthys nobilis

(Big-head carp) ???? Nemipterus japonicus

(Melon coat)

???? Platycephalus indicus

(Bartail flathead)

????Trichiurus haumela

(Hair tail) ??????

Portunus sanguinolentus (Three-spotted crab)

49

?? 2. (??) Table 2. (cont’d)

類??Type ??????

Metapenaeopsis barbata

(Fire prawn) ???? Loligo edulis

(Squid) ???? Sepia spp (Cuttlefish) ?? Tapes philippinarum

(Clam) ????Perna viridis (Green-lipped mussel) ????螺 Babylonia formosae

(Gastropod) ??Ulva lactuca (Sea lettuce)

???? Enteromorpha prolifera

(Sea hair)

??????Porphyra dentate

(Red algae) ??葉??????

Sargassum hemiphyllum

(Brown algae)

????Location ???????????? West of Hong Kong ???????? Hong Kong Waters

?????? Daya Bay ???????????? West of Hong Kong ???????? Hong Kong Waters ???????? Hong Kong Waters

???? Cheung Chau ??露?? Tolo Harbour ???? Cheung Chau ??露?? Tolo Harbour ?????? Daya Bay ???????? Hong Kong Waters

?????? Po Toi O ??露?? Tolo Harbour ?????? Po Toi Island ?????? Po Toi O

??????????數

Total no. of sample collected

0 3 0 0 3 2 0 3 4 3 3 1 2 1 1 2

50

?? 3. ????量度參數???? *

Table 3. Summary of key measurement parameters *

??量類?? Measurement type

??????????

???? Gamma emitting radionuclides

????????Airborne particulate ??????Airborne radioiodine ???????? Wet deposition ???????? Total deposition ???? Rice ????Milk ????Vegetable ????Fruit ????Poultry ??類Meat ???? Land soil

?????? Water samples ??????????粒??Suspended particulate ????Seafood ????Seaweed ????????/ ??????????Sediment ???????? Wet deposition ???????? Total deposition ??????Water vapour ???? Rice ????Milk ????Vegetable ????Fruit ????Poultry ??類Meat ??????Water samples ?????? Underground

water ????Seafood ????Seaweed

????????Sample size

??數 ????(??) Counting time (second)

????Background (CPM)

??數 ??率Counting efficiency (%)

???? 復??率Chemica

l recovery (%)

???????? # Minimum Detection

Activity # (MDA)

??-131 ??-137 I-131 Cs-137

-3

μBq m-310 μBq m20000 m3

-

400 m34 L

55000

- - - -

- - - - - - - - - - - 10 10 10 10 10 10 10 10 10 10 10 10 10

- - - - - - - - - - - - - 20 20 20 20 20 20 20 20 20 20 20

0.0001 m-3- - - - - - - - - - - - - - - - - - - - - - - - - -

0.1 Bq L-1

0.1 Bq L-1

0.03 m24 kg 1 L 1 kg 2 kg 2 kg 1 kg 1 kg 4 L 4 L 2 kg 0.5 kg 2 kg 0.007 L

20000 20000 20000 20000 20000 20000 10000 55000 55000 72000 20000 20000 36000

12 Bq m-2m-2 0.1 Bq kg-1 0.2 Bq L-1 0.3 Bq kg-1 0.2 Bq kg-1 0.1 Bq kg-1 0.3 Bq kg-1 2 Bq kg-1 0.1 Bq L-1 0.01 Bq L-1 0.03 Bq kg-1 1 Bq kg-1 0.4 Bq kg-1

0.2 Bq kg-10.3 Bq L-1 0.4 Bq kg-10.3 Bq kg-10.2 Bq kg-10.4 Bq kg-12 Bq kg-1 0.1 Bq L-1 0.02 Bq L-10.06 Bq kg-12 Bq kg-1 0.5 Bq kg-1

??Tritium

6 Bq L-1 400 Bq m-2 70 Bq m-3 1 Bq kg-1 6 Bq L-1 5 Bq kg-1 4 Bq kg 4 Bq kg-1 4 Bq kg-1 6 Bq L-1 0.4 Bq L-1 4 Bq kg-1 2 Bq kg-1

0.0001 m20.0008 m30.07 kg 0.007 L 0.008 kg 0.01 kg 0.01 kg 0.01 kg 0.007 L 0.1 L 0.01 kg 0.02 kg

36000 36000 36000 36000 36000 36000 36000 36000 36000 36000

51

?? 3. (??) Table 3. (cont’d)

??量類??

Measurement type

??-90 Strontium-90

????????Airborne particulate ???????? Wet deposition ???????? Total deposition ?? Rice ????Milk ????Vegetable ????Fruit ????Poultry ??類Meat ???? Land soil ??????????粒??Suspended particulate ????Seafood????Seaweed????????Airborne particulate ???????? Wet deposition ???????? Total deposition ???? Land soil ??????????粒??Suspended particulate ????Seafood????Seaweed ???????? / ??????????Sediment

????????

Sample size

??數 ????(??)

Counting time (second)

????

Background (CPM)

??數 ??率

Counting efficiency (%)

75 75 75 75 75 75 75 75 75 75 75 20 20 20 20 20 20

???? 復??率

Chemical recovery (%)

100 90 90 90 90 90 90 90 90 90 90 40 60 50 40 40 50

???????? #

Minimum Detection Activity

(MDA)

#

5000 m33 L

30000

1 1 1 1 1 1 1 1 1 1 1 1 1 - - - - - - - -

1 μ Bq m-3 0.001 Bq L-1 0.3 Bq m-2 0.002 Bq kg-1 0.005 Bq L-1 0.005 Bq kg-1 0.003 Bq kg-1 0.002 Bq kg-1 0.005 Bq kg 1 Bq kg-1 0.002 Bq L-1 0.003 Bq kg-1 0.05 Bq kg-1 0.2 μ Bq m-3 0.0002 Bq L-1 0.04 Bq m-2 0.2 Bq kg-1 0.0003 Bq L-1 0.002 Bq kg-1 0.01 Bq kg-1 0.2 Bq kg-1

0.01 m23 kg 1 L 1 kg 2 kg 2 kg 1 kg 0.005 kg 3 L 2 kg 0.1 kg

30000 30000 30000 30000 30000 30000 30000 30000 30000 30000

?-239 Plutonium-239

5000 m33 L

220000

0.02 m20.004 kg 2 L 0.5 kg 0.03 kg 0.005 kg

220000 220000 220000 220000 220000

??:

*

- ??????列??????數????????參??????????????????????????量度參數????????????????????????????????????????

??????????不????參數??行量度?? - ??量????????????????????量????????????量??????????量??????????度????????????????數??????????????數??

??????????量??????????????量????????????????????量??????????????????????????????????????量????????????????????????????????????量????????????數??????????理????????????????????易參????????

#

Note:

*

- The values given in the table are typical values and may vary in practice, and should thus be used as reference only. Under

special circumstances, some samples may be measured under substantially different conditions. - The minimum detection activity (MDA) of a measurement is the lowest activity level that is practically achievable by the

counting system for that measurement. MDA values depend on the characteristics of the measurement system, method of measurement, sample characteristics and measurement conditions, and thus vary with individual samples and measurements. The listed MDAs are typical values under “typical” measurement conditions and serve as a quick reference in interpreting results in this report.

#

52

?? 4. ??零零??年輻????????????????????量??????錄??????????????量率??????????μGy h-1 Table 4. Ambient gamma dose rate recorded by the radiation monitoring network and

thermoluminescent dosimeter network in 2003.

-1

Dose rate in μGy h

??

輻??????????

????????年?????? Station Annual Average ???? Kat O 0.105 ??????King’s Park 0.138 ???? Kwun Tong 0.128 ???? Ping Chau 0.091 ??????Sai Wan Ho 0.100 ?????? Sha Tau Kok 0.101 ?????? Tai Mei Tuk 0.120 ???? Tap Mun 0.087 ?????? Tsim Bei Tsui 0.131 ?????? Yuen Ng Fan 0.116

????????量????????

????????年?????? Location Annual Average ????Cape D’Aguilar 0.12 ???? Cheung Chau 0.10 ????????Chi Fu Fa Yuen 0.14 ??????Clear Water Bay 0.10 ??????Deep Water Bay 0.12

??嶺Fanling 0.10 ??????Happy Valley 0.08

???? Kat O 0.11 ??????King’s Park 0.14 ???? Kwun Tong 0.12 ???? Ping Chau 0.12 ????Sai Kung 0.12 ?????? Sha Tau Kok 0.09

????Shatin 0.13 ??????Shau Kei Wan 0.13 ????Shek Kong 0.11 ????So Uk 0.11 ?????? Tai Lam Chung 0.21 ?????? Tai Mei Tuk 0.13

????Tai Po 0.08 ???? Tap Mun 0.09 ?????? Tsim Bei Tsui 0.13 ????Tsuen Wan 0.13 ???? Tuen Mun 0.16 ??????Wu Kai Sha 0.12 ??朗 Yuen Long 0.10 ?????? Yuen Ng Fan 0.11

??????

Standard Deviation

0.003 0.004 0.002 0.004 0.002 0.002 0.002 0.002 0.002 0.003 ???????????????? Range of 1 min data

0.093 – 0.148 0.120 – 0.205 0.118 – 0.171 0.078 – 0.180 0.091 – 0.149 0.088 – 0.170 0.109 – 0.169 0.077 – 0.134 0.119 – 0.176 0.104 – 0.181

??????

Standard Deviation

0.03 0.02 0.01 0.02 0.02 0.01 0.01 0.02 0.03 0.02 0.03 0.02 0.01 0.02 0.02 0.02 0.02 0.02 0.02 0.01 0.01 0.01 0.02 0.03 0.01 0.02 0.02 ???? Range 0.11 – 0.14 0.09 – 0.11 0.13 – 0.14 0.09 – 0.11 0.11 – 0.13 0.09 – 0.10 0.08 – 0.09 0.10 – 0.12 0.13 – 0.16 0.12 – 0.14 0.11 – 0.13 0.11 – 0.14 0.08 – 0.09 0.12 – 0.14 0.12 – 0.14 0.10 – 0.12 0.10 – 0.12 0.20 – 0.22 0.12 – 0.14 0.08 – 0.08 0.09 – 0.10 0.12 – 0.14 0.12 – 0.14 0.15 – 0.17 0.11 – 0.13 0.09 – 0.11 0.10 – 0.12

53

?? 5. ??零零??年??????????????????????輻????量????

Table 5. Radiation measurement results of the Automatic Gamma Spectrometry System at Ping Chau in 2003

年?????? * Annual Average *

??????Standard Deviation

????????????Range of Daily Average

?????????? ??零零??年???? * Range from 1997

to 2002 * 1.002 – 5.787

??????粒??Alpha

(Bq m-3) ????粒??Beta (Bq m-3) ??-131 I-131 (mBq m-3) ??-137 Cs-137 (mBq m-3) ??????-131 Gaseous I-131 (Bq m-3) ??????????量率 % Ambient gamma dose rate %

-1

(μGy h ) ??:

*

1.261 0.176 1.039 – 1.653

1.963 < 1 < 4 # < 1 < 4 < 1

#

0.606 1.005 – 3.326 1.000 – 10.087

N/A &N/A N/A < 1

0.112 0.003 0.105 – 0.123 0.103 – 0.180

-

#

-

??量?????????????????? “< xx” ??????xx????類??量??????????????????

????????????????????????????零零??年????????????????????????????????????????????????????????

Genie

2000????????????????????????????????????????????來??????????????????????????????數??

&

%

- 不??????N/A ??????

- ????????????????數????????????????????????零零??年六??????????????不??量??????????量率??

Note:

*

- Results below the minimum detectable activity (MDA) are reported as “< xx” where

xx is the typical value of the MDA for that type of measurement. #

- A replacement gamma spectrometry system was commissioned in July 2003. It adopts

the same Genie 2000 software for spectrometry analysis as that used in the Radiation Laboratories at King’s Park. Higher MDA values are reported by Genie 2000 as it employs a more conservative formulation for computing MDAs compared with that of the old system. &

- N/A - not applicable. % - Data were available from January to May only. To avoid duplication of effort,

measurement of ambient gamma dose rate is no longer made by the replacement system from June 2003 onwards.

54

?? 6. ????輻??????????????量率??量????

Table 6. Measurement results of gamma dose rate due to cosmic radiation

??量????Date of measurement

14 Mar 2003

19 Sep 2003

12 Dec 2003

??????????量率(??????????) -1Average gamma dose rate (μGy h) 0.031 0.031 0.033

?? 7. ??零零??年??????????????????????度??量????

Table 7. Measurement results of gamma activities in food and environmental samples in 2003

????????量??度??

??????數 ??度??度 * ???? BRMP ???? #????類??Type Total no. of Activity ????Location #Range Unit BRMP rangesamples with Concentration *measurable activity

???? Rice ???? Mainland 2 0.1 – 0.1 0.1 ≤ 0.9 Bq kg-1 ???? Pork ???? Local ≤ 0.9 Bq kg-1 ???? Nemipterus ????????

japonicus Hong Kong Bq kg-1 (Melon coat) Waters

???? Trichiurus ????????

haumela Hong Kong ≤ 0.2 Bq kg-1 (Hair tail) Waters

見??1. ????(????) Please see 5 0.4 – 2.8 1.3 Land soil (upper) Table 1. ≤ 10 Bq kg-1 見??1. ????(????) Please see 4 0.6 – 1.2 1.0 Land soil (lower) Table 1.

?????? 4 0.4 – 0.8 0.6 Pak Sha Wan ????????(????) ?????? Intertidal 4 0.8 – 1.2 1.0 Tsim Bei Tsui sediment (upper) ?????? 4 0.5 – 0.8 0.7 Sha Tau Kok

?????? 4 0.3 – 0.6 0.5 Pak Sha Wan ????????(????) ?????? Intertidal 4 0.7 – 1.0 0.8 ≤ 3.1 Bq kg-1 Tsim Bei Tsui sediment (lower) ?????? 4 0.4 – 0.7 0.5 Sha Tau Kok

????????

Tai Tan Hoi Hap ?????????? 龍???? Seabed sediment Lung Ha Wan

索???? Picnic Bay

??: *

# - - ????????????????????????量??度????欄?????????????? ??量?????????????????? “< xx” ??????xx ????類??量??????????????????????????????????????????????????????????????

??????“≤ xx”????xx??????量??????度????????

Note: * - The mean activity concentration is reported if there are more than one sample with measurable activities. # - Results that are below the minimum detectable activity (MDA) are reported as “< xx” where xx is the typical

value of the MDA for that type of measurement. When a particular radionuclide was detected only in some of the samples in a certain sample type, the results will be reported as “≤ xx” where xx is the maximum measured activity value.

55

?? 8. ??零零??年????????????????????度??量????

Table 8. Measurement results of tritium activities in food and environmental samples in 2003

類??Type ????????量??度????????數 ??度??度 * ???? BRMP ???? #????Total no. of Activity ????Location #Range Unit BRMP rangesamples with Concentration *measurable activity

???? Mainland Bq kg-1

???? Shenzhen 3 1.5 – 4.4 2.8

Bq L-1 < 6 ?????? 3 3.2 – 5.9 4.9 Sha Tau Kok

???? Mainland 3 0.2 – 5.9 2.9

???? Local 2 3.5 – 4.7 4.1 ≤ 7.4 Bq kg-1 ???? Mainland 2 3.2 – 3.3 3.3

???? Local ???? Mainland 2 1.5 – 2.6 2.1 < 3 Bq kg-1

???? Mainland Bq kg-1

???? Mainland Bq kg-1

???? Mainland Bq kg-1

???? Mainland ≤ 2.2 Bq kg-1 ???? Local 2 0.3 – 0.3 0.3

???? Mainland ≤ 3.5 Bq kg-1 ???? Local ???? Mainland 2 0.2 – 1.0 0.6 ≤ 5.3 Bq kg-1

???? Local Bq kg-1

???? Mainland Bq kg-1

??朗

Yuen Long

????????

Hong Kong

Waters

????????

Hong Kong

Waters

????????

Hong Kong

Waters

??露??

Tolo Harbour

????

Cheung Chau

??露??

Tolo Harbour

??????

Daya Bay

????????

Hong Kong

Waters 2 0.2 – 0.7 0.5 < 2 Bq kg-1 ???? Rice ????(??????) Pasteurized milk ???? Choi sum ???? Pak choi ???? Banana ???? Lychee ???? Mandarin ???? Sugar cane ?? Chicken ?? Duck ???? Beef ????Pig’s liver ???? Pork ???? Aristichthys nobilis (Big-head carp) ???? Nemipterus japonicus (Melon coat) ???? Platycephalus indicus (Bartail flathead) ???? Sepia spp (Cuttlefish) ?? Tapes philippinarum (Clam) ???? Perna viridis (Green-lipped mussel) ????螺 Babylonia formosae

(Gastropod)

Bq kg-1 2 1.2 – 1.6 1.4 < 2 Bq kg-1 Bq kg-1 Bq kg-1 3 2 0.4 – 1.5 0.9 – 1.3 1.1 1.1 < 2 Bq kg-1 Bq kg-1

56

?? 8. (??) Table 8. (cont’d)

類??Type

????????量??度??

??????數 Total no. of ????Location

samples with measurable activity??露?? Tolo Harbour ?????? King’s Park ?????? Sha Tau Kok ?????? Yuen Ng Fan ?????? King’s Park ?????? King’s Park ??龍??????Kowloon distribution tap ?????????? Tuen Mun distribution tap ????濾????Shatin Treatment Works ??????濾????Yau Kom Tau Treatment Works ????濾????Tuen Mun Treatment Works ????濾????Shatin Treatment Works ????B??????Muk Wu B Pumping Station ????濾????Tuen Mun Treatment Works ???????? High Island Reservoir ??????????Plover Cove Reservoir

???? Range

??度??度 *

BRMP ???? #

Activity #

*BRMP rangeConcentration ????

Unit

???? Enteromorpha prolifera (Sea hair) ???????? (降??) Wet deposition (precipitation) ???????? Total deposition ??????????Water vapour

in air

Bq kg-1 7 4 4 8 4

1.1 – 6.0 1.2 – 5.3 2.3 – 5.7 71.0 –

519.0 26.0 – 187.0

3.1 2.7 4.1

Bq m-2 90.3

≤ 242

Bq m-3

≤ 12 Bq L-1

2

0.7 – 5.0

2.9

??????

(????理) Drinking water (treated)

< 6 Bq L-1

4 2.1 – 5.7 4.3

2 3.6 – 5.5 4.6

3 3.1 – 4.0 3.4

< 6

Bq L-1

??????

(??????理) Drinking water (untreated)

4 0.7 – 5.7 3.8

3 2

3.6 – 5.2 4.0 – 5.0

4.6 4.5

57

?? 8. (??)

Table 8. (cont’d)

類??Type ????????量??度????????數 ??度??度 * ???? BRMP ???? #

Total no. of Activity ????Location #Range *BRMP rangesamples with Concentration measurable activity

?????? Sui Hong Court

????

Cheung Hong Estate

???? ≤ 2.8 Wah Fu Estate

????

Wan Tsui Estate

???? Fu Shan Estate

???? Port Island < 6 ?????? Waglan Island

??????

Waglan Island

????

Port Island

??????

Basalt Island ????Unit ?????? Underground water Bq L-1 ????(????) Sea water (upper) ????(????) Sea water (middle) ????(????) Sea water (lower)

??:

*Bq L-1 Bq L-1 < 6 Bq L-1 -

# -

Note:

*????????????????????????量??度????欄?????????????? ??量?????????????????? “< xx” ??????xx ????類??量????????????????????????????????????????????????????????????????????“≤ xx”????xx??????量??????度????????????“---”????????????????BRMP??量?? - The mean activity concentration is reported if there are more than one sample with measurable activities. # - Results that are below the minimum detectable activity (MDA) are reported as “< xx” where xx is the typical

value of the MDA for that type of measurement. When a particular radionuclide was detected only in some of the samples in a certain sample type, the results will be reported as “≤ xx” where xx is the maximum measured activity value. “---” indicates that the sample was not measured in BRMP.

58

????9. ??零零??年????????????????????90??度??量??????

Table 9. Measurement results of strontium-90 activities in food and environmental samples in 2003

類??Type

????????量??度??

??????數 ??度??度 *

???? BRMP ???? #

Total no. of Activity ????Location #

Range *BRMP rangesamples with Concentration measurable activity

???? Mainland 4 5 – 8 6 ≤ 56 ???? Shenzhen 4 13 – 24 17

8 – 81 ??????

4 9 – 15 13

Sha Tau Kok ???? Mainland 4 35 – 140 80 ???? Local 4 12 – 36 24

≤ 570

???? Mainland 4 45 – 153 90 ???? Local 4 25 – 92 58 ???? Mainland 2 4 – 5 5 ≤ 27 ???? Mainland 1 - 4 5 – 14 ???? Mainland 1 - 17 10 – 84 ???? Mainland 1 - 3 2 – 14 ???? Local 2 2 – 4 3 ≤ 37 ???? Mainland ≤ 53

???? Local ???? Mainland 2 8 – 17 13 ≤ 35 ???? Mainland 2 6 – 15 11

≤ 36

???? Local ???? Shenzhen 4 4 – 18 8 ??朗 Yuen Long ???????? Hong Kong Waters ???????? Hong Kong Waters ??露?? Tolo Harbour ???? Cheung Chau ?????? Daya Bay

3

7 – 11

9

≤ 94

????Unit

mBq kg-1mBq L-1

???? Rice ????(??????) Pasteurized milk ???? Choi sum ???? Pak choi ???? Banana ???? Lychee ???? Mandarin ???? Sugar cane ?? Chicken

?? Duck ???? Beef ???? Pork ???? Aristichthys nobilis (Big-head carp)

???? Nemipterus japonicus (Melon coat) ?????? Portunus sanguinolentus (Three-spotted

crab) ?? Tapes philippinarum (Clam) ???? Perna viridis (Green-lipped mussel)

mBq kg-1

mBq kg-1mBq kg-1mBq kg-1mBq kg-1mBq kg-1mBq kg-1mBq kg-1mBq kg-1

mBq kg-1

≤ 21 mBq kg-1

2 5 – 10 8 ≤ 105 mBq kg-1

≤ 32 ≤ 47

mBq kg-1

mBq kg-1

59

?? 9. (??) Table 9. (cont’d)

類??Type

????????量??度??

??????數 Total no. of ????Location

samples with measurable activity?????? Po Toi O ??露?? Tolo Harbour ?????? Po Toi Island ?????? Po Toi O ?????? King’s Park ?????? Sha Tau Kok ?????? Yuen Ng Fan ?????? King’s Park ?????? Yuen Ng Fan ?????? King’s Park 見??1. Please see Table 1. 見??1. Please see Table 1.

2

???? Range

??度??度 *

BRMP ???? #

Activity #

*BRMP rangeConcentration 118

????

Unit

?? Ulva lactuca (Sea lettuce)

???? Enteromorpha prolifera (Sea hair) ?????? Porphyra dentate (Red algae) ??葉?????? Sargassum hemiphyllum (Brown algae) ???????? Airborne particular ????????(降??) Wet deposition (precipitation) ???????? Total deposition ????(????) Land soil (upper)

78 – 157

≤ 1440

mBq kg-1

2 6 7 3 2 7 3 2

209 – 3450.8 – 2.0 0.7 - 3.0 0.7 – 1.6 1.4 – 1.8 1.5 – 10.10.2 – 0.4 1.4 – 3.1

277 1.5 1.6 1.0 1.6

≤ 39

5.5 0.3 2.3

≤ 27.3 ---

Bq m-2 Bq kg-1 mBq L-1

≤ 5 μBq m-3

????(????)

2 1.6 – 1.6 1.6 Bq kg-1

Land soil (lower)

??:

*

- ????????????????????????量??度????欄?????????????? #

- ??量?????????????????? “< xx” ??????xx ????類??量??????????????????????????????????????????????????????????????

??????“≤ xx”????xx??????量??????度????????????“---”????????????????BRMP??量??

Note:

*

- The mean activity concentration is reported if there are more than one sample with measurable activities. #

- Results that are below the minimum detectable activity (MDA) are reported as “< xx” where xx is the typical

value of the MDA for that type of measurement. When a particular radionuclide was detected only in some of the samples in a certain sample type, the results will be reported as “≤ xx” where xx is the maximum measured activity value. “---” indicates that the sample was not measured in BRMP.

60

?? 10. ??零零??年???????????????????239??度??量????

Table 10.

類??Type

????????量??度??

??????數 Total no. of ????Location

samples with measurable activity?????? Po Toi O 見??1. Please see Table 1. ?????? Pak Sha Wan ?????? Tsim Bei Tsui ?????? Sha Tau Kok ?????? Pak Sha Wan ?????? Tsim Bei Tsui ?????? Sha Tau Kok ???????? Tai Tan Hoi

Hap 龍???? Lung Ha Wan 索???? Picnic Bay

???? Range

??度??度 *

BRMP ???? #

Activity #

*BRMP rangeConcentration ????

Unit

Measurement results of plutonium-239 activities in food and environmental samples

in 2003

??葉?????? Sargassum hemiphyllum (Brown algae) ????(????) Land soil (upper) ????????(????) Intertidal sediment (upper)

0.05 ≤ 0.101 Bq kg-1

2 0.11 – 0.120.12 < 0.2 Bq kg-1

3 3

0.12 – 0.140.12 – 0.27

0.13 0.20

2 2

0.11 – 0.160.16 – 0.19

0.14 0.18

≤ 0. 57

Bq kg-1

????????(????)

Intertidal sediment (lower)

??????????

Seabed sediment

??:

*#

- -

????????????????????????量??度????欄??????????????

??量?????????????????? “< xx” ??????xx ????類??量????????????????????????????????????????????????????????????????????“≤ xx”????xx??????量??????度????????

Note:

*

- The mean activity concentration is reported if there are more than one sample with measurable activities. #

- Results that are below the minimum detectable activity (MDA) are reported as “< xx” where xx is the typical

value of the MDA for that type of measurement. When a particular radionuclide was detected only in some of the samples in a certain sample type, the results will be reported as “≤ xx” where xx is the maximum measured activity value.

61

?? 11.????零零??年??????量????????

Table 11. Overall summary of measurement results in 2003

??量????/

????????類??參??數?? # Pathway Mea. results /

ref. values *, # ???????????? % Range % Airborne

BRMP Particulate

???? Range ????

???? Rice

BRMP

?????? Milk ????

Vegetables ??Fish ????理??????????Treated Drinking Water

#

????131I-131 ????137??Cs-137 ????H-3 ????90??Sr-90 ???239??Pu-239

????Unit

????Atmo- sphereic

< 10 ≤ 328 < 0.1 < 0.1 < 0.2 < 0.2 < 0.3 < 0.3 < 0.03 < 0.1 < 0.1 < 0.1

< 10 < 10 0.1 ≤ 0.9 < 0.3 ≤ 0.3 < 0.4 < 0.4 0.04 – 0.10≤ 0.2 < 0.1 < 0.1

--- $ 0.4 < 1 1.5 – 5.9< 6 0.2 – 5.9≤ 7.4 0.2 – 1.6< 2 0.7 – 5.7< 6

0.7 – 3.0 ≤ 5 0.005 – 0.008 ≤ 0.056 0.013 – 0.024 0.008 – 0.081 0.012 – 0.153 ≤ 0.570 ≤ 0.094

< 0.2 < 0.2

μBq m-3

kg-1 L-1 kg-1

Bq kg-1

???? Range BRMP ???? Range BRMP ???? Range BRMP ???? Range BRMP

0.004 – 0.018 < 0.002

< 0.002

L-1

??:

-

% -

$

????????????????????????量??度????欄???????????????? ??零零??年??????類????輻????量??????????????列????

- “---”??????????ERMP??行??????量??

Notes:

*

- “mea.” – measurement; “ref.” – reference. #

- Results that are below the minimum detectable activity (MDA) are reported as “< xx” where xx is the

typical value of the MDA for that type of measurement. When a particular radionuclide was detected only in some of the samples in a certain sample type, the results will be reported as “≤ xx” where xx is the maximum measured activity value. %

- The range of measurement results in 2003 for each of the listed sample types is shown in bold. $

- Measurements not included under ERMP are reported as “---” in the table.

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