A Preliminary Investigation of Radiation Level and Some Radionuclides in Imported Food and Food Products
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OAEP รมา^ A PRELIMINARY INVESTIGATION OF RADIATION LEVEL AND SOME RADIONUCLIDES IN IMPORTED FOOD AND FOOD PRODUCTS by FUKIAT SINAKHOM AND SUCHAT MONGKOLPHANTA library LOAN MATERIAL Please return to the Loan Ides*K F0145 เมษายน 2523 OFFICE OF ATOMIC ENERGY rOI APRIL 1980 BANGKOK , THAILAND We regret that some of the pages in the microfiche copy of this report may not be up to the proper legibility standards, even though the best possible copy was used for preparing the master fiche การrfารวVวเกราะหเของทนทงฟ่รนาพรํงสืน8ะขนศของ ใอโชโฟในอาใเทรนอะข«»ฬผ์,พอง อาหารห!โงทททางประเห!! * A PRELIMINARY INVESTIGATION OF RADIATION LEVEL AND SOKE RADIONUCLIDES IN IMPORTED FOOD AND FOOD-PRODUCTS " ฟเกยรก สิไทกน U9ะ แขาก มงกพํนธุ กองช'fกกากกํมม้นกรง!! fi านํก์งานหล้งงานปรนาผเ*๗นกิ FUKIAT SINAKHOM AND SUCHAT MONGKOLPHANTHA WASTE DISPOSAL DIVISION OFFICE OF ATOMIC ENERGY FOR PEACE เมษายน 2523 APRIL 1980 ส'าน่ก์งานหล*งงานปรมาผู๗นก OFFICE OF ATOMIC ENERGY FOR PEACE ทยงานนเปึน!เวนพนึ๋งของวหยานแนขของ นางijเกยรก สินากม (fmitiงาน) กามหiก์สืกราศวกรรมแาแกรมหาบ่ผทิก ชุ*ไaงกรผมหาาหขาสํย With the rorrpl?Tents of Office of Atomic Fnergy 11.r Peace Thailand This report was prepared as an account of work sponsored by the Office of Atomic Siergy for Peace. Neither the Office of Atomic Energy for Peace, nor any of their employees, or any of their contractors, sub- contractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, com- pleteness or usefulness of any information, apparatus, product or process disclosed, or represents that its use would not infringe privately owned rights. เอก*ทรชJข์น ^Mh ขึ้นโทย rflนกงานฑจ็งงานปรมา^*อรํนค ส์าน้กงานห®']งาน- ป!มา^เไ!อiนก ไมประ1พ้ทวามmiwอบหางกฎหมายในเรอง!ทามนนนอน ทวามรม^ทน ห?® ประโยขนชองขณพ เทรองมอ ฃลคขล หรอกระบวนการใศ ๆ หึ่เปีคเขยในเอกรารน. 2 - นหก่ก์ฆอ การกrษานิ้เป็นการสำท,ทบองท้นเพรำราร'วิเก!าะหกวามแรงร้ง*!เบกาฬะปรมาผของ ไอโรโหปรงf(หมก?งชากยาว โกยเฉหารอยางยง 1ทกนอนสกรากฟ้ขพัใน!ทหารและนลกM14ชอง อาหารหึ่สังเช้ามารำหนายภายในประเหส อาหารหนำมาาเกราะหวิพ้นมVำนวนหงหมก 89 กํว์ซยาง ชงกำเบนการ WTB เป็นประรำหกเกอน เกอนอะทรง ในระหวางปี ห.ก.2519-2520 รากราน- ชุปเปอรมารเกก แธะร้านชายของชำห เป็นหนยมของบุกกฉหวไป นำอาหารกํวอยางมากรารสอบแกมมาtl เปกกรํมกายเกรองวิเกราะหทสืชนกมํฉกแชนแนล 126 ช่อง รงกอกํบหํววํท้ Nal (T1) ธนาศ 3" X 3" กำนวพเวามแรงรง(เของโปนกสเชยม-40 แอะ ชเขยฆ-ร37 รงเป็นไอโชโหปร้งสืหกรวรหน ชกรำกํก์ของการวิเกราะหโปแกสืเชยม-40 เพะ ชเขยม-ไ37 ภายใกสภาาะนมกำ 0.04 และ 0.03 หโกกรก่อกรมนาหนํก์สกกามลำก่น ภายห;fงราก เขากำอย่าง!นเป็นเถ้าแลวนำไฟ่าก์กวามแรงร*'งสืรวมเยกา กวยเครองวักร*งสืเบกา แล้วนำไปวิ เกราะห ป?มายสกรอนเกยม-90 กาย เหกนกการสก,กโกยใช้ tri-n-butyl phosphate เป็นสารสกํก ขลการวิเกราะหความแรงรง้สืรวมเบกา ป?มาซเของโปแกสเชยม-40, ชเชยม-137 และสกรอนเกยม-90 ในกํ'วอยางอาหาร หอสืรุปไกกงการางช้าง•างนิ้ ชวงของกวามเชมขนของ ขน?เของ รานวน กวามแรงรงสิ โปแกส ^ยม-40 สทรอใแกยม-90 ท'วอย่าง อาหารหนำ ชเรยม-137 สกรอนแกยม-90 รวมเบกา หโกกูรฅ่อกรํม์ หโกกูรก่อกทเ หิโกกรก่อกรํม หโกก?ทอกรํม์ อาทาร มาวิเกราะห หโกกรกอกรไJ น.น.สก บ.น.สก น.น.สก แก a เ^ยม น.น.สก - r ปลาหะเฉ 58 0.09-15.10 < 0.04-0.58 <0.03-5.69 0. ^23-0.7808 16.87-826.50 และหอย เนอ 6 2.15-16.77 0.05-0.97 < 0.0-3 0.1298-0.2449 528.25-312QUX' ช?ล 22 2.27-15.81 < 0.04-0.95 < 0.03-2.98 0.0656-1.332-' 22.62-750.00 3 4.31-21.36 <0.04-1.17 <0.03 0.1852-0.3920 80.52-55.61 ผฝืกภํณทํ ผ ABSTRACT A preliminary study of gross beta activity and content of some long-live i radionuclides associated with fission products in various types of imported food and food-products was carried out. Food samples were purchased monthly during 1976-1977 from general wellknown supermarkets and local grocery stores up to a total of 89 samples. The gamma spectrum of long-lived radionuclides was searched using a 128 channel analyzer coupled with 3" X 3" Nal (Tl) crystal detector. T'jro radionuclides were frequently found to be present in these food samples, viz. potassium-40 and cesium-137 and their concentrations were subsequently determined. The limits of detection under the conditions used for potassium-40 and cesium-137 were 0.04 and 0.03 pCi/g-wet weight, respectively. Samples were dry-ashed and counted for gross beta activity utilizing a low background anti-coincidence G.M. counter. The content of strontium-90 was also investigated concurrently by solvent extraction technique employing tri-n-butyl phosphate as an extractant. Results of the study are tabulated. Type of Amount of Jtenge of concentration gross p ! K-40 as-137 Sr-90 3r-90 samples samples analyzed pCi/g-wet pCi/g-wet pCi/g-wet pCi/g-wet pCi/g-Ca wt. wt. wt. wt. Fish and 58 0.90-15.10 <0.04-0.58 <0.03-5.69 0.0523-0.7808 16.87-826.50 shell-fis h Meat 6 2.15-16.77 0.05-0.97 <0.03 0.1298-0.2449 528.25-3120.00 Cereals 22 2.27-15.81 <0.04-0.95 <0.03-2.98 0.0656-1.3321 22.62-750.00 Kilk prod uct 3 4.31-21.36 <0.04-1.17 <0.03 0.1852-0.3920 80.52-95.61 i:!TRCDUCTIC!i It is well recognized that a problem of radiation pollution is playing an important role in our environment at present. Radio- active materials, which emit radiation during their decay, are created as the result of nuclear detonations^ besides nuclear weapons testing, the manufacturing and processing of nuclear fuel, reactor operations and accidents related to the use of nuclear power sources in space vehicles, and from the disposal of radioactive wastes. These are sources of a man-made environmental contamination. For the time being, a radioactive fallout represents the major source of the hazardous long-lived radionuclides of concern to the general population. Since the mid 1950'ร, Problems of exposure to radiation have been stimulated as the result of the expanding use of nuclear energy and the occurrence of the fallout from nuclear testing programs of several nations. The recognition of the damaging effects to tissue by ionizing radiation has created the general awareness that relatively brief exposure to high levels of radioactivity may produce acute illness. Of special significance in connection with normal peacetime pursuits is the fact that prolonged contact with much lower levels may generate less immediately recognizable but potentially bodily impairments. The concern was diminished after the Partial Test Ban Treaty of 1965, eventhough two countries, France and the people's Republic of China who have not signed the treaty, are currently testing nuclear weapons in the atmosphere from time to time. Up to November 1976, the People's Republic of China had already conducted her 21 st nuclear test. AS reported in 1976 that the radioactivity was distributed to many areas in Fuguchima, northern of Japan, also Cs-137 was found to be 113 picocuries per litre of milk in Tokyo which resulted from fallout of that test in China. In regard to the radioactive fallout, the main objectives are to understand the relationships between the amount and patterns of the release and the harm that may affect human beings. There is the real need to monitor the environment, to make prediction as to what will happen from known and anticipated injection of contamination and to know ho* to reduce the exposure to man. In attempting to arrive at an evaluation of the possible dangers associated with the relatively l*w level of fallout, information from bomb explosion, both those tests which have already occurred and those which will occur in the future needs to be known in order to evaluate the eifoct on human health. It is therefore of the greatest importance to obtain observations which can be employed . to evaluate the danger. Cne of the significant steps is the environmental monitoring including the investigation of specific radionuclides in food, water and air. The environmental radioactivity surveillance has been routinely conducted by the Office of Atomic Energy for peace (OAEP) and some other laboratories. The results, up to the present, show no significant contamination of fallout (1,2). In addition, the determination of gross beta activity, Cs-137 and Sr-90 in water around - 5 - the OAEP where a Thai Research Reactor-1 (TRR-1) is situated and believed to be one of the sources of radiation contamination, has been routinely performed. The recent report also indicated no contamination (3,4). Furthermore, the investigation of gross beta activity and jr-90 concentration in rice samples collected from various parts of the country denoted no contamination as well (5). Eversince there is ท^ sources of harmful radiation contamination inside the country, the possible contamination from the outer sources must be brought into the consideration. The amounts of imported foods and food products particularly milk and dairy products were increased greatly in the past. Though the country, since 1970 has changed her status from the country of importer to exporter in canned food industries, many foreign brands and various kinds of canned food are still distributed widely in supermarkets and local grocery stores. As mentioned earlier, some countries still continue the atmospheric nuclear testing, which results in fallout contamination in world wide region. It was also reported that noticable high radiation level was found in a few items of food such as marine fish and milk. These foods were actually not allowed to be ccnsumed in such countries. There is a possibility, however, that those contaminated foods may be transferred into canned foods and exported. Consequently, there is the real need for the consumer to be aware of the problem and set up regulations for acceptable concentration of radionuclide in food. Regarding this reason and the radiation surveillance of long-lived radionuclides particularly fission products in imported foods and food-products has not yet been reported in Thailand at present. Besides, the information obtained will be beneficial for the authorized governmental agencies to be able to set up a maximum permissible limit for radiation level and concentration of specific fission product in those food-stuffs.