Applications of Nuclear
Techniques In Human Life
And Health Across The World:
A Detail Study
Sharmila Pal
Expository Writi...
Table of Contents
Introduction …………………………………………….. 3
Health Care …………………………………………….. 3
Agricultural Production ……………………………...
INTRODUCTION:
Since the past half century, isotopes and ionizing radiation have been greatly used across the world to
the ...
detection with a gamma camera or some other detector. The in vitro applications involve analysis of samples
taken from the...
Single Photon
Emission
Tomography
(SPECT)
Distribution of
radiopharmaceutical
administered to patient
is measured from man...
(Groth “Lasting Applications…”)
Bone Scanning:
One of most common in vivo diagnosis is bone scanning. It provides an effic...
Fig 3: PET image showing the blood flow in the brain
Source: (“PET” Internet)
Renal Scintigraphy:
Renal scintigraphy prove...
fluids. It is also used in the detection of nutritional and endocrinological disorders and to track bacterial and
parasiti...
Medical Treatment:
Therapeutic applications of nuclear techniques are also advancing. Perhaps the most common
techniques o...
Radiotherapy services have expanded rapidly over the last decade. The most developed countries
make few compromises in acc...
Meeting the food needs of expanding populations in developing countries is a formidable challenge. It
must be met within t...
means of measuring soil erosion and sedimentation on a landscape scale. The method is now being used to
provide data for d...
dilution technique to identify elite rhizobial stains as inoculants and legume genotypes which have both high
yield potent...
mutants have a yield potential of 2000 to 2500 kg/ha and are between 1.5 and 4.5 meters tall with long
panicles. Some are ...
PEST CONTROL AND DISEASE CONTROL:
As crop and livestock production intensifies and diversifies, some risks are magnified. ...
and to initiate regular insecticide treatments to be able to sell worm-free fruit (“Transboundary Insect...” 28).
Neverthe...
is simple,” writes Mr. Qian Jihui, the Head of the IAEA Department of Technical Cooperation and Mr.
Thomas Tisue, the acti...
A second role of eradicating livestock disease and pest is through the use of radioisotopes to develop
the specific tests,...
Fig 2: Global Status of Rinderpest In 1987 And In 2000
Source: “International Conference…” (67)
Foot And Mouth Disease:
An...
Along with improving crop and livestock production and eradicating pests and diseases, achieving
food quality and safety a...
Irradiation of food products also helps in facilitating trade in fresh fruits and vegetables. Fresh fruits
and vegetables ...
trade. Over 100 personnel from food quality control laboratories have been trained on analytical and quality
assurance met...
Did You Know?
A recent interesting study has been made by evaluating the usefulness of whole body positron
emission tomogr...
Mentorship Description
I established my mentorship experience with Dr. Michelle Bittle at the University of Washington’s
R...
Bibliography
“Applications of Nuclear Techniques In Medicine”. Aug 23 01 (Jan 16 03).
http://www.iaea.or.at/worldatom/Peri...
Moss WT, Cox JD. Radiation Oncology: Rationale, Technique, Results. St. Louis: Mosby, 1994:
21- 23.
“PET.” 12 Jan 2002 (14...
27
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Application of Nuclear Techniques in Human Life and Health ...

  1. 1. Applications of Nuclear Techniques In Human Life And Health Across The World: A Detail Study Sharmila Pal Expository Writing 11th Grade Ms. Sharon Masse James A. Garfield High School December 25, 2002
  2. 2. Table of Contents Introduction …………………………………………….. 3 Health Care …………………………………………….. 3 Agricultural Production ………………………………… 11 Livestock Production …………………………………… 14 Pest And Disease Control ………………………………. 15 Food Quality And Safety ……………………………….. 20 Conclusion ……………………………………………… 22 Did You Know …………………………………………. 24 Mentorship Description ………………………………… 25 Bibliography ……………………………………………. 26 2
  3. 3. INTRODUCTION: Since the past half century, isotopes and ionizing radiation have been greatly used across the world to the benefit of mankind by improving the standards of human health and life. Since the mid 1960’s the IAEA (International Atomic Energy Agency) and United Nations Food and Agriculture Organization (FAO) have worked together through the Joint FAO/IAEA Division, using their combined technical and managerial expertise and experience to bring the benefits of radiation technology, especially nuclear technology, to developing nations in Asia, South America and Africa. Nuclear techniques are not only being used in the field of medical treatment, but also in agriculture and food security. Isotopes and ionizing radiation are being used constantly to provide practical solutions to the world’s human health concerns, agricultural and livestock production, pest and disease control and food quality and safety issues. HEALTH CARE: Application of nuclear science in human health therapy has become very common in everyday life. Nuclear applications in health care have been a time-honored record of being highly cost-effective in addressing important health problems, such as, malnutrition, cancer, infectious diseases and circulatory disorders. Today they are providing lasting benefits for patients, physicians, medical researchers, and health care practitioners throughout the world. Many nuclear applications have become so well-established and documented that they are preferred more than other methods of medical treatment. This is because they frequently provide unique medical information, or are among the least expensive approaches to a problem. Nuclear applications in health care can be roughly divided into diagnostic, therapeutic and preventive applications. Medical Diagnosis: Diagnostic applications comprise in vivo and in vitro methods. The in vivo applications are characterized by the administration of a radiopharmeceutical to the patient and usually subsequent external 3
  4. 4. detection with a gamma camera or some other detector. The in vitro applications involve analysis of samples taken from the patient, most often blood samples. In Vivo Applications: In vivo applications are a major nuclear medicine technology. The principal role of these procedures is the assessment of organ functions. Radionuclides or compounds that are labeled with radionuclides are administered to the patients to allow specific organ functions to be evaluated by tracing the dynamic bio- distribution of such a compound in specific organs. Tracing of the compound is achieved by external detection of the photon emitted from the radionuclides by using instruments like rectilinear scanners or gamma cameras. Probably the major characteristics of in vivo nuclear medicine procedures is that the amount of radiopharmaceutical needed for in vivo diagnostic studies is very tiny and always in the range of physiological quantities. For instance, for a thyroid scintigraphy, the amount of radioactive iodine employed is over a thousand-fold less than the amount of iodine daily taken up with food. It therefore has no measurable interference with thyroid function and no side effects. Also, the radioactive dose received by the patient for scintigraphies is, in most cases, negligible. As a rule of thumb, it approximates the dose received from one year of natural background radiation per examination. In addition, the in vivo method provides for studying a number of organs and systems. The major fields of application are oncology, endocrinology, cardiology and nephrourology. The most commonly applied instruments an in vivo technologies for nuclear medicine diagnostics constitutes a formidable list. A few of them are listed in Table 1. Table 1: Nuclear Applications In Health Care Principle Application Comparative Advantage Static Gamma Camera Imaging Gamma camera converts photons emitted from a radiopharmaceutical administered to a patient, presenting an image of the element’s distribution Static and dynamic imaging of organ functions High quality images 4
  5. 5. Single Photon Emission Tomography (SPECT) Distribution of radiopharmaceutical administered to patient is measured from many different angles by a rotating gamma camera head. Heart perfusion imaging, brain imaging and examination of spine and liver Improved gamma camera imaging. Permits absolute three- dimensional localization of radiopharmeceutical distribution with 3-D representation of the imaged organ Positron Emission Tomography (PET) Basic organic elements, such as carbon-11, nitrogen-13, oxygen-15 and fluorine-18 are positron emitters. These elements are tagged to common molecules found in the body and therefore can be made specifically for a target organ. By combining a positron emitting isotope with a tracer that is selective for a specific biochemical pathway, it is possible to estimate absolute rates of glucose utilization, protein synthesis, oxygen consumption and blood flow Creates “functional” images of blood flow and metabolic processes. They surpass conventional structural or anatomic images produced by x-ray examination, MRI and even SPECT Rectilinear Scanning Moving detectors map the location of radiopharmeceuticals in a patient’s body. Scanner moves across the organ or the area under examination had been completely surveyed by the scintillation counter. Thyroid imaging Thick crystals and high- energy collimation provide high efficiency and resolution, particularly with radiopharmaceuticals such as Iodine-131 Radionuclide Clearance Studies The rate at which a particular radioactive substance is cleared from the plasma can be determined by calculating the concentration of the substance in plasma and/or urine Renal function examination and study of anatomy Accurate reflection of the functional state of kidneys. Radionuclide Dilution Techniques Techniques involve the administration to the patient of a radionuclide that diffuse throughout the compartment being studied, and whose distribution can be traced. Accurate measurement of total body water, red blood cell (RBC) mass, survival and sequestration, total exchangeable potassium. Chromiun- 51 and sodium chromate is used for labeling the RBCs. Accurate measurements and no toxic side effects, because radionulcides that are used are not hazardous. 5
  6. 6. (Groth “Lasting Applications…”) Bone Scanning: One of most common in vivo diagnosis is bone scanning. It provides an efficient approach to look at the function of bones: any significant injury to the bone will cause an increase in bone metabolism that can be detected by the bone scan. The method is the most efficient way to search for bone metastases in many types of tumors. It is also used in orthopedics for the study of fractures, osteomyelitis or joint replacement. Myocardial Perfusion Scanning: Another common in vivo nuclear medicine technique is myocardial perfusion scanning. This test informs about the presence of heart infraction. If a patient suffers from chest pain, the test will help clarify whether it relates to reduced blood flow to the coronaries (arteries of the myocardium). Perfusion Lung Scanning: Also, perfusion lung scanning is an important frequently performed in vivo nuclear medicine technique. Combined with ventilation lung scanning, perfusion lung scanning is the most efficient technique for the study of pulmonary embolism. This is a dangerous condition originating from blood clots that requires early intensive treatment. Nuclear techniques for diagnosis of lungs developed in the past decade. For example, the development of positron emission tomography (PET) and receptor ligand radiopharmeceuticals. PET allows more accurate visualization of the organ under study than can be obtained with usual gamma camera. It can also provide information on metabolic functions that is impossible to obtain with other techniques. For the time being, PET is available in a limited number of developing countries since the technology is expensive and the radiophrameceuticals difficult to produce. It is envisaged, however, that following the current clinical success, the technology will be made widely available, especially in the field of oncology, neurology and cardiology. Also being developed is a series of new tumor seeking radiopharmeceuticals. By a single injection of the relevant radiopharmaceutical, the body can be scanned for the presence of tumor cells. 6
  7. 7. Fig 3: PET image showing the blood flow in the brain Source: (“PET” Internet) Renal Scintigraphy: Renal scintigraphy proves very useful for they study of kidney functions in patients suffering from elevated blood pressure, diabetes or kidney stones, since it provides a detailed description of renal function, from blood supply to urine formation and excretion. Thyroid Scanning: Thyroid scanning is commonly for the screening of hyperthyroidism and searching for malignant thyroid tumors in patients with nodular goiter. Brain Scanning: The in vivo technique of brain scanning provides importnat information in patients with stroke, epilepsy and Alzheimer’s disease. In Vitro Applications: The second method of diagnosis, in vitro, allows clinical diagnosis without the patient being exposed to radiation. In fact, the patient need not even be present. A blood sample taken from the patient is sent to the laboratory and examined through nuclear techniques such as radioimmunoassay (RIA), or immunoradiometric assay. (IRMA). Radioimmunoassay (RIA): The RIA tests measures precisely previous and current exposure to infection by assessing antibodies. RIA is also used to measure substances such as hormones, vitamins, and the presence of drugs in the body 7
  8. 8. fluids. It is also used in the detection of nutritional and endocrinological disorders and to track bacterial and parasitical infections, such as, tuberculosis and malaria. Supported through IAEA co-ordinated research programs, some 500 hospitals, universities, and laboratories in the developing world alone are engaged in RIA technique treatment of patients. Another application of RIA and IRMA technique includes the detection of tumor markers, which are specific substances secreted by many tumors and can indicate the presence of malignancy (“Applications of nuclear...” Internet). Despite the increased accuracy, as well as cost and convenience factors, tumor markers remain complementary to other diagnostic procedures in the detection of cancer during its early stages, but they are especially valuable in monitoring the progress of disease and the effects of treatment. Molecular Biology Techniques Using Radionuclide Methods: Recently, the development of molecular biology techniques using radionuclides have become very common. Diagnosis of infectious diseases, like, Chagas disease, Leishmaniosis, Hepatitis B and Tuberculosis, can be done by staining the final product of a PCR (Polymerase Chain Reaction) by eithidium bromide, after the electrophoretic separation by means of radioisotopically labeled DNA probe or detected by direct sequence analysis. Phosphorous-32 and sulphur-35 are the commonly used radioisotopes (“Applications of nuclear...” Internet). Also, reverse transcriptase PCR is being used to detect the Hepatitis C virus. Besides PCR, other molecular techniques include single strand confirmation polymorphism (SSCP) and protein truncation tests, which helps further refine diagnosis for muscular dystrophy. Measurement of Stable Isotopes: Measurements of stable isotopes by nuclear techniques have gained widespread strategic application in a variety of heath problems, such as, malnutrition and osteoporosis, through analysis of trace elements. These techniques are now generally considered the best methods for measuring the uptake and bioavailabilty of many important vitamins and nutrients. Commonly used techniques applied for health purposes in developing countries of African and Asia, such as, malnutrition, osteoporosis, obesity and helicobacter pylori, include neutron activation analysis, Inductively Coupled Plasma Mass Spectrometry, dual energy X-ray absorptiometry (DEXA), Parricle-Induced X-Ray Emission and others (“Applications of nuclear...” Internet). 8
  9. 9. Medical Treatment: Therapeutic applications of nuclear techniques are also advancing. Perhaps the most common techniques of nuclear medical treatment are radiotherapy and brachytherapy. Radiotherapy: Radiation therapy is one of the most common treatments for cancer and is used in more than half of all cancer cases. It is the primary treatment for some types of cancer, such as certain non-melanoma skin cancers, head and neck cancers, early-stage Hodgkin's disease and non-Hodgkin's lymphomas (Moss and Cox 21-23). Cancers of the lung, breast, cervix, prostate, testes, bladder, thyroid, and brain are also treated with radiation therapy. Radiotherapy of cancer involves the targeting of radioactivity to tumor cells rather than cells of normal tissues. Beta or alpha emitting radionuclides can be labeled to some compounds which deliver radiation with cellular damaging effect to local tissues, where it accumulates. Many different radiopharmeceuticals that seek out tumors are being used for therapy by different routes and a variety of targeting mechanisms. Treatment of thyroid cancer by iodine-131 has been used for more than 50 years (Dobbs et all 25). Some radiopharmaceuticals selectively accumulate in metastic sites of bone tissue which enables the management of pain. But perhaps, the most common technique of radiotherapy has been Cobalt therapy. An external sealed source of cobalt-60 is used in a teletherapy unit as a source of intense gamma radiation for the treatment of a variety of cancers. Cobalt-60 is also used as a medical tracer to make possible the observation of chemical, physical or biological processes in the body. Fig 4: A patient is placed in the double-headed cobalt-60 revolving therapy unit Source: (Dobbs et all 25) 9
  10. 10. Radiotherapy services have expanded rapidly over the last decade. The most developed countries make few compromises in accessibility of basic radiation oncology services. They have centers where the highest level of technology can be applied, when necessary. Developing nations over the last decade show a threefold increase in the amount of equipment available for use. Of the IAEA’s 130 Member States, only 10 of the least developed countries now lack basic radiotherapy technology (Dobbs et all 25). Table 2: Radiotherapy Centers Worldwide Region Population (Millions) Radiotherapy Centers North America 300.9 1903 Central America 134.1 139 Tropical South America 276.2 266 Western Europe 387 1027 Eastern Europe 390.6 334 Northern Africa 138.2 59 Central Africa 358.6 22 Southern Africa 56.5 21 Middle East 221.3 91 Indian Subcontinent 1245.1 221 South East Asia 477.2 81 East Asia 1430.9 1107 Australia & Pacific Islands 22.6 49 Source: Practical Radiotherapy Planning (25) Brachytherapy: Brachytherapy is a therapeutic nuclear technique of treatment where radioactive sources are inserted into small cavities adjacent to tumors or even invasively directly into tumors to irradiate the cancerous tissues in its proximity. This method, which uses tiny sources of 137-Cs (Cesium), 192-Ir (Iridium), 60-Co (Cobalt), 125 – I (Iodine), 198-Au (Gold), 182-Ta (Tantalum), etc., is very effective for treating primary tumors affecting the uterus, breast, throat, and prostate (Thomadsen 10). But perhaps, cancer of the cervix remains the most common cancer in many developing countries. About 80% of all patients with this malignancy receive brachytherapy as part of their treatment (“Applications of nuclear...” Internet). Cure rates range from 80% in tumors confined to the cervix to 35% in tumors at stage III (“Applications of nuclear...” Internet). These may be over 10 centimeters in size and yet highly curable using brachytheraphy. AGRICULTURAL PRODUCTION: 10
  11. 11. Meeting the food needs of expanding populations in developing countries is a formidable challenge. It must be met within the framework of their still low levels of per capita consumption and the changing food preferences of increasing urbanized societies. Meeting this challenge demands the consideration of these three issue: First, most countries simply have no additional land on which to produce food and industrial crops or livestock. Second, in many countries, land is becoming increasingly affected by soil erosion, salinization or acidification, all of which reduces the production potentiality. And third, the plant and animal genetic resources upon which agriculture and food production depends are undergoing rapid erosion due to widespread adoption of a few high-yielding varieties and breeds (“…Food and Agriculture Development” 4). These trends need to reverse through technology, especially nuclear technology, because otherwise, the immediate and long-term needs for food production cannot be achieved. The emergence of reactor technology and modern agriculture during the second half of the 20th century brought significant development into the fields. The need of nuclear techniques to address these issues lies firstly in their unique sensitivity and specificity as markers, which helps to measure accurately the strategically essential processes that take place within and between soil, plants and animals. Secondly, the need for nuclear applications lies in their capacity to bring about changes in the genetic make-up of plants which makes possible to measure levels of biologically important elements and molecules and hence agriculturally important processes. They also make it possible to trace or change what happens during these processes and to study the rate of what happens when changes in genetics are introduced. Moreover, a further advantage is that they offer a great potential for enhancing the diversity of crop plants. Many experiments have been conducted on this approach, to illustrate how nuclear technology can be used to increase product output and improve key components integral to sustainable food and agricultural development. Diagnosis of Soil Erosion: A major global threat to food security is soil erosion. A suggested approach against soil erosion is to develop capacities within NARS in countries with a range of climatic and landscape conditions to use the spatial and temporal distribution of fallout and naturally occurring radionuclides, such as caesium-137, for estimating rates of soil redistribution (Dietsch 57). The results show that Caesium-137 provides a reliable 11
  12. 12. means of measuring soil erosion and sedimentation on a landscape scale. The method is now being used to provide data for decision-makers to help plan approaches for technologies promoting better soil and water conservation. Efficiency of Water and Fertilizer Use in West Asia: The approach for addressing the severe water shortages and rising value for nitrogen fertilizers in semiarid developing countries, especially in western Asia, is participating farmers to use neutron moisture probes and nitrogen-15 labeled fertilizers for identifying, pilot testing and extending the use of technologies and management practices that lead to more efficient use of water and nitrogen fertilizers for growing crops (Schneider 35). This particular activity focuses, on determining the advantages of providing water and urea through fertigation or drip irrigation. In other words, it has ruled out traditional furrow irrigation and band placement of urea. The IAEA results show that the amount of water used by cotton during the growing season was 4900 cubic meters per hectare (m3 /ha) using drip irrigation and 7600 m3 /ha when applied by the traditional surface method, a saving of 36 % (Vol. 42, No. 1 25). The efficiency with which the water was used to produce biomass almost doubled when drip irrigation was used. Also, the amount of cotton seeds harvested under fertigation was 22 % higher than with traditional fertilizer and water management practices (IAEA Bulletin Vol. 42, No. 1 25). Fertigation therefore proved to be a very efficient technology for maintaining or increasing crops yields while conserving both water and nitrogen fertilizer. Fig1: Cotton under fertigation management in West Asia. Source (IAEA Bulletin Vol. 42, No. 1 25) Production of Grain Legumes in Bangladesh: Increasing productions of grains, especially in Bangladesh, is required on existing farmland to improve food security and save foreign exchange. In Bangladesh IAEA suggests the use of nitrong-15 isotope 12
  13. 13. dilution technique to identify elite rhizobial stains as inoculants and legume genotypes which have both high yield potential and are effective in fixing nitrogen. The results indicates that the country-wide studies demonstrated the large potential to increase grain legume production through inoculation and genotype selection, a pilot plant for largescale production and quality control of inoculants was established, and widespread application of the technology is expected to increase staple legume production by 25%, leading to savings on imports, including fertilizers (Dietsch 57). Chickpea Crops in Pakistan: In Pakistan, the main constraint to higher yields of chickpea is the crop’s susceptibility to the widespread diseases Asochyta blight and Fusarium (Dietsch 57). The IAEA suggested approach is that the Nuclear Institute for Agriculture and Biology should implement a breeding program to induce disease resistance in chickpea by mutation techniques (Dietsch 57). The project led to the release of the first high yielding chickpea mutant variety -- known as “CM-72” -- resistant to Ascochyta blight. Chickpea yields in the Northwest Frontier Province are now about 45% higher than the average of the previous five years (Dietsch 58). A further mutant variety, “CM-88”, has since been released with resistance to both Ascochyta blight and Fusarium wilt, thus providing an alternate source of resistance for chickpea growers. Both mutant varieties cover 70% of the total chickpea area in Pakistan (Dietsch 58). Sorghum Crops in Mali: Sorghum is the most important food crops in Mali where it is grown on 560,000 hectares with an average yield of only 980 kg/ha (Dietsch 58). New higher yielding sorghum varieties using local germplasm are needed to improve food production and conserve biodiversity for future generations. The IAEA suggested approach is to integrate mutation methods within ongoing programs on sorghum improvements by exposing the local material to gamma rays, selecting desired variations and then testing crops under different agro- ecological conditions in the field. The results show that eight improved mutants suited to various sorghum growing regions of Mali and are now included in the list of varieties recommended to farmers by the Department of Agriculture. These 13
  14. 14. mutants have a yield potential of 2000 to 2500 kg/ha and are between 1.5 and 4.5 meters tall with long panicles. Some are early ripening and others have improved tolerance to droughts. (Dietsch 58). LIVESTOCK PRODUCTION: Apart from agricultural demands, demands for livestock products are also increasing fast in many developing countries due to urbanization and income growth. Milk and its processed products offer substantial opportunities for off-farm employment and better food security. The IAEA suggested approach is to assist small scale producers and artificial insemination (AI) services to realize greater potential of crossbred cattle by employing isotopes and hormone radioimmunoassays; and to identify diets based on local resources which meet both the higher nutritional needs and demands for better reproductive and breeding management required by these animals (Fowler and Denekamp 77). The results show supplements known as urea-molassesmultinutrient blocks (UMMB) and related formulations based on local ingredients were identified as cost-effective approaches to improve productivity while conserving and sustainably using natural resources. In Asia, around 1.6 million kg of UMMBs are currently fed to over 25,000 animals belonging to some 6000 farmers (Fowler and Denekamp 78). Milk yields increased on average by 20% while the cost of feeding fell by a factor of three (Fowler and Denekamp 78). Likewise in Latin America, supplementation resulted in better utilization of the available fibrous feeds. It enabled farmers in some countries to raise four times as many animals than was previously possible per unit of savannah land. Reproductive efficiency also improved dramatically. One result is that farmers are increasingly looking towards further increases in productivity through breed improvement utilizing. However, it is clear that by using progesterone measurement in milk, between 30% to 50% of the heat periods in cows are missed by farmers (Fower and Denekamp 78). Of the periods detected, between 15% to 20% are probably incorrect (Fowler and Denekamp 78). Improvements in heat detection, timing of mating, and the overall efficiency of AI services reduced the intervals between calvings to conception by one to three months. This resulted in more milk and calves per lifetime of individual cows and 10% to 30% higher incomes to owners (Fowler and Denekamp 78). In addition, reducing the number of AIs performed at inappropriate times saved the resources of AI service providers that would otherwise be wasted. 14
  15. 15. PEST CONTROL AND DISEASE CONTROL: As crop and livestock production intensifies and diversifies, some risks are magnified. They include the risk of loss and damage to product quality from insect pests and the diseases that they transmit, as well as from a great variety of other diseases transmitted to livestock by viruses, bacteria and parasites. A number of developments are driving the demand and urgency for finding solutions. They include the increased threat of these pests or diseases spreading across international borders. The threat is raised by the greater movement of produce and livestock, the trend towards greater use of pesticides, and the risk of unacceptable levels of residues and damage to plants, animal and insect genetic resources. Being sought are more integrated, biologically oriented, and area-wide approaches to pest and disease management that, where possible, lead to eradication. The roles of nuclear techniques in this area have increased substantially in recent years. One role is through application of ionizing radiation to sterilize but otherwise not affect the behavior of key insect pests, which are then released in large numbers to control or eradicate wild populations (the sterile insect technique, or SIT). The Sterile Insect Technique (SIT): The SIT is the most environment friendly pest control method. It involves mass production and systematic aerial release of radiation-sterilized but behaviorally competent male insects, who seek out females in the wild for mating. These unproductive matings interfere with reproduction of the target population, which declines to the point where it is no longer self-sustaining, leading to eradication. SIT has been the basis for successful eradication campaigns against the New World Screwworm (NWS) in Libya, United States, Mexico and Central America, against the Mediterranean fruit fly in several parts of the world and against the infamous Tsetse flies in Sub-Saharan Africa (“Sterile Insect Technique” Internet). With the use of SIT screwworm has been eradicated from its former range extending from the southern United States to the Isthmus of Panama (“Transboundary Insect...” 28). Eradication of the Medfly: The accidental introduction of the Mediterranean fruit fly (Medfly) into South America in the early 1990s forced farmers, especially in Argentina and Chile, to eliminate fruit varieties most attacked by the pest 15
  16. 16. and to initiate regular insecticide treatments to be able to sell worm-free fruit (“Transboundary Insect...” 28). Nevertheless, major fruit importing countries that are free of this pest require costly post-harvest treatments of fruit, or they quarantine the fruit, for fear of outbreak originating from the presence of the Medfly in commercial shipments. The IAEA suggested approach is to assist the Chilean Agricultural Service to implement a SIT eradication program through construction of a Medfly mass rearing with a production capacity of about 60 million sterile flies per week, and to assist in the release of sterile flies by air (“Transboundary Insect…” 28). Also, assist Argentina to build a rearing facility with a weekly capacity of over 200 million sterile flies and to carry out an eradication program in the provinces of Rio Negro, Nequen, and Medoza. The IAEA results show that eradication was achieved in Chile and the country is now an internationally recognized as a Medfly-free country (“Transboundary Insect…28). This status has significantly supported the expansion of its multi-billion fruit export industry. In Argentina, the quantity and quality of temperate fruit production have increased significantly, insecticide applications have decreased in commercial fruit orchards, and several fruit producing valleys are now recognized by neighboring Chile as fruit fly free. In 1999, Chile allowed the fruit industries in Mendoza and Patagonia Provinces to use its ports for their fruit export (“Transboundary Insect…” 28). Similar SIT technology has also been applied in the Arava Valley of Israel and Jordan to eradicate the Medfly. Alex Volkoff writes that the IAEA results shows that the “Medfly populations in all settlements in the Arava Valley and other places in Israel in Jordan fell dramatically, as have the quantities of fruits and vegetables infested with larvae; also significantly reduced was insecticide use, since sterile flies have replaced bait sprays. The volumes and value of exports have expanded exponentially”(“Transboundary Insect…” 29). Assuming that the Arava Valley becomes Medfly free, agricultural development and diversification will expand as producers take advantage of their pesticide and pest free status to provide peppers and tomatoes to global market. Tsetse Fly: But, perhaps the most severe threat above all to the livestock production comes from the tsetse fly. The tsetse fly transmits trypanosomes that sicken and kill both animals and man. It is one of the major roots of poverty in countries south of the Sahara, an ecological factor that exists nowhere in the world. “The casual link 16
  17. 17. is simple,” writes Mr. Qian Jihui, the Head of the IAEA Department of Technical Cooperation and Mr. Thomas Tisue, the acting head of the Department’s Evaluation Section. “The disease the fly spreads, trypanosomes, which causes sleeping sickness, makes it very difficult to raise productive carrel in tsetse- infested regions…In the whole world, it is only in these regions of Africa where a single disease has so hindered agricultural productivity and largely prevented integration of cattle rearing with crop farming” (“Achievable Breakthrough…” 47). Tsetse infested regions are vast and spreading: parts of 36 countries comprising 9 to 10 million square kilometers are affected (“Achievable Breakthrough…” 47). According to the United Nations Food and Agriculture Organization (FAO), the direct loss in meat and milk production, added to the cost of attempted control programs, totals US $0.6 to $1.2 billion annually (“Achievable Breakthrough…” 47). This rises to US $4.5 billion if losses in potential production are considered. Moreover, the World Health Organization (WHO) estimates that 55 to 60 million people are at risk of human trypanosomosis — sleeping sickness — with more than 300,000 currently infected and 40,000 deaths in 1998 (“Achievable Breakthrough…” 47). Today, better approaches exist to combat the tsetse fly. Mr. Qian Jihui writes, “We now command cost-effective and environmentally friendly measures to remove tsetse from large areas in Africa if the world community chooses to do so” (“Achievable Breakthrough…” 47). As discussed before, the key tool in the final phase of such a tsetse eradication campaign is the sterile insect technique (SIT). The elements essential to the SIT’s feasibility as an area-wide tool are a) industrial scale production of sterilized insects and b) their release from aircraft over the target area. The area wide management approach targets entire insect populations. It has proven its merit many times over with a wide variety of crop and livestock pests and disease vectors. In the case of tsetse, the are-wide concept integrates several control methods for maximum cost-effectiveness and minimum environmental side effects. Semi-automated tsetse rearing systems are being developed. And aerial release technology has been adapted to tsetse’s requirements and is being further refined. Proof of principle took place in Zanzibar in 1995-97, where aerial release of sterilized males over the 1500 square kilometer Unguja Island resulted in the eradication of the tsetse there (“Transboundary Insect Pests…” 29). This increases the potential for widespread introduction of more productive cattle breeds there. Enzyme Linked Immunoassay (ELISA): 17
  18. 18. A second role of eradicating livestock disease and pest is through the use of radioisotopes to develop the specific tests, namely, the enzyme linked immunoassay, or known as ELISA, which is needed to diagnose and monitor the effectiveness of vaccination programs against the major diseases causing livestock losses in developing countries and inhibiting trade. Recent progress has been seen in eradicating the Rinderpest disease and the foot and mouth disease (International Conference…67). Rinderpest Disease: The Rinderpest is arguably the most devastating of all major cattle diseases. It is a highly fatal viral disease of domestic cattle, buffaloes and yaks. It also affects sheep, goats and some breeds of pigs and a large variety of wildlife species. Historically the virus was widely distributed throughout Europe, Africa, Asia and West Asia, but never became established in either the Americas or Australia/New Zealand. In 1986, the goal was set to eradicate it and the causative virus from the world by 2010 (“Rinderpest” Internet). A proven vaccine was available, but a reliable and internationally accepted method had to be developed to diagnose the disease quickly and test the large numbers of blood samples coming into veterinary investigation centers for the purpose of monitoring the effectiveness of the mass vaccination campaigns and if necessary redirecting them. The approach that was suggested at the International Conference On The Study of Environmental Change using Isotopic Techniques was to assist the national veterinary authorities to develop a rapid, simple, and standardized immunoassay test and the strategies and capacitates to use it during mass vaccination campaigns (Dolan 67). Thereafter, to identify remaining pockets and verify national freedom from disease and infection. Data from using the test allowed quantitative performance assessment of vaccination programs and post vaccination surveillance activities, providing strong evidence that only seven countries now remain infected compared with over 30 countries in 1986 (Dolan 67). Chances now are high that global eradication will be achieved on target (See Fig. 2). 18
  19. 19. Fig 2: Global Status of Rinderpest In 1987 And In 2000 Source: “International Conference…” (67) Foot And Mouth Disease: Another serious threat to the livestock is possessed by the food and mouth disease (FMD). For the past sixty years the FMD has been the greatest non-tariff barrier to livestock trade and efforts are being made to bring it under control or eradicate it (“International Conference...” 68). Essential to these aims is effective and rapid diagnosis for targeting vaccination efforts and verifying that animals and regions are free of FMD. One suggested approach by the IAEA is to assist national veterinary laboratories to develop and use the ELISA both to provide rapid and specific diagnosis and to distinguish vaccinated from naturally infected animals; this is an essential requirement for areas or countries moving towards international recognition of freedom from the disease. International Conference On The Study of Environmental Change using Isotopic Techniques of 2001 shows that Chile, Uruguay, and parts of Argentina and Brazil are now internationally certified as free of FMD (Dolan 68). Many other countries in Latin America and Asia have large FMD eradication programs benefiting from application of these essential immunoassay tests. FOOD QUALITY AND SAFETY: 19
  20. 20. Along with improving crop and livestock production and eradicating pests and diseases, achieving food quality and safety also remains a challenging world issue. Achieving food security depends not just on growing food and industrial crops, or on keeping livestock and protecting them from pests and diseases. It also depends on reducing unacceptably high losses which occur after harvest or slaughter, and on efforts to ensure that products reaching consumers are safe, of high quality, and do not pose unacceptable risk to plant and animal health. A number of developments have focused attention on problems of food quality and safety. Developing nations are intensifying diversifying production, more people are moving into large cities, and opportunities for trade are expanding. These developments increase the likelihood of spoilage and the risks to human health from pathogenic micro-organisms, pesticides and veterinary drug residues. They also raise the threat to plant and animal health from insect pests and disease agents which are subject to international quarantine restrictions. Steps to ensure food quality and safety and plant and animal protection are essential components of consumer and agricultural protection in all countries. Controlling Food-Borne Diseases: One of the few technologies addressing these challenges is food irradiation. It has the ability to control spoilage and food-borne pathogenic microorganisms and insect pests without affecting significantly the sensory or other attributes of food products. The IAEA has suggested data collection after irradiating food products such as meat, poultry, seafood and spices. Many countries, including, Brazil, Belgium, Canada, China , Chile, France, Mexico, Netherlands, South Africa, Thailand and USA are using irradiation to control pathogenic bacteria and parasites in several food products (“Food Quality…” 30). Several large commercial irradiators are under construction, especially in the USA, for treating food of animal origin. Irradiation is widely applied to ensure hygienic quality of spices and vegetable seasonings in increasing quantities (See Fig 3). Facilitating Trade In Fresh Fruits And Vegetables: 20
  21. 21. Irradiation of food products also helps in facilitating trade in fresh fruits and vegetables. Fresh fruits and vegetables from developing countries are often infested by tephretid fruit flies and cannot gain access to markets in advanced countries which have strict quarantine regulations against such pests. Conventional quarantine treatments have technical limitations and some are being phased out globally because of environmental concerns. The IAEA suggested method of irradiation as a quarantine treatment of fresh fruits and vegetables is endorsed by regional plant protection organizations which operate within the framework of the International Plant Protection Convention. Several countries, notably the USA and members of the Association of South East Asian Nations (ASEAN), have formulated policies or introduced regulations on this application. In 1995, small commercial-scale application started in the USA and a commercial plant for this purpose is under construction in Hawaii (“Food Quality…” 30). Fig 3: Estimated Quantities of Irradiated Spices And Seasonings Source: “Food and Quality…” (31) Food Contaminants And Residues: Apart from irradiating the food products, nuclear analytical methods, such as, electron capture gas chromatography, X-ray fluorescence and RIA coupled with the use of isotopically labeled compounds, are essential components of the armory used by food control organizations (“Food Quality”…31). These organizations apply the tool for analyzing food samples for compliance with Codex standards as well as for improving sampling and analytical methods. Nuclear analytical methods have been applied in the analysis of contaminants and residues in foods, that come from developing countries and are destined for international 21
  22. 22. trade. Over 100 personnel from food quality control laboratories have been trained on analytical and quality assurance methods for pesticides, veterinary drug residues and mycotoxins through five regional or interregional training courses at the IAEA’s Seibersdorf Laboratories and in Hungary, Sweden, Republic of Korea and Thailand (“Food Quality…” 31). CONCLUSION: The use of nuclear technology in human health, agricultural and livestock production, pest and disease control and food security has been extremely beneficiary. Advances in the medical field hold significant potential for improving health care in many countries. Promising applications are emerging in the field of PET and a new class of radiopharmaceuticals. In vitro applications of radioimmunoassay and measurement of stable isotopes by nuclear techniques are examples of highly successful technologies that hold considerable potential growth. Also, the use of nuclear science in other aspects of human life has played a significant role in improving the standards of life for common people. Today, farmers, processors, consumers and government authorities are benefiting from the practices, technologies, and analytical methods that use or are derived from applying isotopes and ionizing radiation. In other words, the investments made in supporting research and development in the nuclear, biological and agricultural sciences have paid off. The application of nuclear techniques in human life and health is the highly visible peaceful and most important uses of nuclear energy and a major reason cited for continuing with the nuclear research in this field. Concentrated efforts at various laboratories throughout the world are helping in spreading the useful applications of nuclear techniques for the improvement of the quality of human life. But despite all the positive sides of nuclear science, vast majorities of countries have not benefited directly from nuclear power. Yet, in one way or another, many benefit from the continuous flow of new products and the advances made through research and development. 22
  23. 23. Did You Know? A recent interesting study has been made by evaluating the usefulness of whole body positron emission tomography (PET) with 18F-fluoro-2-deoxyglucose (FDG) to detect recurrent ovarian cancer. The research was based on asymptomatically elevated serum levels of tumor marker (Chang et al. “Usefulness of whole…”). When asymptomatically elevated serum levels of CA-125 antigen (a tumor marker), the diagnostic sensitivity, specificity, and accuracy of FDG-PET to detect recurrent ovarian cancers were 95.0%, 87.5%, and 92.9%, respectively. FDG-PET is a useful technique to detect recurrent ovarian cancers for patients suspected of recurrent ovarian cancers due to asymptomatically elevated serum levels of CA-125 antigen. 23
  24. 24. Mentorship Description I established my mentorship experience with Dr. Michelle Bittle at the University of Washington’s Radiology Department. Dr. Bittle helped me tremendously to gain an insight in my field of study. She took her time to show me and explain the workings and principles of the PET scan and the CT scan. I also had the opportunity of looking at several PET and CT images and gaining knowledge of the applications of radiation in the medical field of everyday life and human anatomy, both at the same time. I recall Dr. Bittle, showing me how to analyze the computer generated images of patients, each of which was completely different from the previous. For days, I kept Dr. Bittle engaged with several radiation questions through email. One of which, I recall, was how radiotherapy improved over the last few decades. She even helped by giving references of well-known science journals and articles related to my topic. Dr. Bittle’s help has been extremely helpful in doing my project. Without her assistance, the project would have lacked a very essential component and remained incomplete. 24
  25. 25. Bibliography “Applications of Nuclear Techniques In Medicine”. Aug 23 01 (Jan 16 03). http://www.iaea.or.at/worldatom/Periodicals/Factsheets/English/ntimedic.html#future Bittle, Michelle. UW Radiology Department. Mentorship. 26 December 2002. Chang, Hung, et. al. “Usefulness of whole body positron emission tomography (PET) with 18F-fluoro-2- deoxyglucose (FDG) to detect recurrent ovarian cancer based on asymptomatically elevated tumor marker (CA-125) serum levels.” Neoplasma. Vol. 49, No. 5, 2002: 329-33. Dargie, James. “Nuclear Techniques & Food Security: Fields of Progress.” IAEA Bulletin. Vol. 42, No. 1, March 2000: 25- 27. Dietsch, Carla. Radiation Techniques in Agriculture and Food Production. New York: Oxford University Press, 1998: 57-58. Dobbs, Jane, et. al. Practical Radiotherapy Planning. New York: Edward Arnold, 1999: 25. Dolan, Thomas. “International Conference On The Study of Environmental Change using Isotopic Techniques”. IAEA Bulletin. Vol. 51, No. 3, September 2001: 67-68. Fowler, James and Gorge Denekamp. Nuclear Techniques in Human Life. London: Oxford University Press, 2000: 77-78. Groth, Stephens. “Nuclear Application In Health Care: Lasting Benefits.” IAEA Bulletin. Vol. 42, No.1, March 2000: 35-38. Jihui, Qian and Thomas Tisue. “Achievable Breakthrough: Viewpoint On the Challenge of Creating Tsetse-Free Zones In Sub-Saharan Africa.” IAEA Bulletin. Vol. 42, No. 2, July 2000: 47. L’Annunziata, Michael F. “Food Quality and Safety.” IAEA Bulletin. Vol. 45, No1, April 2001: 30- 31. 25
  26. 26. Moss WT, Cox JD. Radiation Oncology: Rationale, Technique, Results. St. Louis: Mosby, 1994: 21- 23. “PET.” 12 Jan 2002 (14 Nov 03). http://www.lbl.gov/.../Magazine/1994/ scintillators-new2.html “Rinderpest.” 12 Nov 2001 (27 Dec 02). http://www.oie.int/eng/info/en_peste.htm Schneider, Geroge. Nuclear Technology in Agriculture. New York: Orient Longmann, 1999: 35-36. Sigurbjoernsson, Bjoern and Peter Vose. “Nuclear Techniques in Food and Agricultural Development: 1964- 94.” IAEA Bulletin. Vol. 36, No. 3, September 1994: 4. “Sterile Insect Technique.” 2002. (30 Dec 02). http://www.fao.org/News/1998/sit-e.htm Thomadsen, Bruce R. Achieving Quality in Brachytherapy. New York: Institute of Physics, 1999: 10-11. Volkoff, Alex. “Transboundary Insect Pests and Diseases.” IAEA Bulletin. Vol. 61, No. 4, June 2001: 28-29. 26
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