I= RADIOLOGY HAZARDS AND HEALTH IMPACT OF DAILY DIET FOR PAKISTANI POPULATION USING STANDARD MODELS
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Title of Thesis
RADIOLOGY HAZARDS AND HEALTH IMPACT OF DAILY DIET FOR PAKISTANI POPULATION USING STANDARD MODELS

Author(s)
Ms. Perveen Akhtar
Institute/University/Department Details
University of Engineering & Technology/Physics
Session
2005
Subject
Physics
Number of Pages
216
Keywords (Extracted from title, table of contents and abstract of thesis)
radiation, radioactivity, food hygiene, nutrition, food, dietary intakes, cancer

Abstract
To enhance the radiation protection infrastructure and food hygiene in Pakistan, radiological and nutritional aspects of diet were studied through daily elemental intake. Food samples were collected from various ecological areas of the country on market basket method and typical daily diets were prepared. Daily dietary intakes of 7 radiologically important elements (Cs, Th, U, I, Sr, Ca and K) and 7 nutritionally important elements (Fe, Zn, Se, Cr, Mg, Na and Mn) were estimated by using well-known nuclear analytical techniques i.e. NAA, AAS, ICP-AES, ICP-MS etc. as 1st and 2nd priority elements, respectively. Baseline analytical data on these elements have been generated for the detection of any nuclear emergency in the country and its effective handling.

The measured average concentrations of these elements are cesium: 10.4 ng g-1; thorium: 5.1 ng g-1; uranium: 5.2 ng g-1; iodine: 80.1 ng g-1; strontium: 4.9 µg g-1; calcium: 0.86 mg g-1; potassium 4.5 mg g-1; iron 52.4 µg g-1; zinc 22.9 µg g-1; selenium 0.2 µg g-1; chromium 0.2 µg g-1; magnesium: 0.8 mg g-1; sodium: 0.5 mg g-1 and manganese: 17.9 µg g-1. These levels lead to average daily dietary intake of cesium: 6.2 µg thorium: 3.0 µg; uranium: 3.1 µg; iodine: 47.3 µg, strontium: 2.9 mg; calcium: 0.51 g; potassium: 2.7 g; iron: 31.0 mg; zinc: 13.6 mg; selenium: 110 µg; chromium: 130 µg; magnesium: 0.50 g and manganese: 10.6 mg.

Estimated intake values of these elements are compared with the recommended values of International Committee of Radiological Protection (ICRP), World Health Organizations (WHO) and recommended Food Dietary Allowance (FDA) for reference man. Radiological impact due to ingestion of observed radionuclides (i.e. 232Th, C 238U and 40K) on Pakistani adults has been estimated, using dose coefficients of ICRP standard models. The annual intake of thorium, uranium and potassium activities are 3.65, 12 and 2x104 Bq, leading to annual effective dose of 0.80, 0.53 and 178.75 µSvy-1, respectively. The net impact of all these radionuclides is 180.08 µSvy-1. The results reveal that the major contributor to radiation dose is 40K only, whereas activities of 232Th, 238V are comparatively negligible.

Comparison of the net dose with the available published results shows that our values are comparable with annual world average ingestion dose of 180.32 µSV from these radionuclides. Whereas it is-13 times less than the global average values of 2.4 mSv from all sources and 5.5 times less than ICRP recommended limit of 1 mSv for general public. Cancer risk factor from measured annual dose of 180.08 µSv for adult person is estimated as 4.5 x 10-4. Whereas ICRP cancer risk factor for general public is 2.5 x 10-3 and total risk involve from the all natural radiation sources based on global average annual radiation dose of 2.4 mSv is 6.0 x 10-3. The estimated cancer risk factor shows that probability of increase of cancer risk from daily Pakistani diet is only a minor fraction of ICRP values. The risk of cancer from measured radiation in term of loss of life expectancy is also estimated. It is 0.87 days. Whereas risks associated with other activities of normal daily life such as smoking, overeating and drinking are 6 years, 2 years and 1 year, respectively. The estimated values depict no significant radiological health impact.

Food safety and adequacy of radiologically important elements (U, Th, K, I, Cs, Sr and Ca and essential elements (Mg, Na, Fe, Mn, Se, Zn and Cr) have been assessed. Comparison of measured values of these elements with the recommended safe limits reveals that our diet is enriched with majority of the essential nutrients Fe, Zn, Mg, Sr, Se, Cr, Na, Mn, while it is deficient in I and Ca. The nutritional status of the daily diet is estimated as 2515 kcal d-1.

The results show that our diet is radiologically safe and has no significant health detriment. Its food hygiene is good and comparable with the international standards. However, deficiency of some essential elements iodine and calcium demands remedial measures and improvement of dietary habits.

Download Full Thesis
2171.65 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
180.64 KB
2 1 Introduction 1
75.84 KB
  1.1 Rationale 2
  1.2 Historical review 5
  1.3 Elements of Specific Interest 6
  1.4 Objective of study 7
  1.5 Thesis Plan 8
3 2 Human Body 9
154.25 KB
  2.1 Animal Cell 9
  2.2 Tissues 10
  2.3 Organs 11
  2.4 Organ Systems 12
  2.5 Characteristics of Standard Man 19
  2.5.1 Elemental Composition of Human Body 20
  2.5.2 Intake of Elements 22
4 3 Radiation And Radioactivity 24
150.59 KB
  3.1 Radioactivity 24
  3.2 Types of Radiations 26
  3.3 Sources of Radiation 27
  3.3.1 Natural Sources of Radiation 27
  3.3.2 Artificial Sources of Radiation 29
  3.4 Pathways of Radionuclides 31
  3.4.1 Through the Environment 32
  3.4.2 Pathways into the Human Body 35
  3.5 Accumulation of Radioactivity in Organs 36
  3.6 Measurement of Radiation exposure 37
  3.6.1 Dosimetric Quantities 37
5 4 Effects Of Radiation 41
192.95 KB
  4.1 Mechanism of Biologic Action 41
  4.1.1 Direct Effect 43
  4.1.2 Indirect Effect 44
  4.2 Radiosensitivity of Cells 44
  4.3 Types of Radiation Effects 46
  4.3.1 Deterministic Effects 46
  4.3.2 Stochastic Effects 48
  4.4 Cancer Epidemiology 50
  4.5 Cancer Risk 51
  4.6 Recommended Dose Limits 55
  4.6.1 Annual limits of intakes 56
6 5 Standard Models 58
198.49 KB
  5.1 Gastrointestinal Tract Models 59
  5.1.1 Biokinetic Models 61
  5.1.2 Dosimetric Models 67
  5.2 Dose Coefficients 74
7 6 Sampling And Analytical Techniques 77
292.39 KB
  6.1 Study Area 77
  6.2 Sampling Methodology 79
  6.2.1 Sampling Strategy 79
  6.2.2 Collection of samples 80
  6.2.3 Preparation of samples 80
  6.3 Analytical Techniques 82
  6.3.1 Gamma spectrometry 83
  6.3.2 Neutron Activation Analysis (NAA) 86
  6.3.3 Atomic Absorption Spectrometry 90
  6.3.4 Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) 91
  6.3.5 Inductively Coupled Plasma Mass Spectrometry (ICP-MS) 93
  6.4 Quality Control Assurance 94
  6.4.1 Internal Quality Control 94
  6.4.2 External Quality Control 96
8 7 Results 99
93.19 KB
9 8 Discussion: Elemental Contents Of Diet 108
578.44 KB
  8.1 Radiologically Important Elements 108
  8.2 Nutritionally Important Elements 147
10 9 Discussion: Elemental Content Of Water 165
68.43 KB
  9.1 Radiologically Important Elements 167
  9.2 Nutritionally Important Elements 169
11 10 Discussion: Health Impact Of Diet 172
179.06 KB
  10.1 Radiological Impact 172
  10.2 Cancer Risk 182
  10.3 Nutritional Competency 183
  10.4 Nutritional Status 189
12 11 Conclusions 191
42.34 KB
  11.1 Findings 191
  11.3 Achievements 193
  11.4 Recommendations 194
13 12 References 196
98.76 KB
14 13 Annexure
154.38 KB
  13.1 C.V. of author 204
  13.2 Publications list of author 207
  13.3 List of students supervised 215