This document discusses quantities and units used in radiation protection. It defines key terms like quantity, unit, activity, curie, exposure, absorbed dose, equivalent dose, effective dose, and committed dose. It provides examples of common radiation units like grays, sieverts, and roentgens. It also discusses natural and man-made sources of background radiation like terrestrial sources, medical use, nuclear power and fallout. The goal is to quantify radiation exposure and risk to human tissues from different radiation types and energies.
It gives some easy and detailed information about the basics of a radiological physics and will explain about the interactions of Electron in the target atoms.
Linear attenuation coefficient (휇) is a measure of the ability of a medium to diffuse and absorb radiation. In the interaction of radiation with matter, the linear absorption coefficient plays an important role because during the passage of radiation through a medium, its absorption depends on the wavelength of the radiation and the thickness and nature of the medium. Experiments to determine linear absorption coefficient for Lead, Copper and Aluminum were carried out in air. The result showed that linear absorption Coefficient for Lead is 0.545cm – 1, Copper is 0.139cm-1 and Aluminum is 0.271cm-1 using gamma-rays. The results agree with standard values.
Complete detail about the Radiopharmaceutical, General Introduction, Radioactive substance, Radioactive rays like alpha, beta and gamma rays. All the Measurement method to determine the radioactivity of any element and widely used instrument Geiger Muller Counter. And some Radiopharmaceutical product used in many diagnosis , treatment such like sodium iodide solution & capsule, Rose Bengal I 131 and Application of Radiopharmaceuticals.
It gives some easy and detailed information about the basics of a radiological physics and will explain about the interactions of Electron in the target atoms.
Linear attenuation coefficient (휇) is a measure of the ability of a medium to diffuse and absorb radiation. In the interaction of radiation with matter, the linear absorption coefficient plays an important role because during the passage of radiation through a medium, its absorption depends on the wavelength of the radiation and the thickness and nature of the medium. Experiments to determine linear absorption coefficient for Lead, Copper and Aluminum were carried out in air. The result showed that linear absorption Coefficient for Lead is 0.545cm – 1, Copper is 0.139cm-1 and Aluminum is 0.271cm-1 using gamma-rays. The results agree with standard values.
Complete detail about the Radiopharmaceutical, General Introduction, Radioactive substance, Radioactive rays like alpha, beta and gamma rays. All the Measurement method to determine the radioactivity of any element and widely used instrument Geiger Muller Counter. And some Radiopharmaceutical product used in many diagnosis , treatment such like sodium iodide solution & capsule, Rose Bengal I 131 and Application of Radiopharmaceuticals.
Radiation is energy that is given off by particular materials and devices.
Radiation protection, also known as radiological protection, is defined by the International Atomic Energy Agency (IAEA) as "The protection of people from harmful effects of exposure to ionizing radiation, and the means for achieving this". Exposure can be from a source of radiation external to the human body or due to internal irradiation caused by the ingestion of radioactive contamination
radiation control safety, role of Organization in radiation protection and environmental radiological surveillance.
Factors that affect radiation dose:
Regulations and procedures have been developed and implemented to limit radiation dose by regulating the use, storage, transport, and disposal of radioactive material by controlling time, distance and shielding
Time
The short the time spent near the source, the smaller the dose
Distance
The greater the distance the smaller the dose
Shielding
Use of materials to absorb the radiation dose
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
The Gram stain is a fundamental technique in microbiology used to classify bacteria based on their cell wall structure. It provides a quick and simple method to distinguish between Gram-positive and Gram-negative bacteria, which have different susceptibilities to antibiotics
CDSCO and Phamacovigilance {Regulatory body in India}NEHA GUPTA
The Central Drugs Standard Control Organization (CDSCO) is India's national regulatory body for pharmaceuticals and medical devices. Operating under the Directorate General of Health Services, Ministry of Health & Family Welfare, Government of India, the CDSCO is responsible for approving new drugs, conducting clinical trials, setting standards for drugs, controlling the quality of imported drugs, and coordinating the activities of State Drug Control Organizations by providing expert advice.
Pharmacovigilance, on the other hand, is the science and activities related to the detection, assessment, understanding, and prevention of adverse effects or any other drug-related problems. The primary aim of pharmacovigilance is to ensure the safety and efficacy of medicines, thereby protecting public health.
In India, pharmacovigilance activities are monitored by the Pharmacovigilance Programme of India (PvPI), which works closely with CDSCO to collect, analyze, and act upon data regarding adverse drug reactions (ADRs). Together, they play a critical role in ensuring that the benefits of drugs outweigh their risks, maintaining high standards of patient safety, and promoting the rational use of medicines.
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
Basavarajeeyam is a Sreshta Sangraha grantha (Compiled book ), written by Neelkanta kotturu Basavaraja Virachita. It contains 25 Prakaranas, First 24 Chapters related to Rogas& 25th to Rasadravyas.
3. RADIATION UNITS
• TO MEASURE RADIOACTIVITY
• TO EXPRESS ENERGY OF
RADIATION EMITED
• TO EXPRESS AMOUNT OF
ENERGY DEPOSITED IN THE
BODY
• TO QUANTIFY BIOLOGICAL
DAMAGES TO IRIDIATED
TISSUES
5. THE CURIE
1 Curie (Ci) = Activity of 1g of 226
Ra
1g of 226
Ra disintegrate 3.7x1010
atoms per second
∴ 1 Ci = 3.7 x 1010
dis/s
∴ 1 Ci = 3.7 x 1010
Bq
1 Ci = 37 GBq
6. ENERGY OF RADIATION
ELECTRON VOLTS
1eV = 1.6 X 10 –19
J
COBALT- 60 RADIOACTIVE MATERIAL
EMITS TWO GAMMA RADIATIONS OF
ENERGIES 1.17 MeV AND 1.32 MeV.
7. DOSE
USES AS A GENERIC TERM THAT CAN
APPLY TO ANY OF THE RELEVANT
DOSIMETRIC QUANTIES
EXPOSURE
IN A GENERIC SENSE TO MEAN THE
PROCESS OF BEING EXPOSED TO
RADIATION
8. Exposure Unit
•Is a measure of ionization produced in air
•Is used only for X and γ radiation
•Is valid for quantum energy less than 3 MeV
9. X Unit
1 X unit = 1 C/kg air
One exposure unit is defined as that quantity
of x or gamma radiation that produces in air,
ions carrying 1 coulomb of change( of either
sign) per kg air.
10. Exposure
Exposure is measured under conditions of electronic
equilibrium
For photon energies above about 3 MeV, the ranges of
secondary electrons become a significant fraction of
the photon attenuation lengths and the departure from
equilibrium may be significant
Thus, exposure is not defined above photon energies
of 3 MeV
11. Roentgens (2/3)
• Is symbolized by R
• was used as the exposure unit before
SI system was adopted
• is still being used.
12. Roentgen
Is defined as the quantity of x or
gamma radiation that produces ions
carrying one statcoulomb of charge of
either sign per cubic centimeter of air
at STP.
Charge of the electron=1.6x10-19
C =4.8x10-10sC
1C =3x109
sC
13. 13
KERMA
KERMA (Kinetic Energy Released in a Material):
– Is the sum of the initial kinetic energies of all charged
ionizing particles liberated by uncharged ionizing
particles in a material of unit mass
– For medical imaging use, KERMA is usually expressed
in air
SI unit = joule per kilogram (J/kg)
or gray (Gy)
1 J/kg = 1 Gy
14. 14
Mean absorbed dose in a tissue or
organ
The mean absorbed dose in a tissue or organ DT is the
energy deposited in the organ divided by the mass of
that organ.
15. ABSORBED DOSE(1/2)
• MEASURES THE ENERGY
DELIVERED TO ANY MATERIAL
• IN RADIATION PROTECTION
THE MATERIAL CONCERNED IS
THE TISSUE OR ORGAN OF THE
HUMAN BODY
16. ABSORBED DOSE(2/2)
• DEFINED AS THE
“ENERGY ABSORBED
PER UNIT MASS OF
ANY MATERIAL”
• UNIT USED
“GRAY” OR
“RADS”
18. EQUIVALENT DOSE(1/2)
QUANTIFY THE BIOLOGICAL
DAMAGE TO THE ORGAN OR
TISSUE IRRIDIATED
The same dose levels of different radiations
(ie photons and neutrons) do not have the
same level of biological effect
Radiation weighting factor, wR
(related to radiation quality)
19. EQUIVALENT DOSE(2/2)
• BIOLOGICAL
EFFECTS OF AN
EXPOSURE ON A
ORGAN OR TISSUE
DEPEND ON:
• ENERGY TRANSMITTED
TO THE ORGAN OR
TISSUE BY RADIATION
• HAMFULNESS OF THE
TYPE OF RADIATION
INVOLVED (DEGREE OF
POWER OF IONIZATION)
20. Radiation weighting factors,
wR
1
Type and energy ranges
Radiation
weighting
factor, wR
1
1
5
10
20
10
5
5
Photons, all energies
Electrons and muons, all energies
Neutrons, energy < 10 keV
10 keV to 100 keV
100 keV to 2 MeV
> 2 MeV to 20 MeV
> 20 MeV
Protons, other than recoil protons, energy > 2 MeV
Alpha particles, fission fragments, heavy nuclei 20
1) All values relate to the radiation incident on the body, or,
for internal sources, emitted from the source.
22. EFFECTIVE DOSE
Different body tissues have different
biological sensitivities to the same
radiation type and dose
Tissue weighting factor, wT
23. EFFECTIVE DOSE
• MEASURES THE RISK OF
BIOLOGICAL DAMAGE TO
WHOLE BODY TAKING THE
RADIOSENSITIVITIES OF
TISSUE IRRIDIATED IN TO
ACCOUNT
• MEASURES THE RISK
REGARDLESS OF EXPOSURE
INVOLVED.( INTERNAL,
EXTERNAL, PARTIAL OR
TOTAL)
• MEASURES IN THE UNIT OF.
“SIEVERT”( Sv )
24. Roentgen (3/3)
1R = 0.0087 J/kg of air
IR = 0.0087 Gy = .87 Rad
IR = 0.0096 J/kg in Tissue
IR = 0.0096 Gy in Tissue
IR = .96 Rad in Tissue
1 R = 1 Rad
for x and γ rays
IR = 1 rem = .01 Sv
25. Multipliers of the equivalent dose to an organ or tissue to
account for the different sensitivities to the induction of
stochastic effects of radiation.
Tissue or organ wT Tissue or organ wT
Gonads 0.20 Bone marrow (red) 0.12
Colon 0.12 Lung 0.12
Stomach 0.12 Bladder 0.05
Breast 0.05 Liver 0.05
Oesophagus 0.05 Thyroid 0.05
Skin 0.01 Bone surface 0.01
Remainder 0.05 TOTAL 1.00
Tissue weighting factors
26. Committed Dose
Is a useful subsidiary dosimetric quality
to express dose to body during certain
time following an intake of radioactive
material to the body.
Note : The dose delivery to the body
during the above period is at
varying rates.
27. Committed Equivalent Dose
Defined as the time integral of the equivalent dose
rate and denoted by HT( τ )
τ = integration time in years following
the intake.
If t is not specified
Integration time is taken as
50 years for adults
70 years for children
28. Committed equivalent dose:
The quantity H(τ), defined as;
where to
is the time of intake, HT
(t) is the equivalent dose
rate at time t in an organ or tissue T and τ is the time elapsed
after an intake of radioactive substances.When τ is not
specified it will be taken to be 50 years for adults and to age
70 years for intakes by children.
( ) ( )H H t dtT
t
t
o
o
τ
τ
=
+
∫
.
29. Committed effective dose:
The quantity E(τ), defined as ;
where HT
(τ) is the committed equivalent dose to tissue T
over the integration time τ and WT
is the tissue weighting
factor for tissue T.
When τ is not specified it will be taken to be 50 years for
adults and to age 70 years for intakes by children.
( ) ( )E W HT T
T
τ τ= ∑ .
30. Collective Dose(1/2)
Is used to express dose to a
group or a population.
Takes account of the no of
people exposed to a source and
the average dose to the
individual.
36. External terrestrial irradiation
0.4 mSv y-
Varies considerably with soil and rock type
Unusually high background in a few places
in e.g.
•Esperito Santos, Brazil
•Kerala, India
•Guandong province, China
Up to 50 µGy h-1
compared to 0.1 µGy h-1
41. Reasons for elevated levels of
indoor radon
•elevated levels of 238
U and 232
Th series in
the ground
•building material with elevated levels of
238
U and 232
Th series
•tight houses (cold climate…)
43. Man-made Radiation
• Cigarette smoke
• Consumer products
– Building materials
– Smoke detectors
• Industrial use
• Medical use
• Nuclear power
• Nuclear fall out
44. …and artificial sources of
radiation
Medical examinations…
(0.4 mSv.
y-1
)
C. Torudd ; Swedish Radiation Protection Institute
45. …and more artificial sources of radiation
...and nuclear
weapons
(0.005 mSv.
y-1
atmospherical
tests)
Nuclear fuel
cycle…
(0.0002 mSv.
y-1
)
C. Torudd ; Swedish Radiation Protection Institute
49. Practical concequencies of Chernobyl
accident
Effects of radiation and accident situation
•600,000-800,000 persons in cleaning up work
•Approximately 200,000 persons evacuated
•Large areas of land abandoned (30 km zone etc.)
Other effects:
•Cost estimated to 100 billion USD
50. Health concequencies of Chernobyl accident
Effects of radiation and accident situation
Seen:
•Immediate death of 30 persons
•1800 children diagnosed with thyroid cancer (1998)
Statistically:
•15,000 deaths in cancer (global)
Other factors influencing health:
•Poor food supply, social concequencies, anxiety
51. Source Mean effective dose (mSv)
Natural background 2,4
Medical examinations 0,4
Nuclear tests in the atmosphere 0,005
Chernobyl accident 0,002
Nuclear fuel cycle 0,0002
Individual exposure of the world’s population
due to ionising radiation, year 2000
UNSCEAR
54. Lethal Dose= 4Gy
LD 50/60 = 4 Gy
For man of 70 kg
Energy absorbed = 4 x 70 = 280 Joules
= 280/418= 67 calories
= 1 sip
X-ray
55.
56.
57.
58. We live with
1-3 mSv
Can kill
4000 mSv
Radiation
Where to stop, where is the safe point?
What are the effects of radiation?
59. What can radiation do?
Death
Cancer
Skin Burns
Cataract
Infertility
Genetic effects
Editor's Notes
Electronic equilibrium is discussed in more detail in another session, but basically, when the same number of electrons are set in motion in a given volume by the primary radiation as come to rest in that same volume, we say that “electronic equilibrium” has been attained. For electronic equilibrium to exist, the attenuation of the primary radiation beam must be negligible in a distance equal to the mean range of the electrons.
The second major reason that physical quantities are not used directly is that the same quantity (absorbed dose) of different types of radiation may have significantly different degrees of radiation damage – a factor of 10 or more. The term given to this quantity is relative biological effect (RBE). This is due to the differences in microdosimetric distribution of energy deposition. The difference is characterized by the quantity linear energy transfer (LET). In the past, the quality factor was used to compensate for RBE differences. However, the ICRP felt that quality factor implied a level of precision that was not justified, and it was replaced with radiation weighting factor, wR.
The main impact of radiation weighting factor is on neutron dosimetry since fast neutron interactions are characterized by high LET values. However, as defined by the ICRP, wR for neutron is an energy dependent step function. Those who perform neutron dosimetry calculations, particularly fluence to “dose” conversion coefficients find such step functions disagreeable because of the discontinuities that result. Therefore, a smooth approximation has been developed that eliminates these discontinuities. It is accepted by the ICRP as long as it is understood that it is an approximation and that wR is defined by the values in the table.
One of the primary reasons that the physical quantities are not used directly for radiation protection is that different body tissues have different levels of radiation sensitivity and different degrees of susceptibility to radiation induced stochastic effects such as cancer. This table was developed by the ICRP to reflect the relative tissue sensitivity to radiation induction of these effects.