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Tuesday, September 29, 2020

Ignorant members of public - About ionizing radiation

Let us frankly expose the TRUTH – Common man (person) including illiterate, semi-illiterate, and so-called literate or educated, hardly know anything about ionizing radiation. They only know that radiation is very harmful, so many thousands have died in the explosions of atom bombs in Japan; exposed person will lose hair and become impotent, etc etc. How we are going to explain all the benefits we talking about to such a large percentage, may be more than 90% of the population who are lacking an understanding of elementary radiation physics, mathematics, biology and medicine?

Communication is the key. All the practitioners of applications of radiation and radiological protection should focus on ways and means to create awareness amongst the people about radiation, benefits of low level exposures, medical uses in health-care and food preservation, some health effects at high levels of exposures, and how safely the radioactive waste is managed by concerned experts. We should use mass media communication systems and school/college syllabus to maximum possible extent. Desist from use of words, like probability, ALARA and risk analysis when communicating with members of the public.

Sunday, September 27, 2020

Radiological protection in medicine

Use of radiation in medicine has been increasing around the world in the recent past for diagnosis and therapy. The fluoroscopically guided interventional procedures are minimally invasive and used as an alternative to conventional surgery, resulting in reduced patient morbidity and mortality.

Radiation doses to patients from fluoroscopically guided interventional procedures may be high enough to cause skin injuries and increased probability of developing cancer in future years. There is also a risk to staff members of deterministic effects such as cataract formation. Optimization of the patient dose is important.

Although many fluoroscopically guided interventional procedures are conducted in radiology departments, they are increasingly performed by non-radiologists in other areas of the hospital, such as hybrid operating rooms. It is important to ensure that adequate radiation protection training and support services like radiation monitoring are provided to staff members involved in fluoroscopically guided interventional procedures. Radiological protection of the staff members need to be an important consideration while developing new interventional procedures.   

Monday, August 17, 2020

Radioisotope Generator

Radionuclide generator can supply a medical radionuclide in very high specific activity, often a very important concern in modern radiopharmaceutical formulation. It can also be designed to supply the radionuclide in a chemical form that is practically useful in the pharmacy or clinic.

Radionuclide generators have played a major role in the diagnostic nuclear medicine. Various radionuclide generators are in clinical use, particularly, Mo-99/Tc-99m generator. The major part of the radioactive generated in a nuclear medicine laboratory is of Tc-99m, followed by and Ge-68/Ga-68. An account of the available for clinical use and the regulatory challenges are discussed in an article by Knapp, Jr., and Pillai, et al, 2014). In nuclear medicine procedures, target-specific radiopharmaceutical is introduced to the body, the emissions from the radionuclides are detected and transformed into images which can be seen by the expert doctors to facilitate diagnosis. Radionuclides such as Tc-99m, I-131, I-125, P-32, Lu-177, F-18 are produced and used in the medical applications. Radiological protection of the staff is controlled and kept as low as reasonably achievable. Patient dose is optimised for protection of the patient.

Wednesday, July 29, 2020

Some terms explained - radiological protection

As per the ICRP (2007), the threshold dose is defined as the “estimated dose for incidence (EDI) of a specific observable effect in 1% of individuals exposed to radiation”. Tolerance dose is used to denote the maximum amount of radiation a tissue can withstand without developing clinical signs of injury in more than a few percents of individuals. “Clinically significant” term is used to denote the level of severity which is detectable and is associated with noticeable symptoms or sign of impairment of function.
“Cell death” term is used to denote the loss of the cell’s reproductive integrity, without necessarily losing other cell functions. “Cell survival” can be defined as the ability of a cell to proliferate indefinitely to form a colony of its daughter cells.
Humans can tolerate a higher total dose of chronic, low-dose-rate irradiation than an acute single dose. Chronic exposure provides enough time to repair a sub-lethal injury to the cell. Injury to the cell is repaired by the inherent repair mechanism in the body. In addition to this, there are “adaptive reactions” at the cellular, organ, and whole-body level. That is the reason why under chronic exposure situations, a higher total dose is required to develop clinical signs of cell injury as compared to the acute single dose.
It is desirable that the dose limit (100 mSv in 5 years) for occupational exposures is permitted under chronic exposure conditions.  

Monday, May 18, 2020

Probably, the first Code of Practice for Protection of X-ray Operators - 1915

Probably, the first code of practice, a set of 7 radiation protection rules, was issued by British Roentgen Society in November 1915 (The image is reproduced in Bull. of Radiation Protection, Vol. 18 (4), 1995, p. 23).

Recommendations for the Protection of X-ray Operators

The harmful effects produced by X-rays are cumulative and do not generally appear until some weeks or months after the damage has been done. It is to be noted that X-rays of any degree of hardness are capable of producing ill effects, although it is commonly supposed that soft X-rays only are harmful.

It is undesirable that any X-ray treatment should be carried out except under the direction of a qualified medical practitioner experienced in X-ray work.

All X-ray tubes must be provided, when in use, with a protecting shield or cover which prevents the access of the rays to the operators and which encloses the tube, leaving an adjustable opening only sufficiently large to allow the passage of a sheaf of rays of the size necessary for the work in hand. Even with this shielding, the operator may not be completely protected in all cases (e.g., especially in screen work), and the use of movable screens, gloves and aprons is recommended.

Operators should be warned that shields obtainable commercially are often ineffective and test of their opacity should be made.

Whenever possible the cubicle system should be used for X-ray treatment and the operator should be able to make all adjustments from a protected space.

When screen examination is required it is essential that the screen should be covered with thick lead glass of proved opacity and that the screen should be independently supported and not held in the hands of the operator. If the hands are so used they should be properly protected.

The hand or any portion of the body of the operator should never be used to test the hardness or quality of the X-ray tube; any simple form of penetrometer can be easily arranged for this purpose. #radiation #X-rays #radiationsafety #radiology #regulation #healthphysicist #radiologicalprotection

Monday, May 4, 2020


ABSTRACT:  As Mobile /Cellular phone ownership grows throughout the developed as well as the developing world, concerns about the health risks due to radiofrequency emissions from the mobile phone base stations and due to usage of mobile handsets are slowly growing. This article has a look at the concepts used in the mobile phone technology, the power outputs from base stations and mobile handsets, the quantities Specific Energy Absorption Rate (SAR) and power density as a means to assess the effects on biological tissue. The precautionary approach to managing the health risks from mobile phones by specifying exposure guidelines is explored. Having surveyed the relevant epidemiological surveys and finding them inconclusive, NRPB, United Kingdom’s national regulatory body has issued exposure guidelines based on the potential of RF radiation to cause illness or injury through the heating of body tissues. USA’s Federal Communications Commission (FCC) limits are also listed for comparison. For details see:

Shreenivas Vaikuntam and Pushparaja
Radiation protection and Environment
Vol. 26 (3&4), 2003, p. 581-589

Monday, April 13, 2020

Exclusion and exemption criteria for different exposure situations

ICRP in its Publication No. 104 (2007) provide guidance to national regulatory authorities on the scope of radiological protection using the principles of justification and optimization. Advice is provided for deciding the radiation exposure situations that need to be covered by the relevant regulations because their regulatory control can be justified. There are some situations where regulatory control is unjustified and need to be excluded because the exposures are unamenable to control. In some regulated practices, the regulatory control is unwarranted, and exemption from the regulations is found to be the optimum option,

The ICRP documents describe the exclusion and exemption criteria for planned exposure situations and the application of the criteria in emergency and existing exposure situations with some specific examples. The quantitative criteria need to be treated as generic values to the consideration by the national regulatory authorities for defining the scope of the control measures.