DAILY EXCELSIOR Julty 12, 2007 (PTI feature)
‘Nuclear’ news : Who is minding the shop ?
By Dr K S Parthasarathy
Recent controversies surrounding the visit of USS Nimitz, a nuclear aircraft carrier to Chennai, initially gave the false impression that there is no one to mind the shop!
Public had legitimate reasons to worry. The reassuring and prompt statements from scientists who knew the safety features of the reactors on board such ships and the lucid press release from the Ministry of Defence (MOD) allayed these fears to a great extent.
MOD had evolved the process of clearing the harbour for berthing nuclear vessels since January 5, 1988 when Indian navy inducted the nuclear powered INS Chakra into its fleet. The procedures included survey by an Environmental Survey Committee (ESC) set up by the Scientific Advisor to Defence Minister. MOD drew up a Radiation Safety Contingency Plan and implemented it prior to berthing of INS Chakra; the ship operated from 1988 to 1991.
From 15 February 2001 to 3rd November 2006, three nuclear powered ships from USA, three from France and one ship from UK visited India. There were ten visits; nine were to Goa and one to Mumbai. Indian Navy conducted the ‘International Fleet Review’ during which the French Nuclear Submarine Perle berthed in Mumbai harbour from 15 to 20 February 2001.
MOD intimates the ESC of an impending visit by a nuclear powered ship or submarine. ESC proceeds to the port well in advance before the arrival of the nuclear powered vessel and carries out a survey.
Movement of the nuclear powered ship takes place only during daylight hours, in good visibility and with escort tugs in attendance. No other ship is berthed within 200 metre radius of the nuclear powered ship. Ships berthed within 600 metre of the berth are kept at short notice, not exceeding tour hours, to get underway.
Radiation monitoring laboratories manned by scientists from Defence Research and Development Organization (DRDO)/Bhabha Atomic Research Centre (BARC) and Defence personnel, set up onboard a suitable ship, undertake frequent monitoring of water and air samples.
A standing ESC has carried out a detailed survey at Chennai and cleared the visit of USS Nimitz from radiation hazard point of view. The stingent radiation monitoring protocol in place includes periodic monitoring protocol in place includes periodic monitoring and analysis of air and water samples. The agency conducts these activities under the ambit of a well rehearsed Radiation Safety Contingency Plan over seen by a Crisis Management Group and a Crisis Management Cell comprising of scientists from DRDO, BARC, Defence Laboratory, Jodhpur, representatives of the Chennai Port Trust and the Indian Navy.
In spite of the well established and frequently rehearsed procedures in place, the visit of the carrier generated some controversy. Nobody discussed the issues so far though nuclear powered ships have been visiting Indian ports periodically. It is amusing to note that even as late as July 2nd this year news agencies continue to state that USS Nimitz is the first nuclear powered ship to visit an Indian port though the press release dated July 27 from MOD gave details of ten visits during 2001-2006. Our scientists and engineers have been operating nuclear facilities including several nuclear power reactors for the past many decades, a few of these are based at coastal areas. Scientists in the Environmental Survey Laboratories have developed state of the art capability to measure radioactivity in samples of air and water from the sixties.
Plant, site and offsite emergency plans are in place at every nuclear power plant. Preparing relevant documentation and enforcing appropriate plans with the help of scientists and engineers are routine functions for the concerned authorities.
In April 1994, a ‘‘scientist’’ working with an NGO reported that his team measured high levels of radiation in several parts of Lucknow, including MLA's hostel and a few posh areas. Many national dailies and local Doordarshan covered the news.
Three scientists from the Atomic Energy Regulatory Board (AERB) and the Bhabha Atomic Research Centre (BARC) investigated the observations and unambiguously demonstrated that the reported increase in background radiation was due to a deficiency of the instrument. It was sensitive to light and indicated some spurious reading when its detector was exposed directly to sunlight with its window open.
The team measured radiation levels in the locations referred to in the NGO's press release and observed that they were within the range normally expected in that part of the country arising solely from natural background radiation.
AERB publicized the findings of the committee. Though the ‘scientist’’ working with the NGO accepted the conclusions of the committee on the spot, he repeated his claim later and said that he was confident he would ‘‘come out with clinching evidence’’ at an appropriate time.
In September 1994 a report from Washington stated that Pakistan was within hours of sending American supplied F-16 jets on a mission to drop conventional bombs on the nuclear reactors at Trombay. ‘‘Millions of people would have died and it would have been a holocaust beyond anything...had Pakistan attacked the two research atomic reactors, Dhruva and Cirus’’, the report warned.
In response to a senior journalist from a national news agency, I explained the topography of Trombay and the design features of the reactors. I explained that a nuclear facility may have plant, site and offsite emergency plans as appropriate. Detailed analysis has shown that releases, if any, from the reactors at Trombay even in an extreme emergency will not have any offsite impact. I told the journalist that the statement from Washington is ‘most absurd’. The item got wide media coverage and hopefully allayed some fear.
Nuclear and associated community must realize that, often, radiation or nuclear safety matters raise alarm totally disproportionate with any measurable harm. They must address these concerns promptly, honestly and openly. It is at times wiser to be proactive. Media is always receptive to those who are minding the shop !
PTI Feature
Friday, December 14, 2007
Architects of nuclear India
Close collaboration between Dr Homi Bhbabha and Pandit Jawaharlal Nehru helped to lay the foundations of nuclear India. Both of them can be considered as the architects of nuclear India
K.S.Parthasarathy
Daily Excelsior
November 27, 2007
(A PTI Feature)
Architects of Nuclear India
By K S Parthasarathy
We celebrated the 97th birth anniversary of Dr Homi Bhabha on October 30, 2007. Pandit Jawaharlal Nehru's 118th birth anniversary was on November 14, 2007. Nehru helped to translate Bhabha's dreams into reality. They were truly the architects of nuclear India.
On January 4, 1947, while laying the foundation stone of the National Physical Laboratory at New Delhi Pandit Jawaharlal Nehru spoke thus on the necessary of atomic research in India : ‘‘... I do not see how we can lag behind in this very important matter, because atomic energy is going to play a vast and dominant part, I suppose, in the future shape of things... it will make power mobile and this mobility of power can make industry develop anywhere. We will not be tied up by accidents of geography....’’
Dr Bhabha's note on the organisation of atomic research in India submitted to Nehru on April 26, 1948, showed amazingly similar views.
‘‘The report submitted to you, Mr Prime Minister, on my return from Europe and America collected evidence which made it reasonable to believe that within the next couple of decades atomic energy would play an important part in the economy and the industry of countries and that, if India did not wish to fall even further behind industrially advanced countries of the world, it would be necessary to take more energetic measures to develop this branch of science and appropriate larger sums for the purpose.’’
‘‘.. our immediate programme should include extensive and intense search for sources of uranium. These geological surveys would take at least two years if carried out in any careful and exhaustive way and it is possible that their result may be negative. In that case, India would either have to depend on an agreement with a foreign power for the purchase of her uranium... ‘‘Bhabha pleaded. The search continues !
On the first International Conference on the Peaceful Uses of Atomic Energy at Vienna he wrote: ‘‘... What is so gratifying is the cordial atmosphere in which all the... discussions were carried out, entirely free from political bias or cold war hostility. Besides the regular sessions, a number of informal meetings were held among scientists including those from the so called iron curtain countries, at which scientific problems were discussed fully and freely’’. He knew that such ambience at the Geneva conference would be of special interest to his mentor.
By then, the Bandung Conference of Afro-Asian countries was over. Nehru was shortly destined to play the role of the leader of the Non Alignment Movement.
Occasionally, Bhabha led wars to defend his turf. He wanted to keep the construction of the Canada Indian Reactor, a highly technical project, exclusively with the Department of Atomic Energy (DAE). As the project was started strictly outside the Colombo Plan, he argued that there is clearly no advantage in routing related correspondence through the Department of Economic Affairs. ‘‘Indeed it will slow down the entire process’’ he cautioned. Nehru concurred.
Bhabha obtained exemption from certain Government regulations by writing to Nehru who always endorsed his decisions. These include provision of cars at the disposal of scientists during the commissioning of Apsara reactor and supply lunch and dinner at the work site at Trombay.
Bhabha deftly drafted the resolution settting up the Atomic Energy Commission (AEC). He set up AEC, as an organisation ‘‘with full authority to plan and implement the various measures on sound technical and economic principles and free from all non-essential restrictions or needlessly inelastic rules’’.
‘‘The special requirements of atomic energy, the newness of the field, the strategic nature of its activities and its international and political significance have to be borne in mind in devising such an organization’’, the resolution stipulated. AEC has the powers of the Government of India in all its Ministries, in so far as the work of the Department of Atomic Energy is concerned.
Dr Bhabha managed to set up the Secretariat of the Department of Atomic Energy (DAE) at Bombay and not in Delhi. The Department secured exemption from all reference of its civil engineering and construction work to the Central Public Works Department and of its purchase from the Directorate General of Supplies and Disposals. Similarly DAE follows its own procedures to recruit its staff and need not approach the Union Public Service Commission. Bhabha could secure the support of the highest echelons of the bureaucracy because of his rapport with Panditji.
Nehru's letter to ‘‘My Dear Homi’’ written on July 29, 1956 revealed that there was no barrier between these leaders. While discussing the composition of delegates of an International Conference at Vienna, Nehru cautioned, ‘‘I find that some of the other major countries are sending non-technical people as leaders of their delegations. It would probably be advisable for you and your scientific colleagues not to get mixed up too much with the political aspects.’’
While referring to the need to develop scientific temper, Nehru was brutally objective.
He did not spare even scientists. ‘‘--I do not mean that even now our big scientists are really scientific in mind, which I find often they are not. They are scientific in their laboratories; take them outside these and they appear to be frail human beings...’’
After staying in Cambridge for two days in June 1959 to receive an honorary degree of Doctor of Science, Bhabha wrote, ‘‘My dear Bhai, this was evidently a particularly good year for roses. I have never seen such profusion of beautiful roses as was to be found... at the back adjoining the river’’.....
....‘‘I hope some of the scientific laboratories and establishments we are building today will have the beauty of their own, which will have its due effect on those who work here.
I think both Trombay and the Tata Institute of Fundamental Research will be architecturally, and botanically beautiful when they are completed..’’ He eloquently articulated his vision.
Nehru must have acknowledged Homi's sentiments by looking blissfully at the red rose on his jacket !
(PTI) .
K.S.Parthasarathy
Daily Excelsior
November 27, 2007
(A PTI Feature)
Architects of Nuclear India
By K S Parthasarathy
We celebrated the 97th birth anniversary of Dr Homi Bhabha on October 30, 2007. Pandit Jawaharlal Nehru's 118th birth anniversary was on November 14, 2007. Nehru helped to translate Bhabha's dreams into reality. They were truly the architects of nuclear India.
On January 4, 1947, while laying the foundation stone of the National Physical Laboratory at New Delhi Pandit Jawaharlal Nehru spoke thus on the necessary of atomic research in India : ‘‘... I do not see how we can lag behind in this very important matter, because atomic energy is going to play a vast and dominant part, I suppose, in the future shape of things... it will make power mobile and this mobility of power can make industry develop anywhere. We will not be tied up by accidents of geography....’’
Dr Bhabha's note on the organisation of atomic research in India submitted to Nehru on April 26, 1948, showed amazingly similar views.
‘‘The report submitted to you, Mr Prime Minister, on my return from Europe and America collected evidence which made it reasonable to believe that within the next couple of decades atomic energy would play an important part in the economy and the industry of countries and that, if India did not wish to fall even further behind industrially advanced countries of the world, it would be necessary to take more energetic measures to develop this branch of science and appropriate larger sums for the purpose.’’
‘‘.. our immediate programme should include extensive and intense search for sources of uranium. These geological surveys would take at least two years if carried out in any careful and exhaustive way and it is possible that their result may be negative. In that case, India would either have to depend on an agreement with a foreign power for the purchase of her uranium... ‘‘Bhabha pleaded. The search continues !
On the first International Conference on the Peaceful Uses of Atomic Energy at Vienna he wrote: ‘‘... What is so gratifying is the cordial atmosphere in which all the... discussions were carried out, entirely free from political bias or cold war hostility. Besides the regular sessions, a number of informal meetings were held among scientists including those from the so called iron curtain countries, at which scientific problems were discussed fully and freely’’. He knew that such ambience at the Geneva conference would be of special interest to his mentor.
By then, the Bandung Conference of Afro-Asian countries was over. Nehru was shortly destined to play the role of the leader of the Non Alignment Movement.
Occasionally, Bhabha led wars to defend his turf. He wanted to keep the construction of the Canada Indian Reactor, a highly technical project, exclusively with the Department of Atomic Energy (DAE). As the project was started strictly outside the Colombo Plan, he argued that there is clearly no advantage in routing related correspondence through the Department of Economic Affairs. ‘‘Indeed it will slow down the entire process’’ he cautioned. Nehru concurred.
Bhabha obtained exemption from certain Government regulations by writing to Nehru who always endorsed his decisions. These include provision of cars at the disposal of scientists during the commissioning of Apsara reactor and supply lunch and dinner at the work site at Trombay.
Bhabha deftly drafted the resolution settting up the Atomic Energy Commission (AEC). He set up AEC, as an organisation ‘‘with full authority to plan and implement the various measures on sound technical and economic principles and free from all non-essential restrictions or needlessly inelastic rules’’.
‘‘The special requirements of atomic energy, the newness of the field, the strategic nature of its activities and its international and political significance have to be borne in mind in devising such an organization’’, the resolution stipulated. AEC has the powers of the Government of India in all its Ministries, in so far as the work of the Department of Atomic Energy is concerned.
Dr Bhabha managed to set up the Secretariat of the Department of Atomic Energy (DAE) at Bombay and not in Delhi. The Department secured exemption from all reference of its civil engineering and construction work to the Central Public Works Department and of its purchase from the Directorate General of Supplies and Disposals. Similarly DAE follows its own procedures to recruit its staff and need not approach the Union Public Service Commission. Bhabha could secure the support of the highest echelons of the bureaucracy because of his rapport with Panditji.
Nehru's letter to ‘‘My Dear Homi’’ written on July 29, 1956 revealed that there was no barrier between these leaders. While discussing the composition of delegates of an International Conference at Vienna, Nehru cautioned, ‘‘I find that some of the other major countries are sending non-technical people as leaders of their delegations. It would probably be advisable for you and your scientific colleagues not to get mixed up too much with the political aspects.’’
While referring to the need to develop scientific temper, Nehru was brutally objective.
He did not spare even scientists. ‘‘--I do not mean that even now our big scientists are really scientific in mind, which I find often they are not. They are scientific in their laboratories; take them outside these and they appear to be frail human beings...’’
After staying in Cambridge for two days in June 1959 to receive an honorary degree of Doctor of Science, Bhabha wrote, ‘‘My dear Bhai, this was evidently a particularly good year for roses. I have never seen such profusion of beautiful roses as was to be found... at the back adjoining the river’’.....
....‘‘I hope some of the scientific laboratories and establishments we are building today will have the beauty of their own, which will have its due effect on those who work here.
I think both Trombay and the Tata Institute of Fundamental Research will be architecturally, and botanically beautiful when they are completed..’’ He eloquently articulated his vision.
Nehru must have acknowledged Homi's sentiments by looking blissfully at the red rose on his jacket !
(PTI) .
Thursday, December 13, 2007
The first report on how India achieves nuclear safety
The article is a summary of the first National report for the Convention on Nuclear Safety submitted by India in September 2007 to the fourth Review Meeting of Contracting parties to be held in April 2008
K.S.Parthasarathy
Date:13/12/2007 URL: http://www.thehindu.com/thehindu/seta/2007/12/13/stories/2007121350101500.htm Sci Tech
The first report on how India achieves nuclear safety
It lists important safety improvements at each power station, starting with Tarapur
The average capacity factor for the Indian nuclear reactors for 2005-06 was 74 per cent
Among other measures, reduction of radiation doses to workers is notable
Recent debates on the Indo-US agreement for cooperation concerning the peaceful use of nuclear energy compelled the media to look at nuclear power more benignly. Members of the public realised for the first time that nuclear power has a role to play in the energy mix of the country. Those who have concerns on nuclear safety, must read the first ‘National Report for the Convention on Nuclear Safety (September 2007),’ to find out how India achieves nuclear safety . (Please see www.aerb.gov.in or www.dae.gov.in for the text of the report.)
Measures explained
The 208 page report explains the measures taken by India to implement the Convention on Nuclear Safety, the first international legal instrument dealing directly with the safety of civilian nuclear power plants. The Fourth Review Meeting of the Contracting Parties scheduled to be held in April 2008 will examine the report along with 13 others including those from Canada, France, Russia and U.S. The international peer review is unique to the nuclear industry.
The report highlights the steps taken to implement Articles 6 to 19 (Chapter 2 titled ‘Obligations’). It lists important safety improvements at each power station starting with the Tarapur Atomic Power Station (TAPS) which began its operation in 1969. The comprehensive safety review and implementation of safety up-gradations for continued operation of TAPS-1 and 2 are notable.
The report gives graphically the electrical power generated by each reactor in India and its availability and capacity factors. Nuclear Power Corporation of India Limited (NPCIL) deserves congratulations for consistent performance for the past few years.
The average capacity factor for the Indian nuclear power reactors for 2005-06 was 74 per cent. India must compete with other countries now. The U.S. recorded an average capacity factor of 89.6 per cent in 2006 for 105 reactors with 29 reactors exceeding 95 per cent. The comprehensive safety assessments carried out after major events such as the accident at Three Mile Island in the U.S. and that at Chernobyl in the former Soviet Union are very informative. NPCIL implemented the recommendations arising from these assessments.
Following the pressure tube failure incident at the Pickring-2 reactor in Canada, India introduced a major programme to ensure the integrity of the pressure tubes in Indian Pressurized Heavy Water Reactors by enhancing the design as well as in-service-inspection and rehabilitation technologies.
The thoroughness with which AERB reviewed the fire incident at Narora in March 1993 and the tsunami incident at Kalpakkam in December 2004 and ensured implementation of its recommendations is reassuring.
Seismic re-evaluation of old generation reactors, enhanced inspection of certain systems and components, ageing management and reduction of radiation doses to workers are notable.
The directive prescribing ‘formal and elaborate retraining and re-licensing of all the frontline operating staff and the station management personnel’ following a safety-related incident at the Kakrapar Atomic Power Station reflects the no-nonsense attitude of AERB
The report describes the legislative and regulatory framework including the Atomic Energy Act 1962 and the rules framed under it and other legal instruments such as Indian Electricity Act 2003, Environment (Protection) Act 1986 etc.
It highlights the functions and responsibilities of AERB, the Board’s organisational structure and its position in the government which ensures administrative and financial independence in its functioning.
Forum member
AERB participates in the activities of the International Atomic Energy Agency (IAEA).
It is a member of the forum for the CANDU senior regulators with six other countries operating pressurized heavy water reactors. AERB and the US Nuclear Regulatory Commission have held several meetings on safety related topics.
The Board has a cooperation agreement with the French Directorate General of Nuclear Safety and Radiation Protection and the Federal Nuclear and Radiation Safety Authority of Russia.
The measures India takes to comply with other Articles covering the responsibilities of the licensee, financial and human resources, capabilities and limitations of human performance, quality assurance, assessment and verification of safety, radiation protection, siting, design and construction and emergency preparedness are very comprehensive.
Acronyms, jargon
The report contains some tongue-twisting acronyms and incomprehensible jargon (defendable as the report is meant for scientists and engineers!); it also contains a wealth of useful information patiently collected, collated and interpreted from government documents, incident reports, minutes of meetings and publications.
The feedback from the review meetings will help to enhance nuclear safety in countries operating nuclear power plants.
K.S.PARTHASARATHY
Former Secretary, AERB
( ksparth@yahoo.co.uk )
© Copyright 2000 - 2007 The Hindu
K.S.Parthasarathy
Date:13/12/2007 URL: http://www.thehindu.com/thehindu/seta/2007/12/13/stories/2007121350101500.htm Sci Tech
The first report on how India achieves nuclear safety
It lists important safety improvements at each power station, starting with Tarapur
The average capacity factor for the Indian nuclear reactors for 2005-06 was 74 per cent
Among other measures, reduction of radiation doses to workers is notable
Recent debates on the Indo-US agreement for cooperation concerning the peaceful use of nuclear energy compelled the media to look at nuclear power more benignly. Members of the public realised for the first time that nuclear power has a role to play in the energy mix of the country. Those who have concerns on nuclear safety, must read the first ‘National Report for the Convention on Nuclear Safety (September 2007),’ to find out how India achieves nuclear safety . (Please see www.aerb.gov.in or www.dae.gov.in for the text of the report.)
Measures explained
The 208 page report explains the measures taken by India to implement the Convention on Nuclear Safety, the first international legal instrument dealing directly with the safety of civilian nuclear power plants. The Fourth Review Meeting of the Contracting Parties scheduled to be held in April 2008 will examine the report along with 13 others including those from Canada, France, Russia and U.S. The international peer review is unique to the nuclear industry.
The report highlights the steps taken to implement Articles 6 to 19 (Chapter 2 titled ‘Obligations’). It lists important safety improvements at each power station starting with the Tarapur Atomic Power Station (TAPS) which began its operation in 1969. The comprehensive safety review and implementation of safety up-gradations for continued operation of TAPS-1 and 2 are notable.
The report gives graphically the electrical power generated by each reactor in India and its availability and capacity factors. Nuclear Power Corporation of India Limited (NPCIL) deserves congratulations for consistent performance for the past few years.
The average capacity factor for the Indian nuclear power reactors for 2005-06 was 74 per cent. India must compete with other countries now. The U.S. recorded an average capacity factor of 89.6 per cent in 2006 for 105 reactors with 29 reactors exceeding 95 per cent. The comprehensive safety assessments carried out after major events such as the accident at Three Mile Island in the U.S. and that at Chernobyl in the former Soviet Union are very informative. NPCIL implemented the recommendations arising from these assessments.
Following the pressure tube failure incident at the Pickring-2 reactor in Canada, India introduced a major programme to ensure the integrity of the pressure tubes in Indian Pressurized Heavy Water Reactors by enhancing the design as well as in-service-inspection and rehabilitation technologies.
The thoroughness with which AERB reviewed the fire incident at Narora in March 1993 and the tsunami incident at Kalpakkam in December 2004 and ensured implementation of its recommendations is reassuring.
Seismic re-evaluation of old generation reactors, enhanced inspection of certain systems and components, ageing management and reduction of radiation doses to workers are notable.
The directive prescribing ‘formal and elaborate retraining and re-licensing of all the frontline operating staff and the station management personnel’ following a safety-related incident at the Kakrapar Atomic Power Station reflects the no-nonsense attitude of AERB
The report describes the legislative and regulatory framework including the Atomic Energy Act 1962 and the rules framed under it and other legal instruments such as Indian Electricity Act 2003, Environment (Protection) Act 1986 etc.
It highlights the functions and responsibilities of AERB, the Board’s organisational structure and its position in the government which ensures administrative and financial independence in its functioning.
Forum member
AERB participates in the activities of the International Atomic Energy Agency (IAEA).
It is a member of the forum for the CANDU senior regulators with six other countries operating pressurized heavy water reactors. AERB and the US Nuclear Regulatory Commission have held several meetings on safety related topics.
The Board has a cooperation agreement with the French Directorate General of Nuclear Safety and Radiation Protection and the Federal Nuclear and Radiation Safety Authority of Russia.
The measures India takes to comply with other Articles covering the responsibilities of the licensee, financial and human resources, capabilities and limitations of human performance, quality assurance, assessment and verification of safety, radiation protection, siting, design and construction and emergency preparedness are very comprehensive.
Acronyms, jargon
The report contains some tongue-twisting acronyms and incomprehensible jargon (defendable as the report is meant for scientists and engineers!); it also contains a wealth of useful information patiently collected, collated and interpreted from government documents, incident reports, minutes of meetings and publications.
The feedback from the review meetings will help to enhance nuclear safety in countries operating nuclear power plants.
K.S.PARTHASARATHY
Former Secretary, AERB
( ksparth@yahoo.co.uk )
© Copyright 2000 - 2007 The Hindu
Thursday, December 06, 2007
Do cancers soar with CT scans?
Recently Drs David Brenner and Eric Hall claimed that about 1.5 to 2 % of cancers in USA are caused by CT scans. The paper was published by the NEJM on Novemeber 29, 2007.Profesional associations such as the American College of Radiology (ACR), the American Association of Physicists in Medicine (AAPM) and the Radiological Society of North America (RSNA) published critiques on the paper.
Mostly they felt that the conclusions in the paper can create a scare in the minds of public and keep them away from much needed medical procedures. My paper in the Science & Technology issue of the Hindu states that in spite of the controversies, there are many key points of agreement among all.CT Scan is a very useful imaging modality in medically indicated examinations.
Specialist agencies across the board fear that the public may not understand complex scientific arguments. They tend to forget the fact that physicians face the challenge every day. The public will resolve the issues if specialists give all the inputs.
K.S.Parthasarathy
Do cancers soar with CT scans?
Most CT scans result in limited exposure
Benefits from CT scans are not without risks
Useful tool: CT scans are immensely useful in diagnosis and in the guidance of therapeutic procedures.
Recently, Drs David Brenner and Eric Hall, researchers in the Columbia University Medical Centre, New York contended that about 0.4 per cent of all cancers in the U.S. may be attributable to radiation from computed tomography (CT) studies.
They claimed that they used the most scientific radiation risk estimates, and the data on the use of CT from 1991 to 1996.
If current data are used, it may be as high as 1.5 to 2 per cent, they reported in the New England Journal of Medicine (NEJM, November 29, 2007).
Low level radiation
The American College of Radiology (ACR), the Radiological Society of North America (RSNA) and the American Association of Physicists in Medicine (AAPM) reacted to the NEJM paper with predictable alacrity. The effect of low level radiation on living beings continues to be controversial (The Hindu, July 14, 2005).
ACR declared that certain conclusions and comparisons made in the NEJM study may be inappropriate and cause patients to mistakenly avoid getting life-saving medical imaging care.
“Patients need accurate information on which to base their healthcare decisions. They may be terribly confused and unduly distressed by some of the statements in this study,” Dr Arl Van Moore Jr., chairman of the ACR Board of Chancellors cautioned.
“The Brenner article illuminates many issues of importance in regards to CT, but the CT experts in the AAPM feel that much of the message of this article may be misconstrued or misunderstood by the press or by the public who may not be experts in CT,” AAPM warned.
“Advancing technology has increasingly allowed imaging exams to replace more invasive techniques, but has also resulted in increased radiation exposure for Americans” ACR conceded.
ACR and AAPM faulted the study for equating the survivors of atomic bombings to patients undergoing CT scans.
“Most CT examinations are conducted under controlled conditions. They result in limited radiation exposure to a small portion of the body.
Atomic bomb survivors experienced instantaneous radiation exposure to the whole body,” ACR clarified. There were other differences. Brenner and Hall argued that survivors of atomic bombings who received doses similar to patients undergoing CT scans did suffer excess cancers.
AAPM wanted that patients should discuss with their physicians not only the radiation risks of the CT examination, but the risks of not having the diagnostic information that CT provides.
AAPM acknowledged that David Brenner and Eric Hall are esteemed scientists and respected experts in radiation risk and AAPM’s release is in no way meant to impeach or undermine their impressive credentials.
Radiologists, medical physicists and other radiology professionals have long recognised the need to implement CT practice conscientiously and maintain rigorous standards of practice (RSNA, 2007).
The NEJM study focussed attention on overuse of CT. One million children and 20 million adults in the U.S. undergo unnecessary CT scan procedures annually.
Some researchers believe that estimating the number of cancers at low radiation doses has no scientific basis. Others like Brenner and Hall disagree.
But all agree on some key points. CT scans are immensely useful in diagnosing diseases and trauma and in the guidance of interventional and therapeutic procedures.
Not risk free
However, these benefits are not without risks. The individual risk from X-rays associated with a CT scan is quite small, compared to the benefits of diagnosis in medically needed procedures.
It is important to keep the radiation doses during medical X-ray procedures as low as reasonably achievable.
Using CT for routine screening is unjustified (The Hindu, January, 5, 2006). Specialists do not recommend CT coronary angiography of asymptomatic patients for assessing occult coronary artery disease (The Hindu, November 2, 2006).
Physicians must make every effort to reduce radiation dose in CT procedures, especially for children (The Hindu, February 8, 2007). CT should not be used to screen persons for lung cancer (The Hindu, September 13, 2007).
Complex arguments
Specialist agencies across the board fear that the public may not understand complex scientific arguments.
Whether cancers soar with CT scans cannot be answered conclusively. Prudence demands caution in using this powerful medical imaging modality.
They tend to forget the fact that physicians face the challenge every day. The public will resolve the issues if specialists give all the inputs.
K.S. PARTHASARATHY
Former Secretary, AERB
( ksparth@yahoo.co.uk)
© Copyright 2000 - 2007 The Hindu
Mostly they felt that the conclusions in the paper can create a scare in the minds of public and keep them away from much needed medical procedures. My paper in the Science & Technology issue of the Hindu states that in spite of the controversies, there are many key points of agreement among all.CT Scan is a very useful imaging modality in medically indicated examinations.
Specialist agencies across the board fear that the public may not understand complex scientific arguments. They tend to forget the fact that physicians face the challenge every day. The public will resolve the issues if specialists give all the inputs.
K.S.Parthasarathy
Do cancers soar with CT scans?
Most CT scans result in limited exposure
Benefits from CT scans are not without risks
Useful tool: CT scans are immensely useful in diagnosis and in the guidance of therapeutic procedures.
Recently, Drs David Brenner and Eric Hall, researchers in the Columbia University Medical Centre, New York contended that about 0.4 per cent of all cancers in the U.S. may be attributable to radiation from computed tomography (CT) studies.
They claimed that they used the most scientific radiation risk estimates, and the data on the use of CT from 1991 to 1996.
If current data are used, it may be as high as 1.5 to 2 per cent, they reported in the New England Journal of Medicine (NEJM, November 29, 2007).
Low level radiation
The American College of Radiology (ACR), the Radiological Society of North America (RSNA) and the American Association of Physicists in Medicine (AAPM) reacted to the NEJM paper with predictable alacrity. The effect of low level radiation on living beings continues to be controversial (The Hindu, July 14, 2005).
ACR declared that certain conclusions and comparisons made in the NEJM study may be inappropriate and cause patients to mistakenly avoid getting life-saving medical imaging care.
“Patients need accurate information on which to base their healthcare decisions. They may be terribly confused and unduly distressed by some of the statements in this study,” Dr Arl Van Moore Jr., chairman of the ACR Board of Chancellors cautioned.
“The Brenner article illuminates many issues of importance in regards to CT, but the CT experts in the AAPM feel that much of the message of this article may be misconstrued or misunderstood by the press or by the public who may not be experts in CT,” AAPM warned.
“Advancing technology has increasingly allowed imaging exams to replace more invasive techniques, but has also resulted in increased radiation exposure for Americans” ACR conceded.
ACR and AAPM faulted the study for equating the survivors of atomic bombings to patients undergoing CT scans.
“Most CT examinations are conducted under controlled conditions. They result in limited radiation exposure to a small portion of the body.
Atomic bomb survivors experienced instantaneous radiation exposure to the whole body,” ACR clarified. There were other differences. Brenner and Hall argued that survivors of atomic bombings who received doses similar to patients undergoing CT scans did suffer excess cancers.
AAPM wanted that patients should discuss with their physicians not only the radiation risks of the CT examination, but the risks of not having the diagnostic information that CT provides.
AAPM acknowledged that David Brenner and Eric Hall are esteemed scientists and respected experts in radiation risk and AAPM’s release is in no way meant to impeach or undermine their impressive credentials.
Radiologists, medical physicists and other radiology professionals have long recognised the need to implement CT practice conscientiously and maintain rigorous standards of practice (RSNA, 2007).
The NEJM study focussed attention on overuse of CT. One million children and 20 million adults in the U.S. undergo unnecessary CT scan procedures annually.
Some researchers believe that estimating the number of cancers at low radiation doses has no scientific basis. Others like Brenner and Hall disagree.
But all agree on some key points. CT scans are immensely useful in diagnosing diseases and trauma and in the guidance of interventional and therapeutic procedures.
Not risk free
However, these benefits are not without risks. The individual risk from X-rays associated with a CT scan is quite small, compared to the benefits of diagnosis in medically needed procedures.
It is important to keep the radiation doses during medical X-ray procedures as low as reasonably achievable.
Using CT for routine screening is unjustified (The Hindu, January, 5, 2006). Specialists do not recommend CT coronary angiography of asymptomatic patients for assessing occult coronary artery disease (The Hindu, November 2, 2006).
Physicians must make every effort to reduce radiation dose in CT procedures, especially for children (The Hindu, February 8, 2007). CT should not be used to screen persons for lung cancer (The Hindu, September 13, 2007).
Complex arguments
Specialist agencies across the board fear that the public may not understand complex scientific arguments.
Whether cancers soar with CT scans cannot be answered conclusively. Prudence demands caution in using this powerful medical imaging modality.
They tend to forget the fact that physicians face the challenge every day. The public will resolve the issues if specialists give all the inputs.
K.S. PARTHASARATHY
Former Secretary, AERB
( ksparth@yahoo.co.uk)
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