medico friend circle bulletin 160-161 - February-March 1990
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- medico friend circle bulletin 160-161 - February-March 1990
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- March 1990
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POMMUNITY HEALTH CELL
367, 'Srinivasa Nilaya'
4^akkasandra, I Main, I Block,
*
Koramanfala,
BANG^LCRE - 560 034.
160 circle
161 bulletin
February-March 1990
RADIATION AND HEALTH
Anant R. S. Phadke
( A position-paper, based on the background papers
and discussions of the XVIth
Radiation and Health. )
Annual
Health—hazards of common
investigations;
iii)
Food irradiation;
iv)
Other sources of radiation from consume
products—Electronic Display screens.
MFC—meet on
It is customary to give a brief report of the
discussion on the theme of the MFC—annual meet
in the MFC Bulletin. But it was felt that these
reports are too brief, hardly do justice to the
various view points and arguments presented.
Many times the report does not convey even the
consensus in a clear manner. It was, therefore,
decided that this time we change this custom and
publish a position—paper or consensus paper in
the Bulletin to give a clear idea to the readers about
the consensus (alongwith major differences, if any)
emerged and the basis of such a consensus. In
doing so, the paper should draw liberally from the
background—papers so that those who could not
attend and hence did not get these background
papers would get some idea about them.
The discussion in this meet was divided into
four broad areas :—
i)
ii)
Basics of radiation and health and the exp
erience of nuclear power plants;
radiological
Most of the discussion and background
material was focussed on the first area; a clear
consensus also emerged and hence this paper will
focus mainly on this aspect. In the second topic
there was a clear, balanced presentation and not
much debate took place after it. It would, therefore,
suffice to reproduce this paper alongwith a few
additional comments based on the discussion at
the annual meet. On food irradiation also, there
was a lone background paper. The author, A.T. Dudani had not, however come and Surendra Gadekar
made a brief extempore presentation. There was a
lively debate and issues raised would be reported at
the end of this background paper. Only a few lines
are in order about the fourth subtopic. I would end
this introduction by reiterating that this position
paper is not a report of the discussions at the
annual meet. But since there were no sharp differ
ences of opinion, none of the deletions are of major
importance.
HEALTH
HAZARDS
OF
NUCLEAR
Radiation :
Radiation is the emission and propagation of
energy through space of tissue in the form of
waves I Sub-atomic particles. Radiation is basi
cally of two types—ionizing and non—ionizing.
Ionizing radiation has enouh energy to knockout
an electron out of its normal orbit around the nucl
eus of an atom. This results into two 'ions', i. eelectrically charged particles — one the negatively
charged electron and the other, the rest of the atom
which now has a net positive electric charge. When
unstable atoms are split in a nuclear reactor or in
atom bomb, the splitting releases in the form of
heat, blast, and radiation. Radiation is in the form
of Alpha, Gamma rays, X—rays, neutrons.
These
cause ionization in surronding area and hence are
called ionizing radiations. Visible light, infrared.
and ultraviolet rays are non-ionizing radiationsChemicals releasing ionizing radiations are called
radio-active and they have deleterions effects on
health on account of their radio-activity.
Effect of radiation at cellular lelel and on
health :
Release of energy through radio-activity
works through two mechanisms : influx of random
energy and ionizations. Dr. Rosalie Bertel I in her
book, 'No Immediate Danger' describes
briefly
and lucidly the effect of this energy-transfer on
cells and hence on health.
"The result of cell exposure to these micro
scopic explosions with the resultant sudden influx
of random energy and ionization may be either cell
death or cell alteration. The change or alteration
can be temporary or permanent. It can leave the
cell unable to reproduce ( or replace ) itself. Radi
ation damage can cause the cell to produce a
slightly different hormone or enzyme that was
originally designed to produce, still leaving it able
to reproduce other cells capable of generating this
same altered hormone or enzyme. In time there may
be millions of such altered cells. This latter mecha
nism, called biological magnification, can usually
associate with old age. One very specific mutation
which can occur within the cell is the destruction
of the cell-mechanism for resting which normally
causes it to cease reproductive activities after cell
division. This inability to rest results in a runaway
POWER
PLANTS
proliferation of cells in one place, which, if not
destroyed, will form a tumour, either benign or
malignant. The abnormal proliferation of white
blood cells is characteristic of leukaemias; red blood
cell proliferation results in what is called polycy
themia vera.
If the radiation damage occurs in germ cells
the sperm or ovum, it can cause defective offspring"
The defective offspring will in turn produce defec
tive sperm or ova, and the genetic 'mistake* will be
passed on to all succeeding generations, reducing
their quality of life until the family line terminates
in sterilisation and / or death. A blighted or abnor
mal embrynonic growth can result in what is called
a hydatidiform mole instead of a baby.
Exposure to radiation is also known to re
duce fertility, i. e. women become unable to conce
ive or give birth.
Radiation can olso damage an embryo or
foetus while it is developing within the mother's
womb. This is called teratogenic damage, or the
child is said to have a congenital malformation rather
than genetic damage. This means the damage is
not automatically transmitted. For example, a deaf
person, made so by a pre-birth injury may hvae
children with normal hearing..
The complex molecules making up living
organisms are composed of long strands of atoms
forming proteins, carbohydrates and fats. They are
held together by chemical bonds involving shared
electrons. If the ionising radiation displaces one
of the electrons in a chemical bond, it can cause
the chain of atoms to break apart splitting the long
molecule into fragments, or changing its shape by
elongation. This is an 'ungluing' of the complex
chemical bonds so carefully structured to support
and perpetuate life. The gradual breakdown of
these molecular bonds destroys the templates used
by the body to make DNA and RNA ( the informa
tion — carrying molecules in the cell ) or causes
abnormal cell division. The gradual natural break
down of DNA & RNA is probably the cellular phe
nomenon
associated
with what we know as
'ageing'. It occurs gradually over the years with
exposure to natural backgrond radiation from the
radioactive substances which have been a part of
the earth for all known ages. There is evidence
that exposure to medical X-rays accelerates this
breakdown process.
There is ample reason to
think
that fission products within the body
will cause the same kind of acceleration of ageing.
However, unlike medical X—rays, these radioactive
chemicals damage cells by their chemical toxicity
as well as their radiological properties.
The gradual breakdown of human bio-regulatory integrity through ionising and breakage of the
DNA & RNA molecules, gradually makes a person
less able to tolerate environmental changes, less
able to recover from diseases or illness, and gener
ally less able to cope physically with habitat varia
tions.
When the DNA of germ plasm is affected
by radiation it can result in chromosomal diseases.
such as trisomy 21, more commonly known as
Down's Syndrome." (1)
•• In order to have a quantitative sense of
the frequency of the different cell effects caused by
radiation exposure, imagine a colony of 1000 living
cells exposed to a 1 rad X—ray ( about the dose for
one X—ray spinal examination). There would be
two or three cell deaths, two or three mutations or
irreparable changes in cell DNA & about 1 lac ioni
sation in the whole colony of cells ranging from 11
to 460 ionisations per cell. While cells can repair
some damage, no one claims that there is perfect
repair even after only one such X—ray." (2)
Radiation and Heredity
" In 1943 Hermann Muller received a Nobel
Prize for his work on the genetic effects of radiation
and was a dominant figure in developing early
radiation exposure recommendations made by the
International Commission on Radiological Protec
tion (ICUP).
•• Muller predicted the gradual redjction
of the survival ability of the human species, as sev
eral generations were damaged through exposure
to ionising radiation.
This problem of genetic
damage
continues to be mentioned in official
radiation-health
documents under the heading
•• mild mutation " but these matations are not
'counted' as health effects when standards are set
or predictions of health effects of exposure to radia
tions are made. There is a difficulty in distinguish
ing mutations caused artificially by radiation from
nuclear activities from those which occur naturally
from earth or cosmic radiation. A mild mutation
may express itself in humans as an allergy, ashtma,
juvenile diabetes, hypertension, arthritis, high blood
cholesterol level, slight muscular or bone defects, or
other genetic 'mistakes'. (3)
It should be obvious from the above acco
unt that accelerated cancers is only the tip of the
iceberg of health—hazard of radiation. But so far
the debate about radiation—hazards has been prim
arily focussed on whethar there has been cancers
or not.
Safe level and Permissible level :
There is in fact, no safe level of of radia
tion. There is always some cellular damage from
any radiation and part of it cannot be repaied. Re
gulatory agencies have therefore set up permissible
levels of radiation for workers in nuclear—industry
and general population. Permissible level is a trade
off between the facilities made possible by nuclearindustry and 'acceptable' level of damage to healthUniformed, helpless citizens give passive consent
to the unnecessary bartering of health for 'progress'
as defined by the powers that be. As scientific kno
wledge of health —hazards of radiation increased
and people's consciousness rose, the permissible
level for workers decreased from 50—70 REM per
year in 1934 to 5 REM per year in 1956 .... (4)
( REM is the measure of radiation absorbed in
human tissue. It may by noted that 5 REM is equi
valent to 170 chest X—rays. ) For the general
people, the permissible level is one tenth of the
occupational permissible level.
Recently, the
National Research council of the U. S„ the official
research agency in this field, found that the risk of
getting cancer from low levels of radiation appears
to be four times as high as previously estimated.
The permissible level is therefore likely to be reduc
ed from 5 REM to 1—2 REM per year...... (5) Per
missible limits have changed so much that the
whole exercise has turned out to be arbitrary and
meaningless.
HEALTH
HAZARDS OF NUCLEAR
FUEL CYCLE
Production of electricity by nuclear power
plants involves a few steps of cycle nature—mining
of uranium ore; its concentration; manufacture of
fuel-rods; 'burning' of these nuclear-fuel-rods in the
reactor to get heat; treatment and storage of 'spent,
fuel rods after this burning; disposal of this nuclearwaste or reprocessing of these spent fuel rods to
3
recover adequate concentration of uranium for
reuse; transport of radio-active
material [during
these steps ot the cycle. All these steps together
constitute the Nuclear Fuel Cycle and each step has
its own radiation hazards.
Mining, milling, enrichment :
Uranium mining releases
radio-active
random gas which causes lung cancer. But hardly
any effective protective measures are adopted even
in developed countries.
The mined uranium is broken into smal|
pieces (milling) and this also releases much radon.
The concentration of uranium inthe ores is extre
mely low : 0.07%. This ore is therfeore processed to
increase the concentration of uranium to 3%. This
enriched uranium is then injected into fuel—rods.
Nuclear reactors 'burn* these fuel rods to produce
heat which is used to produce steam to rotate the
turbines. At each of these steps, radio-active ura
nium has to be handled. If there is any laxity in the
necessary precautions, dangerous uranium causes
damage to the workers. This is especially true after
the enrichment of uranium. There are numerous
instances all over the world of this laxity. Potenti
ally the most hazardous of all t hese steps is the
'burning* of the fuel-rods.
This process is the
controlled chain—reaction which produces intense
heat. In case of the major accident or a 'electro
melt down* due to uncontrolled heat, the reactor
can explode and intensely radio-active elements
enter the surrounding area in large proportions.
The Chernobyl accident was not a full blown melt
down, yet lacs of people over hundreds of square
kilometers had to be evacuated and thousands
of tonnes of soil had to be scraped and would have
to be stored separately for hundreds of years till its
radio-activity is exhausted,. The possibility of such
a major accident happening was estimated in 1975
to be in ten thousand reactor-years. With one hun
dred reactors operating then, it meant one accident
in one hundred years. But in reality, the experience
shows that a major accident would occur one in
two thousand reactor-years. There are many minor
accident leaks, giving out radio-activity in small
dosages. It is because of these leaks that higher
rates of blood and other cancers have been found
in clusters, in areas surrounding these plants in
workers employed in them. But the nuclear indu
stry has questioned these findings and the debate
is continuing.
Once the fuel is burnt to a specified level,
it is taken out of the reactor and kept in water tanks
to cool down for about 3 to 4 months. After initial
cooling, the spent fuel is reprocessed to separate
unburnt uranium, and a valuable fuel material — plut
onium from fission products. Reprocessing stage
with high degree of remote handling is a chemical
step, and the scale of this remote handling opera
tion is that of a highly
sophisticated chemical
industry. The low level liquid waste from this
industry has to be constantly monitored and acti
vity levels kept under control. The high level liquid
and soild waste is chemically treated, vitrified
( converted in to glass like material ), sealed and
buried at specially designed grave yards, where it will
remain for
generations together.
These need
to be kept watch upon for a period of a few hundred
of years, so that the space is not used for any other
purposes. Leakage and seepage in the waste cont
ainments can pose problems any time for future
generations if they fail to take proper precautions
Reprocessing of spent fuel and waste disposal are
the crucial problems faced by the nuclear industry
world over.
Throughout the fuel cycle, transporation
of radioactive material is involved, requiring tremen
dous care, shielding and safety precautions. Any
mishap due to inadequate care can lead to spread
of contamination or avoidable exposure to people.
The limits on personal exposures force tha
nuclear managers to employ people on temporory
basis for some specific jobs involving radiation
hazard. Civil workers or workers from forces are used
for risky jobs. These persons remain inexperienced
inspite of short training given, if at all. The problam
of temporary workers becomes all the more acute
in developing countries, due to compelling unempl
oyment. Fake names, faulty records of doses, and
total apathy towards the unskilled temporary work
ers multiply their health problems. These people
being not in the regular service cannot be kept track
of for further check—ups even if it is wished so.
In such circumstances correlation of radiation and
its effects is totally out of question.
The pronuclear lobby has maintained that
the dose of radiation due to tho nuclear power
plants is too small,’even less than'natural background
radiation.
Thus in the U. S. the avarage natural
background radiation is 99 milli REM per years per
person, whereas that due to atmospheric weapons
testing and nuclear industry is 4-5 and 1 milli Rem
per year per person, respectively. (7)
There is a
statistical gimmick in there figures.
Whereas every
citizen does receive natural background radiation,
only a miniscule
proportion of the citizens are
employed in the nuclear industry and hence receive
radiation from
this source.
By dividing the
total dose received by all these workers, by total
population of the country (not by number of work
ers employed in the industry ) a misleading averag
ing is done.
The fact is that those employed in the
nuclear industry receive a dose far far higher then
natural background radiation. For example, table 1
gives the dose received by different category of
workers.
Table-1 (8)
Radiation received by workers U. S. A.. 1975
Sr. No.
1.
Occupational
Mean whole body dose
Group
in Milli Rem
Industry
530
other than power plants
2.
Power reactors
760
3-
Fuel fabrication and
560
reprocessing
4-
Nuclear waste
700
disposal
5.
Uranium mills
60
6.
Uranium enrichment
70
In India, the data a e scare to come by. In
the absence of crucial information, let us resort to
table—2 which presents the overall view of the
personal dose monitoring services throughout our
country This service covers roughly 94%, 31%,
20% and 20% of
the radiation workers from
DAE, industry, medical and research units. It should
be borne in mind that in the category 'medical', the
patients are not included. The incidences of overexposures in non—DAE are 2C0 per year.
The
incidences involving exposures more that 10 Rem
are between 25—39 per year. Of these acute over
exposures half the countribution is from the radia
tion workers from medical field. A similar breakup
for DAE workers is not readily avalable to public.
(9)
TABLE-2
Number of Radiation workers monitored and average dose/
year (in India)
Year
1986
1985
Annual
Monitored
Monitored
Annual
ave.
Persons
Ave.
Persons
(mRem)
(mRem)
DAE.
12683
429
12032
456
Industry
4898
227
191
Medical
134^0
79
5255
14292
Research
1803
22
1992
26
66
The above table gives average figures. The
record of some of the plants is extremely bad. For
example, the average dose per employee per year
in the Tarapur plant has increased by 35 times, from
117 m. Rem in 1969 to 4069 m. Rems in 1982Radiation received by Indian workers measured as
human Rems per megawatt, per year has increased
in India from 21 .5 m. Rem in 1969 to 2125 m. rems
in 1980. a level 27% more than that in the U. S.
(10)The exposure to Indian workers is high because
minor leaks due the 'unusual occurance' are more
common.
Lastly, the problem of Nuclear waste dispo
sal has not been solved at all. There is no foolproof
mechanism yet discovered which will completely
isolate the radio-active waste for thousands of
years. What is more no solution seems to be in
sight.
REFERENCES
1)
No Immediate Danger, Rosalie Bartell, the Womens9,
Press, 1985, pp. 27, 29, 30; 2) Rosalie Bartell, op. cit ps
30. 37; 3) Rosalie Bartell, op cit p. 43, 44; 4) Radia
tion and Health, Indian Situation, Background paper for
MFC—meet, 1990, p. 5; 5) New York Times, 20-12-89;
6) Radiation and Health — Indian situation, op cit p,6~7;
7) Radiation and Health, op. cit. Table—2 8) Radia
tion and Health, op, cit. Table—7;
9) Radiation and
Health, op. cit. p—II: 10) State of Indian Environment
Citizens report, 1987 p. 290.
(■) @
5
HAZARDS
OF
II
COMMON RADIOGRAPHIC TECHNIQUES TO
AND PATIENTS
STAFF
Dr. Sham Ashtekar
Introduction :
Diagnostic radiographic techniques consti
tute an extremely important tool in the hands of the
physican today all over world. ;Exposure rates
as 868 exposures per year per thousand population
are prevalent in European countries (1).
In deve
loping countries the rate is quite less as compared
to these. However it also constitutes major source
of radiation to mankind only next to N weapons
and Nuclear Energy processors. Precisely there
fore it has to be used with a lot of discretion and
energy since radiation has proved to be a major
determinant of cancers and genetic mutations.
The X —ray Units In India are mainly opera
ted at two levels.
The first is the X—ray Units in
hospitals and consultant Radiologists processing a
good number of exposures-even 100 a day-required for a range of diagnostic needs. Such install
ations normally use high output, low time exposure
machines with a resonable safety organisation. The
second level is that of the taluka level nursing
homes / clinics, some urban 'Bazar' X —ray clinics
that operate low output, longer time exposure
machines with poor safety organisation.
The general consensus among experts indi
cates that properly used, the usual diagnostic X-ray
procedures do not cause much harm to the patients/
staff considering the contribution they offer in
patient management. But badly organised units can
harm the population in the long run.
This paper
attempts to outline some isssues in this context.
2. Biologic effects of X-rays :
The biologic effects of X—ray can be summed
up as follows :
i)
There is no 'tolerance level' for exposure since
even small doses are biologically not 'lost'. As
far as biological effects are concerned there
is no 'adjustment dose' for radiation.
ii)
The probability of occurrance of X-ray hazards
shows a linear relationship with exposure. More
the dose proportionately, more shall be the
occurence of hazardous effects.
iii)
There is a [sigmoid relationship between the
exposure dose and the severity of the effects.
Thus after an initial threshhold and then steady
rise of dose-severity curve, there is a steep rise
for subsequent dosages till there Is a plateau
of steady rise again. The last segment of
steady rise is accounted for by selective elimi
nation of affected persons due to deaths.
iv)
There are some somatic 'certainty effects' like
radiation erythema, bone marrow fibrosis, radi
ation ulcers, skin cancers etc. which almost
certainly occur after a latency Pperiod, provided
the dose is more than 10 and 100 rads for
whole body and partial body irradiation respe
ctively. These show a sigmoid dose-effect
relationship. In the early days of radiodiagnosis
these were of frequent occurrences because of
poor protection measures. In almost all cases
of such effects, event can be traced back to
some past exposure. These effects are more
severe with time concentrated dose as comp
ared to a time spreaded exposure.
v)
There are some somatic stochastic effects like
organ cancers and leukemias that show a linear
relation as for dose effect. These effects occur
at their respective age profiles, only much more
commonly in the exposed population.
vi)
The genetic effects are always stochastic and
there are two modalities.
First the effect is
mostly lethal to gonadal
cells so that there
is a lower birth rate in the exposed population.
Second—less frequently there are chromosome
abnormalities and mutations. Mutations are
recessive
that show up in later generations
if the other partner also carries recessive trait.
Such chances increase with accumutation of
abnormal genes in the total genetic pool of the
child bearing ( prospective or current ) age
groups. Older parents carrying such abnormlities do not alter the gene pool. The somatic
expression of these abnormalities can be very
severe and in this sense X—rays are a major
threat to to genetic constitution of the popula
tion if effective gonad protection is not offer
ed. Children/persons below 18 years are 10
times prone to such abnormalities as compared
to the adults. (1)
6
vii)
These biologic risks to patients have tobe
weighed against the possible benefits of radio
diagnosis and those on the staff compared to
level of occupational hazards in other profes
sions to get a balanced picture of the risk
profile.
3.
The dose in Radiodiagnosis.
The dose of the exposure is a function of
many factors. The output of the machine in milli
ampere, the time of exposure, the distance of the
subject from the X—ray tube all decide the dose of
the exposure.
Maximum Permissible Dose ( MPD ) is
defined as : The Permissible dose for an individual
is that dose, accumulated over a long period of time
or resulting from a single exposure, which, in the
light of the present knowledge, carries a negligible
probability of severe somatic injuries; furthermore
it is such a dose that any effects that ensue more
frequently are of a minor nature that would not be
considered unacceptable by the exposed individual
and by the competent medical authorities (1).
It is estimated that in the last two decades
in most countries 75—96% of the exposed staff
did not receive more than one tenth of the MPD.
It is also estimated that in no country the genetic
ally significant dose from this source is more than
1 % of the natural background radiation. However,
the same MPD level can not be accepted for child
ren since children are about 10 times susceptible as
compared to adults. (1)
in an 1 8 - year subject causes cancers with manyfold frequency as compared to the same procedure
in a 60 year old
subject.
An elderly
can
take much more dose without cancer risk since
there is relatively shorter survival period for cancers
to develop. Therefore multiple radiographs for
diagnosis of gastric ulcers, renal stones,
barium
shadows involve much less risk than a single exp
osure in a child. Risk changes to more than 1 0,000
times from one situation to another situation (2).
The variation in risk due to these factors
is quite sizeable as will be evident from the risk
in the appendix.
5. Gonadal Doee :
Almost every exposure, save dental or
similarly skin close exposures and well limited (col
limated), exposures, result in some irradiation of the
gonads. Appendix II shows the Gonadal dose
grouping and also bone marrow dose grouping (1).
This will underline the need to lead-shield the
gonads whenever possible.
6. The risk factors, the X-ray machine, design
factors, shielding :
i)
The useful beam size : The X —ray beam direct
ed towards the target I film is known as the
useful (Primary) beam. The useful beamsize
depends upon the design of the X—ray tube
head output and the distance of the subject
from the tube head. Most often unless optical
devices are used to show the field of the beam
the useful beam irradiates, regions that surround
the target region. This can be avoided 'by
optical devices and adjusting the distance
factor.
ii)
Back radiation I scattered radiation : Radiation
other than the useful beam is known as the
back / scattered radiation. This mainly affects
the staff. Adequate distancing of the operators
control panel, lead apron are all necassary to
avoid the exposure to this radiation it can also
affect the patient and suitable position is nece
ssary to minimise this dose (1).
iii)
Fluroscopy : The machine output In fluroscopy
operation is very low but time factor offsets
this advantage. Moreover, staff doing fluorosco
py is necessarily exposed to the useful beam
in a routine manner. Proper darkroom facility,
4. The Estimation of Cancer risk.
There can be no generalisation about
cancer risk from X—rays. Much depends upon
the dose, the organs receiving X—rays, the age of
the subject, positioning of subjects and some other
factors. When a subject is exposed whole bodyall organs may get irradiation but the risk is not
similar in all the organs. Generally extremities are
not sensitive and so also skin, bones and thyroid.
As for dose, every procedure involves different
dosages. Chest radiographs, extremities and thinner
parts/need much less exposure than abdomen. Thi
ck set individuals need more exposure than thin
ones. An AP chest view harms the bone marrow
much more than a PA view. A 'repeat' doubles the
dose and the risk thereof.
Exposure of abdomen
7
room in units operating more than 50 kv mach
ines. As for shielding, lead and wall thickness
are two principal considerations. For every 50
kv rating of the machine a 0.5mm lead thick
ness is necessary to the useful beam ( eg the
fluroscopy procedures ) Stray radiation can be
taken care of by putting a 0.25 mm lead barrier
( the usual lead aprons) provided the staff is di
stanced at about 10 ft from the source.A 9 inch
brick mortar wall is equivalent to 1 mm lead thi
ckness and so is a 6 inch concrete slab. All walls
should be designed to stop the primary radia
tion of the useful beam. Since machine posi
tion, direction of beam, installation etc. can
change subsequently and this should be kept
in mind.
Doors/ windows should be shielded
with a 1mm lead thickness with adequate over
lap so that radiation does not escape the gaps*
It is always better to seek help of radiation
engineers while designing the unit.
timer—indicators; apring switch, lead flaps, lead
gloves, proper dark adaptation and good train
ing are all necessary to minimise dose.
iv)
Calculated Vs actual dose exposure : It is poss
ible to calculate individual exposure doses as
per the readings of MA; Kv time in secs. But
actual doses are found to vary between 0.1
to 0.4 times the calculated dose due to equip
ment doctors. This is known to happen even
in best of units (2). The real way of estimat
ing actual exposure dose is to use special inst
ruments like Gigar counters, crystal dosimeters,
ionisation chambers etc. which i? usually not
done in India though BARC can help do this
on request. It is estimated that much smaller
doses than are actually delivered are really
necessary for most of the procedures.
v)
Leakages from Tube head : There is no other way
to detect leakages from tube head ( that will
give substantia'ly more radiation than the week
back radiation ) than special detectors like
the Geiger counters. Whenever new installa
tions I changes are made it is mandatory to
check for this with the help of special services.
BARC can help in this.
vi)
Film and screens : Insensitive films / screens
entail a longer exposure of the subject and
staff and also reduce machine life. It is neces
sary to use suitable films/screen to minimise
exposure.
vii)
Design and shielding : X—rays can penetrate
and have to be stopped from affecting surroun
ding people by special design and devices. As
far as design is concerned, adequate spacing is
the first important thing. Since rediation at a
given point is inversely proportional to dist
ance from
the source,
a unit housed in
a 10x10 feet room is more hazardous to out
side people than the
same unit housed in a
15x15 feet room. Unfortunately this is a rest
raint in many X —ray clinics. Secondly the
useful beam has to be primarily directed at
exterior wall so that minimum exposure occurs
to the surrounding life. Thus it should not be
directed at the waiting room, wards, street/
passages unless adequately shielded.
The
control panel should be outside the X—ra^
8
viii)
Staff Monitoring for radiation : X—ray unit
staff and other staff routinely comming in con
tact of X—ray units ( Nurses I ward-servants
etc.) are expossd to
radiation.
Unless
proper precautions are taken to
restrct
staff entry in 'switch-on' time,
a great
risk
awaits
the
operating
staff
by way of cancers, leukemias and gonadal
irradiation. Standing behind the X—ray tube.
lead aprons, control panel, adequate distance
are all necessary. The film badge monitoring
is a routine method in upper strata X—ray cli
nics. In the lower category of taluka level
units, bazar clinics and minor units operating in
small nursing homes no such monitoring is
ever done; perhaps with the idea that the dose
involved is low. In this context, the conditions
in the latter category are quite bad since most
of the operators have little knowledge of the
potential
risk of this invisible
menace.
At pressnt there is no working mechanism of
regulating the conditions at such clinics. Alth
ough the total work load is quite small in this
category, the neglect of basic protective factors
understandbly constitutes a very real threat to
both patients end operators.
7. Conclusion :
X—ray are a great help in patient manage
ment. Generally speaking MPD is not exceeded
FACTORS
USING VARIOUS
( Ctd. Page 14 )
A BOMBAY journalist and the
Medico Friends Circle, an organisation
wedded to protecting medical ethics,
have done well to challenge the legal
validity
of the stand taken by the
Maharashtra Medical Council ( MMC )
that
journalists
and members of the
public cannot attend inquiries conduc
ted by it against doctors. What is more
heartening is that the Bombay high
court has granted permission to the
petitioners 1o attend a specific inquiry in
which they had evinced interest, even
though the petition has yet to be admi
tted. It is difficult to understand how
a statutory body can routinely hold in
camera inquiries in matters relating to
medical ethics, which are of utmost impo
rtance to the people. The act establishing
the MMC grants it powers of a civil court.
which makes it all the more necessary
that the proceedings be open to all except
in extraordinary cases.
CANCER
RISK
ESTIMATION
APPENDIX—I
FOR
CHEST
VIEW.
(2)
both in case of staff and patients since there
is a relative paucity of facilities in developing
countries.
As for 'the well equipped clinics
with adequate shielding and care little harm
is done to staff and the risk is acceptable. As
for the lower rung units conditions are apalling; with potential risk for both the patients
and staff and much needs be done to regu
late these units. Gonadal irradiation must be
avoided in early and middle age group when
ever not necessary.
A long [term projection
of 'gonadal irradiations to a fair portion of
population (that is going to bear progeny )
indicates accurrulation of abnormal elements
in the genetic pool and this can be real cause
of concerns cancer risks in the exposed popu
lations is going to increase but no generali
sation can be possible in this regard. Early
age of exposure, no of exposures, procedures
involving high dose to susceptible organs
are all risk factors to be watched.
c
o
X)
z
9
C/5
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o
CM
( Source : The Tinies of India, 8 March 90 )
FOOD
Ill
IRRADIATION — THE
NEW
TOY ?
A. T. Dudani
Although food irradiation has been in use
in U.S.A, for almost 30 years it has not caught
up largely on account of the now well known,
small but crucial Delaney Amendment in 1958 to
the Food, Drugs and cosmetic Act which described
food irradiation as an "additive" instead of "Pro
cess". This puts the onus of proving safety of
any additives squarely on the manufactures. The
rationale being that irradiation resulted in new
molecules in food that were not present before. To
date some 30 countries have permitted commercial
irradiation of 28 different food items. World-wide
annual capacity of food irradiation is about 4 724
lakh tonnes - bulk of which is being used for wheat
( 4 lakh tonnes ) and the balance for spices, fruits
and vegetab'es and seafoods.
Canada has so far sold some 134 Food
Irradiators
world-wide, including
4 to Ind.a
largely for use in sterilisation of medical productsHowever in 1979,
India exported one Irradiator
to Indonesia. This country is endeavouring to
enter food irradiation in a big way and some 5
Food Irradiators are at present in the process of
fabrication and installation in addition to 4 already
in operation.
How Irradiation works ?
Whan radiation strikes other material it
transfers energy. At a certain level this radiation
knocks out elections from the atoms of the material
exposed-which in turn breaks the molecular struc
ture of the material yielding ions or free radicalshence the term ionising radiation. The ions being
chemically very active, easily re-combine with sur
rounding material.
These give rise to potentially
toxic material products ( URPs for short ). While
many of the URPs are similar to those that occur in
cooking of food, some are unique to irradiation and
have been implicated in causation of cancer. For.
mation of URPs has been found to be relared to
the dose of irradiation used. For example 10 KG.
results in about 306 mg of URPs per kg of food.
Thus, irradiation triggers chemical reactions
cau
sing gross disruption of the DNA in the cells, there
by inhibiting cell growth or division. Whereas USA
permits at present 1 KGy ( equivalent of ten million
chest X-Rays ) in India dose of upto 10 KGy has
been permitted.
Irradiation Process :
This itself is not very complicated. Food
is placed on a conveyer belt which takes it to a
chamber and source of ionising irradiation. Prote
ctive casing is removed enabling rays to go through
the food and its packing.
The dosage as also the amount of expo
sure ranging from several minutes to several hours
is pre-determined.
Radiation doses are expressed in terms of
Grays ( Gy ) or in rads ( radiation absorbed dose ),*
one Gy equalling 100 rads (1 Kgy equal to 100,000
rads).
Areas of concern r
There are essentially 4 main areas of con
cern regarding widespread use of ionising radiation
to sterilise, disinfest or stabilse food.
Firstly the chemical impact of heavy doses on the
food itself to ensure that mutagenic or carci
nogenic compounds or URPs are not formed.
Secondly Whether the food is rendered safe from 3
poilage microbes and pathogens like botuli
num and that irradiation does not give rise
to mutants which produce increased amounts
of highly undesirable products
such as
aflatoxins.
Thirdly that vitamins and amino acids, minerals are
not destroyed. A new area of concern is the
possible deleterious effect of irradiation on
antioxidants and other additives in foods.
Fourthly that Irradiation plants do not create any
threat either to environment or any undue
occupational health hazards by way of acci
dents, disposal of waste or transport or radi
oactive material.
What is the record ?
There is irrefutable evidence that irradiated
foods suffer a significant loss of vitamins A, B, C
& E and some essential amino acids, Depending
on doses, in apples 70% loss of Vit. C has been
reported, in case of wheat flour, 67% of thiamine
was lost on irradiation and 8 months storage as
against 25% loss in the non-irradiated control. Like
wise in rolled oats the corresponding loss of Vit. E
was 85% and 26% respectively.
10
USDA has reported that thiamine content of
bacon in raw cooked or freeze driad form degraded
at significantly highter rate during cooking if the
bacon had been irradiated.
Some dangers :
Studies have also shown that gamma irra
diation was unable to inhibit botulinal
toxin
production in frankurters if normal salt content was
reduced
Stimulation and rapid division of naturally
occuring aflatoxin-producing moulds has also been
observed in irradiated foods. Aflatoxins are 1 000
times more carcinogenic than the banned pesticide
Ethyl dibromide for which irradiation has been
suggested as a possible substitute. That fact you
cannot see it, taste it, smell it or even test for it,
also poses problems of misuse.
Call for Ban :
It is not therefore surprising that British
Medical Association, and more recently the Euro
pean Parliament
has called for a ban on food
irradiation. Several scientists, including 2 Nobel
Laureates, Linus Pauling and George Ward have
also supported a ban on food irradiation specially
in view of results of trials at National Institute of
Nutrition (NIN) Hyderabad during 1 973-75 which
showed polyploiding in blood, which has been
linked with cancer. Although this work was caught
up in a fierce controversy, recent evidence notably
from Canada, U. K. & Australia supports the results
obtained at NIN. Studies from US and Japan
Radiation Research Foundation, Tokyo also show
that harmful effects of nuclear radiation from Atomic
bomb 42 years ago had been grossly under-estima
ted due to faulty calculations and US reluctance
to provide information.
Moratorium pending safety assurance :
A conference of delegates from 9 AsiaPacific countries
co-sponsored by International
Organisation of Consumer Union, Penang which
met at Cenberra 9-11 November, 88 has in a Decl
aration urged W. H. O. to re-open the issue and
also called for a world-wide moratorium on further
use and development of food irradiation Juntil vari
ous issues [were sorted out. This is considered
feasible since safe alternatives already exist, which
can
be further developed.
Agency has been
created under the Secretary, Ministry of Health, as
Chairman to deal with all matters relating to irradi
ation or foodstuffs.
It does seem surprising that while this
country faces the imminent prospect .;of its irradia
ted food exports being banned in several countries
and boycotted in others, it is going ahead with
building 5 new commercial irradiators ( hopefully
not for exports).
( Background Paper for XVI Annual Meet of MFC )
a ®
OF XVI ANNUAL GENERAL
BODY MEETING OF
MEDICO FRIEND CIRCLE
REPORT
The XVI annual general body meeting of
Medico Friend Circle held on 29th January 1990 at
Gandhigram Rural Institute, Dindigul Dt.,Tamilnadu.
Aronnd 35 members attended.
The ameeting star
ted at 11.00 A. M.
A brief report of the proceed
ings is given below.
Annual meet in 1991 :
Medico Friend Circle in its last meeting of
the core group at Sevagram, Wardha critically look
ed at the relevance of one-theme annual meets so
far organised by it. Many members felt that:
—the topics for meet are chosen one year in adv
ance on the basis of their topical importance.
However by the time of the annual meet many
other important issues emerge, for which there
is no time for discussion.
—one theme discussion in annual fmeet also does
not let the expertise available even within MFC
members on different health aspects to be
shared with other participants and interested
members.
—one theme meet has restrictied the discussion
on a particular topic for one time. It does not
allow follow-up discussions and not provide
the interest and the expertise on the issue to
grow. This has led to a very high incidence of
change in membership and also the participa
tion in the meet.
Hence, after discussion in this meeting, it
was decided that annual meet in 1991 will be of
11
three days duration and shall have multiple themes
for debate / discussion. Different topics on which
discussions will be organised are :
—primary health care revisited
— alcoholism and health
—sexually transmitted diseases
—privatisation of health care
Persons within MFC have taken up respon
sibility to prepare on these themes. The dates and
venue of the meet shall be decided latter.
Core Group /Mid-Annua! Meet
This will be held from June 9 to 11, 1990
at Sevagram, Wardha.
"Role of MFC like group
in contemporary health movement and how it can
become a more active and vibrant organisation of
health activism*' are some of the important issues
nagging the members of MFC since quite sometimeIn last few core groups, some discussion on these
issues have taken place. Many members have felt
that in order to work out a detailed strategy to
revitalise MFC, there is need to have a lengthy dis
cussion. Hence, it has been decided >to devote ah
three days in mid annual meet for this purpose.
The meeting will be an extended core group in
which all the current members and other interested
persons will be invited.
Involvement in the issues Related to Bhopal
Dur.ng the non-theme discussion, Sathya
and Nishith reported in detail about the current
health problems of Bhopal victims, the secretive
attitude of Government research institutes towards
the data generated by them and new possibilities
of work in Bhopal because of changed political
scene. After discussion it was felt that the work
among Bhopal victims is sensitive and demanding
and so far experience of such a work has not been
encouraging. In this context given MFC's loose
and complex organisational structure today, MFC
as a body will not be able to undertake any major
or continuous
responsibility
in Bhopal in near
future. MFC would however co-operate with other
groups and individuals whenever possible.
Never
theless, MFC has decided to demand from Indian
Council of Medical Research ond other research
bodies involved in research ‘studies among Bhopal
victims to release the reports and conclusions of
their studies for the knowledge of victims and to
supplement the medical work and research under
taken by non-governmental organisations for tha
benefits of victims. It was also decided that MFC
would request to those advisors of ICMR who are
sympathetic, to suggest ICMR to release the reports
of its studies conducted by it. If ICMR does not
respond favourably, MFC will take recoursa to legal
action. MFC would also ^encourage members to
cooperate and assist other groups and individuals
in medical work in Bhopal, in their individual capa
cities.
MFC Bulletin
"The present circulation of tho bulletin is
around 350 and there is an urgent need to increase
it". It was also discussed that members, espe
cially core group members should take up responsi
bility to write articles for publications in the bulletin
regularly.
Anthology : Medical Education-Reexamined
The manuscript of this book is ready and
will be printed soon.
An active search for cheaper
press and necessary funds is on. March has been
fixed as deadline for printing.
NET-EN Booklet
Initial big report on Net-En was prepared
by Sathya and Nalini for writ petition filed in the
Supreme Court to stop the pre-market trial, unless
proper and long term studies have been done.
Later on Anant condensed the report for publication
as a booklet. All comments on the draft has been
received and it is left on the editor of the booklet
to decide which of the comments to publish alongwith the draft. Hopefully, it will be ready soon for
sale.
Problem of Foreign Contribution Registration
Nimitta Bhatt of the Trust for Reaching the
Unreached, Baroda through a letter informed about
the problems of newly created organisation to gee
registration under the Foreign Contribution Regula
tion Act of the Govt, of India. She also sent a
copy of the resolution passed by their organisation.
The general body decided a resolution Jo be sent
to relevent authorities to provide registration to
newly created organisations as soon as possible
and also to simplify the procedure of getting it.
12
All India Meet of Health Activists-
Selection of Executive Committee Members-
The third all India People's Science Cong
ress to be held at Bangalore from 8th to 11th March
1990 is also organising First All India Meet of
Health Activists. MFC has been invited and reques
ted to send 5 delegates. Amar, Anant and Narendra
volunteered to participate. Ravi and Thelma will
be requested to participate on behalf of MFC.
Ravi Narayan, Sathya and Dhruv retired
by rotation after completing two years. Anil Pilgaonkar, S. Sirdhar, Unnikrishnan and Narendra Gupta
continue to be the members in their second year.
ORGANISATIONAL MATTERS
BudgetAudited accounts of the year 1981 and
till 31st March 1989 were placed and passed by
the general body. M is. V. K. Baiisal and Associates
was once again appointed to audit jhe accounts
of MFC for the year 19g9—90. Anew budget for
the year 1 990—91 was worked out and passed.
Election of New Convenor
Narendra Gupta completed his two year
term in February 1990 and wished to be relieved.
Anil Pilgaonkar has been elected as the new Conve
nor of Medico Friend Circle and he will take over
from April 1990 after the end of current financial
year. From April 1990 the organisational office
of Medico Friend Circle will shift Jo 34-B, Noshir
Bharucha Road, Bombay 400 007.
Narendra Gupta
Convenor
PRESS RELEASE
HEALTH BODY SAYS I\10 TO NUCLEAR ENERGY
Medico Friend Circle (MFC) in its XVI th
Annual meet on "Radiation and Health" held at
Ga'ndhigram Rural University from 26th to 28th
January resolved to oppose the production and
use of nuclear energy as being too hazardous for
the health of human beings and to demand that
existing nuclear facilities be de-commissioned and
no new nuclear plants be built.
MFC held an indepth critical discussion
primarily on the health hazards of nuclear power
plants. During this discussion, it was pointed out
that authorities all over the world have concluded
that the quantum of radiation, how so ever small.
invariably cause damage to human tissues and that
there is no level of radiation that can be considered
safe.
Production of nuclear energy damages the
health of the people through exposure to ionising
radiation at all stages of operation. Mining and
milling, transport of radioactive material, burning
of nuclear fuel in the reactors, storage of spent.
nuclear fuel etc. cause radioactive contamination
of the environment.
There is enough scientific
evidence to this end.
Moreover what is of grave
concern is the nature of the health hazards caused
by ionising radiations which could range from
cancers, damage to
the foetus, genetic muta
tion after many generations and would be carried
over to future generations as well.
The MFC meet underlines the special sign
ificance of these health hazards which would affect
the very quality of human race in the future genera
tions to come. Added to this is the predicted
adverse effect on the power to resist infectious
organisms and other stresses. These alarming
health hazards are reasons enough to outright
reject nuclear power.
The participants of MFC meet emphasised
that apart from these major health hazards, there are
many other important health problems like increased
incidence of allergies, asthma, high blood pressure,
hypothyroidism, reduced fertility,
spontaneous
abortion etc. Thus on health
grounds alone,
nuclear energy is to be rejected in absolute terms
with little need to base our judgement on the
comparative analysis of health hazards of different
sources of energy. Any source of energy which
threatens the very survival and quality of human
species has to be rejected and human society must
find a model of development compatible with safe
energy sources.
During the course of the discu
ssion jt became clear that c he health hazards of
13
MEDICO FRIEND
CIRCLE BULLETIN
Today, nuclear energy constitutes
only 1% of total
electricity produced in India, shutting down of nuclear power
plants will thus not result in a crisis on the energy front. The
1% deficit for which the nuclear energy is being produced can
easily be overcome by saving electricity losses in transmission.
Editorial Committee :
Abhay Bang
Anil Petal
Bmayak Sen
Dhruv Mankad
Dinesh Agrawa
Padma Prakash
Sathyamale
Vimal Balasubrahmanyan
SP Kalantri, editor
The MFC meet has also drawn attention to the health
hazards of repeated exposure of pregnant women for prolonged
periods
to
visual Display Terminals ( Screens ) attached to
Computers.
Editorial Office :
Block B/8, Vivekanand Colony,
Sevagram, Wardha-442 102
Subscription /Circulation
Enquiries :
UN Jajoo, Bajajwadi,
Wardha-442 001
Subscription Rates:
Annual
Inland (Rs.)
a) Individual
30
b) Institutional
50
Asia (US dollars)
6
Other Countries
(US dollars)
11
nuclear energy cannot
be minimized despite claims to
the
contrary. Above all, the problem of safe disposal of radioactive
waste for thousands of years has yet to be solved.
Life
300
500
75
125
Please add Rs 5 to the outstation
cheques.
The MFC meet, while affirming the
well established
immense value of radiological investigations has drawn atten
tion to the fact that add'tional cancers do in fact occur due
to exposure to X—rays. The incidence of additional cancers is
extremely low and depends upon the age, sex of the person
exposed and the quality of radiological apparatus. It has been
estimated that in case of adult male persons exposed to these
X—rays, there would be 15 additional cancers per
million
X —rays. Compared to the number of lives saved, & diseases dia
gnosed this risk is extremely low
But nevertheless it follows
that X—-rays must be kept to as minimum as necessary and secon
dly all the precautions necessary to maintain the X—rays units
properly have to be meticulously followed. On both these counts
the situation in Indie especially in Taluka places etc., is much
worse than in the developed countries.
Screening machines
are much more hazardous because their exposure is many times
more and hence it should be restricted to the absolute mini
mum. Atomic Energy Regulatory Board must exercise its powers
to regulate the quality of radiology units.
0 0
Cheques to be drawn in favour
of MFC Bulletin Trust.
( Ctd Page 9 )
Published by Ulhas Jajoo and SP
Kalantri for MFC bulletin trust, 50
LIC quarters.
University
road,
Pune 411 016
and Printed
at
Samyayog Press, Wardha.
Views and opinions expressed In
the bulletin are those of the au
thors and not necessarily of the
organisation.
8.
References :
1)
Manual on Radiation protection in hospital and
General Practice : Volume 1 By C B Braestrup & K J
Viktelof. WHO Publication. Geneva 1974 PP 28,29,
31, 27.
2)
X-RAY. HEALTH EEFECTS OF COMMON EXAMS;
By John W Gofman & Egan O 'Connor, Sierra Club
books, San Fransisco 1985 PP 86, 87, 2. 349
( Background Paper for XVI Annual Meet of MFC )
0 0
14
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