PHILOSOPHY OF SCIENTIFIC EVIDENCE VS SCIENTIFIC RADIFICALISM
: Re-examining Randomized Clinical Trials (RCTs)
by -Dr. Rajan R Patil.
There is increasing uneasiness on over-reliance on certain method scientic enquiry/methods (eg. Radomised clinical trials) as the only and ultimate evidence of truth. Today unfortunately, Radomized Control Trials (RCTs) is considered to be gold standard not because it is actually best- but because is better among current available instruments for establishing evidence in Medical science. Now, how do we define best ? which inherently is a relative term, it suggest of lack of credible alternative.
The circular reasoning applied - evidence generated by RCT is the Best (in today’s time), currently since this best comes out of RCT, hence RCT becomes the best tool.
I wonder, in the course of scientific evolution- What will happen if some day RCT as a theory and concept is faulted and is replaced by alternative theory, a very distinct possibility, given the propencity of science to grow and evolve, making RCT redundant-what will happen to all the ‘scientific evidence’ that we have accumulated in last 70 years that has dictated the medical practice and policy decision in public health. So we need to be open about
Think of malaria, we have perfect science(we think so) accumulated over a century time evidence -but still we continue to be helpless . Well some may argue, its not because of science but because of sociology and programm management issues. How does one explain stupendous success Small pox - not withstanding the very same sociology and programme management challenge in disease control initiative (infact more in that era, given the literacty rates and lesser prosperity). That makes me wonder if we are making sociology and management of disease control as alibi to cover up short comings for the deficiencies of our current ‘evidence based tools’ with which we are fighting malaria/TB?
I had been actually thinking about these issue in those lines in the recent past more in public health context-, but thanks to your concerns and ethical issues raised - prodded me to look at the - philosophy of generating evidence in science from historical/philosphical perspective- On how the concept of ‘scientific evidence’ and methods of generating it has evolved over time.
I present below some logical and philosophical arguments by some of the greatest science thinkers who have questioned science in their times.
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EVOLUTION OF PHILOSOPHY OF SCIENTIFIC INFERENCE-Across time.
INDUCTIVISM
Francis Bacon's Novum Organum, which, in 1620, presented an inductivist view of science. In this philosophy, scientific reasoning is said to depend on making generalizations, or inductions, from observations to general laws of nature; the observations are said to induce the formulation of a natural law in the mind
REFUTATIONISM
Russell was not alone in his lament of the illogicality of scientific reasoning as ordinarily practiced. Many philosophers and scientists from Hume's time forward attempted to set out a firm logical' basis for scientific reasoning. a number of philosophers noted that scientific statements can only be found to be consistent with observation, but cannot be proven or disproven in any "airtight" logical or mathematical sense (Duhem, 1906, transl. 1954; Popper 1934, transl. 1959; Quine, 1951).
This fact is sometimes called the problem of nonidentiftcation or underdetermination of theories by observations (Curd and Cover, 1998). In particular, available observations are always consistent with several hypotheses that themselves are mutually inconsistent, which explains why' (as Hume noted) scientific theories cannot be logically proven. In particular, consistency between a hypothesis and observations is no proof of the hypothesis, because we can always invent alternative hypotheses that are just as consistent with the observations.
In contrast, a valid observation that is inconsistent with a hypothesis implies that the hypothesis as stated is false and so refutes the hypothesis. If you wring the rooster's neck before it crows and the sun still rises, you have disproved that the rooster's crowing is a necessary cause of sunrise. Or consider a hypothetical research program to learn the boiling point of water (Magee, 1985). A scientist who boils water in anopen flask and repeatedly measures the boiling point at lOO°C will never, no matter how many confirmatory repetitions are involved, prove that 100°C is always the boiling point. On the other hand, merely one attempt to boil the water in a closed flask or at high altitude will refute the proposition that water always boils at 100°C.
refutationism or falsificationism. Refutationists consider induction to be a psychologic crutch: Repeated observations did not in fact induce the formulation of a natural law, but only the belief that such a law has been found, For a refutationist, only the psychologic comfort provided by induction explains why it still has advocates.
The philosophy of conjecture and refutation has profound implications for the methodology of science. The popular concept of a scientist doggedly assembling evidence to support a favorite thesis is objectionable from the standpoint of refutationist philosophy because it encourages scientists to consider their own' pet theories as their intellectual property, to be confirmed, proven, and, when all the evidence is in, cast in stone and defended as natural law. Such attitudes hinder critical evalua-
tion, interchange, and progress. The approach of conjecture and refutation, in contrast, encourages scientists to consider multiple hypotheses and to seek crucial tests that decide between competing hypotheses by falsifying one of them. Because falsification of one or more theories is the goal, there is incentive to depersonalize the theories. Criticism leveled at a theory need not be seen as criticism of the person who proposed it. It ha been suggested that the reason why certain fields of science advance rapidly while others languish is that the rapidly advancing fields are propelled by scientists who are busy constructing and testing competing hypotheses; the other fields, in contrast, "are sick hy comparison, because they have forgotten the necessity for alternative hypotheses and disproof" (Platt,1964).
CONSENSUS AND NATURALISM
Some 20th-century philosophers of science, most notably Thomas Kuhn (1962), emphasized the role of the scientific community in judging the validity of scientific theories. These critics of the conjecture-and-refutation model suggested that the refutation of a theory involves making a choice. Every observation is itself dependent on theories. For example, observing the moons of Jupiter through a telescope seems to us like a direct observation, but only because the theory of optics on which the telescope is based is so well accepted. When confronted with a refuting observation, a . cientist faces the choice of rejecting either the validity of the theory being tested or the validity of the refuting observation, which itself must be premised on scientific theories that are not certain (Haack, 2003). Observations that are falsifying instances of theories may at times be treated as "anomalies," tolerated without falsifying the theory in the hope that the anomalies may everitually be explained .
.
In other instances, anomalies may lead eventually to the overthrow of current scientific doctrine, just as Newtonian mechanics was displaced (remaining only as a first-order approximation) by relativity theory. Kuhn asserted that in every branch of science the prevailing scientific viewpoint, which he termed "normal science," occasionally undergoes major shifts that amount to scientific revolutions. These revolutions signal a decision of the scientific community to discard the scientific infrastructure rather than to falsify a new hypothesis that cannot be easily grafted onto it. Kuhn and others have argued that the consensus of the scientific community determines what is considered accepted and what is considered refuted.
Kuhn's critics characterized this description of science as one of an irrational process, "a matter for mob psychology" (Lakatos, 1970). Those who believe in a rational structure for science consider Kuhn's vision to be a regrettably real description of much of what passes for scientific activity, but not prescriptive for any good science. Although many modem philosophers reject rigid demarcations and formulations for science such as refutationism, they nonetheless maintain that science is founded on reason, albeit possibly informal common sense (Haack, 2(03). Others go beyond Kuhn and maintain that attempts to impose a singular rational structure or methodology on science hobbles the imagination and is a prescription for the same sort of authoritarian repression of ideas thatsientists have had to face throughout history (Feyerabend, 1975 and 1993).
The philosophic debate about Kuhn's description of science hinges on whether Kuhn meant to d cribe only what has happened historically in science or instead what ought to happen, an issue bout which Kuhn (1970) has not been completely clear:The idea that science is a sociologic process, whether considered descriptive or normative, is interesting thesis, as is the idea that from observing how scientists work we can learn about how scientists ought to work. The latter idea has led to the development of naturalistic philosophy science, or "science studies," which examines scientific developments for clues about methods scientists need and develop for successful discovery and invention (Callebaut, 195 Giere, 1999).
IMPOSSIBILITY OF SCIENTIFIC PROOF
Vigorous debate is a characteristic of modern scientific philosophy, no less in epidemiology than il other areas (Rothman, 1988). Can divergent philosophies of science be reconciled? Haack (2003 suggested that the scientific enterprise is akin to solving a vast, collective crossword puzzle. In area in which the evidence is tightly interlocking, there is more reason to place confidence in the-answers but in areas with scant information, the theories may be little better than informed guesses. Of th scientific method, Haack (2003) said that "there is less to the 'scientific method' than meets the eye Is scientific inquiry categorically different from other kinds? No. Scientific inquiry is continuou with everyday empirical inquiry=-only more so."Perhaps the most important common thread that emerges from the debated philosophies is tha proof is impossible in empirical science. This simple fact is especially important to observationa epidemiologists, who often face the criticism that proof is impossible in epidemiology, with tln implication that it is possible in other scientific disciplines. Such criticism may stem from a viev
that experiments are the definitive source of scientific knowledge. That view is mistaken on at leas two counts. First, the nonexperimental nature of a science does not preclude impressive scientific discoveries; the myriad examples include plate tectonics, the evolution of species, planets orbiting other stars, and the effects of cigarette smoking on human health. Even when they are possible experiments (including randomized trials) do not provide anything approaching proof and in fact may be controversial, contradictory, or nonreproducible. If randomized clinical trials provide proof, we would never need to do more than one of them on a given hypothesis. Neither physica nor experimental science is immune to such problems, as demonstrated by episodes such as experimental "discovery" (later refuted) of cold fusion (Taubes, 1993).Some experimental scientists hold that epidemiologic relations are only suggestive and believt that detailed laboratory study of mechanisms within single individuals can reveal cause-effect relations with certainty. This view overlooks the fact that all relations are suggestive in exactly the manner discussed by Hume. Even the most careful and detailed mechanistic dissection of individual events cannot provide more than associations, albeit at a finer level. Laboratory studies often involve a degree of observer control that cannot be approached in epidemiology; it is only this control, not the level of observation, that can strengthen the inferences from laboratory studies. And again, control is no guarantee against error. In addition, neither scientists nor decision makers are ofter highly persuaded' when only mechanistic evidence from the laboratory is available.All of the fruits of scientific work, in epidemiology or other disciplines, are at best only tentativi formulations of a description of nature, even when the work itself is carried out without mistakes The tentativeness of our knowledge does not prevent practical applications, but it should keep us skeptical and critical, not only of everyone else's work, but of our own as well. Sometimes etiological hypotheses enjoy an extremely high, universally or almost universally shared, degree of certainty The hypothesis that cigarette smoking causes lung cancer is one of the best-known examples. Thes hypotheses rise above "tentative" acceptance and are the closest we can come to "proof." But ever these hypotheses are not "proved" with the degree of absolute certainty that accompanies the proof of a mathematical theorem.
Ref : Kenneth J Rothman et al. Modern Epidemiology. 3rd Ed.
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-- --
Dr. Rajan R Patil
Division of Epidemiology
School of Public Health
SRM University
Potheri, Kattankulathur - 603203
Greater Chennai,
INDIA.
Cell: 9445811610 & 9025378036
Email : rajanpatil@yahoo.com
Tuesday, April 26, 2011
Saturday, January 8, 2011
सिलिकोसिस स्क्रीनिंग टूल्स
SILICOSIS SCREENING TOOLS- DEMYSTIFIED FOR COMMUNITY
- Rajan R Patil*
There is a widespread movement in the voluntary sector to highlight the adverse impact caused by indiscriminate mining on environment and health hazards. Working in mines is fret with multitude of health hazards from minor skin lesions to fatal accidents. There increasing emphasis for teaching lay volunteers some simple methods and tools so that they could detect and quantify environmental problems in their community to attract attention of local authorities and health experts alike. .
Silicosis is a common Occupational health hazards faced by the miners. Prolonged inhalation of fine dust over the years lead to loss of elasticity of lungs leading to fibrosis of lungs, which decreases efficiency of lungs. Health being technical subject, it calls for objective assessment of health hazards. Objective assessment is also necessitated in the court of law to qualify as and evidence that can stand the test of scrutiny in the context of workmen compensation issues.
The challenge is to develop/adapt simple tests that can be performed by lay persons at the same time yielding valid results. Conducting complicated scientific tests with expensive equipments by trained professionals may not always be feasible due to various reasons. Suspicion on the part of employers and fear among the mining workers with respect to job security are the major hindrance in carrying out large empirical studies.
In the light of above, two methods have been adapted and modified to suite field level action by volunteers to objectively assess lungs
1. Candle blowing test: A candle is placed at the distance of 30cm on the table and
the mining worker is requested to blow off the candle light. Generally a person with normal lungs is able to put off the candle light with ease. A person with lung problem will have difficulty in put off the candle light.
2. Counting test: A mining worker is requested to count the numbers loudly in
single breath without pause & without inhaling air mid way. Note the count at which the participant gives up counting. Person with lung problems will give up very early in the counting.
The above two tests has been found to a very easy to use screening tools that can be easily applied by community volunteers. These tests could be applied to a group mining workers and the results could be compared with non mining group who serve as control group. The two groups could be compared on the basis of proportion of individual failing to blow the candle off in two groups. To compare and contrast Counting test results, Mean count at which individuals give up counting could be taken for comparison.
These two tests could be administered by lay persons with some training. These tests could also be used to promote behavior change among mining workers to encourage them to use of protective equipments like mask, gloves, etc.
Correspondence:
*Dr. Rajan Patil
Epidemiologist
School of Public Health
SRM University
Potheri Kattankulathur-603203
Greather Channai
Email: rajanpatil@yahoo.com
Cell :9445811610
- Rajan R Patil*
There is a widespread movement in the voluntary sector to highlight the adverse impact caused by indiscriminate mining on environment and health hazards. Working in mines is fret with multitude of health hazards from minor skin lesions to fatal accidents. There increasing emphasis for teaching lay volunteers some simple methods and tools so that they could detect and quantify environmental problems in their community to attract attention of local authorities and health experts alike. .
Silicosis is a common Occupational health hazards faced by the miners. Prolonged inhalation of fine dust over the years lead to loss of elasticity of lungs leading to fibrosis of lungs, which decreases efficiency of lungs. Health being technical subject, it calls for objective assessment of health hazards. Objective assessment is also necessitated in the court of law to qualify as and evidence that can stand the test of scrutiny in the context of workmen compensation issues.
The challenge is to develop/adapt simple tests that can be performed by lay persons at the same time yielding valid results. Conducting complicated scientific tests with expensive equipments by trained professionals may not always be feasible due to various reasons. Suspicion on the part of employers and fear among the mining workers with respect to job security are the major hindrance in carrying out large empirical studies.
In the light of above, two methods have been adapted and modified to suite field level action by volunteers to objectively assess lungs
1. Candle blowing test: A candle is placed at the distance of 30cm on the table and
the mining worker is requested to blow off the candle light. Generally a person with normal lungs is able to put off the candle light with ease. A person with lung problem will have difficulty in put off the candle light.
2. Counting test: A mining worker is requested to count the numbers loudly in
single breath without pause & without inhaling air mid way. Note the count at which the participant gives up counting. Person with lung problems will give up very early in the counting.
The above two tests has been found to a very easy to use screening tools that can be easily applied by community volunteers. These tests could be applied to a group mining workers and the results could be compared with non mining group who serve as control group. The two groups could be compared on the basis of proportion of individual failing to blow the candle off in two groups. To compare and contrast Counting test results, Mean count at which individuals give up counting could be taken for comparison.
These two tests could be administered by lay persons with some training. These tests could also be used to promote behavior change among mining workers to encourage them to use of protective equipments like mask, gloves, etc.
Correspondence:
*Dr. Rajan Patil
Epidemiologist
School of Public Health
SRM University
Potheri Kattankulathur-603203
Greather Channai
Email: rajanpatil@yahoo.com
Cell :9445811610
Wednesday, December 22, 2010
Investigating genetic outcomes following 1984 Toxic Union Carbide Disaster in India- Epidemiological challenges.
INVESTIGATING GENETIC OUTCOMES FOLLOWING 1984 TOXIC UNION CARBIDE DISASTER IN INDIA- EPIDEMIOLOGICAL CHALLENGES.
- Rajan R Patil*
[Published in : International Journal of Occupational Medicine and Environmental Health 2010;23(4):1 – 2DOI 10.2478/v10001-010-0025-4]
Abstract
Indian Council for Medical Research [ICMR] has called for proposals to study long term effects of 3rd December 1984 Union Carbide Industrial Disaster at Bhopal, one of the worst industrial disaster in the world, releasing poisonous Methyl Iso-Cyanate [MIC] gas into the environment affecting neighborhood population. Proposals are invited to study long term effect, if any , of toxic gas exposure on exposed population namely : - Genetic disorders, Low birth weight, Growth and development disorders, Congenital malformation, Biological markers of MIC exposure. [1]. This paper questions the appropriateness of launching a community based epidemiological study to investigate the possibility of genetic effects with a very short term environmental exposure to a chemical in a gaseous form.
Key Words
MIC, Genetic effects, India, health effects, bhopal
Discussion
Even designing such a study is exceptionally fret with challenges, starting with exposure ascertainment. Who is an exposed case? In the present case, there is no alternative to testimonial of affected people two and half decades back? Secondly, 25yr down the line, population composition within 2km radius of disaster site is so drastically different due to in and out migration- defining the study population and the sampling frame, and hence the opportunity to assess dose response keeping distance from the industrial site as the yard stick is completely lost. Compensation issue is bound to make many un-exposed claiming to exposed. The government list of 'victims' prepared for legal purposes, is highly political in nature, hence authenticity is always a suspect.
Purely from Occupational health point of view and for want of biological plausibility reasoning- there is no documented evidence of a chemical (in gaseous state) causing genetic effect following single exposure (inhalation) for a short duration(a day or two).
Inhalation related exposure like pneumoconiosis group are either particulate/fibrous form. Gases are known to elicit only immediate reaction ranging from irritation in eyes to fatal poisoning all essentially acute effects.
Absence of any precedence of short term exposure for a day or two in gaseous form. I am stressing on brief only two days exposure since the hazardous gas is expected to be in the atmosphere for only few hours in high concentration immediately after industrial disaster and following day concentration of MIC in the air is bound to negligent or due to air current. There was no evidence of heavy fog on Dec 3-4 1984 to believe that fog or Smog could have trapped MIC leading continued high concentration exposure to surround population. Neither is the MIC or its effluents radio active to suspect that population were at continued risk of exposure months and year after it was released accidentally in environment.
Repeated Genetic studies of exposure to environmental pollution and have clearly demonstrated that its only the chronic chemical exposures can cause genetic damage. [2]Except for Radio-active class, generally chemicals especially those taking GI route through ingestion have been to seen to cause genetic especially on somatic cells even effecting second generations. Classic case being Diethyl stilbestorol and Vaginal cancer of daughter whose mothers consumed DES during their pregnancy. Profound effect like birth defect was seen among drugs like the one infamous Thalidomide disaster. Please note in all the above case studies the route was orally ingested chemicals-drugs.
Even for chronic exposure to chemicals- persistent organic pollutants after decades life time of exposures there has been no conclusive evidence of genetic effects. The case in point has been DDT which is one of the most widely studied chemical on human health on which human have lived through food chain since it first started to be manufactured in 1938 [3].
To look for genetic effects as out come of Bhopal gas disaster do not have rationale because for mutations occur hazardous agent has to work on germ cells, and only Mutations with large effects, such as chromosomal rearrangements, can lead to “birth defects” only then there is potential for its effect be passed to the offspring. Now, such profound effects can not be expected with acute exposure of duration of a day or two as in case of industrial disaster in Bhopal and hence can not be expected to leading to trans-generational effects.
Researchers since then have been trying to document adverse effects in long stretched cohort studies for humans with generation time of 20 years were first exposed to vast number of synthetically produced chemicals. By mid 60s these individuals began to bear children and began to produce first generation of human exposed hazardous chemicals in utero-the first generation born with chemicals in their tissue. About 1980 this generation reached reproductive age, and the search for adverse health comes in their offspring continues even after 80 years which is a very miniscule time period for any genetic effects. [3]
Moreover, Indian union carbide disaster case, absence of biological marker for MIC, makes it nearly impossible to unerroneously classify study population into exposed and unexposed group to study unfavorable outcomes
Bhopal MIC exposure issue, 25 years down the line, inherent with nearly irresolvable methodological issues, all of which have potential to negate both positive or negative association equinamiously, either way findings will questioned.
In the past human epidemiological studies to determine genetic outcome of exposure have questioned only the health of the exposed individuals. It is not surprising that many epidemiological studies have failed to elicit any associations to link adverse health effects to chemicals (Type II error).
My reason for calling genetics studies of Bhopal gas disaster unethicality stems from the fact that In research ethics the appropriateness study design and its methodology and its duration are among essential requirement that is expected be in commensurate with expected out comes. Bhopal genetic study lacking any biological justification, and search of effects in small time line of 25 years and ICMR constraints of research funding capping it on to the maximum of Rs 30 lakhs INR all put together do not lend itself to proper genetic study outcome.
Yes, Studies on search for a biological marker for MIC, adverse health outcomes like exploring the effects of MIC acting as endocrine disruptors and mimics, human sperm counts, adverse reproductive outcome like miscarriages etc, high SMR among exposed. Studies looking for current health problems among the victims should be desirable so that they additional new victims affected by the gas may be brought and medical care and cared for alleviating their suffering and if the need be compensated financially.
Conflict of interest : None
Reference:
1. Call for Research Proposals on the Long term effect(s) of MIC gas , if any, on the Bhopal Population either exposed or affected (in December 1984) website http://icmr.nic.in/ (downloaded on Oct 1st 2009)
2. John W. Bickhama, Shabeg Sandhub, Paul D. N. Hebertc, Lounes Chikhid and Raghbir Athwal. Effects of chemical contaminants on genetic diversity in natural populations: in Mutation Research/Reviews in Mutation Research
Volume 463, Issue 1, June 2000, Pages 33-51.
3. Theo Colborn. The Wildlife/Human Connection: Modernizing Risk Decisions Environmental Health Perspectives 102, Supplement 12, December 1994
Correspondence
Dr. Rajan R Patil
Asst Professor.
Division of Epidemiology
School of Public Health
SRM University
Potheri, Kattankulathur - 603203
Greater Chennai,
INDIA.
Cell: 9600110872
Email : rajanpatil@yahoo.com
- Rajan R Patil*
[Published in : International Journal of Occupational Medicine and Environmental Health 2010;23(4):1 – 2DOI 10.2478/v10001-010-0025-4]
Abstract
Indian Council for Medical Research [ICMR] has called for proposals to study long term effects of 3rd December 1984 Union Carbide Industrial Disaster at Bhopal, one of the worst industrial disaster in the world, releasing poisonous Methyl Iso-Cyanate [MIC] gas into the environment affecting neighborhood population. Proposals are invited to study long term effect, if any , of toxic gas exposure on exposed population namely : - Genetic disorders, Low birth weight, Growth and development disorders, Congenital malformation, Biological markers of MIC exposure. [1]. This paper questions the appropriateness of launching a community based epidemiological study to investigate the possibility of genetic effects with a very short term environmental exposure to a chemical in a gaseous form.
Key Words
MIC, Genetic effects, India, health effects, bhopal
Discussion
Even designing such a study is exceptionally fret with challenges, starting with exposure ascertainment. Who is an exposed case? In the present case, there is no alternative to testimonial of affected people two and half decades back? Secondly, 25yr down the line, population composition within 2km radius of disaster site is so drastically different due to in and out migration- defining the study population and the sampling frame, and hence the opportunity to assess dose response keeping distance from the industrial site as the yard stick is completely lost. Compensation issue is bound to make many un-exposed claiming to exposed. The government list of 'victims' prepared for legal purposes, is highly political in nature, hence authenticity is always a suspect.
Purely from Occupational health point of view and for want of biological plausibility reasoning- there is no documented evidence of a chemical (in gaseous state) causing genetic effect following single exposure (inhalation) for a short duration(a day or two).
Inhalation related exposure like pneumoconiosis group are either particulate/fibrous form. Gases are known to elicit only immediate reaction ranging from irritation in eyes to fatal poisoning all essentially acute effects.
Absence of any precedence of short term exposure for a day or two in gaseous form. I am stressing on brief only two days exposure since the hazardous gas is expected to be in the atmosphere for only few hours in high concentration immediately after industrial disaster and following day concentration of MIC in the air is bound to negligent or due to air current. There was no evidence of heavy fog on Dec 3-4 1984 to believe that fog or Smog could have trapped MIC leading continued high concentration exposure to surround population. Neither is the MIC or its effluents radio active to suspect that population were at continued risk of exposure months and year after it was released accidentally in environment.
Repeated Genetic studies of exposure to environmental pollution and have clearly demonstrated that its only the chronic chemical exposures can cause genetic damage. [2]Except for Radio-active class, generally chemicals especially those taking GI route through ingestion have been to seen to cause genetic especially on somatic cells even effecting second generations. Classic case being Diethyl stilbestorol and Vaginal cancer of daughter whose mothers consumed DES during their pregnancy. Profound effect like birth defect was seen among drugs like the one infamous Thalidomide disaster. Please note in all the above case studies the route was orally ingested chemicals-drugs.
Even for chronic exposure to chemicals- persistent organic pollutants after decades life time of exposures there has been no conclusive evidence of genetic effects. The case in point has been DDT which is one of the most widely studied chemical on human health on which human have lived through food chain since it first started to be manufactured in 1938 [3].
To look for genetic effects as out come of Bhopal gas disaster do not have rationale because for mutations occur hazardous agent has to work on germ cells, and only Mutations with large effects, such as chromosomal rearrangements, can lead to “birth defects” only then there is potential for its effect be passed to the offspring. Now, such profound effects can not be expected with acute exposure of duration of a day or two as in case of industrial disaster in Bhopal and hence can not be expected to leading to trans-generational effects.
Researchers since then have been trying to document adverse effects in long stretched cohort studies for humans with generation time of 20 years were first exposed to vast number of synthetically produced chemicals. By mid 60s these individuals began to bear children and began to produce first generation of human exposed hazardous chemicals in utero-the first generation born with chemicals in their tissue. About 1980 this generation reached reproductive age, and the search for adverse health comes in their offspring continues even after 80 years which is a very miniscule time period for any genetic effects. [3]
Moreover, Indian union carbide disaster case, absence of biological marker for MIC, makes it nearly impossible to unerroneously classify study population into exposed and unexposed group to study unfavorable outcomes
Bhopal MIC exposure issue, 25 years down the line, inherent with nearly irresolvable methodological issues, all of which have potential to negate both positive or negative association equinamiously, either way findings will questioned.
In the past human epidemiological studies to determine genetic outcome of exposure have questioned only the health of the exposed individuals. It is not surprising that many epidemiological studies have failed to elicit any associations to link adverse health effects to chemicals (Type II error).
My reason for calling genetics studies of Bhopal gas disaster unethicality stems from the fact that In research ethics the appropriateness study design and its methodology and its duration are among essential requirement that is expected be in commensurate with expected out comes. Bhopal genetic study lacking any biological justification, and search of effects in small time line of 25 years and ICMR constraints of research funding capping it on to the maximum of Rs 30 lakhs INR all put together do not lend itself to proper genetic study outcome.
Yes, Studies on search for a biological marker for MIC, adverse health outcomes like exploring the effects of MIC acting as endocrine disruptors and mimics, human sperm counts, adverse reproductive outcome like miscarriages etc, high SMR among exposed. Studies looking for current health problems among the victims should be desirable so that they additional new victims affected by the gas may be brought and medical care and cared for alleviating their suffering and if the need be compensated financially.
Conflict of interest : None
Reference:
1. Call for Research Proposals on the Long term effect(s) of MIC gas , if any, on the Bhopal Population either exposed or affected (in December 1984) website http://icmr.nic.in/ (downloaded on Oct 1st 2009)
2. John W. Bickhama, Shabeg Sandhub, Paul D. N. Hebertc, Lounes Chikhid and Raghbir Athwal. Effects of chemical contaminants on genetic diversity in natural populations: in Mutation Research/Reviews in Mutation Research
Volume 463, Issue 1, June 2000, Pages 33-51.
3. Theo Colborn. The Wildlife/Human Connection: Modernizing Risk Decisions Environmental Health Perspectives 102, Supplement 12, December 1994
Correspondence
Dr. Rajan R Patil
Asst Professor.
Division of Epidemiology
School of Public Health
SRM University
Potheri, Kattankulathur - 603203
Greater Chennai,
INDIA.
Cell: 9600110872
Email : rajanpatil@yahoo.com
Monday, May 11, 2009
Bhopal Gas Disaster: Will Industry ever Accept Health Impact Evidence?
There is a debate over the recent ICMR's call for research proposals to investigate long term genetic effects of bhopal gas disaster on the population sarrounding disaster site. While scientific community is concerned over the methodological challenges involved in doing such research studies for validity reasons, many advocacy groups welcome such studies.
If we expect by launching research on genetic study now, the results could be used for advocacy tool to help seek justice to Bhopal gas victims, by taking these scientific evidence to the courts that will result in union carbide meekly accepting verdict and be forced to provide compensation and relief to the Bhopal gas victims…. then I am afraid we are being very too naïve about corporate games.
Insisting for causal link has been one of the alibi used by Industry to keep on procrastinating and diverting attention. Industry chaps are smart enough to know that eliciting such one-to-one link is long drawn process very often decades-generations pass by.
Historically too, Industry has very successfully used this very coy for self defence, right from Landmark studies by Doll and Hill in 1950s very first time linking cigertte smoking and Lung Cancer- expectedly Tobacco industry scoffed at results and reject it outrightly.
The link between Asbestose and mesothelioma has been proven beyond doubt way back in 1940s, but asbestose mining and industry have shown scant respect to any of these evidence are are still thriving industry in India inspite of international ban.
More contemporary examples have been studies on aerial Endosulphan spray on cashew plantaion in Kasargod(Kerala) and birth defects outcomes in 1990s leading to ban on endosulphan. Inspite of all the studies including international experts coming down to india , still the endosulphan industry managed to get the stay order and spraying was resumed.
Personally, I have seen it all, being in the centre of their game, I along with my colleagues have been involved in legal battle with pesticide industry for documenting and publishing occupational health hazards of pesticides among cotton farmers in Warangal district of Andhra Pradesh. The case has been going on since 2003. But before they dragged us to court they tried persuade us withdraw our findings, not to publish it etc. when we did not relent, they sent us legal notices, threatened us with compensation of 10 crore!- our crime- “harming their buisness interests”!! Classic example of corporate intimidation indeed. Court thing is the card they play because they know once in court the case keeps going on for ages. I along with my colleagues have to make personal appearance at court in AP -a ritual that we are used to every 6 months. Now the case has move to Supreme court.
Morale of the story.
Lets not fall into Industry games of distracting us from the real issue. Science may be sancro sanct to all of us. But Industry has hardly shown any respect for any scientific research findings.. The core issue is to provide relief and compensation to bhopal gas victims for all the suffering which they are waiting for last 25 years.
At least on the 25th anniversary, I suggest the stand we should be taking is Union carbide as an MNC along better own up its misdeeds in India . Rather than we PROVING something (adverse health outcome), Let us reverse the tables on them and insist that onus should be on Union Carbide to DISPROVE that certain grivious and previously unknown rare medical problems rightly mentioned by you among exposed victims are NOT because of MIC exposure and let the Industry launch studies to search for alternative explanation how and why it occurred if not for MIC, let them come out with an explanation
This is acceptable in the court of law, There have been many precedents where courts have shifted the onus of proving something on the perpetrator of the crime rather than the victims proving their innocence.
I am reminded of one of Galib’s shayari in urdu- which so aptly summarises Bhopal gas victim’s predicament- on how much more they needs to show their pain (to Industry) even after 25 years…..which is equally true for endless evidence we have to show..
dard-e-dil likhuun kab tak? Jaauun un ko dikhalaa duun
Ugaliyaan figaar apanii KhaamaaKhoon_chakaan apanaa
[figaar=wounded/sore, Khaam/green/raw/sore]
[KhaamaaKhoon.N= fresh blood, chakaan=dripping]
roughly translated…
“how long should I ( Bhopal gas victim) write about my pain ( for last 25 years), let me go and show(to union carbide), my finger which have not only become sore& raw but have got wounded and blood is dripping from the fingers”.
regards,
--
Dr. Rajan R Patil
Asst Professor.
Division of Epidemiology
School of Public Health
SRM University
Potheri, Kattankulathur - 603203
Greater Chennai,
INDIA.
Cell: 9600110872
Email : rajanpatil@yahoo.com
If we expect by launching research on genetic study now, the results could be used for advocacy tool to help seek justice to Bhopal gas victims, by taking these scientific evidence to the courts that will result in union carbide meekly accepting verdict and be forced to provide compensation and relief to the Bhopal gas victims…. then I am afraid we are being very too naïve about corporate games.
Insisting for causal link has been one of the alibi used by Industry to keep on procrastinating and diverting attention. Industry chaps are smart enough to know that eliciting such one-to-one link is long drawn process very often decades-generations pass by.
Historically too, Industry has very successfully used this very coy for self defence, right from Landmark studies by Doll and Hill in 1950s very first time linking cigertte smoking and Lung Cancer- expectedly Tobacco industry scoffed at results and reject it outrightly.
The link between Asbestose and mesothelioma has been proven beyond doubt way back in 1940s, but asbestose mining and industry have shown scant respect to any of these evidence are are still thriving industry in India inspite of international ban.
More contemporary examples have been studies on aerial Endosulphan spray on cashew plantaion in Kasargod(Kerala) and birth defects outcomes in 1990s leading to ban on endosulphan. Inspite of all the studies including international experts coming down to india , still the endosulphan industry managed to get the stay order and spraying was resumed.
Personally, I have seen it all, being in the centre of their game, I along with my colleagues have been involved in legal battle with pesticide industry for documenting and publishing occupational health hazards of pesticides among cotton farmers in Warangal district of Andhra Pradesh. The case has been going on since 2003. But before they dragged us to court they tried persuade us withdraw our findings, not to publish it etc. when we did not relent, they sent us legal notices, threatened us with compensation of 10 crore!- our crime- “harming their buisness interests”!! Classic example of corporate intimidation indeed. Court thing is the card they play because they know once in court the case keeps going on for ages. I along with my colleagues have to make personal appearance at court in AP -a ritual that we are used to every 6 months. Now the case has move to Supreme court.
Morale of the story.
Lets not fall into Industry games of distracting us from the real issue. Science may be sancro sanct to all of us. But Industry has hardly shown any respect for any scientific research findings.. The core issue is to provide relief and compensation to bhopal gas victims for all the suffering which they are waiting for last 25 years.
At least on the 25th anniversary, I suggest the stand we should be taking is Union carbide as an MNC along better own up its misdeeds in India . Rather than we PROVING something (adverse health outcome), Let us reverse the tables on them and insist that onus should be on Union Carbide to DISPROVE that certain grivious and previously unknown rare medical problems rightly mentioned by you among exposed victims are NOT because of MIC exposure and let the Industry launch studies to search for alternative explanation how and why it occurred if not for MIC, let them come out with an explanation
This is acceptable in the court of law, There have been many precedents where courts have shifted the onus of proving something on the perpetrator of the crime rather than the victims proving their innocence.
I am reminded of one of Galib’s shayari in urdu- which so aptly summarises Bhopal gas victim’s predicament- on how much more they needs to show their pain (to Industry) even after 25 years…..which is equally true for endless evidence we have to show..
dard-e-dil likhuun kab tak? Jaauun un ko dikhalaa duun
Ugaliyaan figaar apanii KhaamaaKhoon_chakaan apanaa
[figaar=wounded/sore, Khaam/green/raw/sore]
[KhaamaaKhoon.N= fresh blood, chakaan=dripping]
roughly translated…
“how long should I ( Bhopal gas victim) write about my pain ( for last 25 years), let me go and show(to union carbide), my finger which have not only become sore& raw but have got wounded and blood is dripping from the fingers”.
regards,
--
Dr. Rajan R Patil
Asst Professor.
Division of Epidemiology
School of Public Health
SRM University
Potheri, Kattankulathur - 603203
Greater Chennai,
INDIA.
Cell: 9600110872
Email : rajanpatil@yahoo.com
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