Guide to Risk Assessment and Biosafety in Biotechnology, GRABBGuide to Risk Assessment and Biosafety in Biotechnology, GRABBAn Initiative of the United Nations Environment Programme (UNEP)
| SECTION: | BIOLOGICAL CONTAINMENT | |||
| TITLE: | Contained Use of Genetically Modified Organisms | |||
| BY: | Julian Kinderlerer | |||
| LABEL: | CUG | UPDATEIDTH="28%">UPDATED: | 31 Dec 1997 | |
Are there differences in the way in which containment is handled in different countries?
What is protected when considering contained use?
Risk Assessment and Risk Management
Risk Assessment for the contained use of modified Organisms
Damage and expression are usually associated with the insert and the gene product
Summary of Laboratory Containment Requirements
The first uses to=15>
The first uses to which genetic modification were able to be put involved the use of micro-organisms in containment. Almost from the very beginning of the use of recombinant techniques it was realised that organisms could be designed which might prove to be 'dangerous' to those working with them, and to the environment. It was recognised that the technology provided a new means of forming organisms which were significantly different from those that had been known up to that point.
Because the first uses of modified micro-organisms were in the laboratory, it was primarily human health and safety that mattered. It is presumed that biological agents are hazardous, and may affect those handling them in predictable ways.
Containment must be used when micro-organisms are used whose function is known to be hazardous to humans, or where the presence or function of the organisms is unknown (as in clinical samples). Where an organism is not known to have pathogenic properties, it is assumties, it is assumed to be safe, presumably because had it been pathogenic (to immuno-competent individuals) it would have been observed to be so. Most human pathogens have been described and assigned by the WHO to 4 groups which relate to their likely effect on anyone coming into contact with them. Problems arise when considering new organisms created in the laboratory. How may these be assigned?. Where can a classification of risk to those in the laboratory or development environment be obtained?
The presumption that the organism is a micro-organism results from the presumption that it is the health and safety of those
who come into contact with the organism that need protection. Having identified the Group into which an organism falls, it
is possible to identify the containment requirements that are needed to protect the handlers.
The initial concern for the health and safety of the handlers must now be modified to take into account the impact on the environment in the event of escape from containment or where release is intended. A plant or animal pathogen may havethogen may have no effect on humans, is likely to be placed in Group 1, and minimal containment requirements identified. If this increases the probability of escape into the environment, problems may well arise. If environmental risks are taken into account, then it is not only micro-organisms that fall within the terms of any containment requirements, for animals and plants may have implications as well.
A consideration of the safe use of genetically modified organisms, whether for use under contained conditions or for releases into the environment is hard. We really do not know where to start, particularly for release. We know that the introduction of novel species into a new environment can (and does) go wrong on occasion. Does the insertion of a gene into an organism that has been present in an environment for a very long period of time make a new novel organism? Where do we start assessing the risk associated with the insertion of the gene into a well-characterised organism, let alone those whichhose which might be novel in a particular environment? What happens when we agree that a particular organism is safe in Britain or in the Netherlands (for example), does that mean it is completely safe when used or grown in Spain or Greece? If designed for safe use in a temperate climate, is the organism safe for 'escape' into a tropical environment? If not, how do we assure that the permission to proceed to the use of the modified organism in one country (or region) does not extend to the whole world? This problem is exacerbated by the rules which have been put into place through the operation of the World Trade Organisation, which would appear to require an importing country to provide scientific evidence for the lack of safety of a particular import rather than require the exporting country to justify its safety assessment.
The risks posed by the newly manufactured organism are dependent on the uses to which they are put, but significantly often the risks may be considered in a narrow framework simmework simply because of the particular use, and perhaps an extension of use of the organism may not result in a 'proper' reconsideration of risk; in examining the safety of the organisms we have to try and determine what should be considered hazardous and it has not proved simple to identify the issues contributing to risk. Let me try to use an example to explain this problem. When a field trial of a new genetically modified oil-seed rape is proposed to the UK Government, the proposal will not usually consider the use of the plant as a food or feed, for the proposal is only concerned with the initial field trials. The ability to transfer the genes to wild relatives or to other oil rape plants adjacent to the trial field has been one of the main concerns, although whether this should be of concern is open to debate in the UK. Where seed is kept from year to year it could be a major problem, but where new seed is purchased in each year, and the seed merchant guarantees the quality of the seed, is there a probl a problem if a gene for say herbicide resistance is passed into wild relatives?- only where the wild relatives constitute weeds and need controlling within the agricultural environment itself, not if they only grow in areas that are not controlled by herbicide application. But there is a reason for trying this new construct, which must be its commercial exploitation. Should we not consider the general implications of the use of this new organism at an early stage, rather than waiting and considering the safe use of the organism within the narrow confines of the application itself.
At the other end of the scale, and one that has caused considerable problems to Europe over the last few months, and which will continue to provide real problems, is as follows. Suppose we approve an organism as completely safe for use within the European Union, whether it is anywhere in the geographical confines of Europe or restricted to 'cold' climate agriculture (for example). We have made this product and obviously waniously want to sell it as widely as possible -They have their own legislation relating to the use of such organisms, and may not be happy with our safety assessment; can they stop us marketing our 'product' because of safety concerns? What weight should our safety assessment play in their consideration of the safety issues? Our permission to market the product may be just as valid as their decision not to allow marketing of the product, perhaps because of indigenous organisms. How do we guard against protectionism cloaked within safety concerns? In the case of a developing country, where there might not be legislation that governs biosafety. Should we simply export to them without considering the risks that our organism might pose to them? If so, are we prepared to face the risk that a slightly 'more' modified organism returns to haunt us?
What about the opposite problem, where we receive biological products from other countries. We may know that it has been modified if it has come from the USA or CanUSA or Canada, but if it comes from countries which have no legislation in place to allow for the assessment of risk associated with modified organisms? How likely is it that their products will appear on our markets and pose problems for us in the future.
Within the European Union there are two directives that cover this part of Biosafety. Both directives were drafted in 1990, and required implementation within member states by 1993. 90/219 governs the contained use of genetically modified micro-organisms, whilst 90/220 governs both the release of the organisms into the environment and the marketing of any modified organism, whether for release of for contained use. The primary difference is that 90/219 assumes containment, and that the regulatory structure can be specific for the member state. 90/219 sets minimum standards for the making, use or keeping of the organisms, and member states are free to have legislation that extends both the range and scope of the directive. In the UK the legislation cislation covers all organisms, not only micro-organisms. Release is different, for even an experimental release has the potential for crossing the boundaries between states, and therefore, the harmonisation of community legislation is important. The marketing of modified organisms is also likely to be community-wide, even though geographical constraints may be applied. 90/219 is therefore global, and must be implemented 'as is' within the community, without allowing real discretion in member countries.
These directives have been criticised by many, for a multitude of reasons: perhaps the most important reason (not usually stated) is that they appear to be different from that which has been implemented in the USA. There are major problems with both directives.
It was always intended that the directives would change with time, in that the authors wrote into it that product specific legislation could exempt a particular substance from consideration as long as the risk assessment procedure in thedure in the specific legislation was at least as comprehensive as that identified in 90/220. It was also assumed that it was based on a presumption of a learning curve, that each case would be argued on its merits, but taking into account evidence and information obtained from previous releases of similarly modified organisms. Hence the legislation allowed for the institution of simplified procedures - or 'fast-track', where consent to release the modified organisms could be given much more quickly and easily than for a totally unknown construct. There are therefore, no major changes expected in this Directive, as most desirable changes (as far as industry is concerned) can be accomplished by product-specific legislation or through fast-track procedures. We remain different from the United States in many important respects.
There are significant differences in the containment requirementsequirements in different countries. Although both the United States and the United Kingdom developed their regulatory systems following the Moratorium self-imposed by scientists in the 1970's, the regulatory systems moved apart significantly. In the United States it was decided not to impose new regulatory burdens on the biotechnology laboratory or industry. Guidelines for the safe use of modified organisms were introduced, in particular the NIH Guidelines, which imposed a set of safety precautions on those funded by the NIH for the safe use of modified organisms. Most industries, although not funded by NIH, followed these guidelines, at least in spirit.
In Europe, however, a statutory regulatory system is in force, which requires an assessment of the risks associated with the use of modified organisms in containment. The statutory system in Europe also depends on a Directive (90/679) which defines the conditions in which biological agents (whether genetically modiflly modified or not) may be used in the workplace. Most of this discussion relates to the system in place in Europe, as it is not dissimilar to that expected but not required by law in many countries.
We turn to the use of genetically modified organisms in containment. Containment includes both the research stage, where modifications are made, development work whether in the laboratory, greenhouse or growth room, and in plant where modified micro-organisms are used as factories to produce new products. In this instance it is not intended that the modified organism is released into the environment, and if being used at a commercial or industrial level, they would only be being used as factories. The concerns are different. There is a peripheral problem with the environment, only if there is inadvertent escape, or if there are waste products that might contain viable organisms does the environment need considering. The true concern is with human heah human health and safety - protecting all those who might come into contact with the organisms during their production or use. The approach taken in the risk assessment is different to; here we devise confinement and containment that will minimise a risk. The risk might be substantial, like modifying HIV in order to unravel its 'secrets', or with polio virus to try and understand how it works, or why it only infects particular types of cell. The risk management procedures will minimise the risks and allow the work to proceed. How again, are we to determine the risk?
The original Directive which was produced for the European Union, 90/219 was clearly flawed. It worked on the basis type of work and of the hazard, rather than on the true risk.
The Directive defined two types of activity, Groups A and B. If the work was for research or development purposes, or non-commercial, or non-industrial, it was group A, otherwise B. The only purpose of these two groups was to identify the notification and consent requirements for the work. The the work. The separation is at least partially justified on the basis of the risk to workers - Group B work might involve less qualified or involved personnel who would not understand the risk, but takes little account of either risk or hazard.
Micro-organisms are then classified as type 1 or type 2. Type 1 organisms are those that pose no risk to human health or safety; type 2 organisms are all others. The classification is largely based on the host organism. I find it difficult to link the risk assessment with these classifications, which simply identify the needs of notification and consent once again. A risk assessment is still needed, but that which is closely defined is not the risk, but whether a consent is required.
Discussions concerning this Directive and possible modification have proceeded almost since it was first agreed in 1990. A change to a risk rather than hazard based system, with notification and consent based on risk rather than hazard or type of activity has bee ssessment - risk management system with the consent - notification system. That which I have to say here concerns the latest version that I have seen, somewhat later than that presented to the parliament, and dated November 1996. I have to state that I believe the draft Directive to be a massive improvement on that which we have now, and workable in that it directly relates the results of the risk assessment to the containment that would be required to minimise the risk.
The main provision is withinwithin article 5 of the draft, which states
The directive continues to define the requirements for notification or permission for each of the 4 classes defined above.
The major requirements of the Directive apply to the risk assessment and to the definition of techniques that are included within the definitions. These both appear in annexes, and there is still discussion as to which of these annexes should be adaptable to technical progress (modifiable without having to modify the directive) and which not. The discussion that follows closely follows the text of the draft directive, for obvious reasons. The discussion between competent authorities and the commission to try to achieve an agrachieve an agreed text to this directive often becomes bogged down in detail, which results in extremely careful choice of words. As the directives are translated into each of the Community languages, and the meaning of words in each of these languages may well differ, this seems pointless, but problems between member States may often be resolved by judicious choice of words.
In Annex III we see the Principles which would be followed for the assessment of risk, which include
The procedure used to perform this risk assessment involves first identifying the harmful properties of the host organism, and then the properties of the donor organism, vector and finally the modified organism, making sure that only organisms for which
are classified as class 1.
The user should take account of the various tables classifying pathogens for animals, plants and humans (90/679 and 93/88) in assigning organisms to classorganisms to classes.
Selection of containment and control measures should then be made on the basis of the level of risk associated with the modified organisms together with information on the likely environment into which the organism could escape; characteristics of the use (e.g. scale) and any non-standard operations. This should lead to assignment to one of the classes defined previously.
A variety of tables appear in the draft directive to define the conditions of containment that are needed for each of the four classes of risk.
This is crucially important where the 'micro-organism' being used is a plant or animal pathogen, or even a plant or animal cell. The initial test, for risk to humans, indicates lack of problem and hence safe usage in relatively light containment, but the impact on the environment may be severe should they escape, and hence the need for greater containment (both physical and biological) is indicated.
From this example we see that it is the absence of familiarity which brings the necessity of precautions when handling genetically modified organisms.
It is easiest to consider the risk if we start assuming containment, for all procedures which finally result in a marketed modified organism will begin in the laboratory. In some senses this is where most of the hazard is likely to be found, or where risk potential is greatest, for the least is known about modified organisms in the research environment, and scientists are more likely to modify pathogens or try and identify genes which will be 'useful' from a variety of organisms which are not fully characterised.
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If the organisms are contained we have first to consider only the probable effect on human health and assume that our containment system will isolate our organism from the environment.
The European Union defines "contained use" as being within physical barriers, whether or not supplemented by chemical or biological barriers to escape or release into the open environment. The definition includes the modification of organisms and their storage, culture, use, transportation or destruction for which physical barriers are used to limit their contact with both the general population outside the containment and the environment. A genetically modified large animal might be considered to be in containment, if the definition depended on an ability to recall the 'organism' in the event of a problem, rather than a physical fence between that organism and the wider environment.
In order to assess the risk for contained use, it is usual to follow a scheme where we
Our modified organism is conceptually separable into the host organism, into which genetic information is inserted; the donor organism, from which the genetic information has been derived; the vector which shuttles the information between these organisms, and the insert, which contains one or more genes which display biological activity. It is useful to consider each of these in attempting to assess to assess the likely hazard posed by the modified organism.
When working in containment all cells, whether they are microorganisms, plant, animal or human cells, are considered to be micro-organisms when used in culture. This is only important in that the European Community Directive (EC 90/219) deals with contained use of modified micro-organisms. Animals and whole plants used in containment are not covered by a Europe-wide Directive, although many of the countries have "over-implemented" the directive so as to include all organisms used in containment.
In general, however, it is only microorganisms which are considered pathogenic to humans, although plant cells may produce toxic and allergenic substances which pose a hazard to the worker in the containment facility. (The concept of toxicity includes mutagenicity, carcinogenicity, neurotoxicity and environmental effects).
For each of the donor, host, vector and modified organisms we may consider the hazard they pose, which will provch will provide information which allows a first approximation to the hazard likely to be posed by the modified organism.
Before considering the properties of each of these, we may consider whether it is likely that the modified organism differs from the host organism at all. It is almost certain that the genetic information transferred to the host cell is an infinitesimal fraction of that incorporated within the host cell. The gene or genes that are inserted are likely to be well characterised and the changes in phenotype are predictable - otherwise there would be no point in the modification (except in the laboratory where making gene libraries provide the possibility of totally unknown mixtures of organisms). However, the genetic modification might affect the host range of the host organism, or its capacity to utilise a different set of metabolites, or might convert the host organism into a pathogen, or alter its ecological niche, or the balance of organisms within that niche. The point of insertiof insertion of the characterised genes within the genome of the modified organism is unknown. All that this paragraph says, however, is that we should treat our organism as a totally new organism, and base a risk assessment on encountering an unknown organism. Are the hazards unique to modified organisms, or should we treat this as equivalent to a newly isolated organism?
If we were to treat this as a newly isolated organism, we would be discarding a great deal of information which we possess! Where would risk-assessment start? The implication would be that the organism should be treated as a very dangerous pathogen until proved otherwise, and surely the insertion of a non-toxic gene into a species like Saccharomyces cerevisae which has never been shown to have pathogenic properties would be extremely unlikely to produce a very dangerous human pathogen.
We obviously start with information relating to the host species, take into account all the information available from the donor and vector tand vector to allow a preliminary risk assessment for the final modified organism. The risk management procedures that will then follow will include some monitoring to ensure that the risk assessment performed in this way is not seriously wrong.
The genetic modification might affect the host range of the host organism, its capacity to survive under different conditions, and the susceptibility to effective treatment or prophylaxis in the event of infection. It might also alter its capacity to utilise different substrates or alter its balance with other ecologically interrelated populations. Nevertheless, it is the pathogenic properties of the host organism that determine the starting point for our assessment of the likely hazard posed by the modified organism.
Infection followed by disease will depend on the microorganisms ability to multiply in the host and on the host's ability to resist or control the infection. It has proved useful to categorise all microorganisms into 4 the four WHO groups WHO groups which define their pathogenicity to humans; only the first group are non-pathogens. This categorisation applies only to the infectivity towards humans, and is of significance only, therefore, for the contained use of organisms:
The intention of this categorisation, which applies to non-modified organisms as well, is to identify appropriate containment which would be required to protect those working with the organisms. The higher the hazard group, the greater the containment required to control the organism and ensure that it does not infect those working with it.
Pathogenicity is not a simple characteristic. Many genes must interact appropriately for a microbe to cause disease. the pathogen must possess and express characteristics such as recognition factors, adhesion ability, toxigenicity and resistance to host defence systems. Single gene modifications of organisms with no pathogenic potential or history, or even the introduction of multiple genes unlikgenes unlikely to confer pathogenicity are unlikely to result in unanticipated pathogenicity. For example, E. coli K12 has been disabled to remove some of the factors that might be associated with pathogenicity (wild type E. coli is a group 2 pathogen). The factors which have been lost include the cell-surface K antigen, part of the LPS side chain, the adherence factor (fimbriae) that enable adherence to epithelial cells of human gut, resistance to lysis by complement and some resistance to phagocytosis. This variant of E. coli is a common host organism for genetic modifications within the laboratory.
The starting point for the risk assessment is, therefore, an assumption that the level of risk associated with the modified organism is at least as great as that of the host organism (until proved otherwise, either by direct observation, or by argument where the factors which are likely to enhance or decrease pathogenicity are considered as in the case of K12 above). Whether inWhether in the laboratory or in industry the capacity to choose a host means that in all but a few cases the host organism will have been chosen to be in hazard category 1. It is assumed that the modified organism will be used under the same containment as the host wild-type organism unless the modification inserts information which would alter the pathogenicity.
The vector has also to be considered, both for its own potential for pathogenicity and for its ability to transfer the insert to other than the intended organism - horizontal transfer of the information. Most vectors used for E. coli contain no sequences which might result in pathogenic behaviour. The presence of genes coding for antibiotic resistance might be of concern, but for most of these the antibiotic resistance is already so common in the environment that it can be discounted.
Most common E. coli vectors are transfer deficient, but the ability to transfer information either directly or with the assistance ofsistance of other plasmids and the host range of the vector must be taken into account when considering the safety of the mechanism of insertion of the required genes into the host organism.
The properties of the insert are again of importance in considering the risk assessment for the modified organism. Clearly if the information encodes a toxic gene product, or one which is known to be likely to modify the pathogenicity of the organism into which it is inserted, the great the risk. If the gene product is non-toxic and is not one which may pose a risk to the people working with the organism in containment, the risk management will largely be based on the pathogenicity of the host organism.
In most instances the characteristics of the donor organisms are of less relevance to the risk assessment than those of the host. If the donor organism is merely used as a source of well characterised DNA for a selectable phenotype or a promoter or other control sequence, the characteristics of the donor arhe donor are unimportant to the risk assessment. If however, the insert contains genes which are biologically active, toxins or virulence factors, then information from the donor organism are of consequence. The construction of cDNA or genomic libraries make it essential to consider all the possible hazards associated with the donor organism, and in this instance, the hazard group may well have to be the higher or the two within which the host and donor fall.
It is now possible to examine the modified organism and consider the likely risk. During the 1970's Dr. Sidney Brenner and others in the United Kingdom attempted to systematise the approach by considering three factors - Access, Damage, and Expression. The approach was incorporated in the United Kingdom's approach to risk assessment for contained use of bacteria, and is discussed in detail in a document produced by the Advisory Committee on Genetic Modification in the United Kingdom. The latest version of the guidance was published in 1993 and pr993 and provides clear guidance as to the risk assessment for the contained use of genetically modified microorganisms (including any cells in culture). The guidance note is free and may be obtained from the Health & Safety Executive in Britain. More information is available by looking at the newsletters published by the ACGM which are available on the internet on http://www.shef.ac.uk/~doe
Access is a measure of the probability that a modified micro-organism, or the DNA contained within it, will be able to enter the human body and survive there. It is a function of both host and vector. Depending on the organism being used, there are a number of routes of entry which allow access. The properties of the vector, particularly mobilisation functions need to be taken into account. In general if the organism is capable of colonising humans then access is high, whereas if the host is disabled so as to require the addition of specific nutrients not available in humans or outside of the culture media and edia and is also sensitive to physical conditions or chemical agents present in humans, then the access factor is likely to be low.
Expression is a measure of the anticipated or known level of expression of the inserted DNA; if the 'gene' inserted is intended to be expressed at a high level, for example, by deliberate in-frame insertion down-stream of a strong promoter, expression is likely to be high. If the insert is simply there to allow probes to detect the DNA, and is non-expressible DNA, i.e. with no foreseeable biological effect or gene containing introns which the host is incapable of processing, then the expression factor will be low. Examination of the final product, the modified organism itself, will determine the actual expression, which may be higher or lower than expected.
Damage is a measure of the likelihood of harm being caused to a person by exposure to the GENETICALLe GENETICALLY MODIFIED MICRO-ORGANISM, and is independent of either expression or access. It is associated with the known or suspected biological activity of the DNA or of the gene product. The activity of the organism which results in any toxic, allergenic or pathogenic effect need be taken into account within this parameter. It may be that the biological activity of a protein is dependent on the host cell system in which it is expressed. An oncogene expressed in a bacterium will have no discernible effect, when present in a human cell, problems may arise. The full biological function of many gene products require post-translational modification which will not occur within a bacterial cell normally. The potential biological activity of the gene product should be considered in the context of where an how it has been expressed and the effect on its structure and activity of the mode of manufacture. The range of 'damage' might be from
Once an estimate of each of these param these parameters has been made (in the United Kingdom this is numerical in steps of 10-3), they may be combined. The result provides a qualitative measure of the risk, and allows a containment level to be assigned for the use of the organism in order to protect those working with the GENETICALLY MODIFIED MICRO-ORGANISM.
Unfortunately, this Brenner scheme is only easily applicable to a small class of experimental uses of modified micro-organisms, but the number of experiments in research laboratory environments which fit the requirements for the application of this scheme make its retention useful.
Modified organisms may be used in containment in laboratories (or pilot plants) or may be used in an industrial setting. It may be that the primary distinction here is not the size of plant or type of organism, but rather the skill and training of those working in the facility.
It is likely that a research or development laboratory will be working with organisms which pose a greater threat ater threat to either the individuals working therein or to the environment than do those organisms developed for large scale factory use. The great majority of organisms used in industrial production are well-characterised, 'familiar' organisms capable of being used under conditions of 'Good Industrial Large Scale Practice' or GILSP. Given that it is usually possible to 'choose' the parental organism into which a gene is inserted for a particular 'industrial' purpose, there would be no good reason to choose an organism likely to pose problems to either those working in the facility, or to the environment in the event of an escape.
The same logic would apply to the development stage where 'industrial' use of the modified organisms is being planned. There is a possible extra hazard in that it is at this stage that the modified genes may be inserted into the organism, and the unpredictability of insertion site may, arguably, require slightly greater care than that taken at the production facility.
ity.In the research laboratory, organisms may be pathogenic to humans and/or to the environment, as it is here that fundamental research would be conducted. Experiments will involve organisms and /or inserts which may be injurious to the health of the workers or to those who are incidentally on site in the laboratory.
Level 1 is the lowest level or containment, and requires no extra precautions above those required for good microbiological practice. In general, this means that
The conditions for higher levels of containment, where the organism is considered a pathogen, are listed in the guidance note (see footnote ). For level 2, the major addition are the need to ensure that access to the laboratory is restricted to those needing to enter; that there be adequate space for each worker (at least 24 m3); an autoclave must be readily accessible and all waste materials must be made safe before disposal either by autoclaving or by incineration.
| Level 1 | Level 2 | Level 3 | Level 4 | ||
| Laboratory suite: isolation | no | no | partial | yes | |
| Laboratory: sealable for fumigation | no | no | yes | yes | |
| Ventilationinward airflow/ negative pressure | Optional | Optional | yes | yes | |
| through safety cabinet | no | Optional | Optional | no | |
| mechanical: direct | no | no | Optional | Yes | |
| mechanical: independent ducting | no | no | Optional | Yes | |
| Airlock | no | no | Optional | Yes | |
| with shower | with shower | no | no | no | Yes |
| Wash handbasin | yes | yes | yes | yes | |
| Effluent treatment | no | no | no | yes | |
| Autoclaveon site | no | no | no | no | |
| in suite | no | yes | yes | no | |
| in lab: free-standing | no | no | Optional | no | |
| in lab: double-ended | no | no | no | yes | |
| Microbiological safety cabinet / enclosure | no | Optional | yes | yes | |
| Class of cabinet / enclosure | - | class I | class I/III | class III |
There will be risks to the environment for contained use of m risks to the environment for contained use of modified organisms as well. The escape of modified organisms used in laboratories should be of little significance as they should have been disabled so that, in the event of escape, they will be unable to survive. However, the assumption has been that the only concern is risk to human health and safety. The risk assessment has been predicated on this, and the possibility that the organism may be a danger to other organisms within the environment has not been fully considered in the discussion. The concept of the 'environment' which includes land, air and water as well as other organisms and humans, is so broad when compared to the enclosed environment of the laboratory that is it difficult to define a clear step-wise approach to risk assessment. The risk assessment must try to consider all possibilities of what could go wrong, and attempt to ensure that these cannot happen, largely through the design of the organism being used. Methods for retrieving the situatiosituation should an organism escape from containment become important, and need to be planned at the outset rather than relying on the containment procedures to work. This is particularly important where the organism is a Level 1 organism as it will not infect humans, but if it escapes could be disastrous to plants, insects or other animals.
The extra hazards that need be taken into account so as to assess the risk should an organism escape from the laboratory environment include (a great deal of that which follows was included in Chapter 1, but is felt to be important enough to be repeated here):
The potential to survive, establish and disseminate within an environment distant from that in the laboratory. This may include the displacement of other organisms, or the modification of the ecosystem so that other organisms disappear or are replaced. Indirect effects may follow the establishment of a new organism.
Pathogenicity to animals and plants is clearly significant. The characteristicharacteristics of the host organism and the modified organism which are relevant to pathogenicity, toxicity, virulence, allergenicity, colonisation, predation, parasitism, symbiosis and competition need be considered. If the host is pathogenic, the modified organism may be to a greater or lesser extent, and this should be considered.
The potential for transfer of the genetic material should also be considered. Conjugative plasmids, transmissible vectors or transposable elements which could contribute to the undesirable spread of genetic material between the GENETICALLY MODIFIED MICRO-ORGANISM and other organisms must be considered in the risk assessment.
The products of the gene expression which might be toxic to organisms other than humans needs consideration, or where the precautions taken in the laboratory to protect humans from the toxic effects are no longer present in the environment. An organism that has the potential to cause negative effects on other organisms as a result of an inserof an inserted gene coding for a toxic product will pose a hazard.
The organism may have the potential to cause negative effects on other organisms and these should be considered.
The loss of a gene in the organism is not a hazard in itself, but such instability may lead to the incorporation of the genes in other organisms which may result in harm to the environment. Again this must be considered, even though escape is not expected.
Large scale use of modified organisms in containment is different from use in the laboratory in a number of ways. In the first instance, it is almost certainly true that the organisms used in development or for industrial and commercial use are non-pathogenic. They are generally used under conditions of 'Good Industrial Large Scale Practice' (GILSP) defined by a working group of OECD.
The hazards posed by large-scale fermentation of genetically modified micro-organisms are of the same nature as for other biological agents, in particular< in particular
There is nothing intrinsically more hazardous about the large scale use of genetically modified organisms in containment other than the potential for a greater degree of exposure to an organism and its biologically active products or the possibility that workers in an industrial plant are less skilled at handling biological material than laboratory workers. In general, large scale users may well have chosen the best characterised host organism, as knowing the conditions under which the organism is likely to thrive makes industrial use more cost-effective.
The criteria for organisms to be used under Good Ind under Good Industrial Large Scale Practice conditions include
Organisms which are used to manufacture biologically active chemicals will obviously not fall within the definition of GILSP in many circumstances
REFERENCES
1. Contained use is defined the new article 2 to be any activity in which micro-organism are genetically modified or in which such genetically modified micro-organisms are cultured, stored, transported, destroyed, disposed of or used in any other way, and for which specific containment measures are used to limit their contact with the general population and the environment, and micro-organism means any microbiological entity, cellular or non-cellular, capable of replication or of transferring genetic material including viruses, viroids, animal and plant cells in culture.
2. Microbiological Risk Assessment: an Interim Report, 1996, Advisory Committee on Dangerous Pathogens, H Pathogens, HMSO London.
3. Grinstead J (1995) "Risk Assessment and Contained Use of Genetically Modified Microorganisms", in Genetically Modified Organisms: A Guide to Biosafety, Tzotzos GT (Ed) CAB International, Oxford, ISBN 0 85198 972 1
4. Grinstead J (1995) "Risk Assessment and Contained Use of Genetically Modified Microorganisms", in Genetically Modified Organisms: A Guide to Biosafety, Tzotzos GT (Ed) CAB International, Oxford, ISBN 0 85198 972 1, p26-27.
5. Grinstead J (1995) "Risk Assessment and Contained Use of Genetically Modified Microorganisms", in Genetically Modified Organisms: A Guide to Biosafety, Tzotzos GT (Ed) CAB International, Oxford, ISBN 0 85198 972 1, p28
6. modified organisms are generally used under conditions of 'Good Industrial Large Scale Practice' (GILSP) defined by a working group of OECD.
7. Advisory Committee on Genetic Moon Genetic Modification: Laboratory Containment Facilities for Genetic Manipulation ACGM/HSE Note 7 (1993) UK. These notes are currently being re-written to form a compendium of advice on the contained use of modified organisms, and should be available in the new form during 1997.
8. Advisory Committee on Genetic Modification: Laboratory Containment Facilities for Genetic Manipulation ACGM/HSE Note 8 (June 1988) UK.
9. Advisory Committee on Genetic Modification: Laboratory Containment Facilities for Genetic Manipulation ACGM/HSE Note 8 (June 1988) UK.
10. Organisation of Economic Co-operation and Development Group of National Experts on Safety in Biotechnology. 1986, ISBN 92-64-12857-3.
11. Advisory Committee on Genetic Modification: Laboratory Containment Facilities for Genetic Manipulation ACGM/HSE Note 6 (1987) UK.