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REACH REGULATION

VIEWS: 21 PAGES: 15

									                  EUROPEAN COMMISSION
                  ENTERPRISE DIRECTORATE-GENERAL
                  ENVIRONMENT DIRECTORATE-GENERAL




                        REACH REGULATION
                  PUBLIC INTERNET CONSULTATION


A - Contact details
(Please enter your contact details)

Name: REISS
Organisation : PRO ANIMA (Paris), Doctors and Lawyers for Responsible
Medicine (London), Alliance for Responsible Science (London, Paris,
Rome),for Medical Advancement (London) and Animal Aid (London)
Address : (PRO ANIMA) 16, rue Vezelay
Post/zip code : F75008
City/Town : Paris
Country : France
Telephone : +33 1 64 86 58 24 (office) +33 1 60 12 14 54 (home)
Fax : +33 1 60 12 14 54
E-mail: cjreiss@yahoo.com



B - Confidentiality

       I would like my identity to be kept confidential
       (please leave this box blank if you agree that your name and organisation
       will be identified on the Commission’s website for public access)



C - SME

       Are you a small or medium sized enterprise? (EC legal definition)
       please specify the number of members:



D - Description of your primary activities
(please select only one of the following)

Industry

       Manufacturer
       Importer
       Downstream user
       Distributor
       Trade association
       Other

NGO

       Environmental group
       Animal welfare group
       Trade union
       Consumer organisation


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Other: Board of scientists aimed at applying scientific progress to
improve health security and care




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Public authorities

        EU Member State government
        Other national government
        International organisation
        National or regional authority

Other

        Academic or technical institute
        Worker in chemicals or downstream industry
x       EU citizen
        Other


Please structure your response according to the following topic areas and
provide comments or proposals for amendments to the legislation. Please
comment on those topics that are relevant to you.

When finished, please send your document to the following address:
entr-env-ec-reach@cec.eu.int.

Thank you in advance for your contribution.

E - Topics :

1.      Duty of care
2.      Chemical safety assessment
3.      Information flow
4.      Registration procedure
5.      Polymers
6.      Intermediates
7.      Data requirements
8.      Data sharing/consortia formation
9.      Procedures for downstream users
10.     Evaluation procedure
11.     Authorisation procedure
12.     Restrictions procedure
13.     The Agency
14.     Other




                              Contribution to REACH


                        By the scientific board of PRO ANIMA,


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                                  16, rue Vézelay, F75008 Paris
                           +33 1 45 63 10 89, proanima@wanadoo.fr
                         chair : prof. Claude Reiss, cjreiss@yahoo.com
                                     (corresponding author).
                               Vice-chair:       Dr     André     Ménache,      menache
@netvision.net.il


       EU authorities are right in having decided that some 100,000 man-made
chemicals, to which we are exposed, must be assessed for their adverse effects on our
health and our environment. The prospect that these assessments will be carried out at
the manufacturer’s expense, that they will involve a very large number of animals and
that they will not be completed for several decades at least, is cause for concern.
Those most concerned are consumer organizations, and private charities whose aim is
to promote human health. Some of these groups have challenged the scientific validity
of observations and results, because they were obtained from animal-based research.
They contend that adverse effects of chemicals can only be reliably assessed for the
species tested, and are irrelevant for any other species, humans in particular. They
claim that health statistics data fully support their case.
       It is actually striking to observe the huge progress made over the past century
in the development of products from chemical, petrochemical, agrochemical and
pharmaceutical industries, whilst the methods for assessing the risks of chemical
products have remained almost unchanged and still depend exclusively on animal
models. It is therefore timely, before starting the risk assessment of the 100,000
chemicals, to carefully examine whether recent scientific progress, which contributed
more accurate testing methods, could provide benefits, in particular by improving
consumer safety. To this end, we will examine the following six topics:
              1) Human health statistics gathered over the past few decades: do these
                  statistics point towards negative health trends, e.g. an increase in the
                  incidence of major diseases? If so, what proportion can be ascribed
                  to insufficient prevention and to man-made chemicals?
              2) Are the testing procedure presently in use satisfactory for reliable
                  prevention of major diseases?


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             3) Are there better methods for assessing toxic risks? Can such methods
                 be applied without delay?
             4) Science-based toxic risk assessment (SBT).
             5) Merits of SBT over animal model-based procedures.
             6) Merits and benefits of SBT for interested parties.


Morbidity and mortality statistics in the EU: alarming trends.
Despite the fact that life expectancy in EU countries is high, this benefit is offset by
high   morbidity    rates.   Several    million   EU     citizens    suffer   debilitating
neurodegenerative conditions (Alzheimer’s and Parkinson’s disease, Multiple
Sclerosis (MS), Autism, etc.) Although for most of these diseases, the increase in the
number of cases correlates roughly with the increase in life expectancy, a rapid
increase of neurodegenerative conditions (MS in particular) has been observed among
people between 20 and 40 years of age, and even in children (autism). The steepest
rise in morbidity and mortality has, however, been seen in cancer. In France for
instance, since 1990, the number one cause of death for people aged 35 to 65 years
has been cancer. The proportion of deaths due to all cancers except lung cancer,
among people of age 40 to 45 years, has increased six-fold between 1950 and 1980,
and 300,000 new cancers are diagnosed annually, with a significant increase in the
number of cancer cases likely to be linked to hormones. One woman out of 13 was
affected by breast cancer in 1970. Today, it is one in seven.
       It is generally agreed that 5-10% of all cancers are linked to genetic defects,
and this figure has remained fairly constant. Hence exogenous (outside) factors,
especially lifestyle (smoking, alcohol, dietary excess, etc) and cancer-promoting
(carcinogenic) products present in our food and in our environment are responsible for
9 out of 10 cancers. Since lifestyle has steadily improved over the past decades (less
smoking, more modest and equilibrated diet), it is likely that at present, environmental
carcinogens are the main culprits responsible for causing the 1.7 million new cancers
diagnosed in EU countries annually. This is clear evidence that either these products
have not been tested for their carcinogenic potential, or have been tested by methods
which failed however to detect this danger.




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       To assess the efficacy of these methods, let us examine how they perform in
an area where they are applied most stringently: the assessment of prescription drug
toxicity. Despite the fact that many years of research are invested in any particular
drug development and testing, adverse drug reactions (side effects) rank as the fourth
leading cause of death in the EU, claiming 20,000 lives annually in France (some
120,000 lives in the EU).
       It is then obvious that the current testing methods are failing to protect
efficiently public health. What are these methods? As required by law, toxicity testing
in general, and for prescription drugs in particular, must be performed on animals, i.e.
“models” which are believed to display biological reactions similar to those of
humans. It is therefore worthwhile analysing the relevance of the “animal model”
concept in relation to human health.


Is resorting to animal models for human health issues based on rational
principles?


                There is remarkably simple, yet clear proof that no animal species can
substitute as a reliable biological model for another species. A species is defined in
terms of its reproductive isolation, meaning that members from different species
cannot interbreed. This is because a given species has its own unique genetic make-up
(from number, organisation and structure of chromosomes, through to regulation and
control of gene expression). Modern biology has clearly demonstrated that the genetic
make-up of an individual determines the precise biological activities of its cells,
tissues, and organs. Hence, individuals from different species have different genetic
make-ups and therefore display different biological activities, even if some appear
similar. The statement that members of a given species can substitute as reliable
biological models for other species is therefore invalid.
        In particular, the assumption that results obtained in some mammalian species
are valid for humans is unfounded and seriously compromises human health. Consider
for instance the chimpanzee, our closest relative (in evolutionary terms). If exposed to
the human immunodeficiency virus (HIV), the chimpanzee does not respond (in
humans it causes AIDS); if injected with the hepatitis B virus, one out of ten or so
chimpanzees might develop a mild form of hepatitis and will recover quickly (in
humans, the virus causes chronic hepatitis and sometimes liver cancer); and when
injected with the Ebola virus, the chimpanzee dies of hemorrhagic fever, as do
humans. In other words, the best animal model we know behaves opposite, differently
or identically, to humans. Nobody can forecast the result, which can only be arrived at
after observing the test in both species. Testing animal models is therefore useless at
best, and dangerous to humans (the French blood scandal occurred because “experts”,



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noting that the chimpanzee showed no response, approved of HIV-contaminated
blood samples going onto the market).
        A conservative estimate of the number of deaths in France, resulting from this
flawed testing methodology of prescription drugs and carcinogenic products in animal
models alone, ranges from 100,000 to 120,000 a year . Assuming that similar rates per
capita are valid in other EU nations, some 600,000 to 750,000 citizens in total will die
prematurely within the EU year after year.

What is the basis of valid toxic risk assessment for humans?

         Resorting to animals for assessing toxic risks in humans goes back to medieval
times, as it was the only way to get a vague indication of the risk. The scientific
revolution provides us with far more reliable means.
         Toxicology is the science of life (biology) in the environment of the toxic
product (the xenobiotic). Over the past half century, biology has made unprecedented
leaps, moving away from empiricism, and instead, towards exact science when it
comes to cellular and molecular biology. Toxicology can benefit from the concepts,
methods and tools developed in modern biology and thereby achieve the status of an
almost exact science.
         Second, the cell is where life starts. It is therefore not surprising that the
answers to practically all problems in biology must first be sought at the cell level.
Human diseases almost invariably have a cellular origin, whether the cause is endo- or
exogenous. This holds true for cancer, neuropathologies, and cardiovascular diseases,
to cite the most frequent and life-threatening diseases in EU countries. It follows that
harm done to the cell by a toxic substance is the first step to diseases linked to the
body’s environment (including food, polluting substances etc).
         The stage is then set for Science Based Toxicology (SBT), as opposed to the
traditional toxicity assessment by means of animal models. SBT has its roots in
modern molecular and cellular biology, from which it will select and adapt the
methods and tools best suited for its goals. The study of human cells in the
environment of the toxic product will then be the first step for reliable assessment in
humans.
         Modern biology made also impressive progress in the study of integrated
systems, at the tissue, organe and systemic levels. Non-invasive methods (various
tomographies, functional testing of biochemical activies in organes etc) are available
allowing to complete molecular and cellular human risk assessment of substances to
which consumers are extensively exposed (prescription drug, food additive, pesticide
etc).

       Science-Based Toxicology.

        Our purpose is not to develop a detailed scientific programme of SBT, but to
sketch for a broad, interested audience the main outlines of molecular and cellular
SBT, based on 15 years of experience with these methods. Indeed, not only have
some of the scientists who contributed to this report been active in performing
research and developing methods and tools for SBT, they have also organized
international workshops aimed at bringing together world-class specialists in their
own particular field of molecular and cellular toxicology (First European Workshop


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in Molecular Toxicology, Sophia-Antipolis (France) 1996, Second European
Workshop in Molecular Toxicology, Paris 1999) and published the proceedings of
these workshops (Molecular Toxicology (1997) VSP publishing, Reiss, Parvez and
Labbe editors, Molecular Responses to Xenobiotics (2001) Elsevier publishing,
Parvez, Reiss and Labbe editors, Special Issue of TOXICOLOGY 153 (2000), n° 1-3,
guest editors Parvez and Reiss).
        Toxicity responses can be acute and systemic, they can also be delayed, either
because of an accumulation of minor damages which manage to finally overcome
cellular defence and repair mechanisms (a major cause of liver and kidney diseases),
or because the development of the disease takes a long time following induction (a
typical example is cancer, as it takes on average 5 to 10 years between the onset of
proliferation of a cell and the detection of the resulting tumour). Hence the necessity
to assess both the short- and long-term toxic responses.
        Cellular studies are best performed on primary cultures, but established cell
lines allow for preliminary investigations. An interesting complement to the methods
described below is in silico evaluation of the toxic effects of a molecule, derived from
its chemical structure (structure-activity relationship), which is increasingly reliable in
forecasting the adverse biological activities of the molecule, even before it has bee n
synthesized.

        Molecular and cell toxicology.
        Metabolism of the xenobiotic. In order to enter the cell, the xenobiotic has to
cross lipid or aqueous barriers and may need to be metabolised to that end. This can
be done by activating the expression of various cellular genes, which may involve
specific metabolizing enzymes (mono oxygenases, including members of the P450
family, Acetyltransferases, Epoxide Hydrolases, Glutathio-S-Transferases,
Methyltransferases, Sulfotransferases, UDP-glycosyltransferases etc, nuclear
transcription factors, like the PRX receptor activated by a majority of drugs and
involved in many adverse drug effects, xenobiotic transporters (metallothioneines, P-
glycoprotein family), etc. The resulting metabolites need to be carefully identified,
since some happen to be highly toxic, even though the unmetabolized xenobiotic is
not. Since primary targets of xenobiotics are the liver and the kidney, cells from these
organs should be tested first. Methods: in vitro testing of the enzymatic activity of the
involved genes, DNA chips (kits commercially available) allowing to monitor the
expression of many of these genes, identification of metabolites by mass
spectrometry, etc.
        Intracellular toxicity assessment. Once the xenobiotic or its metabolite has
entered the cell, the effect on the latter and its fate must be monitored. In response to
even mild aggression, the cell will mobilize a series of genes, either to protect itself,
or to have the damage repaired.
        Many members of the families of genes involved (stress genes and various
repair enzyme genes) are known and can be recruited as “reporters”.which inform to
the toxicologist of the target, the extent of the damage and the ability of the cell to
overcome the damage. Briefly, by standard genetic engineering techniques, the
control element (promoter) of the stress or repair gene is fused to a DNA sequence
coding for a coloured, fluorescent, or luminescent protein. This “reporter” is
introduced in the cell. As an example, assume that the control element has been
borrowed from a gene in charge of the repair of a DNA strand break, fused to the


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coding sequence of luciferase (a protein used by the firefly to produce its light). If the
cell harbouring this “reporter” is exposed to a product which lights up the cell, it can
be concluded that the product has entered the cell, has damaged the genetic material
(it is therefore potentially mutagenic). The fate of the cell, exposed to various doses of
the product, tells us about its ability to survive and how it will cope with the product
in the long run. Presently, reporter gene-loaded cells are commercially available,
allowing to trace quickly and inexpensively xenobiotics responsible for stress
(including oxidative), various kinds of DNA damage, membrane damage etc.
         The disadvantage with reporters is the necessity to guess the gene targeted by
the xenobiotic. This problem is overcome with commercially available DNA chips,
carrying hundreds or thousands of gene elements known to be involved in toxic
response (Toxicogenomics). A DNA chip is a checkerboard of squares of micrometer
size carrying a short fragment of a gene. By standard biochemical manipulations, the
expression of each of these genes gene can beindividually visualized. The DNA chip
allows to watch the simultaneous (transcription) behaviour in the cell’s nucleus of all
genes present on the chip, whether the genes are stimulated, repressed or unaffected
by the xenobiotic.
         DNA chips are the ultimate tools for monitoring the first part of gene
expression, transcription. In order to have a full view of the xenobiotic activity on
gene expression, the second part of expression, translation, during which the gene
product is actually synthesized, must be monitored also. This can be done with the
tools of Toxicoproteomics (2D gel or capillary electrophoresis, protein chips, mass
spectroscopy, and many new methods under rapid development). Toxicoproteomics
account for the xenobiotic-induced protein modifications (chemical or structural),
modifications of proteolytic processes, aggregation etc, which have been identified
recently as representing important stages in many severe diseases (neurodegenerative
disorders, dementia, diabetes type 2 etc).

        Genotoxic activities of xenobiotics need to be identified and monitored with
particular attention, since the failure to accurately assess their effects is the main
factor responsible for the steep rise in cancer incidence observed over the past 50
years. These effects and activities can lead to DNA mutations, which can be
monitored by a wealth of techniques (directly on DNA: precisely (sequencing) or
roughly (“Comet”); or indirectly, by monitoring the expression of DNA repair genes).
Tumorigenesis is promoted by mutation, or inactivation, of genes involved in the
regulation of cell growth and division. This leads to deregulation of pathways in
charge of controlling programmed cell death, response to growth factors, cell
migration etc. DNA chips are available allowing to characterize the transcription
status of several hundreds of the genes involved in tumorigenesis, when the cell is
exposed to some xenobiotic.
        Carcinogenic events can also be induced by non-genotoxic mechanisms,
occurring at various steps (“check points”) of the cell cycle (division) or at the level
of the higher organisation of the genetic material (chromatin). Of particular interest
are the so-called tumour suppressors, as for instance the much celebrated protein p53,
one of the “guardians of the genome”. This protein has control over the integrity of
the genetic material of the cell. If some mutagenic event has occurred, p53 will
immediately interrupt the cell cycle, until the damage has been repaired. If the repair
has not been achieved within a few hours, p53 will force the cell into apoptosis


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(“suicide”), thereby preventing transmission of the damage to the cell’s progeny.
Xenobiotics targeting p53 (or other tumour suppressors), either by mutating its gene,
or by modifying its structure, will abolish the “guardian” activity of the protein, so
that mutations can go over to the cell’s progeny and eventually induce uncontrolled
cell proliferation (over half of solid tumours carry inactive forms of p53). Many
commercial kits are available allowing to monitor the state of tumour suppressors and
checkpoint gene expression, at the transcription or the protein level, in particular for
cancers thought to depend on hormons (breast cancer and estrogen receptor signaling,
prostate cancer and androgen signalling). DNA chips are also available allowing to
monitor the expression, in the presence of a xenobiotic, of hundreds of human genes
involved in the major steps of tumorigenesis, from deregulation of pathways in cell
growth and division, DNA damage response, genome stability and repair, to cell
adhesion, invasion, metastasis, angiogenesis etc.
        Cytotoxic xenobiotics target the cell’s organisation, its equipment, its
metabolism etc. This toxicity is often signalled by intense expression of stress genes
(in particular oxidative stress, see “reporter” gene section above). Cells initially
respond by producing “chaperones” and other enzymes to protect themselves from the
xenobiotic’s action. The severity and length of the exposure can elicite more global
cellular responses, like growth arrest, scenescence, necrosis, cell death by apoptosis,
even cell proliferation and carcinogenesis. The targets of cytotoxicity are the various
cellular compartments and components, in particular mitochondria, which can trigger
apoptosis. For instance, xenobiotics can trigger the apoptosis pathway involving the
Bcl2 gene family. The corresponding proteins oligomerize, insert into the
mitochondrial membrane, inducing the release of its content (including the CARD
family), some of which trigger cell death. Cytotoxicity can be established by
monitoring the expression of a long list of housekeeping genes, and genes involved in
necrosis, apoptosis, growth arrest, senescence etc.
        The methods mentioned so far can be applied to any type of cell but those
from organs most exposed to xenobiotics (liver, kidney, skin) should be assessed first.

        Specific methods exist for the molecular assessment of a variety of xenobiotics
which target particular biological functions. Here is a short list.
        Reproductive toxicity can be monitored at the cell level, for instance by
studying the activation by a xenobiotic of hormone receptors present at the surface of
specific cells. As an example, “endocrine proliferators” can mimic natural hormones
and unduly induce the hormone-specific signal, or they can saturate specific hormone
receptors and thereby preclude access of the normal hormone and delivery of its
signal. Xenobiotics, including a large class of pesticides, which can induce
abnormalities of male reproductive organs, or promote tumours in tissues and organs
which are under hormonal control (breast, ovary, prostate), can be identified in
cultures of cells taken from these organs and tissues.
        Developmental toxicity (including teratogenesis), linked to xenobiotics
targeting the cell cycle, growth factors or cell components involved in development
signalisation (classes of RNAs, chromatin components, etc.), can be assessed by
monitoring the interaction of the xenobiotic with these molecular components of the
cell. DNA chips are available allowing to monitor the action of xenobiotics on many
human genes involved in regulation of the cycle phases (cyclins, cyclin-dependent
kinases and their regulators: inhibitors, phosphatases, kinases)


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        Neurotoxicity can be the consequence of the action of a xenobiotic on
molecules involved in neuronal communication (a majority of insecticides target these
molecules!). Several standard methods make it possible to assess this class of
neurotoxicity on neuronal cells in culture. Electrochemical signals sent down the
length of a neuron, or from one neuron to another, are mediated by 3 classes of ion-
specific channels (passive channels, which maintain resting membrane potential,
chemically gated channels which recognize neurotransmitters and initiate an action
potential, which isthen propagated by voltage-gated channel) and two broad classes of
neurotransmitters, those acting directly on chemically gated ion channels and causing
them to open, and those acting indirectly and more slowly, involving G-protein
coupled receptors and the production of secondary messengers. DNA chips carrying
genes of ion channels and neurotransmitter (including neurotrophins, which are
thought to play an important role in neuronal development) transporters are available,
allowing to monitor the effect of a xenobiotic on these essential actors in
neurobiology.
        Neurotoxic agents can also target neuronal cells by affecting their capability to
synthesize proteins in their native conformation. Misconformed proteins tend to
accumulate in or around the cell, to aggregate and form fibers, plaques or tangles
which force the cell to commit apoptosis (due to intracellular accumulation of
misfolded proteins) or impair cell to cell communication (extracellular deposit of
proteinaceous aggregates). Parkinsonism (apoptosis of dopaminergic cells),
Alzheimer’s disease (Apbeta plaque and tau fiber deposit), Creuzfeld-Jacob disease
(prion deposit) and more than 20 other forms of dementia belonging to the family of
“conformational disease”, can result from the production of misconformed proteins by
the cellular protein synthesis apparatus (see below). Xenobiotics can target this
equipment, either directly (production of stress which excessively mobilizes and
secludes stress proteins, like chaperons, involved in protein folding) or indirectly
(unscheduled order to produce large quantities of proteins, and to proliferate, which
depletes the cell’s resources for protein synthesis and favours misfolding). Testing
xenobiotics for their capability to induce protein misfolding, which is straightforward
using reporter genes, is an urgent necessity, considering the significant number of
elderly patients, and more recently, even people below 40 years of age, suffering from
debilitating conformational diseases.

       Immunotoxicity, inflammatory response. Inflammation is both the normal
response of the body to pathogenes, and a key intermediate of disease states which
can be induced by xenobiotics, such as allergies, asthma and arthritis. The signaling
cascade of inflammatory response is propagated by the secretion of small
glycoproteins (cytokines) and their binding on receptors of target cells. DNA chips
bearing tens of human cytokins genes involved in the inflammatory response and of
genes of their receptors are available, allowing to simultaneously determine their
expression profiles in cells exposed to some immunitoxic xenobiotic.

        Molecular methods exist to assess membrane toxicity (modification of
polarity, size and structure of lipid rafts, etc.), epigenetic toxicity (xenobiotic
producing DNA methylation, acylation or phosphorylation of chromatin, which can
seriously affect the program of gene expression), etc. Because of the polymorphism of
the human population, assessment of cellular toxicity for classes of the human


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population sharing common polymorphism patterns could be made, using class-
specific DNA chips for instance, which would allow one to list xenobiotics which are
especially harmful, or conversely, safe, for members of the class (polymorphism-
specific and idiosyncratic toxicology). For instance, a large human polymorphism is
found in the p450 family of metabolizing enzymes.
        Signal transduction and intracellular toxicity targets cell-cell and cell-
extracellular matrix (gap junction) interactions, endo- or exocrine processes, etc.
Many cell types receive external signals (hormones...) which they “transduce”
(translate) by some mechanism (signal transduction pathway) into changing their
behaviour or characteristics. G-protein coupled receptors for instance form a large
family of cell surface receptors involved in signal transduction. They are activated by
a large variety of ligands, including chemicals and most drugs. Chemical stress can
activate signal transduction via the NFkB transcription factor, released by the
phosphorylation of the inhibitory IkB family of proteins or the Rel subunits. Once
NFkB translocates in the nucleus, it induces transcription and expression of many
genes such as those encoding cytokins, adhesion molecules, inhibitors of apoptosis
etc. MAP kinase signaling operates through a cascade of kinases which also activate
transcription factors of a variety of genes. Signaling by the TGFb superfamily causes
growth inhibition. Again, DNA chips carrying hundreds of human genes involved in
signal transduction allow to monitor the action of xenobiotics on these genes.
        The fate of the extracellular matrix, the substratum to wich cell attach via
adhesion molecules on the cell surface to help define tissue shape, structure and
function, when exposed to a xenobiotic, can be monitored via the expression profile
of molecules involved in cell-cell and cell-tissue interaction, like cell adhesion
molecules (integrins, cadherins, catenins, selectins), extracellular matrix proteins
(lamins, fibronectin, fibrinogen), protease (matrix metalloproteinases, serine and
cystein protinases, cathepsin) and protease inhibitors (maspin). DNA arrays are
available, allowing to monitor the expression of hundreds of the genes involved,
providing valuable information on the effect of a xenobiotic on primary steps in tissue
and organ development.

        In summary, using techniques based on molecular toxicity, we can obtain a
clear view of the mechanism by which the substance or product is harmful, at what
doses the cell can resist, and most importantly the long-term effect on the cell. The
experiment takes a few days on average, can be performed in large parallel screening
set-ups (various cell types or doses for instance), are relatively inexpensive, easy to
standardize, and require tiny amounts of the xenobiotic (important in drug testing).
The results are quantitative (large range of linear dose-response), reproducible and,
most importantly, are valid for the species which provided the cells. These points
represent definite scientific and economic advantages, even though advanced
technical skills are required for most of these methods.

       Scientific assessment of organ, tissue and systemic toxicity.
       We estimate that the assessment of the toxic risk by molecular and cellular
approaches can be extended with some 90% reliability to the organ, tissue and
systemic level. Nevertheless, this uncertainty must be further reduced, especially for
prescription drugs and products to which consumers are exposed for long periods of
time, or at high doses (food additives, pesticides). In special cases, the product can be


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tested in perfused tissues or in organ slices, which allow one to monitor the reponse of
the cells integrated in their normal environment. Due to supply problems and rapid
degradation of the slices, these tests are difficult to carry out routinely. It is much
easier to rely on non-invasive methods, which allow one to monitor human
volunteers, under strict clinical test conditions (with informed consent), the effect of
the xenobiotic on the tissue or functioning organ in situ. Of particular value are
imaging techniques (MRI, PET scan, etc) which allow one to identify the organ
targeted by the xenobiotic, the metabolism and the elimination of the latter. Valuable
complementary information on the functioning of particular organs can be obtained
by standard biochemical and biomedical tests.

       Merits of SBT over traditional (animal-based research) toxicity
assessment.

        As shown above, the biological reactions of individuals of a given species are
unique. Occasionally, individuals from different species may display similar gross
responses when exposed to the same toxic product, but one should never be misled by
these chance phenomena. First and foremost, the mechanism through which a product
induces some pathological reaction can be rather different in different species. 60% of
the drugs in use are metabolized in humans by the same member of the P450 family
(which can lead to synergistic drug activation), but several, different members of the
p450 family are involved in apes, dogs and rodents. Second, long-term effects in
humans cannot be assessed in species with a shorter life expectancy. In mice,
spontaneous cancer development commences at the age of 10 months, whereas in
humans it usually starts after the age of 40 years, and the mechanism of cancer
promotion are known to be very different in both species. The strain to strain
susceptibility for cancer in mice can vary a hundredfold, certain strains tolerate
eostrogen doses many times higher than others, with no apparent ill-effects. Even if
the gross response in two different species looks alike in the short term, the
underlying mechanism which determines the long-term outcome is very likely
different and therefore can lead to vastly different outcomes. Incidentally, it would be
useless to perform SBT for a given species on cells or cell cultures belonging to a
different species.

       Benefits of SBT for interested parties.

        The most obvious benefit would be consumer safety. SBT allows one to
understand the mechanism by which a substance produces its adverse effects, which
then allows one to forecast its long-term effects. By identifying cancer-promoting
products, cancer prevention would be significantly boosted. As a result of science-
based assessment of carcinogenic substances and consequently, we estimate that
cancer morbidity figures could be halved within the next 3 to 5 years. The reliable
assessment of drug toxicity could save tens of thousands of lives a year. Neurotoxic
substances (80% of insecticides are neurotoxic) could be identified and removed from
the market, preventing damage to the neuronal development of children (according to
the FDA, this could be the case for rotenone). Detection and removal of endocrine
proliferators would prevent both abnormal development of sex organs and most
hormone-dependent cancers (breast, ovary, prostate).


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                   ENVIRONMENT DIRECTORATE-GENERAL




        Improved consumer safety would result in the immediate alleviation of socio-
economic costs resulting from diseases, whose rates are presently soaring in EU
countries.
        The benefits of SBT assessments for industry are many. SBT experiments take
a few days on average, can be performed in large parallel screening set-ups (various
cell types or doses for instance), are relatively inexpensive, easy to standardize, and
require tiny amounts of the xenobiotic (important in drug testing). The results are
quantitative (large range of linear dose-response), reproducible and, most importantly,
are reliable and valid for the species under investigation. Furthermore, understanding
the mechanism of the adverse effect may allow the chemist to modify the xenobiotic
and remove, or alleviate, its toxicity (with the help of Structure-Activity-Relationship
models, for example), and improve the quality of the product. Since SBT tests are
easily standardized and are independent of subjective parameters, the tests remain
valid across political borders, which allows for unrestricted circulation of the SBT-
tested goods among EU countries. These are definite scientific and economic
advantages.
        It is true however that advanced technical skill is required for most of SBT
methods, and that the lab equipment required is expensive.
        SBT procedures apply to other species and can therefore be used to assess
environmental toxicities in any animal or plant species.
        Since SBT procedures necessarily avoid “model” species, they would satisfy
animal welfare organizations.
        Finally, resorting to SBT methods would improve the image of the EU, both
inside the EU countries (consumers would be grateful for better protection of their
health) and outside the EU, as the EU could lead the way for effective improvement
of environmental health issues worldwide.

      How to proceed with the rapid and practical implementation of SBT in
the EU:

        A strategy for the EU to hasten the introduction of SBT methods could be
based on the following steps:
        1. Elaborate a detailed SBT programme. To this end, create and fund a board
of specialists. Our organizations are ready to contribute their experience to this end.
        2. Fund and set up a european pilot lab in SBT (e.g. at the Joint Research
Center?).
        3. Fund and train SB Toxicologists. Organize a 6 to 8 month training course,
in the pilot lab, with conferences attended by leading specialists in the field, for
graduate or postgraduate fellows from all EU countries.
        4. Encourage all EU countries to set up SBT pilot labs, led by the trained SB
Toxicologists, and train more SB Toxicologists, locally.
        5. Support industrial initiatives aimed at conversion to SBT methods.
        6. Issue directives stating that all new products brought to the market must
have been tested as safe by SBT methods, namely at the molecular and cellular level
for products to which exposure is limited, and in addition at the tissue, organ
(especially liver and kidney) and systemic level for products to which exposure is
significant (prescription drugs, food additives, pesticides, etc.) Products already on the



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                  ENTERPRISE DIRECTORATE-GENERAL
                  ENVIRONMENT DIRECTORATE-GENERAL




market should be tested by SBT methods within 3 to 5 years, those failing to pass the
test should be withdrawn (support for the development of safe equivalents?).

                     For the scientific board,

                      Prof. Claude REISS, Molecular Biologiste, former research
director with the French National Center for Scientific Research (CNRS).




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