Importance of risk assessment for risk
There are a vast number of chemicals, both synthetic and natural, to which
man and the environment are exposed. They may have beneficial effects
- such as those conferred by vitamins - but all chemicals are toxic when
given in a large enough dose. The range of toxicity is over 109
and thus there is a continuing need to define which chemicals represent
a risk to health or the environment so that efforts can be directed to
controlling those which present the greatest harm to the largest number
In the particular context of chemicals
which disrupt the endocrine system, there have been many observations
of adverse effects occurring in humans or vertebrate species which have
been linked to the presence of natural or synthetic chemicals in the environment,
frequently without any evidence of causality. There are also observations
of chemicals which have oestrogenic properties in human tissue, milk,
food or the environment. It is often implied, frequently wrongly, that
adverse effects are inevitable from the presence of these contaminants.
The use of risk assessment can assist in resolving some of the uncertainties
arising from observations of chemical contamination or adverse effects
by providing a quantitative assessment of the relationship between the
contaminant and the adverse effect.
For commercial organisations, the
identification of chemicals which can be used safely is of paramount importance.
For some chemicals, where the effect is dependant on the presence of the
chemical (for example the treatment of disease with medicines), defining
the conditions for safe use is important to protect the consumer. In other
cases, the presence of the chemical in the consumer product is adventitious
(for example the presence of chemicals in effluent, or the presence of
pesticide residues, carcinogenic mycotoxins or oestrogenic compounds in
food) and the issue is to what level must the chemical be controlled in
order to preserve the environment and health.
The consumer is protected by the regulatory
processes which are part of the legal framework for the registration
of chemicals for certain uses (e.g. pharmaceuticals, pesticides, food
additives, cosmetics or industrial chemicals). Equally the protection
of public health requires the identification of toxic natural products
and the introduction of the appropriate control measures to minimise
risk. For most examples of regulatory action, the assessment of the
risk posed by the presence of the chemical is one of the key steps
in the decision making process. Eliminating chemicals completely,
particularly natural products such as mycotoxins, is practically impossible
and the development of high resolution analytical methods has demonstrated
the presence of traces of such chemicals in virtually every product.
The question is thus the same: To what concentration should the contaminant
or natural product be limited in order to allow the benefits of the
product (food, medicines etc.) to be realised without undue risk?
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