The Process of Risk Assessment

In all cases the process of risk assessment of food chemicals has up to now ignored the effect of the other constituents present in that food. The scientific approach to risk (or benefit) assessment has so far demanded a... 

Hazard is commonly defined as the potential to cause harm . A hazard can be defined as aproperty or situation that in particular circumstances could lead to harm (Smith et al., 1988). Risk is a more difficult concept to define. The term risk is used in everyday language to mean chance of disaster . When used in the process of risk assessment it has specific definitions, the most commonly accepted being The combination of the probability, or frequency, of occurrence of a defined hazard and the magnitude of the consequences of the occurrence (Smith et al., 1988). 

The processes of risk assessment, risk evaluation, decision-making, observation, re-evalnation and corrective decision-making must be stractured in a comprehensible and clear way in order to create legitimacy and confidence. This in-clndes stages where interest groups ate involved (proceduralisation 1). Risk information and communication alone ate not sufficient. 

Exposure assessment is the third step in the process of risk assessment. 

Hazard characterization, also known as dose-response assessment, is the second stage in hazard assessment, and the second step in the process of risk assessment. At this step, the No-Observed-Adverse-Effect Level (NOAEL) and the Lowest-Observed-Adverse-Effect Level (LOAEL) are derived for the observed effects, where possible and appropriate. 

Hazard identification is the first step in the process of risk assessment, and hazard characterization is the second step. The hazard assessment is also known as effect assessment and is addressed in detail in Chapter 4. 

The process of risk assessment is quite complex and can be more fully appreciated at the end of the first third of the course. There have been many good articles and books written over the last ten years which present various points of view on perceived versus actual risk. 

This ADI calculation process is based on the assumption that humans are at least as sensitive as the most sensitive laboratory animal exposed to the most sensitive test. This concept is not based on any scientific evidence but is used as a precaution against the uncertainties inherent in the process of risk assessment. The ADI corresponds to the quantity of residues consumers can take each day throughout their lives without incurring any appreciable risk to their health and, as such, expresses the intention to keep the risk to public health so low as to be insignificant. Under this perspective, the setting of this value is therefore strongly influenced by the concept of risk management. 

To discuss the dose-response relationship, it is necessary to consider the dose of a chemical, the nature of the response to it, and what factors affect the response to the chemical. These considerations are also important in the process of risk assessment for any chemical. 

Answers to these questions provide an outline of the risk assessment process, in terms of requisites of the process itself. The next part is to address the technical extrapolation issues within the process of risk assessment. 

The process of risk assessment was first formalized (NRC, 1983) by the United States National Academy of Sciences through its National Research Council in 1983. The three stages of risk analysis are defined as risk assessment, risk management and risk communication (Figure 10). The important principle is the functional and organizational separation of exposure and risk assessment from risk management to avoid any non-science-driven influences on the assessment procedures. However, many interactive elements are essential for a systematic risk assessment and management process. 

The process of risk assessment for hazardous waste sites is still under development, and so necessarily is the development of regulations that build on risk assessment, but the commitment to utilize risk assessment appears firm. 

Risk assessments may be conducted for individual chemicals or for complex mixtures of chemicals. In the case of complex mixtures such as hazardous waste sites, the process of risk assessment itself becomes quite complex. This complexity results from simultaneous exposure to many substances with the potential for numerous chemical and biological interactions, exposure through multiple media and pathways, and exposure to a wide range of target organisms with different susceptibilities (e.g., infants, adults, humans, animals, organisms). 

The process of risk assessment generally involves considering different classes of hazard such as physical hazards, electrical hazards, biological hazards, radiation hazards (where appropriate), and hazards due to service failure. Each of these classes is then analyzed in detail to determine the acceptability of associated risks. 

Government agencies have begun to recognize and respond to criticisms about risk assessment and its use, and have noted areas for improvement. Reports by the National Research Council (1994 Stem and Fineberg, 1996) and the Presidential Commission on Risk Assessment and Risk Management (1997) recommended changes to the process of risk assessment that would ... 

The first section of this chapter provides a discussion of hazard assessment, classification of potentially dangerous substances, and the process of risk assessment. A summary of the mandatory and voluntary initiatives for regulating chemicals and biocides in the United States and Europe is also included together with information on the regulatory aspects of hazard communication. The second section deals with the scientific aspects of hazard identification and risk assessment of carcinogenic chemicals within the regulatory context. 

The United States employs precautionary approaches throughout the process of risk assessment and management so that the overall level of precaution in a given regnlatory decision is appropriate. .. When analysts assess risks, they frequently nse conservative or defanlt assnmptions or explicitly add safety margins or nncertainty factors to characterize a plansible npper bonnd. 

Most short-term tests in bacteria and mammalian cell cultures have been designed primarily for hazard identification and, thus, can represent only the starting point in the process of risk assessment. Whether or not the observed effects are relevant for human exposure depends on bioavailability, absorption, metabofism, half-lives, and other factors that require investigation in vivo. 

The process of risk assessment for carcinogens, depending upon the jurisdictions, has involved one of the following approaches (Younes et al. 1998) ... 

The National Research Council (2) has divided the process of risk assessment into four components. These are ... 

The process of risk assessment differs for manufacturing processes involving microorganisms in order to take into account the ability of the organisms to multiply (or die) and to adapt and produce toxins. One scheme (the Brenner scheme) uses access, expression and damage as the 3 headings under which the risks for microorganisms can be assessed [9]. 

But it is important to remember that the limiting factor may be one single part of the analytical chain - chemical detection, or exposure, or benefits - or ultimately, it may be the limited ability of the human mind to attribute social values to the myriad of risk and benefit descriptors and to calculate conclusions accounting for all of them. Improvements in the process of risk assessment must therefore achieve balance both among the various types of scientific and economic inputs to a decision and with the ability of the decision maker to use the inputs. But even then we all do not, nor should we necessarily, have the same set of values to apply to the decision, assuring interesting and controversial pesticide risk debates for some time in the future. 

Nontechnical Summary In this paper, the process of risk assessment with compounds which exhibit chronic but not acute toxicity is first reviewed. The remainder of the paper is spent on reviewing the procedure for quantifying absorption through the skin. The test animal used is the rhesus monkey since previously published work has shown this animal to yield data most similar to man. Data are presented on oryzalin for which dermal absorption was less than 2 percent of the applied dose. The problems and shortcomings of the procedure as well as its advantage (similarity to man) are also discussed. 

Clearly the process of risk assessment in relation to landfill is not easy, but it is an approach that sits easily alongside sustainable development for as indicated earlier, sustainability is of relatively little value without "development", and as long... 

The process of risk assessment can be defined as t/ie evaluation and quantification of the likelihood of undesired events and the likelihood of injury and damage that could be caused by the risks. It also involves an estimation of the results resulting from undesired events. 

By considering exposure as well as hazard, the process of risk assessment estimates the potential for the inherent hazards of a material actually to be realised during its life cycle. It should be carried out if a proposed solvent/preparation is subject to specific water pollution controls or has been classified as dangerous to the environment. The results will lend support to discussions with pollution authorities. 

HO DECIDES what s safe And how do they make that determination Another principle of safety is assessing the risks of hazards. Understanding how we each view risk affects how we behave in the laboratory, and affects how we interpret safety information. Not everyone makes the same choice given a set of dangers and options. This chapter is about the process of risk assessment and the means by which scientists share information about hazard levels posed by chemicals. Students involved in research projects have to learn to develop their sense of judgment about risk as they plan and conduct experiments. Will you know how to decide what s safe when presented with the design of a new experiment ... 

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