Practical work risk assessments

The outcome of the risk assessment process must be recorded and appropriate safety information must be passed on to those at risk. For most practical classes, risk assessments will have been carried out in advance by the person in charge and the information necessary to minimize the risks to students may be given in the practical schedule. You will be asked to carry out risk assessments to familiarize yourself with the process and sources of information. Make sure you know how your department provides such information and that you have read the appropriate material before you begin your practical work. You should also pay close attention to the person in charge at the beginning of the practical session, as they may emphasize the major hazards and risks. In project work, you will need to be involved in the risk assessment process along with your supervisor, before you carry out any laboratory work. Any new materials synthesized during the project should be treated with the utmost respect. An example of a risk assessment is shown in Fig. 2.2. 

Exposure assessments have become an essential element of contemporary risk assessment (NAS/NRC, 1983). The primary purpose of exposure assessment is to qualitatively and/or quantitatively determine exposure and absorbed dose associated with a particular use practice or human activity. Contemporary exposure assessors and risk managers place a high premium on accurate data obtained by monitoring chemical exposure scenarios and critical human activities or work tasks. 

The book has been based primarily on our experiences achieved through many years of practical work as risk assessors within different areas of toxicological risk assessments of chemicals. We have also consulted essential key references for the state of the art as well as relevant Web sites. Links to Web sites were checked right before we forwarded the manuscript to the publisher (1 July 2007) however, as Web sites are undergoing continuing development, links might have changed since then. 

From the standpoint of practical regulatory assessment, it would be desirable to reach a consensus on the selection of methods for routine use for pesticide risk assessments while recognizing that there may be scientific reasons for preferring alternative methods in particnlar cases. Such a consensus does not yet exist. Further case studies are required, covering a range of contrasting pesticides and scenarios, to evaluate the available methods more fully. While a consensus is lacking, it is important that reports on probabilistic assessments clearly explain how their methods work and why they were selected. 

Waller, R. (1994) Conservation Risk Assessment A Strategy for Managing Resources for Preventive Conservation, Preprints of the Contributions to the Ottawa Congress, Preventive Conservation-Theory, Practice and Research. The International Institute for Conservation of Historic and Artistic Works IIC, Canada,... 

The ability to use probabilistic approaches to assess dietary pesticide exposure has also changed much of the emphasis of pesticide risk assessment practices from assessing long-term (chronic) exposure to short-term (acute) exposure. Deterministic approaches worked well with chronic assessments since the day-to-day variability in food consumption patterns and the variability of pesticide residue levels tended to average out over the course of a 70-year exposure period. Deterministic approaches have also often been used in the assessment of acute dietary risk by assuming an upper percentile level of food consumption and the maximum detected or allowable level of residue. The point estimate determined in this manner is then compared with the RfD to determine the acceptability of exposure under the specified conditions. 

For addressing multispecies risk of mixture toxicity, we propose the following same procedure that is followed in general mixture studies in single-species ecotoxi-cology. That is, one must consider exposure, look at exposed species groups when necessary in view of the assessment endpoints, consider the mode of action of the components, and apply either of the sets of models based on this information. The practical protocols for mixture risk assessment that stem from this choice are worked out and discussed in the section below. 

Bolt HM, Mumtaz MM. 1996. Risk assessment of mixtures and standard setting working towards practical compromises. Food Chem Toxicol 34 1179-1181. 

Source Information obtained from Landesman, L (2001). Chapter 5 Hazard assessment, vulnerability analysis, risk assessment and rapid heaith assessment In Public health management of disasters The practice guide. Washington, DC American Pubiic Heaith Association. The author gratefully acknowledges Dr. Linda Landesman and the American Public Heaith Association for permission to reproduce this work. 

---