Prioritization and Hazard Assessment of Chemicals

The persistence and fate of a pollutant depend as much on environmental factors as on its physico-chemical properties. Hence, it is important that testing protocols be designed to maximize the applicability of the end results to different environmental conditions. It is necessary to decide how closely 

The resolution in prediction does not necessarily increase linearly with the refinements made on the relation describing a given environmental process (O Neill, 1971 Miller et al., 1976). In the case of screening models, there is an optimum point above which an increase in the complexity of the model does not increase the usefulness of its predictions as basic indicators of behavior patterns (Roberts etaL, 1981). Complex models can mask some very basic problems inherent to our data base. There are fundamental dangers in this situation where we can create elegant scenarios and complex tables of numbers that do not possess well-established or reasonable confidence limits (Roberts etaL, 1981). Thus, a less-detailed model is preferable to permit the user to recognize easily its limitations and make scientific adjustments accordingly. 

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Process Hazard Analysis— An organized effort to identify and evaluate hazards associated with chemical processes and operations to enable their control. This review normally involves the use of qualitative techniques to identify and assess the significance of hazards. Conclusions and appropriate recommendations are developed. Occasionally, quantitative methods are used to help prioritize risk reduction measures. 

Organization for HAZMAT Emergencies Part 1 Hazards Analysis Uses case studies to explain hazard identification, vulnerability analysis, risk assessment toxicity, flammability, and reactivity of chemicals prioritizing hazards and how vapor plumes are affected by weather and chemical composition. 

The EU approach to chemicals control is based on a stepwise process of hazard assessment, risk assessment, and risk management. This process assists a rational prioritization in the allocation of limited resources to achieve a high level of health and environmental protection. Because this process often involves uncertainties due to insufficient or inconclusive scientific evidence, the precautionary principle may need to be applied in cases where there are indeed reasonable grounds for concern that health or the environment may be seriously endangered. The precautionary principle was first recognized in international law in the World Charter for Nature, adopted by the UN General Assembly in 1992. At the Rio Conference on the Environment and Development, Principle 15 states that in order to protect the environment, the precautionary approach shall be widely applied by... 

To perform a risk assessment and then prioritize the exposure measurement effort requires an approximate initial exposure potential assessment. For each chemical present and for each source of exposure for that chemical, an estimate of exposure can be made. These exposure estimates combined with a toxicity estimate from the hazard data can then be combined to yield a risk estimate which can be used as a basis for prioritization of the measurement and monitoring effort. 

An environmental health rapid assessment tool for use by EHOs accessing affecting sites immediately postcyclone divides assessment into key themes of drinking water, sewerage, waste, asbestos, food safety, personal hygiene, vectors, and chemical hazards. The tool has a section for EHOs for prioritizing environmental health issues and priorities in line with the key themes. 

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