Assessment of chemical risks

In a catchment area, industries, particularly those involved in extraction, manufacturing and processing, may be important in the assessment of chemical risks of drinking-water because they can be the source of significant contamination. 

The implementation of Agenda 21, in particular chapter 19 on the Environmentally Sound Management of Toxic and Dangerous Products and the references to aspects of chemical pollution in its other chapters, also requires a broader approach to the assessment of chemical risks than that embodied in the original UNEP list [1]. 

Assessment of chemical risks in the Indian context and anticipatory action for abatement by regulatory agencies have been taken up as follows ... 

Against this background, it is essential that the chemical industry determines in a realistic manner the actual risk posed by its products. Assessment of chemical risk gives the data on which to base the saifety of chemical industry workers, the public at large and the environment. 

The recognition of the hazard of a chemical is the first step of a prevention approach. From the exhaustive inventory of the sources of danger in the workplace, all the professionals of the SHE (Safety Health and Environment) team will perform a detailed assessment of chemical risks to workers at their workplace. With no possibility of replacing a hazardous substance by another which would not or would be less dangerous, professional actors of prevention must, before anything else, inform all workers about the risks of these substances. Finally, they will select, implement, and enforce collective and individual measures of prevention. It is this approach that we develop later in this chapter. 

Richardson, M.L. (ed.) (1988) Risk Assessment of Chemicals in the Environment, The Royal Society of Chemistry, London. 

Determination and assessment of the risks of hazardous chemical agents requires knowledge of, among other things, the nature of the agents, the type and duration of the exposure, the gravity of risk, and the criteria chosen for the OEL. The purpose is to make quantitative measurements of the work environment in order to compare the exposure with the limit value by means of an independent scientific assessment using the best available scientific methodol-... 

J. Rodricks, and R. Tardiff, Assessment and Manogement of Chemical Risks. Washington D.C., American Chemical Society, 1984. 

To assess tlie overall potential for noncarcinogenic effects posed by more dian one chemical, a liazard index (HI) approach has been developed based on EPA s Guidelines for Healdi Risk Assessment of Chemical Mixtures. This approach assumes that simultaneous subtlu eshold exposures to several chemicals could result in an adverse healtli effect. It also assumes tliat tlie magnitude of the adverse effect will be proportional to tlie sum of the ratios of the subtlireshold exposures to acceptable exposures. The non cancer hazard index is equal to tlie sum of the hazard quotients, as described below, where E and tlie RfD represent the same exposure period (e.g., subclironic, clironic, or shorter-term). 

Concise International Chemical Assessment Documents (CICADs) are published by the International Programme on Chemical Safety (IPCS) — a cooperative programme of the World Health Organization (WHO), the International Labour Organization (ILO), and the United Nations Environment Programme (UNEP). CICADs have been developed from the Environmental Health Criteria documents (EHCs), more than 200 of which have been published since 1976 as authoritative documents on the risk assessment of chemicals. 

A biomarker is here defined as a biological response to an environmental chemical at the individual level or below, which demonstrates a departure from normality. Responses at higher levels of biological organization are not, according to this definition, termed biomarkers. Where such biological responses can be readily measnred, they may provide the basis for biomarker assays, which can be nsed to stndy the effects of chemicals in the laboratory or, most importantly, in the field. There is also interest in their employment as tools for the environmental risk assessment of chemicals. 

Recently, there has been a growth of interest in the development of in vitro methods for measuring toxic effects of chemicals on the central nervous system. One approach has been to conduct electrophysiological measurements on slices of the hippocampus and other brain tissues (Noraberg 2004, Kohling et al. 2005). An example of this approach is the extracellular recording of evoked potentials from neocortical slices of rodents and humans (Kohling et al. 2005). This method, which employs a three-dimensional microelectrode array, can demonstrate a loss of evoked potential after treatment of brain tissue with the neurotoxin trimethyltin. Apart from the potential of in vitro methods such as this as biomarkers, there is considerable interest in the use of them as alternative methods in the risk assessment of chemicals, a point that will be returned to in Section 16.8. 

Quantitative risk assessment is now used extensively for determination of chemical and microbial risks in food. This concept helps to systematically and scientifically judge whether certain hazardous compounds may reach unacceptable risk levels when ingested. Quantitative risk assessment can support both quality design and quality assurance but, we discuss it from the assurance perspective. In the past decade, much attention has been paid to assessment of microbial risks due to then-typical differences as compared to chemical risks ... 

Safe, S. (1998) Hazard and Risk Assessment of Chemical Mixtures Using the Toxic Equivalency Factor Approach. Environmental Health Perspectives, 106(Suppl. 4), 1051-1058. 

Most of the provisions of the Toxic Substances Control Act (TSCA) of 1976 (PL 94-469) rely in some way on risk assessment of chemicals. Under the reporting requirements of the statute, any manufacturer, processor, or distributor of a chemical for commercial purposes must inform the EPA immediately after discovering any information which "reasonably supports the conclusion" that a chemical substance or mixture "presents a substantial risk of injury to health or to the environment" unless the EPA Administrator has been adequately informed already. EPA is mandated to establish regulations for testing new or existing substances when it is determined that there is not enough health or environmental information, that testing is necessary to develop such information and that the chemical or mixture "may present an unreasonable risk of injury to health or the environment."... 

The analysis of chemical risk is a process comprising the following elements hazard identification, exposure assessment, dose-response assessment, and risk characterization [6]. Figure 1 shows the main elements that constitute the risk characterization process together the methodologies used for their determination. The essence of risk characterization is to relate the exposure (the concentration of a... 

Van Leeuwen CJ, Hermans JLM (1995) Risk assessment of chemicals an introduction. Kluwer Academic, Dordrecht... 

Health IfEa (1999) Risk assessment approaches used by UK government for evaluating Human Health Effects of Chemicals. Risk Assessment, Toxicology Steering Committee (RATSC)... 

EcoFate EcoFate is a software package for conducting ecosystem based environmental and ecological risk assessments of chemical emissions by point and non-point sources in freshwater and marine aquatic ecosystems, including lakes, rivers and marine inlets... 

Olsen SI, Christensen FM, Hauschild M et al (2001) Life cycle impact assessment and risk assessment of chemicals -a methodological comparison. Environ Impact Assess Rev 21 385 104... 

The potential for a compound to induce carcinogenicity is a crucial consideration when establishing hazard and risk assessment of chemicals and pharmaceuticals in humans [53]. To date, the standard approach to assess carcinogenicity at a regulatory level is the 2-year bioassay in rodents. According to the recent REACH... 

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