摘要:

A 100-fold safety or uncertainty factor has been used for about 40 years to derive safe daily intakes for humans based on animal studies; the 100-fold factor comprises separate 10-fold factors to allow for species differences and inter-individual variability. Each factor has to allow for toxicokinetic and toxicodynamic differences. Sub-dividing the 10-fold factors into kinetic and dynamic defaults, which when multiplied give a product of 10, offers a number of advantages. The main rationale for this sub-division is so that chemicalspecific data can be introduced to replace one or more of the default sub-factors, hence contributing to a chemical-related overall factor. However, sub-division of the 10-fold factors has allowed analysis of the appropriateness of the overall 10-fold defaults, and analysis of special situations, such as infants and children. The establishment of an acute reference dose based on animal studies has to allow for both species differences and inter-individual variability; comparison with the factors used for chronic effects suggests that modification of the usual defaults may be appropriate under certain specific circumstances, but that the usual default of 100 remains appropriate for most cases.

ISSN:0265-203X    

DOI:10.1080/026520300412555

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The question of the variability of pesticide residues and acute risk assessment has arisen in the context of the work of the European Commission's Scientific Committee for Plants (SCP). A brief outline is presented of European Community legislation on pesticide residues and the authorization of plant protection products. It is stated that although chronic risk assessment is systematically carried out in connection with the fixing of Community MRLs, the same has not applied for acute risk assessment. The reasons for this situation have been the absence of an agreed methodology, acute reference dose (RƒD) and adequate dietary and residue data. It is stated that in the opinion of the Scientific Committee for Plants an acute risk assessment should be considered on a routine basis and that steps should be taken to ensure the availability of the necessary data. Possible implications for risk communication and the authorization of plant protection products in the EC are also discussed.

ISSN:0265-203X    

DOI:10.1080/026520300412564

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The passage of the Food Quality Protection Act (FQPA) in August of 1996 increased the role of risk assessment in the decision-making process of the US Environmental Protection Agency (EPA). Although the law and guidance issued by the EPA provide for more sophisticated risk assessments, the databases for many chemicals may not be robust enough for such data-sensitive analyses. FQPA mandated a major change in how the EPA evaluates the safety of pesticides. This change was immediate, without provision for a phase-in period. Consequently, the EPA is still in the process of learning how to evaluate pesticides under the new paradigm. The EPA's task was further compounded by the lack of scientifically tested methodologies for evaluating aggregate and cumulative risk, as required under the new law. Clearly, the EPA is still in a state of transition between evaluating aggregate and cumulative risks to pesticides and evaluating them one chemical and one exposure route at a time. In all likelihood, the transition period will continue as the discipline of risk assessment develops the mental constructs and computational methodologies to fulfil the requirements of the law. In this interim period, therefore, policies are needed so the regulators and the regulated industry know what is currently acceptable, and how the EPA's thinking is evolving.

ISSN:0265-203X    

DOI:10.1080/026520300412573

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

A number of developments have taken place in addressing consumer risk to pesticide residues. Progress is being made to harmonize an international database to allow short exposure assessments to be carried out on a routine basis and a number of initiatives have been arranged to support this process. Since Codex Alimentarius Commission has adopted these proposals, they will become an integral part of the process for assessing and accepting Codex MRL s in the future.

ISSN:0265-203X    

DOI:10.1080/026520300412582

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor