Toxicity Testing Strategies to Determine Needs and Priorities (1984) / Chapter Skim
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5. FUTURE DEVELOPMENT, IMPLEMENTATION, AND REFINEMENT OF THE SYSTEM
5. FUTURE DEVELOPMENT, IMPLEMENTATION, AND REFINEMENT OF THE SYSTEM
Pages 285-294
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From page 285... ...
DEVELOPMENT The system as illustrated is potentially capable of screening tens of thousands of substances and determining -- after specified informationgathering steps -- for which of them it would be warranted to apply a battery of short-term tests or a long-term carcinogenicity bioassay. To a lesser extent, it could screen the same universe of chemicals to select those which should be tested for other health effects.
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From page 286... ...
This will require both a value judgment as to the severity of an effect and a scientific judgment as to the availability of tests, the number of toxic substances in the universe, accuracy of the tests, and the importance of classifying chemicals correctly with respect to such effects. · Development of data elements, estimation of their accuracy, estimation of the number of chemicals that cause a health effect, determination of misclassification costs, and development of corresponding decision rules for the additional health effects selected.
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From page 287... ...
· Definition of a universe of substances and preparation or augmentation of data bases with environmental chemicals, food constituents, pyrolysis products, etc. · Development of software for building computerized files for Stage 1 operation, including provisions for maintaining status lists ("dormant,n "on test," "Stage 2 minidossiers complete," etch.
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From page 288... ...
· Design of a feedback and control system for continuous updating of the system. · Provision of an effective interface between the established agency nomination process and the proposed "long-list" process.
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From page 289... ...
One must, for example, consider what constitutes "truth" for the purposes of evaluation when there is uncertainty about the interpretation of the results of tests in terms of health effects in humans.
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From page 290... ...
Each group could be asked questions to ascertain its perceptions on exposure or health effects. Using techniques from epidemiology (Buffler and Sanderson, 1981)
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From page 291... ...
One concerns perceptions of the relative harmfulness of various health effects; in general, the amount of resources devoted to the study of a health effect varies as a function of the degree of public concern about it. The second issue concerns the relative costs of errors in misclassifying chemicals.
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From page 292... ...
One requirement is that their results be able legitimately to alter expert opinion regarding degree of concern about a chemical. Whether the potential for such alteration justifies even their low costs can be addressed systematically by value-of-information analysis in the framework described in this report.
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From page 293... ...
The decision will depend much more heavily on the resources available for testing than on the concern engendered by having a large set of poorly understood chemicals. One response to this situation is to delegate responsibility to the scientific community as a whole, on the assumption that the diversity of interests in that community will ensure that troublesome chemicals quickly come to attention.
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