EXPOSURE ASSESSMENT

Input: Emerging Issues

A number of critical exposure assessment research needs were identified in the first decade of the National Occupational Research Agenda (NORA).

• Research is needed to advance and streamline the hazard and exposure assessment processes associated with emerging technologies.
• New methodologies will be required to better anticipate and recognize problem areas and to produce exposure assessments that address risk assessment, management, and communication issues.
• Control banding methods should be enhanced, and additional modeling methods should be developed and validated to address other needs such as exposure classification, exposure ranking, data interpretation, expert systems, and complex exposure scenarios such as mixtures and nonambient conditions.
• Methodologies between disciplines that rely on exposure assessment should be integrated.
• Available information on the relationships between exposure and health outcomes must continue to be gathered and published as a practical guide for epidemiological studies to improve the consistency and quality of exposure assessment, as well as to identify gaps in the knowledge base and opportunities for improvement of exposure assessment.
• The National Occupational Exposure Survey should be updated and expanded.
• The necessary contents of a national occupational exposure database are being developed, and such a database should be implemented.
• A data interpretation and analysis guide should be developed. For example, the AIHA has published a document, entitled A Strategy for Assessing and Managing Occupational Exposure, which advances the work on determining compliance with an occupational exposure limit. Further work is needed to determine sampling strategies so that the decision process can be based on modeling efforts.
• Refinement of injury risk assessment, such as developing accurate exposure durations, will identify at-risk workers. It can also result in cost-effective control and intervention strategies, exposure-response relationships, and more accurate risk assessments.
• Control banding, a qualitative predictive model, should be considered as a new approach to exposure assessment.
• Methodology is needed to measure nontraditional exposures such as work organization and other stressors.
• Methodology and reporting of results should be standardized to make it easier for all to understand and use exposure assessment data.
• A biomarker database should be developed. This database would list the biomarker and the stage of validation.
• A national biomonitoring manual should be developed from which standardized methods could be drawn.
• Guidelines should be developed that could be used by occupational safety and health practitioners to use biomarkers and guidelines to interpret and communicate biomarker results.

A number of additional critical research recommendations were also developed in the first decade of NORA for issues related to the assessment of mixed exposures:

• Develop and implement new surveillance methods to determine the number of workers exposed to mixtures, the range of exposure concentrations, and the associated health effects.
• Partner to characterize mixed exposures within specific occupations and industries.
• Conduct research to better understand the biological mechanisms and toxicology of mixed exposures.
• Understand and integrate experimental data from the molecular to the whole organism level, including proteomics and genomics.
• Develop methods to measure and predict deviations from additivity.
• Develop and validate mechanism-based exposure-response models.
• Develop the concept of the ‘virtual human’ by means of computer simulation.
• Develop default parameters for mechanistically based risk estimation and extrapolation models.
• Develop biosensors or measurement technologies that indicate whole mixture toxicity.
• Identify, develop, and validate biomarkers of exposure and response for workers exposed to mixed exposures.
• Determine the effectiveness of engineering controls and personal protective equipment for mixed exposures, including the potential adverse effects of specific mixtures on the controls and equipment.