Metrics occupational exposure

As with the case of mass, there are several approaches to metrics for this aspect. One can simply sum numbers and/or mass of chemicals possessing hazards in different areas for example, process safety, occupational exposure, or environmental hazard. Typically, most companies will use a banding approach for materials that allows a quick identification of the hazard category, and usually marries hazard with a suggested control approach for example, layers of protection, pressure relief valves, and so on. One is then able to rapidly identify issues and potential opportunities for elimination, substitution, or control. 

The approach to developing metrics for process safety is analogous to those that might be used to assess Occupational Exposure risk. One can cite as well several indices that have been developed as metrics for estimating and ranking the safety of a given process or chemical reaction, such as the DOW fire and explosion index,the Stoessel index ° for hazard assessment and classification of chemical reactions, the Inherent Safety Index, the Prototype Index for Inherent Safety, amongst others. ... 

The exposure metrics in studies of effects in children exposed as a result of then-parent s occupational exposure to pesticides are frequently based on pesticide use records or on questionnaire data, rather than on actual measurements of pesticide exposure in children (Kristensen et al, 1996 Garry et al 1996). 

The Immune Building Program of the Defense Advanced Research Projects Agency (DARPA) used FBE as a primary metric. FBE is defined as the fraction of the building (by volume) in which occupant exposures would exceed a prescribed level or guideline, typically evaluated as a function of the mass of agent released. 

Data on bone Pb and various toxic endpoints in humans have generally been generated for adults, and for adult populations having either occupational exposures or principally environmental contacts with the element. Bone Pb in children, for reasons presented in earher chapters, does not lend itself and has not lent itself to serving as a stable dose/exposure metric versus PbB in the very young child. 

Once there is a measure of the concentration of the pesticide in the exposure medium (air, water, food, etc.) in contact with the body or the actual concentration that comes into contact with the body, a daily dose metric can be calculated (e.g. maximum, average, geometric mean, etc.). This typically involves developing a mathematical equation that expresses dose as a function of pesticide concentration and other important parameters referred to as human exposure factors (USEPA, 1999a). In the context of this discussion, the term human exposure factor refers specifically to (a) human characteristics, such as body weight, surface area, life expectancy, inhalation rates for air and consumption rates for food, drinking water and soil (b) human behaviors, such as activity patterns, occupational and residential mobility and consumer product use, which are used by exposure assessors to calculate potential dose. 

OCCUPATIONAL AND RESIDENTIAL RISK ASSESSMENT 371 AOELs Versus MOEs 371 Route Considerations 372 Uncertainty and Safety Factor Selection 372 Aggregation and Cumulative Risk Assessment 372 CO-OPERATIVE REGULATORY ACTIVITIES 373 SUMMARY AND CONCLUSIONS 374 Terminology 374 Framework 374 Data Requirements 374 Methodological Guidance 375 Development and Utility of Databases 375 Modeling Initiatives 375 Data Analysis 375 Metric Selection 376 Research Needs 376 Exposure Mitigation 376 Risk Assessment 376 REFERENCES 376... 

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