Exposure analysis aggregate

Wilson, N.K., Chuang, J.C., Lyu, C., Menton, R. and Morgan, M.K. (2003) Aggregate exposures of nine preschool children to persistent organic pollutants at day care and at home. Journal of Exposure Analysis and Environmental Epidemiology, 13,... 

Blancato JN, Knaak JB, Power F (2000) Use of PBPK models for assessing absorbed dose and ChE inhibition from aggregate exposure of infants and children to organophosphorous insecticides. Presented at 10th Annual Meeting of the International Society of Exposure Analysis, Monterey, CA (Abstract 3F-09o)... 

Although selection of the appropriate analysis techniques is often very problem specific, the basic elements of human health risk analysis are few, as presented in Figure 1. The figure shows that the aggregate risk to human health from exposure to an airborne pollutant results from two factors (1) the spread of the primary agent (and/or its... 

Pang, Y., Macintosh, D.L, Camann, D.E. and Ryan, P.B. (2002) Analysis of aggregate exposure to chlorpyrifos in the NHEXAS-Maryland investigation. Environmental Health Perspectives, 110, 235 10. 

Pharmacokinetic calculations yielded estimates of chlorpyrifos intake of 0.05-1 pg/kg per day in the general population. The model estimates compare favorably with pathway analysis estimates of aggregate chlorpyrifos exposure from numerous dose routes, including indoor inhalation, dermal contact, and food ingestion (Shurdut et al. 1998 Pang et al. 2002). The calculated exposure doses ranged from 0.02 to 1 pg/kg per day. Further... 

Aggregate exposure assessment is naturally more complex than the methods used for dietary risk assessment. In the simplest analysis a worst case can be established for each source and exposure route and then summed to give a total exposure. If this were below any threshold of concern such as the PTWI then no further action would be required. However, if the total worst case exposure was above a PTWI then it is unlikely to reflect the real situation since the probability that any individual would be exposed to each source by each route at the maximum level is very remote. 

Scenario uncertainty includes descriptive errors (e.g. wrong or incomplete information), aggregation errors (e.g. approximations for volume and time), errors of assessment (e.g. choice of the wrong model) and errors of incomplete analysis (e.g. overlooking an important exposure pathway). 

Incomplete and irrelevant specification of the above elements of the exposure scenario may be related to lack of knowledge, descriptive errors, aggregation errors, errors in professional judgement and incomplete analysis (USEPA, 1992). 

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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