Characterization of the relationship between personal exposures to VOCs and behavioral, socioeconomic, demographic variables: Analysis of the 1999-2000 NHANES VOC data set
S.W. Wang, S. Tong, P.G. Georgopoulos
Environmental and Occupational Health Sciences Institute, UMDNJ - R.W. Johnson Medical School and Rutgers University, Piscataway, NJ
The objectives of the study presented here are (a) to examine the relationship between personal exposures to selected VOCs among individuals in a subpopulation of the National Health and Nutrition Examination Survey (NHANES) participants and demographic, socioeconomic, and behavioral variables using data collected in the 1999-2000 NHANES VOC Project, and (b) to identify the “best predictors” among these variables in determining personal exposure levels of the selected VOCs. These individuals were a representative subsample of NHANES participants between the ages of 20 and 59 years. In addition to personal exposure measurements to ten VOCs, information about individual demographic, socioeconomic status, as well as time and activity data for the exposure period are available for these participants. The time and activity data collected via the specially designed questionnaire can help identify possible sources of exposures and characterize activities that might contribute to exposure. A systematic data analysis procedure is employed to the step-by-step resolution of limitations that may exist in the 1999-2000 NHANES VOC dataset; these include missing values, collinearity, non-linearity, interaction effects etc., which are explored and addressed through graphical exploratory analysis, canonical correlation analysis, and non-parametric exploratory analysis such as Classification And Regression Trees (CART) with the Bootstrap Aggregating (Bagging) algorithm. The data analysis outcomes provide valuable information on characterizing significant exposure factors among demographic, socioeconomic, and activity variables to affect personal exposures.
This work is funded in part by a University Partnership Agreement between the U.S. Environmental Protection Agency (USEPA) and EOHSI. Viewpoints expressed here do not necessarily reflect the views of USEPA or its contractors.