The German Exposure Factors Database – RefXP

The Federal Environment Agency provides extensive current data facilitating population-based exposure modeling and assessment. These reference data describe inter alia

• food and drinking water consumption

• time-location and activity patterns

• soil and dust ingestion

• residential characteristics

• anthropometrics

of the general German population typically stratified by gender and age.

A major update and expansion of these data was achieved in 2006 by the research project Evaluation of standards and models for probabilistic exposure assessment – Xprob, which was carried outwithin the framework of the German Environment and Health Action Programme (APUG) in German  Xprob reviewed and assessed available data on various factors influencing human exposure to environmental and other stressors, with the aim of consistently compiling data supporting distribution-based (probabilistic) exposure estimation.

Based on the German “Standards for Exposure Estimation” published in 1995 by the German Environmental Health Council (AUH) scientists reviewed more than 50 sources of literature and survey files. They identified various additional datasets useful for exposure modeling and assessment purposes from Federal agencies and offices, from the German Federal States, and from scientific institutions and universities.

The Xprob scientists consolidated and organized these data by developing the German Exposure Factors Database – RefXP. The RefXP database contains the recommended reference values and statistical distributions for the German population. RefXP provides data descriptions in English and is available on the Internet for free download.

Another key output of the Xprob project is the SAS© script for fitting reference distributions to exposure factor data to allow performance of gender and age stratified probabilistic exposure estimations.

Results obtained using this script can directly be imported into the German Exposure Factors Database – RefXP .

Final report of the Xprob project

This German-language three-part report with English language summary provides extensive information on the scientific approaches used in Xprob : the development of the German Exposure Factors Database – RefXP , recommendations on exposure factors, and several case studies on probabilistic exposure modeling. The appendix of this report additionally provides guidance on how to carry out probabilistic modeling with RefXP data using the software @Risk©.