Recent exposome projects under the European Union FP7 research program: Global screening of environmental exposure-disease associations and biomarkers.

Background: Studies in migrant populations and other investigations clearly show that the ‘environment’ plays an important role in the etiology of many chronic diseases, but characterizing the environmental risk factors is currently far more challenging than identifying genetic factors.

Aims: We recently conducted two ‘proof-of-principle’ studies in which the global screening of environmental exposure-disease associations and biomarkers was the central aim. In the design and conduct of these studies issues arose regarding appropriate study designs, suitability of existing biobanks, laboratory technologies, and statistical analyses.

Methods: The CLEAR study is a global screening study of environmental contaminants and reproductive health in Greenlandic and European populations. The EnviroGenomarkers study is a study on identifying genomic biomarkers of environmental health with a specific focus on lymphoma. Results: Several pilot studies have been performed to study the suitability of using existing biobanked materials (i.e EPIC cohort) for exposomic research. These evaluations indicated that under certain conditions biobanked materials can be used. Statistical tools were developed to deal with nuisance variance in the laboratory analyses and methods were explored to deal with the large P small n problem. This problem refers to the fact that within exposome research it is like that the number of parameters (p) is much larger than the number of observations (n).

Conclusions

: These early studies on the exposome in relation to environmental diseases have shown promise with regard to the use of existing biobanked materials; have indicated methodological issues with regard to epidemiological designs; and have revealed the need for the development of statistical tools to aid the appropriate analyses of exposomic data.