Exposome in human health: Utopia or wonderland?

The current human exposome primarily emphasizes the total environmental exposure during an entire life. The characteristics of "lifelong" and "all environmental factors" make it very challenging to bring the exposomic study into real-life applications. Herein, we mainly discuss the typical application scenarios of exposomics and how to conduct an exposomic study to establish relationships between the exposome and human health. To increase the feasibility and efficiency, we propose that (1) an exposomic study can start with health events during critical-window periods; (2) both data- and hypothesis-driven exposomics should be combined to prioritize the risk of environmental factors; and (3) reliable statistical analysis of high-dimensional data of external and internal exposure factors are urgently needed. With standardization of the exposomic study, it will be critical to build a "wonderland" for human health.