Applying hair exposome for linking environmental exposure to reproductive health: A comprehensive review and research perspective

Increasing evidences have revealed a close relationship between various environmental exposures and reproductive health. The real-world complex exposure scenario along with intricate interactions effects of these exposures has high demands of exposome-wide association studies for human risk assessment. With the development of exposomic studies, applying hair exposome to link environmental factors and reproductive health outcomes has obvious potential advantages. However, the reliability of utilizing hair to characterize exposome is always of high concern for researchers. In this review, we briefly summarized studies about the effects of environmental exposures on several typical reproductive health outcomes, described state-of-the-art situation of applying hair exposome for reproductive health risk assessment, elucidated the advantages (e.g., containing abundant exposure factors, low expenses for sampling, and tracing exposure history), and proposed the unsolved issues in this area. We also conducted a comprehensive discussion about the reliability of various hair biomarkers and primarily established the biomarker databases. Finally, a standardized framework on using hair exposome for reproductive health study was proposed to provide fundamental approach for future studies. We concluded that it is promising to apply hair exposome to evaluate the effects of the environmental factors on human reproductive health.