ABSTRACT
Background: Numerous epidemiological studies showed close relationships of outdoor air pollution with increased risk of cancer, infection, and cardiopulmonary diseases. However, a very limited number of studies investigate the potential biomarkers of the co-exposures of particle matters (PM) and bioaerosols, especially under current circumstances of the Coronavirus disease 2019 (COVID-19) pandemic. In the present study, we aimed to identify metabolic candidate biomarkers that are associated with co-exposure to PM and bioaerosols.Methods: We performed an unbiased gas/liquid chromatography-mass spectroscopy (GC/LC-MS) approach to detect urinary metabolites of 92 samples from young healthy individuals collected at three different time points with exposure to clean, polluted ambient, and purified air , followed by a cycling test after air re-pollution and re-purification with two additional time points. Subsequently, we compared metabolomic profiles in between two-time points via an integrated analysis, plus KEGG enriched pathway and time series analysis.Findings: We identified 33 and 155 differential metabolites (DMs) associated with PM and bioaerosol exposure, respectively. The results from KEGG data and time series analysis indicated significantly enriched pathways and dynamic alterations of metabolomic profiles, respectively. 16-Dehydroprogesterone and 4-Hydroxyphenylethanol in urine might be used as biomarkers for diagnosis of PM- or bioaerosol-relevant diseases.Interpretation: The present studies revealed dynamic alterations in urinary metabolites of young healthy humans with the cycling of the clean and polluted air environment. Our findings help to investigate detrimental health effects of airborne PM and bioaerosols in a real-time manner and improve clinically diagnostic tools for PM- and bioaerosol-related diseases.Funding Information: This work was financially supported by the National Natural Science Foundation of China [NSFC Grant no. 81673958, 82074262, and 81828010]; CAMS Innovation Fund for Medical Sciences [CIFMS 2016-I2M-3-013]; The Drug Innovation Major Project of China [2018ZX09711001-007-002].Declaration of Interests: The authors declare no conflicts of interest in this work.Ethics Approval Statement: Our study was approved by the Ethical Committee of Guang'anmen Hospital. All recruited subjects provided written informed consent.