Association between mercury exposure and lung function in young adults: A prospective cohort study in Shandong, China

Background: Mercury has been associated with many adverse health outcomes. However, limited studies have explored the association between blood mercury concentrations and lung function. Objective: To examine the association between blood mercury concentrations and lung function among young adults. Methods: We conducted a prospective cohort study among 1800 college students based on the Chinese Undergraduates Cohort in Shandong, China during August 2019 and September 2020. Lung function indicators including forced vital capacity (FVC, ml), forced expiratory volume in 1 s (FEV1, ml) and peak expiratory flow (PEF, ml) were collected with a spirometers (Chestgraph Jr. HI-101, Chest M.I., Tokyo, Japan). The blood mercury concentration was measured using inductively coupled plasma mass spectrometry. We divided participants into low (<= 25 percentiles), intermedi-ate (25-75 percentiles), and high (>= 75 percentile) subgroups according to blood mercury concentrations. The multi-ple linear regression model was used to examine the associations between blood mercury concentrations and lung function changes. Stratification analyses by sex and fish consumption frequency were also conducted. Results: The results showed that each 2-fold increase in blood mercury concentrations was significantly associated with - 70.75 ml [95 % confidence interval (CI): -122.35, -19.15] change in FVC, -72.68 ml (95%CI: -120.36, - 25.00) in FEV1, and -158.06 ml (95%CI: -283.77, -32.35) in PEF. The effect was more pronounced among par-ticipants with high blood mercury and male participants. Participants who consumed fish more than once a week more likely to be affected by mercury. Conclusion: Our study indicated that blood mercury was significantly associated with decreased lung function in young adults. It is necessary to implement corresponding measures to reduce the effect of mercury on the respiratory system, especially for men and people who consumed fish more than once a week.