Ambient PM2.5 components might exacerbate bone loss among middle-aged and elderly women: evidence from a population-based cross-sectional study.

Background: Previous studies have primarily focused on the links between fine particulate matter (PM_2.5) and bone health among the general population instead of PM_2.5 components and the specific population. We aimed to investigate the associations between PM_2.5 components and bone health among middle-aged and elderly women.

Methods: A total of 748 middle-aged and elderly women were randomly sampled from 32 streets/villages in Hubei Province. The concentrations of ambient PM_2.5 and its components were extracted across various residential areas from the Tracking Air Pollution in China (TAP) dataset. Bone mineral density measurements were obtained from dual-energy X-ray absorptiometry scans of study participants. Multivariable logistic and linear models were employed to assess the relationship between PM_2.5 and its components and bone loss.

Results: Per interquartile range (IQR) increase in nitrate (NO₃^-) and ammonium (NH₄⁺) concentrations were associated with 1.65 [95% confidence intervals (CI): 1.13, 2.30] and 1.77 (95% CI: 1.26, 2.49) times higher odds of osteoporosis, respectively. Long-term exposure to sulfate (SO₄^2-), NO₃^-, and NH₄⁺ was negatively associated with T-scores and bone mineral density in L1-L4 lumbar vertebrae. In addition, the elderly, women who have experienced menarche after the age of 14, and postmenopausal women were more susceptible to the water-soluble inorganic salts of PM_2.5.

Conclusion: The study emphasizes the need for comprehensive policies addressing air quality, with a specific focus on vulnerable populations such as middle-aged and elderly women. Public health interventions aimed at reducing ambient PM_2.5 concentrations and minimizing exposure to its harmful components are crucial in mitigating the adverse impact on skeletal health and improving the overall well-being of communities.