Associations between short-term PM2.5 exposure and hematological indices in healthy subjects

<bold>Introduction:</bold> Air pollution is recognized for its association with respiratory diseases; however, its impact on hematological alterations remains elusive. This study aims to investigate the correlation between short-term exposure to PM_2.5 and hematological parameters in healthy subjects. <bold>Materials and Methods:</bold> Between 2018 and 2022, we recruited 559 healthy individuals in Taipei, Taiwan. Hematological parameters (RBC, Hb, Hct, MCV, MCH, and MCHC) and 1-day, 7-day, and 1-month average PM_2.5 exposure data were collected. Multiple linear regression models were employed to explore associations between PM_2.5 and hematological parameters, adjusting for age, sex, BMI, and smoking status. <bold>Results:</bold> A 1µg/m³ increase in 1-month PM_2.5 was associated with a 0.0173g/dL increase in MCHC (95%CI=0.0023~0.0323, p<0.05). Among females, a 1µg/m³ increase in 1-month PM_2.5 correlated with a 0.0088M/µL decrease in RBC (95%CI=-0.0167~-0.0005, p<0.05) and a 0.0178g/dL increase in MCHC (95%CI=0.0001~0.0355, p<0.05). For subjects aged <65, a 1µg/m³ increase in 7-day PM_2.5 was associated with a 0.0139M/µL decrease in RBC (95%CI=-0.0246~-0.0032, p<0.05), a 0.2518fL increase in MCV (95% CI = 0.0427 ~ 0.4609, p<0.05), and a 0.1027pg increase in MCH (95%CI=0.018~0.1875, p<0.05). A 1µg/m³ increase in 1-month PM_2.5 was associated with a 0.0107M/µL decrease in RBC (95%CI=-0.0199~-0.0019, p<0.05), a 0.0789fL increase in MCV (95%CI=0.0108~0.1469, p<0.05), and a 0.0313g/dL increase in MCHC (95%CI=0.0105~0.0521, p<0.05). <bold>Conclusion:</bold> This study reveals a significant association between increased PM2.5 pollution and noteworthy alterations in blood parameters, impacting both red blood cell count and cell hemoglobin concentration.