Long-term exposure to ambient air pollution and serum liver enzymes in older adults: A population-based longitudinal study.

PURPOSE: To investigate the association of long-term exposure to ambient air pollution with serum liver enzymes in older adults.

METHODS

In this longitudinal study, we investigated 318,911 adults aged 65 years or older and assessed their long-term residential exposure to particulate matter with an aerodynamic diameter ≤2.5 µm (PM2.5), particulate matter with an aerodynamic diameter ≤10 µm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3). Linear mixed models and generalized linear mixed models were implemented for exposure-response analyses.

RESULTS

Each interquartile range (IQR) increase of PM2.5, PM10, SO2, NO2, CO, and O3 exposures was significantly associated with a 4.6%, 4.6%, 5.6%, 4.6%, 6.2%, and 3.6% increase in alanine aminotransferase (ALT), and a 4.6%, 5.2%, 3.6%, 3.3%, 6.1%, and 4.0% increase in aspartate aminotransferase (AST), respectively. Each IQR increase of PM2.5, PM10, SO2, NO2, CO, and O3 exposures was significantly associated with a 23%, 24%, 28%, 17%, 31%, and 19% increase in odds of elevated ALT (>40 U/L), and a 32%, 39%, 40%, 32%, 57%, and 25% increase in odds of elevated AST (>40 U/L), respectively.

CONCLUSIONS

Long-term exposure to ambient air pollution was significantly associated with increased serum liver enzyme levels in older adults, suggesting that air pollution exposures may induce hepatocellular injury.