Abstract
The impact of exposure to fine particulate matter (PM(2.5)) on the incidence of knee osteoarthritis is unclear, especially in Beijing which is a highly polluted city. We conducted a time-series study to examine the correlation between PM(2.5) exposure and outpatient visits for knee osteoarthritis in Beijing. Changes (in percentage) in the number of outpatient visits corresponding to every 10-μg/m(3) increase in the PM(2.5) concentration were determined using a generalized additive quasi-Poisson model. There were records of 9,797,446 outpatient visits for knee osteoarthritis in the study period from 1 January 2010 to 31 December 2017. The daily concentration of PM(2.5) was 86.8 (74.3) μg/m(3) over this period. A 10-μg/m(3) increase in PM(2.5) concentrations on lag days 0-3 was associated with a 1.41% (95% confidence interval: 1.40-1.41%) increase in outpatient visits for knee osteoarthritis. Females and patients aged above 65 years were more sensitive to the adverse effects of PM(2.5) exposure. The present findings demonstrate that short-term exposure to PM(2.5) resulted in an increase in the number of outpatient visits for knee osteoarthritis in Beijing. The findings shed light on the effects of air pollution on knee osteoarthritis and could guide risk-mitigating strategies in cities such as Beijing.