Air pollution, including PM10, as a potential risk factor for the development of appendicitis in Korea: a case-crossover study

Objectives: Interest in the association between particulate air pollution and appendicitis risk has been increasing in recent years, and previous studies have suggested a link between particulate matter ≤10 μm in diameter (PM10) and appendicitis. However, robust evidence is currently lacking. This study explored the association between short-term PM10 exposure and appendicitis using data from Ewha Womans University Mokdong Hospital, Seoul, Korea, between January 1, 2001 and December 31, 2018. Methods: We employed a time-stratified case-crossover design using data from 6,526 appendicitis patients taken from the hospital's electronic medical records system. We analyzed the data using a conditional logistic regression model adjusted for daily mean temperature and relative humidity. The effect size of PM10 was estimated in terms of each 10 μm/m3 increase in PM10 concentration. Sex, season, and age group were analyzed as subgroups. Results: Appendicitis patients had been exposed to higher levels of PM10 concentrations 3 days (OR 1.045, 95% CI : 1.007–1.084) and 7 days (OR, 1.053; 95% CI, 1.005–1.103) before hospital admission. The case-crossover analysis stratified by sex, age, and season showed that the male sex, being aged under 10, and the cold season were associated with a significantly stronger association between appendicitis and PM10 concentrations. Conclusion: Our study found that PM10 concentrations were associated with appendicitis in boys aged under 10. The cold season was also a risk factor. Further research with a larger sample size and with other pollutants is required to clarify the association between PM10 and appendicitis.