Relationship between air pollution and outpatient visits for nonspecific conjunctivitis in Taiwan

Abstract

Background: As a directly exposed part of the human body, the eyes are susceptible to external stimulations of air pollution. The ill effects of air pollution on human eyes are mostly irritation and inflammation, with conjunctivitis being a significant problem. Method: This study investigates the impact of air pollution on nonspecific conjunctivitis based on the data from ophthalmologic outpatient visits. The research focuses on the significance of air pollution's impact on ocular health. Data for ophthalmology outpatient visits were obtained from the National Health Insurance Research Database of Taiwan. Ambient air monitoring data were obtained from the Taiwan Environmental Protection Administration air pollution monitoring stations. Six regulated air pollutants were included in the studies. This study used symbolic data analysis to investigate the association between daily air pollutant concentrations and the number of outpatient visits for nonspecific conjunctivitis as well as the relationship between climate factors and air pollutants. Results: O3 (t-value=2.292, p-value=0.025) is positively correlated with nonspecific conjunctivitis cases; this result is the same as plot (d) in Figure 3. The relationship between nonspecific conjunctivitis cases and CO (t-value=-1.183, p-value=0.240) / NO2 (t-value=0.653, p-value=0.516) / NO2 (t-value=0.653, p-value=0.516) / SO2 (t-value=-0.942, p-value=0.349) is not statistically significant. Conclusion: The result of this study shows that the air pollutant, O3 is significantly related to nonspecific conjunctivitis. The air pollutant, O3 can increase chances of outpatient visits, suggesting that is a possible cause for nonspecific conjunctivitis.

Environmental influences on ophthalmic conditions: A scoping review

“…43 Higher levels of O 3 were also associated with the risk of developing nonspecific conjunctivitis (t-value = 2.292; p = 0.025) in a case-crossover study. 39 A time-stratified casecrossover study from China reached a similar conclusion. 36 Multivariate conditional logistic regression analyses showed that a 10 ppb increase in O 3 was positively associated with conjunctivitis (OR = 1.04; 95% CI: 1.03-1.04).…”

“…A cohort study identified that there was a positive association between higher levels of O 3 and allergic conjunctivitis (OR = 2.09; 95% CI: 0.49–3.69) 43 . Higher levels of O 3 were also associated with the risk of developing nonspecific conjunctivitis ( t ‐value = 2.292; p = 0.025) in a case‐crossover study 39 . A time‐stratified case‐crossover study from China reached a similar conclusion 36 .…”

“…Although one case‐crossover study in Taiwan 39 reported no statistically significant association between PM 2.5 and conjunctivitis visits, five others found that increased PM 2.5 is associated with an increase in conjunctivitis‐associated outpatient visits 34–38 . A cohort study in São Paulo, Brazil investigated the association between PM 2.5 and allergic conjunctivitis and found a positive association from May to July (OR = 9.05; 95% CI: 0.16–4.24) 40 …”

“…Although most studies from China (2), Taiwan (2) and Japan (1) report no statistically significant association between CO and conjunctivitis visits, [38][39][40][41]45 one casecrossover from China reports that an increase in CO leads to a mild increase in conjunctivitis-associated outpatient visits (OR = 1.0012; 95% CI: 1.0001-1.0023). 35…”

“…The association between PM 2.5 and all-cause conjunctivitis is also not unanimously agreed upon: whereas some researchers found a positive association, [34][35][36][37] a casecrossover study found no association. 39 This might be due to a difference in controlling factors and notably in the control of meteorological variables. Another casecrossover study also reported a positive significant association between PM 2.5 and conjunctivitis visits for every 10 μg/m 3 increase in concentration.…”