Ocular Surface Effects of the 2008 Buenos Aires Wildfires

Abstract

Purpose: : To analyze the acute ocular surface effects of exposure to air pollutants emitted during a pasture burning episode.

Methods: : Particulate matter (PM), NOx, CO and SOx concentrations (cc) measured during April 16 to 20 (highest wildfire activity) were compared with cc measured during the rest of the year. A panel study was carried out involving 258 volunteers’ living in the Metropolitan Area of Buenos Aires (MABA), Argentina. All participants answered a symptoms questionnaire, which included a score of severity (1 to 4). G1 (n= 102) was evaluated between April 17th to 20th.; G2 (n=105) between May 14th to 19th; and G3 (n=51) on April 19th (G3a) and on May 18th. G3 subjects were also evaluated by ophthalmologic and laboratory tests. Sales of units of anti-allergic drops and artificial tears were analyzed. Statistical analysis was performed using one-way ANOVA, the Tukey HSD test and the Chi-Square test

Results: : During the period of highest fire activity, CO levels and total PM cc measured in the MABA were two orders of magnitude higher than the average for the region, and one order higher than the corresponding air quality guidelines. NOx values were higher than those usually registered, but SOx levels did not present significant variations. Table 1 shows the percentage of subjects with symptoms and [ ] the score of severity. Significant differences were found between G1 and G3a versus G2 and G3b (p≤0.01). There were no significant differences between groups concerning Schirmer I test, rose Bengal and fluorescein score, tear lysozyme levels and impression cytology. Sales of anti-allergic drops and artificial tears increased 57%.

Conclusions: : Exposure to wildfire smoke was associated with an increase in the frequency and severity of eye symptoms, a decrease in TBUT values, increased medication.

Keywords: cornea: tears/tear film/dry eye • conjunctivitis • inflammation