Comparative study of tear lipid composition in two human populations with different exposure to particulate matter in La Plata, Argentina

Abstract

To identify the changes in the lipid profile of the tear film in two human populations exposed to different levels of particulate material, and its relationship with dry eye, by gas chromatography with mass spectrometry (GC-MS) detection. A panel study involving 78 volunteers, who live and work in two locations in Argentina with different pollution levels: urban zone (n = 44) and industrial zone (n = 34). We measured the mean levels of particulate matter (PM) exposure. The tear samples were analyze by gas GC-MS detection and the dry eye was diagnose using Schirmer test, fluorescein breakup time, vital staining with fluorescein and lissamine green, and lid parallel conjunctival folds (LIPCOF). Statistical analysis was performed using Chi-Square, Bartlett's, Mann-Whitney tests, and Multiple Correspondence Analysis. PM 10 level was significantly higher in industrial zone than in urban area (p < 0.05). Subjects exposed to higher levels of PM 10 in outdoor air presented more presence of fatty acids (FA) of long chain, a higher proportion of saturated fatty acids (SFA), and lower unsaturated fatty acids (UFA), showing a differentiated profile, which may be associated with a PM level. The incidence of dry eye was greater in the industrial zone (p < 0.001), showing in both populations for this pathology higher FA ω-6 levels, which are responsible for the inflammation process. The lipid profile in populations exposed to higher levels of PM 10 , like the industrial zone, shows a differentiated profile of FA and more incidence of dry eye with higher FA ω-6 levels, which are responsible for the inflammation process.

Tear Fluid as a Matrix for Biomonitoring Environmental and Chemical Exposures

“…For example, the TFLL properties are dictated by its lipid composition (e.g., the types of lipids, saturation content, ratio of the short-to long-chain fatty acids), and this is demonstrated by the varying properties of different TFLL models (especially with the incorporation of free fatty acids) 104 . Changes in the TFLL composition induced by air pollution are predictable, and these patterns can differentiate air pollution exposure groups 105 . Gas chromatography mass spectrometry analysis of fatty acid concentrations in the tear uid of volunteers have reveled associations between air pollution and the fatty acid pro le of the tear uid 105 .…”

“…Changes in the TFLL composition induced by air pollution are predictable, and these patterns can differentiate air pollution exposure groups 105 . Gas chromatography mass spectrometry analysis of fatty acid concentrations in the tear uid of volunteers have reveled associations between air pollution and the fatty acid pro le of the tear uid 105 . Speci cally, people living in an urban (low-pollution) location exhibited a signi cant difference in the concentration of 15 fatty acids compared to volunteers from an industrial (high-pollution) location (p < 0.05) 105 .…”

“…Gas chromatography mass spectrometry analysis of fatty acid concentrations in the tear uid of volunteers have reveled associations between air pollution and the fatty acid pro le of the tear uid 105 . Speci cally, people living in an urban (low-pollution) location exhibited a signi cant difference in the concentration of 15 fatty acids compared to volunteers from an industrial (high-pollution) location (p < 0.05) 105 . A signi cantly greater concentration of long-chain fatty acids (p < 0.05) and a signi cant increase in the saturated-to-unsaturated fatty acid ratio (p < 0.05) was reported in the group exposed to more air pollution; multivariate analysis of chain length and saturation ratio demonstrated statistically signi cant clustering (p < 0.0001) 105 .…”

Monitoring human genotoxicity risk associated to urban and industrial Buenos Aires air pollution exposure

“…Gravimetry was used to determine the particle content in each sample. PM collection was carried out simultaneously in both areas following the methodology of (Gutierrez et al 2019).…”

Tear analysis as the next routine body fluid test

“…From another aspect, the ocular surface is directly exposed to the outside environment, thereby making tear composition incredibly sensitive to external environmental changes. One recent study reported significant differences in tear lipid composition in two human populations with different exposure to particulate matter in urban and industrial zones [ 6 ], which can be valuable in characterizing environmental pollution and its impact on disease. In addition, tear chemical composition is sensitive to internal emotional and psychological states.…”