Impact of lachrymal film's alterations and corneal sensibility on fine particle exposure

The effects of air pollution on human health are known since several years. The epidemiological research carried out in the 1990s focused on new health damages due to environmental pollutant concentration usually present in urban areas. The ubiquitous particulate matter (PM) pollutant is made up by several substances with toxic characteristics, such as sulfates, nitrates, metals and numerous organic chemical substances absorbed on the surface; it has a high penetration quality and is carried on, even at great distance. We have investigated the possible alterations of the lachrymal film (the thin transparent layer that covers the corneal and conjunctival epithelium with lubricating, protective and antimicrobial functions) in population, particularly exposed to air pollution caused by fine PM. This study has been carried out on the resident population in urban area of Taranto (Southern Italy). On 236 examined patients, three tests have been performed: Schirmer's test for evaluating the lachrymal function, Break Up Time (B.U.T.) test for investigating the possible qualitative alterations of the mucolipic layer of the lachrymal film, and ocular Ferning test for providing information on the tear osmosis as well as on their stability. No significant variations of the lachrymal film's alterations in the two tested control groups have been noticed in presence of different air pollutants levels and/or, in particular, the atmospheric fine particles.