Occupational effect of sugarcane biomass burning on the conjunctival mucin profile of harvest workers and residents of an adjacent town - A Brazilian panel study. (January 2020)

• Record Type: Journal Article
• Authors: Matsuda, Monique; Braga, Alfésio L.F.; Marquezini, Mônica Valeria; Monteiro, Mário L.R.; Saldiva, Paulo H.N.; de Santos, Ubiratan
• Is Part Of: Experimental eye research. Volume 190(2020)
• Publication Date: 2020-01
• Subjects: Air pollution -- Sugar cane burning -- Ocular surface -- Conjunctiva -- Mucin -- Goblet cell -- Inflammation; Ophthalmology -- Periodicals; Eye -- Periodicals; Œil -- Périodiques; Ophthalmology; Periodicals; Electronic journals; 612.8405
• DOI: 10.1016/j.exer.2019.107889
• Languages: English
• ISSNs: 0014-4835

Abstract

Abstract: Pre-harvest burning of sugarcane fields produces large amounts of air pollutants which are known to cause health problems, including ocular surface abnormalities. In this study, we evaluated the effect of biomass burning on mucus quality and mucin gene expression (MUC1, MUC5AC, MUC16) in the conjunctiva of sugarcane workers (SWs) and residents of an adjacent town (RTs). Impression cytology samples of the inferior tarsal and bulbar conjunctiva of 78 SWs and 32 RTs were collected before (T1) and immediately after (T2) a 6-month harvest period. The neutral, acid and total mucus content of goblet cells was determined by PAS and AB staining. The levels of MUC5AC, MUC1 and MUC16 mRNA in the conjunctiva were measured by real-time PCR. Compared to RTs, SWs had higher levels of bulbar acid mucus and MUC16 mRNA and tarsal MUC5AC mRNA at T2 and lower levels of neutral mucus at T1 and T2. In the SW group, MUC1 mRNA levels were higher at T2 than at T1, but the levels of neutral and acid mucus were similar. In the RT group, acid mucus decreased and neutral mucus increased in the bulbar and tarsal conjunctiva at T2. In conclusion, our findings show that sugarcane harvesting is associated with abnormalities in mucus quality and content and changes in mucin mRNA levels on the ocular surface. This may help explain the ocular inflammatory signs and symptoms observed in subjects exposed to air pollutants and high temperatures from sugarcane biomass burning. Highlights: Sugarcane burning is known to produce large amounts of air pollutants at the harvest season. Impression cytology of bulbar and tarsal conjunctiva of sugarcane workers and residents nearby town were collected. The samples were processed to analysis the mucus profile (neutral, acid) and the MUC1, MUC5AC and MUC16 mRNA levels. Sugarcane workers had lower levels of conjunctiva neutral mucus than the town residents before and after the harvest season. Sugarcane harvesting decreased acid and increased neutral mucus and MUC5AC mRNA levels in the conjunctiva in town residents.