title: Ocular symptoms and tear film break up time (BUT) among junior high school students in Penang, Malaysia - Associations with fungal DNA in school dust.
abstract: There are few studies on ocular effects of indoor mould exposure in schools, especially in the tropics OBJECTIVE: To study associations between eye symptoms and tear film break up time (BUT) in students and demographic data and fungal DNA in schools.
  
  
  
  A school environment study was performed among randomly selected students in eight randomly selected secondary schools in Penang, Malaysia. Information on eye symptoms and demographic data was collected by a standardised questionnaire. BUT was measured by two methods, self-reported BUT (SBUT) and by the non-invasive Tearscope (NIBUT). Dust was collected by vacuuming in 32 classrooms and analysed for five fungal DNA sequences. Geometric mean (GM) for total fungal DNA was 7.31*104target copies per gram dust and for Aspergillus/Penicillium DNA 3.34*104target copies per gram dust. Linear mixed models and 3-level multiple logistic regression were applied adjusting for demographic factors.
  
  
  
  A total of 368 students (58%) participated and 17.4% reported weekly eye symptoms the last 3 months. The median SBUT and TBUT were 15 and 12s, respectively. Students wearing glasses (OR 2.41, p=0.01) and with a history of atopy (OR=2.67; p=0.008) had more eye symptoms. Girls had less eye symptoms than boys (OR=0.34; p=0.006) Indoor carbon dioxide in the classrooms was low (range 380-720ppm), temperature was 25-30°C and relative air humidity 70-88%. Total fungal DNA in vacuumed dust was associated with shorter SBUT (4s shorter per 105target copies per gram dust; p=0.04) and NIBUT (4s shorter per 105target copies per gram dust; p<0.001). Aspergillus/Penicillium DNA was associated with shorter NIBUT (5s shorter per 105target copies per gram dust; p=0.01).
  
  
  
  Fungal contamination in schools in a tropical country can be a risk factor for impaired tear film stability among students.
authors.affiliation: Uppsala University, Department of Medical Science, Occupational and Environmental Medicine, University Hospital, 75185 Uppsala, Sweden. Electronic address: dan.norback@medsci.uu.se.
authors.forename: Dan
authors.initials: D
authors.lastname: Norbäck
authors.affiliation: United Nations University-International Institute for Global Health, 56000 Kuala Lumpur, Malaysia; Department of Community Health, National University of Malaysia, 56000 Kuala Lumpur, Malaysia.
authors.forename: Jamal Hisham
authors.initials: JH
authors.lastname: Hashim
authors.affiliation: Department of Environmental and Occupational Health, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
authors.forename: Zailina
authors.initials: Z
authors.lastname: Hashim
authors.affiliation: Department of Community Health, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia.
authors.forename: Vinoshini
authors.initials: V
authors.lastname: Sooria
authors.affiliation: Department of Community Health, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia; Environmental Health, Allied Health Science College Sg Buloh, Ministry of Health Malaysia, 47000 Sungai Buloh; Selangor, Malaysia.
authors.forename: Syazwan Aizat
authors.initials: SA
authors.lastname: Ismail
authors.affiliation: Uppsala University, Department of Medical Science, Occupational and Environmental Medicine, University Hospital, 75185 Uppsala, Sweden.
authors.forename: Gunilla
authors.initials: G
authors.lastname: Wieslander
mesh_terms: D000293:Adolescent; D016902:Air Pollution, Indoor / Q000032:analysis*; D001230:Aspergillus / Q000235:genetics; D004271:DNA, Fungal / Q000032:analysis*; D004391:Dust / Q000032:analysis*; D005128:Eye Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D008296:Malaysia / Q000453:epidemiology; D008297:Male; D010407:Penicillium / Q000235:genetics; D012574:Schools; D013334:Students; D013666:Tears
chemical_list: D004271:DNA, Fungal; D004391:Dust
keywords: Eye symptoms; Fungal DNA; Mould; School environment; Tear film break up time (BUT)