title: Heterogeneity in microbial exposure in schools in Sweden, Poland and Jordan revealed by analysis of chemical markers.
abstract: We used gas chromatography--tandem mass spectrometry to analyze microbial components in 85 samples of airborne dust from schools in Jordan, Sweden, and Poland. To collect the samples, we allowed dust to settle on plexiglass plates hanging in the breathing zone in school buildings during both summer and winter. In each of the three countries, we conducted such sampling in two schools: one in an urban environment and the other in rural surroundings. The microbial marker profiles differed significantly between the schools and seasons. For example, samples from Jordan contained remarkably low levels of ergosterol (marker of fungal biomass) and high levels of 3-hydroxy acids (markers of lipopolysaccharide) of 10, 12, and 14 carbon chain lengths relative to such acids of 16 and 18 carbons in comparison with samples from Sweden and Poland. This dissimilarity in 3-hydroxy fatty acid distribution indicates significant differences in the populations of Gram-negative bacteria. We also noted that muramic acid (marker of bacterial biomass) exhibited the smallest variation between schools and seasons. In summary, our results demonstrate that exposure to microorganisms in indoor air in school buildings may differ markedly between countries, between seasons, and between urban and rural environments.
authors.affiliation: Department of Medical Microbiology, Dermatology and Infection, Lund University, Sölvegatan 23, 223 62 Lund, Sweden.
authors.forename: Loay
authors.initials: L
authors.lastname: Wady
authors.forename: Asem
authors.initials: A
authors.lastname: Shehabi
authors.forename: Bogumila
authors.initials: B
authors.lastname: Szponar
authors.forename: Christina
authors.initials: C
authors.lastname: Pehrson
authors.forename: Yezhou
authors.initials: Y
authors.lastname: Sheng
authors.forename: Lennart
authors.initials: L
authors.lastname: Larsson
mesh_terms: D000293:Adolescent; D000391:Air Microbiology; D016902:Air Pollution, Indoor; D000704:Analysis of Variance; D015415:Biomarkers / Q000032:analysis*; D018533:Biomass; D002648:Child; D002675:Child, Preschool; D004391:Dust / Q000032:analysis*; D004875:Ergosterol / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis; D005260:Female; D006801:Humans; D007597:Jordan; D008297:Male; D009112:Muramic Acids / Q000032:analysis; D011044:Poland; D015203:Reproducibility of Results; D012423:Rural Health; D012574:Schools; D012621:Seasons; D013548:Sweden; D014504:Urban Health
chemical_list: D015415:Biomarkers; D004391:Dust; D005227:Fatty Acids; D009112:Muramic Acids; D004875:Ergosterol