title: Lacrimal Cytokines Assessment in Subjects Exposed to Different Levels of Ambient Air Pollution in a Large Metropolitan Area.
abstract: BACKGROUND
  Air pollution is one of the most environmental health concerns in the world and has serious impact on human health, particularly in the mucous membranes of the respiratory tract and eyes. However, ocular hazardous effects to air pollutants are scarcely found in the literature.
  
  
  METHODS
  Panel study to evaluate the effect of different levels of ambient air pollution on lacrimal film cytokine levels of outdoor workers from a large metropolitan area.
  
  
  METHODS
  Thirty healthy male workers, among them nineteen professionals who work on streets (taxi drivers and traffic controllers, high pollutants exposure, Group 1) and eleven workers of a Forest Institute (Group 2, lower pollutants exposure compared to group 1) were evaluated twice, 15 days apart. Exposure to ambient PM2.5 (particulate matter equal or smaller than 2.5 μm) was 24 hour individually collected and the collection of tears was performed to measure interleukins (IL) 2, 4, 5 and 10 and interferon gamma (IFN-γ) levels. Data from both groups were compared using Student's t test or Mann- Whitney test for cytokines. Individual PM2.5 levels were categorized in tertiles (lower, middle and upper) and compared using one-way ANOVA. Relationship between PM2.5 and cytokine levels was evaluated using generalized estimating equations (GEE).
  
  
  RESULTS
  PM2.5 levels in the three categories differed significantly (lower: ≤22 μg/m3; middle: 23-37.5 μg/m3; upper: >37.5 μg/m3; p<0.001). The subjects from the two groups were distributed unevenly in the lower category (Group 1 = 8%; Group 2 = 92%), the middle category (Group 1 = 89%; Group 2 = 11%) and the upper category (Group 1 = 100%). A significant relationship was found between IL-5 and IL-10 and PM2.5 levels of the group 1, with an average decrease of 1.65 pg/mL of IL-5 level and of 0.78 pg/mL of IL-10 level in tear samples for each increment of 50 μg/m3 of PM2.5 (p = 0.01 and p = 0.003, respectively).
  
  
  CONCLUSIONS
  High levels of PM2.5 exposure is associated with decrease of IL-5 and IL-10 levels suggesting a possible modulatory action of ambient air pollution on ocular surface immune response.
authors.affiliation: Laboratory for investigation in Ophthalmology (LIM-33), University of Sao Paulo Medical School, Sao Paulo, SP, Brazil.
authors.forename: Monique
authors.initials: M
authors.lastname: Matsuda
authors.affiliation: Laboratory for investigation in Ophthalmology (LIM-33), University of Sao Paulo Medical School, Sao Paulo, SP, Brazil.
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Bonatti
authors.affiliation: Laboratory of Experimental Air Pollution (LPAE), University of Sao Paulo Medical School, Sao Paulo, SP, Brazil.
authors.forename: Mônica V
authors.initials: MV
authors.lastname: Marquezini
authors.affiliation: Laboratory of Experimental Air Pollution (LPAE), University of Sao Paulo Medical School, Sao Paulo, SP, Brazil.
authors.forename: Maria L B
authors.initials: ML
authors.lastname: Garcia
authors.affiliation: Pulmonary Division-Heart Institute(InCor), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Sao Paulo, SP, Brazil.
authors.forename: Ubiratan P
authors.initials: UP
authors.lastname: Santos
authors.affiliation: Laboratory of Experimental Air Pollution (LPAE), University of Sao Paulo Medical School, Sao Paulo, SP, Brazil.|Environmental Exposure and Risk Assessment Group, Collective Health Post-graduation Program, Catholic University of Santos, Santos, SP, Brazil.
authors.forename: Alfésio L F
authors.initials: AL
authors.lastname: Braga
authors.affiliation: Laboratory for investigation in Ophthalmology (LIM-33), University of Sao Paulo Medical School, Sao Paulo, SP, Brazil.
authors.forename: Milton R
authors.initials: MR
authors.lastname: Alves
authors.affiliation: Laboratory of Experimental Air Pollution (LPAE), University of Sao Paulo Medical School, Sao Paulo, SP, Brazil.
authors.forename: Paulo H N
authors.initials: PH
authors.lastname: Saldiva
authors.affiliation: Laboratory for investigation in Ophthalmology (LIM-33), University of Sao Paulo Medical School, Sao Paulo, SP, Brazil.
authors.forename: Mário L R
authors.initials: ML
authors.lastname: Monteiro
mesh_terms: D000328:Adult; D000368:Aged; D000393:Air Pollutants / Q000009:adverse effects* / Q000276:immunology; D001334:Automobile Driving; D001938:Brazil; D002947:Cities; D004781:Environmental Exposure / Q000009:adverse effects*; D006801:Humans; D056747:Immunomodulation; D007371:Interferon-gamma / Q000096:biosynthesis / Q000378:metabolism; D016753:Interleukin-10 / Q000096:biosynthesis / Q000378:metabolism; D007376:Interleukin-2 / Q000096:biosynthesis / Q000378:metabolism; D015847:Interleukin-4 / Q000096:biosynthesis / Q000378:metabolism; D015848:Interleukin-5 / Q000096:biosynthesis / Q000378:metabolism; D007765:Lacrimal Apparatus / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D052638:Particulate Matter / Q000009:adverse effects / Q000276:immunology; D013666:Tears / Q000737:chemistry / Q000276:immunology; D001335:Vehicle Emissions / Q000032:analysis
chemical_list: D000393:Air Pollutants; C508609:IL10 protein, human; C508598:IL4 protein, human; C508599:IL5 protein, human; D007376:Interleukin-2; D015848:Interleukin-5; D052638:Particulate Matter; D001335:Vehicle Emissions; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma