title: Traffic-related air pollution and spectacles use in schoolchildren.
abstract: OBJECTIVE
  To investigate the association between exposure to traffic-related air pollution and use of spectacles (as a surrogate measure for myopia) in schoolchildren.
  
  
  METHODS
  We analyzed the impact of exposure to NO2 and PM2.5 light absorbance at home (predicted by land-use regression models) and exposure to NO2 and black carbon (BC) at school (measured by monitoring campaigns) on the use of spectacles in a cohort of 2727 schoolchildren (7-10 years old) in Barcelona (2012-2015). We conducted cross-sectional analyses based on lifelong exposure to air pollution and prevalent cases of spectacles at baseline data collection campaign as well as longitudinal analyses based on incident cases of spectacles use and exposure to air pollution during the three-year period between the baseline and last data collection campaigns. Logistic regression models were developed to quantify the association between spectacles use and each of air pollutants adjusted for relevant covariates.
  
  
  RESULTS
  An interquartile range increase in exposure to NO2 and PM2.5 absorbance at home was respectively associated with odds ratios (95% confidence intervals (CIs)) for spectacles use of 1.16 (1.03, 1.29) and 1.13 (0.99, 1.28) in cross-sectional analyses and 1.15 (1.00, 1.33) and 1.23 (1.03, 1.46) in longitudinal analyses. Similarly, odds ratio (95% CIs) of spectacles use associated with an interquartile range increase in exposures to NO2 and black carbon at school was respectively 1.32 (1.09, 1.59) and 1.13 (0.97, 1.32) in cross-sectional analyses and 1.12 (0.84, 1.50) and 1.27 (1.03, 1.56) in longitudinal analyses. These findings were robust to a range of sensitivity analyses that we conducted.
  
  
  CONCLUSIONS
  We observed increased risk of spectacles use associated with exposure to traffic-related air pollution. These findings require further confirmation by future studies applying more refined outcome measures such as quantified visual acuity and separating different types of refractive errors.
authors.affiliation: ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Pompeu Fabra University, Barcelona, Spain.|Ciber on Epidemiology and Public Health (CIBERESP), Madrid, Spain.
authors.forename: Payam
authors.identifier: http://orcid.org/0000-0002-2325-1027
authors.initials: P
authors.lastname: Dadvand
authors.affiliation: ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Pompeu Fabra University, Barcelona, Spain.|Ciber on Epidemiology and Public Health (CIBERESP), Madrid, Spain.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Nieuwenhuijsen
authors.affiliation: ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Pompeu Fabra University, Barcelona, Spain.|Ciber on Epidemiology and Public Health (CIBERESP), Madrid, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Basagaña
authors.affiliation: ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Pompeu Fabra University, Barcelona, Spain.|Ciber on Epidemiology and Public Health (CIBERESP), Madrid, Spain.
authors.forename: Mar
authors.initials: M
authors.lastname: Alvarez-Pedrerol
authors.affiliation: ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Pompeu Fabra University, Barcelona, Spain.|Ciber on Epidemiology and Public Health (CIBERESP), Madrid, Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Dalmau-Bueno
authors.affiliation: ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Pompeu Fabra University, Barcelona, Spain.|Ciber on Epidemiology and Public Health (CIBERESP), Madrid, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Cirach
authors.affiliation: ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Pompeu Fabra University, Barcelona, Spain.|Ciber on Epidemiology and Public Health (CIBERESP), Madrid, Spain.|Institute of Environmental Assessment and Water Research (IDAEA), Spanish National Research Council (CSIC), Barcelona, Spain.
authors.forename: Ioar
authors.initials: I
authors.lastname: Rivas
authors.affiliation: Institute for Risk Assessment Sciences, Division Environmental Epidemiology, Utrecht University, Utrecht, The Netherlands.|Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Bert
authors.initials: B
authors.lastname: Brunekreef
authors.affiliation: Institute of Environmental Assessment and Water Research (IDAEA), Spanish National Research Council (CSIC), Barcelona, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Querol
authors.affiliation: ARC Centre of Excellence in Vision Science, Research School of Biology, College of Medicine, Biology and Environment, Australian National University, Canberra, Australia.|Department of Preventive Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Ian G
authors.initials: IG
authors.lastname: Morgan
authors.affiliation: ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.|Pompeu Fabra University, Barcelona, Spain.|Ciber on Epidemiology and Public Health (CIBERESP), Madrid, Spain.|IMIM-Parc Salut Mar, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Sunyer
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects / Q000032:analysis; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D002648:Child; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004784:Environmental Monitoring; D005139:Eyeglasses / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D009216:Myopia / Q000453:epidemiology / Q000209:etiology*; D009585:Nitrogen Dioxide / Q000009:adverse effects / Q000032:analysis; D052638:Particulate Matter / Q000009:adverse effects / Q000032:analysis; D053260:Soot / Q000009:adverse effects / Q000032:analysis; D013030:Spain / Q000453:epidemiology; D001335:Vehicle Emissions / Q000032:analysis
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D053260:Soot; D001335:Vehicle Emissions; D009585:Nitrogen Dioxide