title: Exposure to indoor pollutants and Wheeze and asthma development during early childhood.
abstract: BACKGROUND
  This review aimed to summarize existing epidemiological evidence of the association between quantitative estimates of indoor air pollution with early childhood respiratory disease.
  
  
  METHODS
  We carried out a systematic literature search of peer-reviewed epidemiological studies undertaken in "westernized" countries that have assessed exposure to indoor pollutants and asthma and wheeze from infancy up to the age of 5.
  
  
  RESULTS
  The search, between January 2004 and February 2014 yielded 1840 studies for consideration. Following application of eligibility criteria to titles and abstracts 22 independent studies were deemed relevant for further review. Two additional studies were next identified through examination of the references' lists of these studies. Of these 24 selected studies, 16 adopted a prospective cohort design and 8 were case-control studies. Fourteen studies assessed exposure to bio-aerosols, 8 studies assessed exposure to specific air chemicals and two studies assessed exposure to bio-aerosols and air chemicals. Furthermore, 11 studies examined the association of exposure with asthma and 16 with wheeze. Findings indicate that existing studies have reported contradictory effects of indoor pollutants levels and occurrence of asthma/wheeze.
  
  
  CONCLUSIONS
  Additional research to establish causality and evaluate interventions to prevent disease onset is needed.
authors: Florence Nightingale School of Nursing and Midwifery, King's College London, London SE18WA, UK. evridiki.patelarou@kcl.ac.uk.
authors: Evridiki
authors: E
authors: Patelarou
authors: Department of Thoracic Medicine, Medical School, University of Crete, Heraklion 71414, Greece. tzanakis@med.uoc.gr.
authors: Nikolaos
authors: N
authors: Tzanakis
authors: MRC-PHE Centre for Environment and Health, NIHR Environmental Hazards Health Protection Research Unit, King's College London, London SE19NH, UK. frank.kelly@kcl.ac.uk.
authors: Frank J
authors: FJ
authors: Kelly
mesh_terms: D016902:Air Pollution, Indoor / Q000009:adverse effects*; D001249:Asthma / Q000139:chemically induced / Q000453:epidemiology*; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D012135:Respiratory Sounds / Q000503:physiopathology*