title: Preconceptional and perinatal exposure to traffic-related air pollution and eczema in preschool children.
abstract: BACKGROUND
  Evidence linking prenatal exposure to outdoor air pollution with eczema in early childhood is scare, and the role of components of air pollution and exposure timing remains unclear.
  
  
  OBJECTIVE
  We investigated the association between exposure to air pollution during preconceptional and perinatal period and the risk of eczema in preschool children.
  
  
  METHODS
  We conducted a prospective cohort study of 2598 children aged 3-6 years in Changsha, China. The prevalence of eczema was assessed by a standardized health questionnaire administered by the parents. Individual exposures to nitrogen dioxide (NO2), sulfur dioxide (SO2) and particulate matter with an aerodynamic diameter≤10μm (PM10) during the 4th-6th and 1st-3rd month before pregnancy, entire pregnancy, and three trimesters were estimated by an inverse distance weighted (IDW) method based on concentrations measured at monitoring stations. Association between childhood eczema and exposure to air pollution was examined by logistic regression models in terms of odds ratio (OR) and 95% confidence interval (CI) for an interquartile range (IQR) increase in exposure.
  
  
  RESULTS
  Life-time prevalence of eczema in preschool children in Changsha was 28.6%. Childhood eczema was associated with traffic-related air pollutant NO2during 3 months before pregnancy and entire pregnancy with adjusted ORs=1.19 (95% CI: 1.04-1.37) and 1.21 (95% CI: 1.03-1.42) respectively. The highest risk of eczema was observed for the 1st trimester exposure to NO2[OR=1.26 (95% CI: 1.09-1.46)]. However, no association was detected for SO2and PM10exposure during any window. High-level exposure to NO2during the whole time period significantly increased the effect of NO2in all windows on eczema risk as compared with low-level exposure. Sensitivity analysis indicated that the association between both preconceptional and perinatal exposure to NO2and childhood eczema was consistent and robust, and this association was modified by some personal, parental hereditary and indoor environmental factors.
  
  
  CONCLUSIONS
  Our findings support the hypothesis that early childhood eczema is associated with exposure to traffic-related air pollutant during both preconceptional and perinatal period, especially at a high level of exposure.
authors.affiliation: School of Energy Science and Engineering, Central South University, Changsha, Hunan, China.
authors.forename: Chan
authors.initials: C
authors.lastname: Lu
authors.affiliation: School of Energy Science and Engineering, Central South University, Changsha, Hunan, China.
authors.forename: Linjing
authors.initials: L
authors.lastname: Deng
authors.affiliation: School of Energy Science and Engineering, Central South University, Changsha, Hunan, China.
authors.forename: Cuiyun
authors.initials: C
authors.lastname: Ou
authors.affiliation: Institute of Environmental Health, Central South University, Changsha, Hunan, China; The Third XiangYa Hospital, Central South University, Changsha, Hunan, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Yuan
authors.affiliation: Department of Dermatology, XiangYa Hospital, Central South University, Changsha, Hunan, China; The State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Chen
authors.affiliation: School of Energy Science and Engineering, Central South University, Changsha, Hunan, China; Institute of Environmental Health, Central South University, Changsha, Hunan, China; XiangYa School of Public Health, Central South University, Changsha, Hunan, China. Electronic address: qhdeng@csu.edu.cn.
authors.forename: Qihong
authors.initials: Q
authors.lastname: Deng
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects; D000397:Air Pollution / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D004485:Eczema / Q000139:chemically induced / Q000453:epidemiology*; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects*; D009585:Nitrogen Dioxide / Q000009:adverse effects; D010290:Parents; D052638:Particulate Matter / Q000009:adverse effects; D018812:Paternal Exposure / Q000009:adverse effects*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology*; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D013458:Sulfur Dioxide / Q000009:adverse effects; D011795:Surveys and Questionnaires
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D013458:Sulfur Dioxide; D009585:Nitrogen Dioxide
keywords: Air pollution; Allergic disease; Preconceptional exposure; Pregnancy; Trimester