title: [Exposure level and risk factors of heavy metal in prenatal period among Shanghai infants].
abstract: OBJECTIVE
  To explore the exposure level and risk factors of heavy metal among Shanghai infants in their prenatal period.
  
  
  METHODS
  A total of 1652 pregnant or puerperal women were recruited from 10 midwifery-qualified hospitals in Shanghai since October 2008 to October 2009, by the stratified cluster sampling method. They answered the questionnaire and their umbilical cord blood and serum were collected to detect the content of Pb, Hg, Mn, Cd, As and Tl. The risk factors were analyzed by single and multiple regression methods respectively.
  
  
  RESULTS
  The median value of the content of Pb, Hg, Mn, Cd, As and Tl were 41.00, 1.88, 4.10, 0.03, 0.86 and 0.02 µg/L respectively. The Hg concentration of pregnant women who ate fish for 4 - 7 times per week (9.7% (160/1652)) was 2.76 µg/L, which was higher than that of pregnant women who only ate fish for 1-3 times per week (49.3% (814/1652)) and those who seldom ate fish (40.0% (661/1652)); the Hg concentration in the two groups above were 2.41 and 2.03 µg/L separately. The difference had statistical significance (χ(2) = 36.40, P < 0.001). Meanwhile, the concentrations of Pb and Tl in the group of pregnant women whose houses were remodeled by PVC pipe (85.0% (1404/1652)) was higher than the concentrations in group of pregnant women whose houses were remodeled by galvanized pipe (15.0% (248/1652)); the Pb concentration in the two groups above were 45.54 and 40.00 µg/L (Z = 2.54, P < 0.05) and the Tl concentration in the two groups above were 0.021 and 0.018 µg/L (Z = 2.97, P < 0.05). However, the As concentration in the group of PVC pipe remodeled was 4.33 µg/L, which was lower than that in the group of galvanized pipe (9.37 µg/L). The difference had statistical significance (Z = 3.99, P < 0.01). The concentrations of Mn, Cd and Tl in the groups of pregnant women whose house had been remodeled in the last 3 years (38.0% (628/1652)) were 14.78, 0.51 and 0.022 µg/L separately, which were all significantly higher than those in the groups of women whose houses' were not remodeled (62.0% (1024/1652)), whose concentrations were 11.01, 0.29 and 0.02 µg/L respectively. The differences had statistical significance (Mn: Z = 2.46, P < 0.05; Cd: Z = 2.38, P < 0.05; Tl: Z = 2.81, P < 0.01).
  
  
  CONCLUSIONS
  The infants in Shanghai were exposed to heavy metals in their prenatal period. The main sources of the exposure were daily diet and remodeled pollution.
authors.affiliation: Shanghai Key Lab of Children's Environmental Health, Shanghai Institute for Pediatric Research, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, China.
authors.forename: Xiao-Dan
authors.initials: XD
authors.lastname: Yu
authors.forename: Chong-Huai
authors.initials: CH
authors.lastname: Yan
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Shen
authors.forename: Ying
authors.initials: Y
authors.lastname: Tian
authors.forename: Lu-Lu
authors.initials: LL
authors.lastname: Cao
authors.forename: Xiao-Gang
authors.initials: XG
authors.lastname: Yu
authors.forename: Mei-Qin
authors.initials: MQ
authors.lastname: Wu
authors.forename: Li
authors.initials: L
authors.lastname: Zhao
authors.forename: Jun-Xia
authors.initials: JX
authors.lastname: Liu
authors.forename: Xin
authors.initials: X
authors.lastname: Zhou
mesh_terms: D000328:Adult; D002681:China; D004787:Environmental Pollution; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects*; D019216:Metals, Heavy / Q000009:adverse effects*; D011247:Pregnancy; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: D019216:Metals, Heavy