title: Applicability of a filter paper method to measure blood lead levels in large populations of Chinese children.
abstract: BACKGROUND
  Capillary filter paper can be useful for screening blood lead concentrations in large populations of geographically dispersed Chinese children.
  
  
  METHODS
  A total of 159 at 0-6 years of age were enrolled in the study when they came for routine pediatric care. Paired venous and capillary filter paper samples were collected from all subjects. Graphite furnace atomic absorption spectrophotometry was used to measure blood lead concentrations. Comparability of the lead assay methods was assessed. The concordance coefficient between these two methods was 0.87 (p < 0.01). The values of blood lead concentrations measured by the different methods were comparable statistically. The sensitivity of the filter paper method was 85%, 73% and 75%; specificity was 92%, 99% and 100%; the positive predictive value was 86%, 89% and 100%, and negative predictive value was 91%, 98% and 99% at cut-offs of 10, 15 and 20 microg/dl, respectively. The Youden's index was 77, 71 and 75 at those cut-offs. Values obtained via the filter paper method appeared to be relatively stable up to 4 weeks post-collection.
  
  
  CONCLUSIONS
  The filter paper method for lead determinations has a sufficiently high sensitivity and specificity and correlates well with venous sampling. The ease with which this technique can be performed and screened samples can be sent to a centralized laboratory by regular mail indicates that it is a promising and attractive reference method, particularly in large populations of widely dispersed young children in China and other countries.
authors.affiliation: Research Center for Childhood Lead Poisoning Prevention, Xin-Hua Hospital, Shanghai Second Medical University, 1665 Kong Jiang Road, Shanghai 200092, China. xmshen@online.sh.cn
authors.forename: Xiao-Ming
authors.initials: XM
authors.lastname: Shen
authors.forename: Yi-Wen
authors.initials: YW
authors.lastname: Zhang
authors.forename: Sheng-Hu
authors.initials: SH
authors.lastname: Wu
authors.forename: Chong-Huai
authors.initials: CH
authors.lastname: Yan
authors.forename: Jie-Min
authors.initials: JM
authors.lastname: Ying
authors.forename: Ren-Qiu
authors.initials: RQ
authors.lastname: Li
mesh_terms: D002648:Child; D002675:Child, Preschool; D005374:Filtration; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007854:Lead / Q000097:blood*; D012680:Sensitivity and Specificity
chemical_list: D007854:Lead