title: Arsenic and fluoride exposure in drinking water: children's IQ and growth in Shanyin county, Shanxi province, China.
abstract: BACKGROUND
  Recently, in a cross-sectional study of 201 children in Araihazar, Bangladesh, exposure to arsenic (As) in drinking water has been shown to lower the scores on tests that measure children's intellectual function before and after adjustment for sociodemographic features.
  
  
  OBJECTIVE
  We investigated the effects of As and fluoride exposure on children's intelligence and growth.
  
  
  METHODS
  We report the results of a study of 720 children between 8 and 12 years of age in rural villages in Shanyin county, Shanxi province, China. The children were exposed to As at concentrations of 142 +/- 106 microg/L (medium-As group) and 190 +/- 183 microg/L (high-As group) in drinking water compared with the control group that was exposed to low concentrations of As (2 +/- 3 microg/L) and low concentrations of fluoride (0.5 +/- 0.2 mg/L). A study group of children exposed to high concentrations of fluoride (8.3 +/- 1.9 mg/L) but low concentrations of As (3 +/- 3 microg/L) was also included because of the common occurrence of elevated concentrations of fluoride in groundwater in our study area. A standardized IQ (intelligence quotient) test was modified for children in rural China and was based on the classic Raven's test used to determine the effects of these exposures on children's intelligence. A standardized measurement procedure for weight, height, chest circumference, and lung capacity was used to determine the effects of these exposures on children's growth.
  
  
  RESULTS
  The mean IQ scores decreased from 105 +/- 15 for the control group, to 101 +/- 16 for the medium-As group (p < 0.05), and to 95 +/- 17 for the high-As group (p < 0.01). The mean IQ score for the high-fluoride group was 101 +/- 16 and significantly different from that of the control group (p < 0.05). Children in the control group were taller than those in the high-fluoride group (p < 0.05); weighed more than the those in the high-As group (p < 0.05); and had higher lung capacity than those in the medium-As group (p < 0.05).
  
  
  CONCLUSIONS
  Children's intelligence and growth can be affected by high concentrations of As or fluoride. The IQ scores of the children in the high-As group were the lowest among the four groups we investigated. It is more significant that high concentrations of As affect children's intelligence. It indicates that arsenic exposure can affect children's intelligence and growth.
authors: Shanxi Institute for Prevention and Treatment of Endemic Disease, Linfen, 041000 Shanxi Province, People's Republic of China. sxdb@public.lf.sx.cn
authors: San-Xiang
authors: SX
authors: Wang
authors: Zheng-Hui
authors: ZH
authors: Wang
authors: Xiao-Tian
authors: XT
authors: Cheng
authors: Jun
authors: J
authors: Li
authors: Zhi-Ping
authors: ZP
authors: Sang
authors: Xiang-Dong
authors: XD
authors: Zhang
authors: Ling-Ling
authors: LL
authors: Han
authors: Xiao-Yan
authors: XY
authors: Qiao
authors: Zhao-Ming
authors: ZM
authors: Wu
authors: Zhi-Quan
authors: ZQ
authors: Wang
mesh_terms: D001151:Arsenic / Q000009:adverse effects*; D001827:Body Height; D001835:Body Weight; D016022:Case-Control Studies; D002648:Child; D002657:Child Development; D002681:China; D004781:Environmental Exposure; D005260:Female; D005459:Fluorides / Q000009:adverse effects*; D006801:Humans; D007360:Intelligence; D008297:Male; D012424:Rural Population; D014873:Water Pollutants / Q000009:adverse effects*; D014881:Water Supply
chemical_list: D014873:Water Pollutants; D001151:Arsenic; D005459:Fluorides