title: Identification of environmental sources of lead exposure in Nunavut (Canada) using stable isotope analyses.
abstract: BACKGROUND
  Blood lead levels (BLLs) were measured in the adult Inuit population of Nunavut, Northern Canada, during the Inuit Health Survey (IHS) in 2007-2008. Approximately 10% of the adult participants had BLL over the Health Canada's guidance of 100μg/L.
  
  
  OBJECTIVE
  1) To repeat the measurement of BLL among the IHS participants with high BLL and household members including pregnant women and children under 10years of age; 2) to measure lead (Pb) concentrations in environmental samples to identify potential sources and 3) to explore how Pb from environmental samples contributes to BLL using Pb stable isotopic analyses.
  
  
  METHODS
  Blood samples were collected from 100 adults and 56 children in 2012. A total of 169 environmental samples (tap water, house dust, paint, country food, soil, and ammunition) were collected from 14 houses from three communities where the IHS participants had the highest BLL. Total Pb concentrations and Pb isotope mass balance were determined by inductively coupled plasma-mass spectrometry (ICP-MS).
  
  
  RESULTS
  The geometric mean of BLL was 43.1μg/L; BLL increased with age and was higher in adults than children (71.1 vs. 17.5μg/L). Median Pb concentrations in water (1.9μg/L) and dust (27.1μg/m(2) for wiped dust, 32.6mg/kg for vacuum dust coarse fraction, and 141.9mg/kg for vacuum dust fine fraction) were generally higher than in other parts of Canada. Median Pb concentrations of food and soil coarse and fine fractions were low (36.6μg/kg, 5.4mg/kg and 11.8mg/kg respectively); paint chips exceeded the Canadian guidelines in two houses (median: 3.8mg/kg). Discriminant analyses and isotope ratio analyses showed that ammunition and house dust are major sources of Pb in this study population.
  
  
  CONCLUSIONS
  Analyses of Pb stable isotopes are useful to identify the routes of exposure to Pb. This approach can contribute to develop targeted public health programmes to prevent Pb exposure.
authors: Centre for Advanced Research in Environmental Genomics, University of Ottawa, 30 Marie Curie, Gendron 160, Ottawa, Ontario K1N 6N5, Canada.
authors: Myriam
authors: M
authors: Fillion
authors: Centre for Advanced Research in Environmental Genomics, University of Ottawa, 30 Marie Curie, Gendron 160, Ottawa, Ontario K1N 6N5, Canada.
authors: Jules M
authors: JM
authors: Blais
authors: Centre for Advanced Research in Environmental Genomics, University of Ottawa, 30 Marie Curie, Gendron 160, Ottawa, Ontario K1N 6N5, Canada.
authors: Emmanuel
authors: E
authors: Yumvihoze
authors: Department of Health, Government of Nunavut, Box 1000, Station 1000, Iqaluit, Nunavut X0A 0H0, Canada.
authors: Maya
authors: M
authors: Nakajima
authors: Department of Health, Government of Nunavut, Box 1000, Station 1000, Iqaluit, Nunavut X0A 0H0, Canada.
authors: Peter
authors: P
authors: Workman
authors: Department of Health, Government of Nunavut, Box 1000, Station 1000, Iqaluit, Nunavut X0A 0H0, Canada.
authors: Geraldine
authors: G
authors: Osborne
authors: Centre for Advanced Research in Environmental Genomics, University of Ottawa, 30 Marie Curie, Gendron 160, Ottawa, Ontario K1N 6N5, Canada. Electronic address: laurie.chan@uottawa.ca.
authors: Hing Man
authors: HM
authors: Chan
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D002675:Child, Preschool; D060766:Drinking Water / Q000737:chemistry; D004391:Dust / Q000032:analysis; D004781:Environmental Exposure / Q000032:analysis* / Q000517:prevention & control; D004784:Environmental Monitoring / Q000706:statistics & numerical data*; D004785:Environmental Pollutants / Q000032:analysis* / Q000097:blood / Q000633:toxicity; D005260:Female; D005500:Follow-Up Studies; D006798:Housing; D006801:Humans; D004930:Inuit; D007554:Isotopes / Q000032:analysis; D007854:Lead / Q000032:analysis* / Q000097:blood / Q000633:toxicity; D008297:Male; D013058:Mass Spectrometry; D020957:Nunavut; D010150:Paint / Q000032:analysis; D011247:Pregnancy; D012987:Soil / Q000737:chemistry
chemical_list: D060766:Drinking Water; D004391:Dust; D004785:Environmental Pollutants; D007554:Isotopes; D012987:Soil; D007854:Lead
keywords: Blood; Dust; Environment; Exposure; Inuit; Lead