title: Windblown lead carbonate as the main source of lead in blood of children from a seaside community: an example of local birds as "canaries in the mine".
abstract: BACKGROUND
  In late 2006, the seaside community in Esperance, Western Australia, was alerted to thousands of native bird species dying. The source of the lead was thought to derive from the handling of Pb carbonate concentrate from the Magellan mine through the port of Esperance, begun in July 2005. Concern was expressed for the impact of this process on the community.
  
  
  OBJECTIVE
  This study was designed to evaluate the source of Pb in blood of a random sample of the community using Pb isotope ratios.
  
  
  METHODS
  The cohort comprised 49 children (48 < 5 years of age) along with 18 adults (> 20 years of age) with a bias toward higher blood lead (PbB) values to facilitate source identification.
  
  
  RESULTS
  Mean PbB level of the children was 7.5 microg/dL (range, 1.5-25.7 microg/dL; n = 49; geometric mean, 6.6 microg/dL), with four children whose PbB was > 12 microg/dL. The isotopic data for blood samples lay around two distinct arrays. The blood of all children analyzed for Pb isotopes contained a contribution of Pb from the Magellan mine, which for young children ranged from 27% up to 93% (mean, 64%; median, 71%). Subtraction of the ore component gave a mean background PbB of 2.3 mug/dL. Several children whose PbB was > 9 microg/dL and most of the older subjects have complex sources of Pb.
  
  
  CONCLUSIONS
  The death of the birds acted as a sentinel event; otherwise, the exposure of the community, arising from such a toxic form of Pb, could have been tragic. Isotopic data and mineralogic and particle size analyses indicate that, apart from the recognized pathway of Pb exposure by hand-to-mouth activity in children, the inhalation pathway could have been a significant contributor to PbB for some of the very young children and in some parents.
authors.affiliation: Graduate School of the Environment, Macquarie University, Sydney, New South Wales, Australia. bgulson@gse.mq.edu.au
authors.forename: Brian
authors.initials: B
authors.lastname: Gulson
authors.forename: Michael
authors.initials: M
authors.lastname: Korsch
authors.forename: Martin
authors.initials: M
authors.lastname: Matisons
authors.forename: Charles
authors.initials: C
authors.lastname: Douglas
authors.forename: Lindsay
authors.initials: L
authors.lastname: Gillam
authors.forename: Virginia
authors.initials: V
authors.lastname: McLaughlin
mesh_terms: D000818:Animals; D001717:Birds; D002254:Carbonates / Q000633:toxicity*; D002648:Child; D006801:Humans; D007854:Lead / Q000097:blood* / Q000633:toxicity; D016273:Occupational Exposure; D018571:Sentinel Surveillance; D014904:Western Australia
chemical_list: D002254:Carbonates; D007854:Lead; C043262:lead carbonate