Volume 405, Issues 1–3, 1 November 2008, Pages 180–185
Lead shot contribution to blood lead of First Nations people: The use of lead isotopes to identify the source of exposure
Abstract
Although
lead isotope ratios have been used to identify lead ammunition (lead
shotshell pellets and bullets) as a source of exposure for First Nations
people of Canada, the actual source of lead exposure needs to be
further clarified. Whole blood samples for First Nations people of
Ontario, Canada, were collected from participants prior to the
traditional spring harvest of water birds, as well as post-harvest.
Blood-lead levels and stable lead isotope ratios prior to, and after the
harvest were determined by ICP-MS. Data were analyzed by paired t-tests
and Wilcoxon Signed-Ranks tests. All participants consumed water birds
harvested with lead shotshell during the period of study. For the group
excluding six males who were potentially exposed to other sources of
lead (as revealed through a questionnaire), paired t-tests and Wilcoxon Signed-Ranks tests showed consistent results: significant (p < 0.05) increases in blood-lead concentrations and blood levels of 206Pb/204Pb and 206Pb/207Pb towards the mean values we previously reported for lead shotshell pellets; and a significant decrease in 208Pb/206Pb
values towards the mean for lead shotshell pellets. However, when we
categorized the group further into a group that did not use firearms and
did not eat any other traditional foods harvested with lead ammunition
other than waterfowl, our predictions for 206Pb/204Pb, 206Pb/207Pb and 208Pb/206Pb
hold true, but there was not a significant increase in blood-lead level
after the hunt. It appears that the activity of hunting (i.e., use of a
shotgun) was also an important route of lead exposure. The banning of
lead shotshell for all game hunting would eliminate a source of
environmental lead for all people who use firearms and/or eat wild game.
Keywords
- Lead shotshell;
- Subsistence hunting;
- Waterfowl;
- Lead isotope ratios;
- Blood lead;
- First Nations
- Corresponding author. Tel.:
+1 519 888 4567x32762; fax: +1 519 746 0292.
Copyright © 2008 Elsevier B.V. All rights reserved.
