A meta-analysis of observational studies of the association between chronic occupational exposure to lead and amyotrophic lateral sclerosis.

This work was funded in part by a contribution agreement from the Public Health Agency of Canada to conduct systematic review of factors affecting the onset and progression of 14 neurological conditions under the National Population Health Study of Neurological Disease in Canada. Dr Cashman holds a Canada Research Chair in Neurodegeneration and Protein Misfolding Diseases at the University of British Columbia; Dr Little holds a Canada Research Chair in Human Genome Epidemiology at the University of Ottawa; and Dr Krewski holds the McLaughlin Chair in Risk Science at the University of Ottawa. Authors Wang, Gomes, Cashman, Little, and Krewski have no relationships/conditions/circumstances that present potential conflict of interest. The JOEM editorial board and planners have no financial interest related to this research. Supplemental digital contents are available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (www.joem.org).