title: Identifying potential exposure reduction priorities using regional rankings based on emissions of known and suspected carcinogens to outdoor air in Canada.
abstract: BACKGROUND
  Emissions inventories aid in understanding the sources of hazardous air pollutants and how these vary regionally, supporting targeted reduction actions. Integrating information on the relative toxicity of emitted pollutants with respect to cancer in humans helps to further refine reduction actions or recommendations, but few national programs exist in North America that use emissions estimates in this way. The CAREX Canada Emissions Mapping Project provides key regional indicators of emissions (total annual and total annual toxic equivalent, circa 2011) of 21 selected known and suspected carcinogens.
  
  
  METHODS
  The indicators were calculated from industrial emissions reported to the National Pollutant Release Inventory (NPRI) and estimates of emissions from transportation (airports, trains, and car and truck traffic) and residential heating (oil, gas and wood), in conjunction with human toxicity potential factors. We also include substance-specific annual emissions in toxic equivalent kilograms and annual emissions in kilograms, to allow for ranking substances within any region.
  
  
  RESULTS
  For provinces and territories in Canada, the indicators suggest the top five substances contributing to the total toxic equivalent emissions in any region could be prioritized for further investigation. Residents of Quebec and New Brunswick may be more at risk of exposure to industrial emissions than those in other regions, suggesting that a more detailed study of exposure to industrial emissions in these provinces is warranted. Residential wood smoke may be an important emission to control, particularly in the north and eastern regions of Canada. Residential oil and gas heating, along with rail emissions contribute little to regional emissions and therefore may not be an immediate regional priority.
  
  
  CONCLUSIONS
  The developed indicators support the identification of pollutants and sources for additional investigation when planning exposure reduction actions among Canadian provinces and territories, but have important limitations similar to other emissions inventory-based tools. Additional research is required to evaluate how the Emissions Mapping Project is used by different groups and organizations with respect to informing actions aimed at reducing Canadians' potential exposure to harmful air pollutants.
authors: Spatial Sciences Research Lab, University of Victoria - Geography, PO Box 3060 STN CSC, Victoria, BC, V8W 3R4, Canada. elsetton@uvicssrl.ca.
authors: Eleanor M
authors: EM
authors: Setton
authors: Spatial Sciences Research Lab, University of Victoria - Geography, PO Box 3060 STN CSC, Victoria, BC, V8W 3R4, Canada. basilveerman@gmail.com.
authors: Basil
authors: B
authors: Veerman
authors: Spatial Sciences Research Lab, University of Victoria - Geography, PO Box 3060 STN CSC, Victoria, BC, V8W 3R4, Canada. anderse@uvic.ca.
authors: Anders
authors: A
authors: Erickson
authors: Spatial Sciences Research Lab, University of Victoria - Geography, PO Box 3060 STN CSC, Victoria, BC, V8W 3R4, Canada. steeved@uvic.ca.
authors: Steeve
authors: S
authors: Deschenes
authors: Spatial Sciences Research Lab, University of Victoria - Geography, PO Box 3060 STN CSC, Victoria, BC, V8W 3R4, Canada. rozc@uvic.ca.
authors: Roz
authors: R
authors: Cheasley
authors: Spatial Sciences Research Lab, University of Victoria - Geography, PO Box 3060 STN CSC, Victoria, BC, V8W 3R4, Canada. karla@carexcanada.ca.
authors: Karla
authors: K
authors: Poplawski
authors: Occupational Cancer Research Centre, Cancer Care Ontario, 525 University Avenue 3rd Floor, Toronto, ON, M5G 2L3, Canada. Paul.Demers@cancercare.on.ca.
authors: Paul A
authors: PA
authors: Demers
authors: Spatial Sciences Research Lab, University of Victoria - Geography, PO Box 3060 STN CSC, Victoria, BC, V8W 3R4, Canada. pkeller@uvic.ca.
authors: C Peter
authors: CP
authors: Keller
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis* / Q000517:prevention & control*; D002170:Canada; D002273:Carcinogens / Q000032:analysis*; D004781:Environmental Exposure; D004784:Environmental Monitoring; D062305:Geographic Mapping; D006801:Humans
chemical_list: D000393:Air Pollutants; D002273:Carcinogens