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Table 2 Summary of Canadian indicators of lifetime excess cancer risk for known carcinogens and each relevant exposure pathway

From: Risk-based indicators of Canadians’ exposures to environmental carcinogens

Carcinogen Average Concentration Data Quality Lifetime Excess Cancer Risk Estimates
    Average concentration andCPF1 from:
    CA2 HC3 EPA4
Indoor Air      
Arsenic and compounds --- gap - - -
Asbestos 8.5x10-5 f/ml very low 10.8 - 1.3
Benzene 2.4 μg/m3 moderate 78.0 11.4 21.1
Benzo[a]pyrene 1.9 x10-4 μg/m3 very low 0.2 < 0.1 -
1,3-Butadiene 0.12 μg/m3 low 23.4 - 3.9
Cadmium and compounds --- gap - - -
Chromium (hexavalent) --- gap - - -
Diesel engine exhaust 0.84 μg/m3 very low 300.2 - -
Formaldehyde 33.3 μg/m3 low/moderate 227.2 - 486.8
Nickel and compounds 8.5 x10-4 μg/m3 low 0.3 0.9 -
Radon 100 Bq/m3 moderate/ high - - 23,655.0
TCDD --- gap - - -
Outdoor Air      
Arsenic and compounds 4.3x10-4 μg/m3 moderate 0.1 0.3 0.2
Asbestos 2.0 x10-5 f/ml very low 2.5 - 0.3
Benzene 0.86 μg/m3 high 2.0 0.3 0.5
Benzo[a]pyrene 1.4 x10-4 μg/m3 moderate <0.1 < 0.1 -
1,3-Butadiene 0.096 μg/m3 high 1.3 - 0.2
Cadmium and compounds 1.2 x10-4 μg/m3 moderate 0.1 0.1 <0.1
Chromium (hexavalent) 1.6 x10-5 μg/m3 low <0.1 0.1 <0.1
Diesel engine exhaust 1.4 μg/m3 very low 35.6 - -
Formaldehyde 1.6 μg/m3 moderate 0.8 - 1.7
Nickel and compounds 7.0 x10-4 μg/m3 moderate <0.1 0.1 -
Radon 24 Bq/m3 moderate - - 371.0
TCDD 9.7 x10-10 μg/m3 moderate <0.1 - <0.1
Drinking Water      
Arsenic and compounds 1.9 μg/l moderate 74.0 88.8 74.0
Benzo[a]pyrene --- gap - - -
1,3-Butadiene --- gap - - -
Chromium (hexavalent) 1.2 μg/l moderate 12.9 - -
TCDD --- gap    
Food and Beverages      
Arsenic and compounds varies by food low 25.9 31.0 25.9
Benzene varies by food very low 4.4 10.0 2.4
Benzo[a]pyrene varies by food very low 2.2 0.4 1.4
1,3-Butadiene varies by food gap - - -
Chromium (hexavalent) varies by food gap - - -
TCDD varies by food gap    
Indoor Dust      
Arsenic and compounds --- gap - - -
Benzo[a]pyrene 2.91 μg/g low 22.9 4.4 14.0
Chromium (hexavalent) 4.25 μg/g very low 1.2 - -
TCDD --- gap    
  1. 1. CPF = cancer potency factor.
  2. 2. CA = California Office of Environmental Health Hazard Assessment.
  3. 3. Health Canada.
  4. 4. United States Environmental Protection Agency.
  5. Substances that were negligible or not carcinogenic in a specific pathway were excluded.