Cuyahoga County 1990 Air Toxics - Exposure Estimates1 and Cancer Hazard Ratios2
by Source Amount             
Hazardous Air Pollutants Background Sources3 (mg/m3) Area Sources4 (mg/m3) Point Sources5 (mg/m3) Mobile Sources6 (mg/m3) Estimated Exposure - All Sources (mg/m3) Cancer Benchmark7 (mg/m3) Cancer Hazard Ratio2
dichlorobenzene-p 0.000 0.118 0.055 0.000 0.173 0.15 1
trichloroethylene 0.081 0.622 0.077 0.000 0.780 0.59 1
ethylene dibromide 0.008 0.000 0.000 0.000 0.008 0.0045 2
acrylonitrile 0.000 0.027 0.000 0.000 0.027 0.015 2
dichloropropene-1,3 0.000 0.058 0.000 0.000 0.058 0.027 2
methyl chloride 1.200 0.048 0.002 0.000 1.250 0.56 2
chloroform 0.083 0.016 0.006 0.000 0.105 0.043 2
ethylene dichloride 0.060 0.033 0.000 0.000 0.093 0.038 2
acetaldehyde 0.000 0.445 0.000 0.725 1.170 0.45 3
vinyl chloride 0.000 0.050 0.000 0.000 0.050 0.012 4
carbon tetrachloride 0.880 0.014 0.008 0.000 0.902 0.067 13
benzene 0.480 0.485 0.208 1.640 2.813 0.12 23
formaldehyde 0.250 0.922 0.051 1.562 2.784 0.077 36
butadiene-1,3 0.000 0.074 0.000 0.236 0.310 0.0036 86


1. Based on USEPA Cumulative Exposure Project modelling data - 1990 sources            
2. Ratio of estimated exposure (all air sources) divided by cancer benchmark
3. Background sources = natural sources, long-range transport, resuspension              
4. Area sources = e.g., other manufacturing, commercial, service industry, consumer products              
5. Point sources = e.g., metal manufacturing, utilities              
6. Mobile sources = cars, trucks, buses, farm equipment, boats, trains, planes              
7. USEPA estimated one-in-a-million excess cancer risk for lifetime exposure.  

Prepared by Environmental Health Watch [3/4/99]              

 

Cuyahoga County 1990 Air Toxics - Exposure Estimates1 and Cancer Hazard Ratios2            
by Source Percentage            
Hazardous Air Pollutants Background Sources3 Area Sources4 Point Sources5 Mobile Sources6 Estimated Exposure - All Sources (mg/m3) Cancer Hazard Ratio2
ethylene dibromide 100% 0% 0% 0% 100% 2
methyl chloride 96% 4% 0% 0% 100% 2
carbon tetrachloride 98% 2% 1% 0% 100% 13
chloroform 79% 16% 5% 0% 100% 2
ethylene dichloride 65% 35% 0% 0% 100% 2
acrylonitrile 0% 100% 0% 0% 100% 2
dichloropropene-1,3 0% 100% 0% 0% 100% 2
vinyl chloride 0% 100% 0% 0% 100% 4
trichloroethylene 10% 80% 10% 0% 100% 1
dichlorobenzene-p 0% 68% 32% 0% 100% 1
butadiene-1,3 0% 24% 0% 76% 100% 86
acetaldehyde 0% 38% 0% 62% 100% 3
benzene 17% 17% 7% 58% 100% 23
formaldehyde 9% 33% 2% 56% 100% 36

           
1. Based on USEPA Cumulative Exposure Project modelling data - 1990 sources            
2. Ratio of estimated exposure (all air sources) divided by cancer benchmark            
3. Background sources = natural sources, long-range transport, resuspension            
4. Area sources = e.g., other manufacturing, commercial, service industry, consumer products            
5. Point sources = e.g., metal manufacturing, utilities            
6. Mobile sources = cars, trucks, buses, farm equipment, boats, trains, planes

Prepared by Environmental Health Watch [3/4/99]            

Chart Cuyahoga County 1990 Air Toxics Estimates - Major Background Sources

Chart Cuyahoga County 1990 Air Toxics Estimates - Major Mobile Sources

Chart Cuyahoga County 1990 Air Toxics Estimates - Major Area Sources

 

 

 

 

 

 

 

 

 

 

 

 

Comparison** of Modeled1 and Monitored2 Hazardous Air Pollutant Concentrations    
CLEVELAND, OHIO
           
Hazardous Air Pollutants Modeled1 Concentration (mg/m3) Measured2 Concentration (mg/m3) Cancer Benchmark Concentration3 (mg/m3) Modeled Hazard Ratio4 Measured Hazard Ratio5
Benzene 3.76 4.54 0.12 31 38
Methyl chloride 1.25 1.38 0.56 2 2
Methylene chloride 2.66 2.27 2.1 1 1
p-Dichlorobenzene 0.27 0.6 0.15 2 4
Styrene 0.2 1.08 2 <1 1
Tetrachloroethylene 1.43 1.3 1.7 1 1
Xylene 6.12 6.15 NO BENCHMARK    
           
** In a 2-tailed paired t test, there was no significant difference between the modeled and measured values.        
1. USEPA 1990 Cumulative Exposure Project-Hazardous Air Pollutants - computer modeled air concentrations from 1990 source data for Cleveland census tracts 1106.00 and 1047.02 (locations of the Broadway and Tikhon air pollution           monitoring stations respectively).
2. OhioEPA 1997 Ohio Air Quality Report - calculated average of 2 monitoring stations in the city of Cleveland (4950 Broadway and 2547 Tikhon).  
3. USEPA estimated one-in-a-million excess cancer risk for lifetime exposure.        
4. USEPA estimate of air concentration projected to result in one-in-a-million excess cancer risk for lifetime exposure
5. Modeled concentration divided by cancer benchmark concentration.          
6. Measured concentration divided by cancer benchmark concentration.