290 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1956 



ALL SOURCES 



EXCEPT 



MOTOR VEHICLES, 



ALL SOURCES 



2 4 6 8 10 12 14 16 18 20 22 24 2 4 

 HOUR OF DAY 



8 10 12 14 16 18 20 22 24 

 HOUR OF DAY 



Figure 15. — Contributions of industry (petroleum and other industries) and of cars to the 



ozone pollution. 



sources. In the first case it would appear that the contribution of the 

 industry to ozone concentration at the California Institute of Tech- 

 nology is 9 percent, in the second case it would be 56 percent. This 

 apparent difference is due to the fact that the contribution of each of 

 the pollution sources to the ozone concentration are not directly ad- 

 ditive since a chemical reaction is included in our mathematical model. 

 In the case of figures 11 and 12 no such reaction was included and the 

 total concentration of "important" pollutants was equal to the sum 

 of the contributions from each of the sources. This is not necessarily 

 true when a chemical reaction is playing a part in the atmospheric 

 pollution. Figures 15c and 15d represent similar results for the con- 

 centratins obtained for cars only and for all sources except cars. 



REDUCTION OF POLLUTION FROM EXISTING SOURCES 



To avoid using temporary emergency measures too often, the pos- 

 sibility of permanently correcting an unsatisfactory pollution situa- 

 tion might be studied and the effect of the local sources of neighbor- 

 hood pollution in each locality should first be examined. In the case 

 illustrated in figure 13, the contribution of the incinerator operation 

 to the pollution level would be evaluated. From this evaluation it can 

 be determined whether the contribution of the local sources of pollu- 

 tion to the neighborhood pollution is too large; where necessary, 

 remedies can be applied. This may correct many local situations where 

 the main responsibility for the pollution lies with the local sources. 



