Exhaust control devices were certified in 1965 for new car installation. Most 1966 and later model domestic cars and pickups will be equipped with exhaust control systems designed to meet the Department's standard of 275 p.p.m. hydrocarbons and 1.5 percent carbon monoxide. By 1968, imported cars will be required to meet standards appropriate to their engine sizes. The effect of the exhaust control program is shown in figures 1 to 5. Hydrocarbon emissions in Los Angeles by 1970 will have been reduced to the 1957 level. This is far short of the desired goal, which is the 1940 level. In 1970, more stringent standards for exhaust hydrocarbons and carbon monoxide will be in effect. If exhaust control systems meet these standards, further reduction in vehicular pollutants will be realized. If it is assumed that evaporative emissions from fuel tank and carburetor are controlled to the level of the department's standards beginning with 1970 model cars, there will be yet an additional decrease in hydrocarbon emissions. The graphs show that slightly over 80 percent of the total vehicular hydrocarbons and 70 percent of carbon monoxide emissions would be eliminated by 1980. This would be a large reduction, close to the program's goal for Los Angeles. The greatest rate of reduction in emissions can be achieved only by a crash program involving used cars-figure 6 depicts this. However, steadily increasing vehicle registration will gradually force total emissions upward. By 1980, total hydrocarbon emissions in Los Angeles will be about the same, with or without used car control. Hydrocarbon emissions for the four areas, as shown in figures 1 to 4, all display similar trends. The program is aimed at reducing emissions to the 1940 level in Los Angeles. By 1980, however, emissions in smaller urban areas, such as San Diego and Sacramento, will be above their 1940 levels because of their much higher anticipated growth rates. Fortunately, acceptable air quality in these smaller areas does not require as high a degree of control as in Los Angeles because of the smaller vehicle population. Carbon monoxide is emitted only from the vehicle's exhaust. Its emission trends in the four areas, as shown in figure 5 will be similar to the hydrocarbon trends. When California embarked on the motor vehicle emission control program, it was contemplated that once the department of public health had adopted emission standards, these would be soon implemented with control devices for new and used vehicles. In practice, the program has advanced much slower than had been expected. Control devices, except those for crankcase emissions have not quickly followed the standards. Instead, there has been a considerable time lag. Exhaust control systems have not become available for used cars. Even if used car devices were available, the current law covers used cars only when registration is changed and is limited to air pollution control counties. 1966 and 1967 domestic cars have been equipped with exhaust control systems, but new trucks, buses, and small cars will not be so equipped until the 1968 models. Standards for evaporative emissions, oxides of nitrogen, smoke and odor have been established, but no devices for the control of these emissions have been submitted to the motor vehicle pollution control board for certification. Development of suitable means to control vehicle exhaust was a slow process. Initially there was widespread interest in device development. The lure of a ready-made market provided the incentive for several companies to enter the field. But when after several catalytic and afterburner mufflers were certified, the automobile manufacturers introduced devices of their own. The new car market was eliminated insofar as independently developed devices were concerned. The withdrawal of these companies from competition has removed much of the stimulus for further device development by automobile manufacturers. Projection of surveillance data shows that as vehicle mileage accumulates, the average emissions from vehicles with exhaust control systems will not meet the current standards of 275 parts per million hydrocarbons and 1.5 percent carbon monoxide. Some exhaust devices become less effective because the condition and adjustment of the engine and the device change as vehicle mileage accumulates. At present, there is no effective inspection and enforcement system to insure that maintenance is provided by the car owner. Such maintenance might be necessary to insure continued compliance with standards. The Federal Government entered the field of motor vehicle pollution control with the enactment of the Clean Air Act of 1963, which directed the Secretary of Health, Education, and Welfare to set na tional standards for motor vehicle emissions. The Federal Government has used the California standards for hydrocarbons and carbon monoxide as bases for certification of devices beginning with 1968 model cars. California has already added evaporative emission standards and adopted stricter exhaust standards effective in 1970. Both changes are essential to the State. Unless the Federal standards are made as stringent as those in California, they will be of no benefit to California and may possibly be in conflict with California's needs. It is imperative, therefore, that California continue to establish its own standards based on its needs. A review of all the factors involved indicates that there is no simple and inexpensive solution to the complex problem of motor vehicle-created air pollution. The problem has many aspects. It is legal, political, social, economical and technological. The final solution must incorporate considerations for all these aspects. The motor vehicle control program in California has reduced emissions of hydrocarbons and carbon monoxide into the atmosphere. In spite of the increasing number of vehicles, there has been a reversal in emission trends for the first time. If the goal of prewar air quality is to be achieved, there must be a high degree of emission control. Consequently, the program requires that effective systems be available, and that virtually no cars be exempt. Lack of efficient control of some emissions, large numbers of cars uncontrolled, and deterioration in efficiency of control systems will lead to air quality poorer than that desired. Under the present program, which is oriented towards the installation of control systems on new cars, the reduction of contaminants emanating from motor vehicles will be gradual. In order to accomplish a rapid improvement, within a few years, exhaust emissions from all cars (new and used) must be controlled. Even if events follow the lines depicted in Figures 1 to 5, growth of motor vehicle usage beyond 1980 leads again to a rising trend. Curtailment of emissions from post-1980 vehicles must begin well in advance of that time. Motor vehicle registration is increasing at a rapid pace; control programs are usually less effective than planned; there is a long-time delay between the establishment of standards and the development of exhaust and evaporative control devices. For these reasons, and because of the poor prospect of exhaust control for used cars, it is important to consider far more stringent motor vehicle emission standards than those already adopted. Senator MUSKIE. Thank you very much. I think it is very helpful to the record. Senator Murphy? Senator MURPHY. No questions. Senator SPONG. No questions. Senator MUSKIE. Thank you very much. If you had come on earlier in the day, I am sure there would have been more questions. The next witness, Mr. Edward A. Schuck, Statewide Air Pollution Research Center, University of California, Riverside. STATEMENT OF EDWARD A. SCHUCK, STATEWIDE AIR POLLUTION RESEARCH CENTER, UNIVERSITY OF CALIFORNIA, RIVERSIDE, CALIF. Mr. SCHUCK. The importance of oxides of nitrogen to air pollution problems can hardly be overemphasized. There are only two of these oxides which have direct implications for air pollution. These are nitric oxide and its oxidation product, nitrogen dioxide. Because nitric oxide is readily converted to nitrogen dioxide, and vice versa, it is impossible to talk about either of these oxides as isolated contaminants. These conversion reactions plus the many roles which these oxides of nitrogen play in air pollution problems have been the source of much confusion. This confusion is caused by focusing attention on only one of the many reactions involved. This confusion also lends ready ammunition to those who wish to delay or prevent consideration of control measures. Today I will attempt to outline the significant reactions involved and their consequences. The first point to consider is the source of these oxides. Nitric oxide, a colorless relatively nontoxic gas, is formed from oxygen and nitrogen in the air whenever this air is heated to a sufficiently high temperature. Thus, our automobile engines, our steam generating power plants which provide us with electricity, and even our home heating systems are efficient producers of nitric oxide. The relative amounts contributed by these various sources will vary from city to city. For example, in Los Angeles, there are 840 tons of oxides of nitrogen emitted to the atmosphere every day. Of this total 50 to 75 percent comes from the automobile engine while electric power plants contribute about 17 percent. Senator MUSKIE. Has anything been done about controlling those emissions from stationary sources? Mr. SCHUCK. As far as I know, there has been no action taken. On the other hand, in New York City the contribution from electric power plants may be equal to or greater than that produced by automobiles. Regardless of the relative contribution of these sources, we can say with assurance that no urbanized area is free of these oxides because we are at the moment dependent on the high temperature combustion of fossil fuels for most of our power demands. The first reaction occurs as these exhaust gases, which contain a high concentration of nitric oxide, are discarded into the atmosphere. This particular reaction involves the combination of nitric oxide wth oxygen of the air to form nitrogen dioxide which is a highly colored toxic gas. This conversion reaction is rapid at the high nitric oxide concentrations characteristic of undiluted exhaust gases and very slow at the low concentrations characteristic of completely diluted exhaust. Thus, this action converts some definite fraction of the nitric oxide to nitrogen dioxide during the exhaust dilution process. For example, in Los Angeles nighttime air 25 percent of the total oxides of nitrogen appears as nitrogen dioxide. The rate of dilution, the temperature of the diluting air, and the concentration of nitric oxide in the exhaust stream are the three factors which determine the fraction of nitric oxide converted in nitrogen dioxide. These considerations lead us to a sobering thought. Since nitrogen dioxide is a relatively toxic gas, we are most fortunate that the concen tration of nitric oxide in automobile exhaust is no higher than presently observed. Higher nitric oxide emissions might result in exposing our freeway drivers to damaging concentrations of nitrogen dioxide. This dilution reaction should serve as a warning to highway designers. It is obvious that unlimited horizontal and vertical highway expansions will interfere with the exhaust dilution process thus providing more time for more nitric oxide to be converted to nitrogen dioxide. We should also look with a jaundiced eye at any new automobile power plant which has vastly increased nitric oxide emissions. The exhaust concentration of nitric oxide is a critical factor since the reaction tells us that a 50 percent increase in nitric oxide exhaust concentration will cause a 100 percent increase in the amount of nitrogen dioxide produced during dilution. In this sense I would like to call your attention to a recent report by L. J. Fuller, the Los Angeles County Air Pollution Control Officer, in which he states that automotive devices which are required on California automobiles are failing to meet the State hydrocarbon and carbon monoxide standards. He further reports the chilling fact that these devices are causing a 50 percent increase in the oxides of nitrogen emissions. If true this is an appalling situation even if the devices were meeting the State hydrocarbon standards, appalling because we are attempting to control one type of undesirable pollutant at the cost of substantially increasing the concentration of another equally undesirable pollutant. So far we have seen that atmospheric dilution of exhaust gases results in a substantial conversion of nitric oxide to nitrogen dioxide. This is most readily observed during nighttime hours because during daylight hours there are other reactions which upset this ratio of nitric oxide to nitrogen dioxide. Since nitrogen dioxide is a highly colored gas, it results in a visibility reduction and is responsble for the brownish-red color which is so typical of the atmosphere in the vicinity of our urbanized areas. However, in addition to absorbing visible light, nitrogen dioxide is an efficient absorber of the ultraviolet sunlight which reaches the earth's surface. The absorption of energy causes the nitrogen dioxide to dissociate into nitric oxide and oxygen atoms. When this dissociation occurs in the presence of certain hydrocarbons, a series of reactions are initiated whose end results are the production of powerful eye irritants and phytotoxicants. If, as usually is the case, sulfur dioxide is present in this reacting mixture, and aerosol is formed which results in a drastic reduction in visibility. It should be noted that these certain hydrocarbons, as well as the sulfur dioxide, are almost invariably present in the exhaust emissions which produce our oxides of nitrogen. Thus, while a particular urban atmosphere may be dominated by sulfur dioxide, we can rest assured that all three compounds are usually present in urban atmospheres. Another atmospheric reaction which we observe in Los Angeles during the daylight hours is the rapid conversion of the bulk of the nitric oxide to nitrogen dioxide and the subsequent disappearance of the nitrogen dioxide into products. One of these products which incorporates a molecule of nitrogen dioxide is an extremely powerful eye irritant and phytotoxicant. This product is named peroxyacetyl nitrate. Another powerful phytotoxicant produced in these reactions is ozone. Thus, we can see that nitrogen dioxide is of prime impor |