Motor Vehicles, Air Pollution,and Public Health

RICHARD A. PRINDLE, M.D., M.P.H., and CHARLES D. YAFFE, M.S.

The following material is adapted from a statement

before the Joint State Government Commission ofthe General Assembly of the Commonwealth ofPennsylvania, June 8, 1962. The statement was

based on a three-part report, "Motor Vehicles, AirPollution, and Health" (H. Doc. 489), submittedto the U.S. Congress in June 1962. Because of theparticular interest of the commission, proportion¬ately more emphasis was given to standards andcontrols in the statement. Copies of the report are

available from the Congress and from the Divisionof Air Pollution, Public Health Service, Washington25, D.C.

MOTOE VEHICLES, like the dragons ofold, have a foul and fiery breath. From

their tailpipes and crankcases these modernmonsters spew forth a steady stream of pollut¬ants, visible and invisible, odorous and odorless,into the atmosphere. These emissions are un-

questionably obnoxious; whether and to whatdegree they are also noxious is under intensivestudy by the Public Health Service.Before 1955 the Service and other Federal

agencies had conducted limited research activi¬ties on some aspects of air pollution. With thepassage of Public Law 84-159 in 1955, furtherFederal activity was authorized, and researchwas centralized in the Public Health Service.Emissions from motor vehicles were investi¬gated as a part of the total air pollution prob¬lem, and it was recognized early that these wereimportant contributors, especially in certainareas of the United States. With the passage,

Dr. Prindle is deputy chief and Mr. Yaffe is staffadviser, Office of the Chief, Division of Air Pollu¬tion, Public Health Service.

in 1960, of Public Law 86-493 (commonlycalled the Schenck Act, after its sponsor, Con-gressman Paul F. Schenck of Ohio), added im-petus was given to the study of motor vehicleemissions. This act authorized and directed theSurgeon General of the Public Health Serviceto make a study and report to Congress, byJune 1962, from the standpoint of the publichealth, on the discharge of substances into theatmosphere from the exhaust of motor vehicles.

Production of Emissions

The nature and volume of exhaust emissionsdischarged by a motor vehicle at any time de¬pend on how it is being driven. In evaluatingemissions, four basic driving maneuvers mustbe considered: (a) cruising, uniform speed;(b) acceleration, increasing speed; (c) decelera¬tion, decreasing speed; and (d) idling, stand¬ing still with motor running.The typical U.S. automobile has a four-stroke

Otto cycle gasoline engine with four, six, or

eight cylinders. Pistons move up and down inthese cylinders and transmit their motion byconnecting rods to the crankshaft and thencethrough the transmission to the wheels. Agasoline-air mixture is drawn by a vacuum fromthe carburetor into each cylinder, where it iscompressed and then ignited by an electricspark from the spark plug. The burning gasesexpand and produce pressures which force thepistons down, driving the crankshaft.The conflicting requirements for easy start¬

ing, fuel economy, power, and the various per¬formance characteristics which the public de¬mands necessitate compromises in the designand the adjustment of the engine. The nature

Vol. 77, No. 11, November 1962 955

and volume of the exhaust gases are affected bythese compromises.In addition, the nature and composition of

the fuel used also affect the nature of theseemissions. Fuel is a complex mixture composedalmost entirely of hydrocarbons. If these are

completely burned in an adequate air supply,the theoretical end products are carbon dioxideand water. Under ordinary driving condi¬tions, the air-to-fuel ratio is such that insuffi¬cient oxygen is supplied. The result is emissionof substantial amounts of substances other thancarbon dioxide and water, including such im¬portant compounds as carbon monoxide andnumerous partially burned hydrocarbons, inthe form of alcohols, aldehydes, ketones,phenols, acids, peroxides, and others. Also,under the conditions of temperature and pres¬sure present, a certain amount of nitrogen andoxygen combine in the cylinder to produce var¬

ious oxides of nitrogen, which are also impor¬tant emissions.The volume of exhaust gases which may be

derived varies considerably during the opera¬tion of an automobile, ranging from as low as

5 or 6 cubic feet per minute to as much as 200cubic feet per minute. This tremendous rangeseriously complicates the task of determiningthe amounts of contaminants released into theair and adds to the difficulty of designing anddeveloping satisfactory systems for the controlof exhaust.Aside from the exhaust, the crankcase is the

other principal source of pollution. MostAmerican automobiles have a system of crank¬case ventilation which employs a "road drafttube." With this system, air flowing past themoving vehicle aspirates crankcase fumesthrough a tube from the crankcase. Thesefumes are derived principally from fuel-airmixtures which escape past the pistons downinto the crankcase. Replacement air is drawnin through the oil filter cap and air inlet. Untilrecently, this was thought to be only a smallproportion of the total emissions produced by acar. More recent evidence has disclosed thatbetween 20 and 40 percent of the total hydro¬carbons discharged escape via the crankcase.These "blowby" gases are greatest when theengine is working under a heavy load.A small additional amount of hydrocarbons,

possibly 5 percent of such emissions, may be lostby evaporation from the fuel tank and an equalamount by evaporation from the carburetor,particularly after the engine has stopped and isstill warm. Fuel tank evaporative losses are

particularly affected by local temperature andhumidity conditions.

Magnitude of the ProblemOf approximately 75 million motor vehicles

registered in the United States, about 62 mil¬lion are passenger automobiles. This repre¬sents a 2y2-iold increase over the 32 millionregistered in 1942. Judging by projections ofexpected future economic and populationgrowth, it seems reasonable to forecast 100 mil¬lion cars, trucks, and buses within the next 10years.Motor fuel is consumed at the rate of ap¬

proximately 60 billion gallons per year. Thisamounts to about 1 gallon per person per dayand represents an average car travel of approxi¬mately 10,000 miles per year, using 800 gallonsof fuel. In Pennsylvania, for example, 3,625,-000 automobiles were registered in 1960. Thisrepresents the third largest registration in num¬bers, exceeded only by the States of Californiaand New York. In the metropolitan area ofPhiladelphia, there were 473,269 cars, whichrepresents 3,730 cars per square mile, third onlyto Washington, D. C, with 4,100, and Denverwith 3,951. Pittsburgh, because of the largermetropolitan area, and with the same numberof cars (474,981), had only 650 cars per squaremile. Pennsylvanians used 3,377,892,000 gal¬lons of gasoline in 1960, again exceeded only byCalifornia and New York State.

If the research conducted in Los Angeles on

the volume of contaminants emitted from auto¬mobiles can be extrapolated to other parts ofthe nation, then we may estimate for Pennsyl¬vania the following annual discharge of con¬

taminants: carbon monoxide, 5 million tons;hydrocarbons, 700,000 tons; nitrogen oxides,about 300,000-6,000,000 tons. These are only a

few of the contaminants emitted which may beof considerable significance.Photochemical SmogMotor vehicle emissions mix with other pol¬

lutants in the atmosphere and may react with

956 Public Health Reports

these and with each other. Of greater impor¬tance is that sunlight plays a significant role ininfluencing these reactions and in producingchanges in the chemical makeup of the atmos¬pheric pollution. It has been demonstrated inthe laboratory that hydrocarbon and oxide ofnitrogen mixtures, when irradiated by sunlight,produce other compounds, including ozone, re¬lated oxygen-carrying compounds known col-lectively as oxidates, and numerous other chem¬ical substances, including acids and aldehydes.Ultraviolet light from solar radiation can leadto the change of nitrogen dioxide to nitricoxide, along with the release of highly reactiveatomic oxygen, part of which forms ozone.

These complex photochemical reactions leadto the production of aerosols, minute particulatesubstances, which obscure the horizon and de¬crease visibility. In addition, this change ofchemical composition resulting from solar ir¬radiation makes it extremely difficult to assessthe individual contributions of various types ofengine operation, types of engines, types of fuel,and the numerous other factors which con¬tribute to the total complex. Finally, sincemany of these compounds produced in the airchange further with great rapidity into othercompounds, it is difficult to assess which ones

adversely affect human health, property, andvisibility. From our recent studies, however,we conclude that many of the newly formedcompounds are more reactive and more irritat-ing than their "parent" substances.

Biological Effects

Although the adverse effects of air pollutionrange from economic damage, reduction of visi¬bility, and injurious effects on crops and ani¬mals, to illness and death in people, the role ofmotor vehicles in producing these effects is notfully defined.The presence in community air of pollutants

from motor vehicles has been established. Fur¬ther, it has been shown that vegetation can beseverely damaged by some of these substances,whether they are produced artificially in thelaboratory by direct chemical means, in simu-lated test runs in which automotive exhaust isirradiated by artificial sunlight, or in the am-bient atmosphere of urban areas. This damageis found in many areas of the United States. A

recent report on this subject, "Air Pollution as

It Affects Agriculture in New Jersey," pre¬pared by Robert H. Daines, Ida A. Leone, andIlene Brennan, of the Department of PlantPathology of the New Jersey Agriculture Ex¬periment Station at Rutgers University, con¬

tains the following statements."While injury to vegetation from acid gases

appears to be decreasing in New Jersey and2,4-D herbicides no longer pose a problem, in¬jury from ozone and other oxidants is increasingin frequency by virtue of a greater populationconcentration. Ozone injury has now reachedthe point of seriously threatening the commer¬

cial production of spinach and possibly endive,chicory, and some varieties of petunias in manyareas. Although photochemically producedcompounds other than ozone which are respon¬sible for oxidant injury do not at present rep¬resent as great a threat to as many crops in NewJersey as ozone, damage has been observed on

celery, spinach, and a few greenhouse cropsfrom these compounds. As our populationgrows further, increase in sources of emissionof the constituents responsible for the produc¬tion of ozone and other oxidants can be expectedin urban areas, especially in this age of auto¬mobile travel, rendering the air pollution prob¬lem especially serious in large cities. . . .

"With the sources of contamination, cars,home, and industrial fires, refineries, etc, beingso numerous both in and bordering New Jersey,it is not surprising that test tobacco plants,placed in 14 different locations in New Jerseyduring the growing season just passed, showedinjury from ozone in every location. It appearstherefore that this new problem, while beingmost serious near such cities as Philadelphiaand New York, can be expected to affect sensi¬tive plants in all areas of the State."The problem described in New Jersey can

also be expected, of course, to affect sensitiveplants in similar areas throughout the country.

Studies on animals have demonstrated thatguinea pigs exposed to automotive exhaust, ata concentration several times normal, for 1, 2,and 4 weeks, were especially susceptible to se¬vere pulmonary disease. This came to light ac¬

cidentally, following an epidemic whichproduced pneumonia in the test animals. Sig¬nificantly higher mortality occurred in the ani-

Vol. 77, No. 11, November 1962 957

mals exposed to irradiated exhaust, comparableto heavy photochemical smog, than in animalsexposed to nonirradiated exhaust or in controlanimals, which had also experienced the epi¬demic but were exposed only to pure air. Thisfinding parallels the results of another studyin which animals exposed for only 2 hours tonitrogen dioxide, at levels similar to those foundon occasion in community atmospheres, weremuch more susceptible to infection from certainpneumonia organisms. This resulted in more

serious illness and more deaths among themthan in the control animals, which were exposedto the same organisms but otherwise breathedonly pure air.

Physiological experiments in which measureswere made of respiratory function of laboratoryanimals, including resistance to breathing,breathing rate, and the depth and pattern ofrespirations, have shown that the greatestchanges occurred in those animals exposed toirradiated exhaust. In general, these changesoccurred when the animals were exposed toconcentrations two or more times higher thanthose found in the average community. How¬ever, some physiological changes have occurredin animals exposed to concentrations at com¬

munity levels, and specific pollutants have pro¬duced effects at or near these concentrations.This would appear to indicate that the observedmaximum levels present in some communitiesat this time are borderline with respect to caus¬

ing immediate effects and changes in pulmonaryfunction.

Studies on human beings have been extremelylimited, since it is not desirable to expose per¬sons deliberately under laboratory conditions,and since it is extremely difficult to find personsin the normal community who are exposed solelyto automotive exhaust; that is, without otherprevalent factors, such as cigarette smoke, otherair pollutants, and various occupational haz¬ards. In addition, those few groups of personsespecially exposed to motor vehicle emissions,such as vehicular tunnel workers, are in situa¬tions where the exhaust may not be irradiatedby the sunlight, and therefore the supplementalchemical reactions which may be of extra physi¬ological importance to the person may notoccur. However, it has been demonstrated thatthose individuals in the general population who

have preexisting pulmonary disease, specificallyemphysema, show improvement of variousphysiological functions when they are protectedin specially built rooms provided with protec¬tive filtering equipment. When they return tothe normal atmosphere of the polluted urbanarea, their pulmonary function tests show de¬terioration. Emphysema, a long-term chronicdisease of the lungs, causes severe disability andultimately may lead to death. It has shown an

alarming increase in the past 10 years, havingrisen fivefold nationally as a cause of death.

Cancer

Also of real concern is the possible role of mo¬tor vehicle exhaust in the causation of cancer.Of particular interest are cancers of the respira¬tory system, which, because of its direct expo¬sure to inhaled air, is more likely to be affectedby any chemical pollutants in the air.

Statistical studies and epidemiologic surveysof populations have disclosed that cancer of thelung has increased manyfold. As a cause ofdeath in males it has multiplied five times in thepast 20 years. Further, it has been shown thatmany more cases and many more deaths occurin urban areas and that these increase as thesize of the city increases.At the same time, chemical analysis has dem¬

onstrated numerous substances in automobileemissions which are known to produce cancersand tumors in animals. Recent studies at theSloan-Kettering Institute in New York haveattempted to assay the quantity and significanceof these pollutants in automobile exhaust.However, it has not yet been possible to dem¬onstrate conclusively the association betweenthese pollutants and specific cases of lung cancerin man.

Last year, on the other hand, workers at theUniversity of Southern California producedtrue cancers in the lungs of mice, similar tothose found in human beings. In these experi¬ments, the mice were infected with a viral in¬fluenza. After recovery, they were exposedeither to clean air or air containing ozonizedgasoline. Other laboratory animals, which hadnot been infected with the influenza, were sim¬ilarly exposed either to the pure air or the sim-ulated smog. Uninfected animals showed no

958 Public Health Reports

changes in their lungs. Approximately 8 per¬cent of the animals which had been infectedand then exposed only to pure air showed cer¬

tain changes in the lungs similar to those oftenfound in persons living in urban areas or inheavy smokers. These lesions are thought tobe associated with cancer. The striking find¬ing, however, was that 30 percent of the animalswhich had been infected and then exposed to thesimulated smog developed true cancers. Underthese conditions, it appears that air pollutantsrelated to vehicular emissions play a role, atleast as a co-factor, in the production of lungcancers.

Standards

Complete scientific standards for air pollu¬tion control are still to be developed. A fewlimited standards have been established andthese are generally of two types: standards forambient air quality, designed to provide a safeor comfortable community level; and standardsfor emissions, designed to control the amountsput into the atmosphere by specific sources. Inrelation to the motor vehicle, only Californiahas developed standards. Here, air qualitystandards for the ambient air were establishedfirst and then emission standards consistent fortheir maintenance were set for vehicles.The California standards were adopted fol¬

lowing the enactment in 1959 by the CaliforniaState Legislature of laws which made it man¬datory for the State department of publichealth to develop such standards for both airquality and motor vehicle exhaust. Standardsfor several pollutants were adopted by the Stateboard of health on December 4, 1959. Thesepioneer efforts are tentative and the health de¬partment has specifically cautioned that theymay be modified or otherwise changed as new

information becomes available.In developing the ambient air standards,

California authorities attempted to determinethe effects on human health and comfort, on

animals and plants, and on visibility, whichwere likely to occur at various concentrationsof contaminants. The standards were not setto establish a fine line of demarcation betweengood air and bad, but rather to indicate theapproximate point at which pollution may have

some undesirable effect under certain circum¬stances.

These standards were devised on the basisof the health effects of pollutants on people,including those who might be most susceptible,such as the aged or the very young, and thekind of effects. These effects included: acutesickness or death; insidious or chronic disease;alteration of important physiological functionsuch as ventilation of the lung, transport ofoxygen, or adaptation to dark; untoward symp¬toms which "might lead a person to seek medicalattention and relief"; and discomfort from airpollutants "sufficient to lead individuals tochange residence or place of employment."The effects on vegetation were related to acutedamage leading to unmarketability; insidiousor chronic effects, leading to impaired yield;and alteration of fundamental biochemicalprocesses without overt damage.On the above bases, a graded set of standards

was established, and three levels to correspondto the degree of seriousness were defined as

follows:"Adverse11 level. The adverse effects of air pollu¬

tants are those likely to lead to untoward symptomsor discomfort. This level is one at which eye irrita¬tion occurs and at which costly and undesirable effectsoccur on biological systems other than humans, suchas damage to vegetation; reduction in visibility; or

property damage of sufficient magnitude to constitutean economic burden.

"Serious" level. These are levels likely to lead toinsidious or chronic disease or to significant alterationof important physiological function in sensitive groups.Such an impairment implies a health risk for personsconstituting a sensitive group but not necessarily forpersons in good health.

"Emergency11 level. This level is one in which pol¬lutants or combinations of pollutants and meteoro-logical factors are likely to lead to acute sickness ordeath for a sensitive group of people.

It is recognized that standards set for singlepollutants are not necessarily applicable to com¬binations of pollutants. The possibility ofsuch combinations, along with unusual weatherconditions or the presence of particulate matter,seriously complicates the task of establishingreasonable levels. For these reasons no singlelevel of a given pollutant, ordinarily withouteffect at that level, should be interpreted as a

guarantee that lower concentrations are safe or

free from effect. It is known, for example, that

Vol. 77, No. 11, November 1962 959

particle size may modify the toxicity of an in-haled particulate, and in some cases, that twoor more pollutants may act in conjunction toincrease the action of one or the other or both.Motor vehicle emission standards were de¬

rived in California by estimating the degreeof control required to achieve the conditionsspecified by the ambient air standards with re¬

spect to expected emissions from all sources inLos Angeles County in 1970. These estimatesindicated that an 80 percent reduction in hydro¬carbons and a 60 percent reduction in carbonmonoxide emitted from motor vehicles wouldbe required. These emissions are to be meas¬

ured during a specific driving cycle which in-corporates 11 different modes for evaluation ofspecific exhaust emission control devices. These11 modes were developed to simulate averagedriving patterns observed in the Los Angelesarea. Under these test conditions, the Stateauthorities concluded that the hydrocarbonsemitted should be less than 275 parts permillion by volume (as hexane) and that the car¬

bon monoxide should not exceed 1.5 percent byvolume.Although nitrogen dioxide is listed in the

group of chemicals known as "oxidants" andtherefore is included in the ambient air stand¬ards, no standard for nitrogen dioxide per se

is included yet in the California motor vehicleemission standards.In December 1960, the California Board of

Health adopted a standard for crankcase emis¬sions of hydrocarbons of 0.15 percent by weightof the supplied fuel.

Control of Motor Vehicle Emissions

In considering the control of motor vehicleemissions, attention has been concentrated on

two major sources of pollutants, the exhaust andthe crankcase. Although schemes have beendevised for control of evaporative losses, theconsensus to date has been that attention shouldbe focused on the two more significant sources.

For the control of crankcase emissions a sim¬ple solution has been devised. This is merelyto provide a tube from the crankcase whichwill return the emissions to the intake of theautomobile. Several devices have been mar¬

keted ; some provide for the reentry of the fumes

into the intake manifold and others provide forreentry into the carburetor either before or afterthe air cleaner. Although there are technicaldifferences in these approaches, the basic pat¬tern is the same; that is, to return the emissionsso that they may be burned in the engine. Anumber of devices which meet the State emissionrequirements have now been approved by theCalifornia board. The Automobile Manufac¬turers Association has recommended to its mem¬ber companies that all new cars produced fordomestic use be equipped with a crankcase emis¬sion control device, beginning with the 1963models.Thus, it appears that substantial progress

will be made in the control of pollution fromthe crankcase. The anticipated reduction oftotal emissions of hydrocarbons, by approxi¬mately one-fourth, is a useful first step in thecontrol of air pollution from automobiles, andmay be sufficient to postpone in some localitiesthe necessity for additional control methods.The approaches to control of hydrocarbon

and carbon monoxide emissions from the ex¬

haust which currently offer most promise useafterburner devices. Two major types haveevolved and presently are under test in Cali¬fornia or in development stages by variousmanufacturers. One uses a catalyst in a muffler-type device to cause the combustion reactions,begun in the engine, to go to completion andresult in the ultimate incineration of the par¬tially burned hydrocarbons present in the ex¬haust. The other device provides a direct flamewhich will accomplish the same burning process.The California board has decided that any de¬vice approved must meet the established emis¬sion standards throughout a period of 12,000miles of driving.There are numerous difficulties with these

devices, including the fact that any afterburnermay overheat, with consequent damage to itsstructure or to a catalyst, if present, when con¬

centrated exhaust mixtures are passed throughit; for example, during extended downhill de¬celeration. One of the problems with the cata-lytic device has been the "poisoning" of thecatalyst caused by lead additives in the gaso¬line. This results in a shortened lifetime forthe catalyst and requires that it be changed or

rejuvenated after a period of use. The direct-

960 Public Health Reports

flame afterburner occasionally requires addi¬tional fuel, particularly on starting. It mustalso withstand higher temperatures. On theother hand, it has the advantage of accomplish-ing its purpose the moment the engine hasstarted and the flame has been turned on. Withthe catalytic afterburner, there is frequently a

longer waiting period before the catalystwarms up sufficiently to accomplish effectiveincineration.At present, no device has been approved by

the California board for exhaust control, al¬though four have thus far been selected for12,000-mile-in-use tests.Other possibilities for control of exhaust

emissions which have not been completely ex-

plored include modifications of the engine orof methods of supplying fuel. There is amplejustification for believing supplementary de¬vices, such as afterburners, are merely a meansof correcting the result of a basic defect. En¬gine modification or redesign would possiblyget to the core of the problem more directlyand provide a surer and more positive tech¬nique. For this reason the President, in hismessage on consumer protection, has asked theSecretary of Health, Education, and Welfareand the Secretary of Commerce to meet withthe automobile manufacturers to discuss fur¬ther such approaches which might benefit thenation's health.

Recently, the automotive industry experi-mented with mechanisms which affect carbu-retor air-to-fuel ratios and spark advance andretard. These mechanisms are stated to reduceconsiderably the quantity of emitted hydro¬carbons.Proper engine maintenance can be of substan¬

tial assistance in decreasing excessive emissions.Assuring a proper air-to-fuel ratio and pro¬viding correctly adjusted and timed ignitionspark and properly seated valves help to reduceexhaust emissions. Maintenance of correctpiston-and-cylinder tolerances and use of accu¬

rately fitted rings will reduce blowby emissions.A final approach is fuel modification. In Los

Angeles County regulation was promulgatedwhich required that gasoline should have a

lower content of the chemical hydrocarbongroup known as olefins, since there was evidencethat these were more reactive and produced

more irritating compounds from automobileexhaust. However, there is also evidence thatthe engine will produce some of these same

pollutants, whether or not olefins are present,and reduction of olefins in the original gasolineonly results in a partial reduction in the amountemitted. Further, this technique increasesother gasoline constituents, such as aromatics,which, while possibly reducing the amount ofmore photochemically active constituents, mayproduce more of those which are potentiallymore hazardous.

Conclusions

1. Although motor vehicles produce a varietyof pollutants from four sources, the exhaust andthe crankcase are the greatest contributors.

2. Automotive emissions consist principallyof carbon monoxide, carbon dioxide, the oxidesof nitrogen, and a variety of unburned or par¬tially oxidized hydrocarbons. Some of thesesubstances are rapidly toxic in high concentra¬tions when they are emitted, and there is evi¬dence that some emissions when present in lowconcentrations over extended periods, may pro¬duce adverse effects on biological systems.

3. Some of these emission products, whenmixed in the urban atmosphere and irradiatedby sunlight, participate in complex chemicalreactions which result in the formation of pho-tochemical smog. Many of these substancesare more highly reactive chemically and theyappear to be more dangerous than the originalemissions. These products also may be acutelytoxic in high concentrations, and they may beharmful when present in low concentrations forextended periods.

4. In many communities, automotive emis¬sions are already damaging agricultural cropsand reducing visibility.

5. Preliminary evidence indicates that cur¬rent concentrations of automotive emissions inmany community atmospheres are borderline inrespect to producing adverse effects in man andanimals. Concentrations two or three timesthose found in ambient air have produced ad¬verse and even serious effects in laboratoryanimals.

6. Some substances in automotive exhausthave produced tumors and cancers in laboratory

Vol. 77, No. 11, November 1962 961

animals. Under certain conditions, inhalationof these substances led to cancer. Althoughthe evidence at hand does not provide directcause-and-effect proof, it does warrant furtherimmediate research.

7. Crankcase emissions, which constitute ap¬proximately one-fourth of the total hydrocar-bon emissions, can be controlled by existingdevices. The Automobile Manufacturers As¬sociation has recommended to its member com¬

panies that all new cars be equipped with a

crankcase emission control, beginning in 1963.8. Means for control of exhaust emissions are

not yet sufficiently developed for general ap¬plication. Appropriate modification of theengine, fuel, or fuel supply system may be a

partial solution.9. Proper maintenance and operation of

motor vehicles can contribute significantly tothe reduction of automotive emissions.

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Podiatry and the Nation's Health.1962; 32 pages. The American Podi¬atry Association, 3301 16th St. NW.,Washington 10, D.C.Senior Citizens and How They Live.An analysis of 1960 census data.Part I: The national scene. July1962; 16 pages. Office of ProgramPolicy, Housing and Home FinanceAgency, Office of the Administrator,Washington 25, D.C.

Better Health Care for Canadians.Summary of major findings, withrecommendations, of the submissionby the Canadian Welfare Council tothe Royal Commission on HealthServices, May 1962. 16 pages. An¬nual Report. Canadian WelfareCouncil. 1962; 8 pages. CanadianWelfare Council, 55 Parkdale Ave.,Ottawa 3.

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