Final Report: Emissions from Diesel and Gasoline Engines Measured in Highway Tunnels

EPA Grant Number: R828112C107
Subproject: this is subproject number 107 , established and managed by the Center Director under grant R828112
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: Health Effects Institute (2000 — 2005)
Center Director: Greenbaum, Daniel S.
Title: Emissions from Diesel and Gasoline Engines Measured in Highway Tunnels
Investigators: Gertler, Alan W. , Grosjean, Daniel
Institution: Desert Research Institute
EPA Project Officer: Chung, Serena
Project Period: April 1, 2000 through March 31, 2005
RFA: Health Effects Institute (1996) RFA Text |  Recipients Lists
Research Category: Health Effects , Air


Emissions from motor vehicles have substantially changed over the last decade because of new fuels, changed engine designs, and improved emission-control technology. Studies of the health effects associated with exposure to motor vehicle exhaust increasingly are complicated by the changing nature of emissions over time. Both studies described in this report measured emissions from diesel and gasoline engines in highway tunnels. One study analyzed particulate matter and gaseous emissions and compared these data with previous measurements; the other focused on aldehyde emissions.

Ambient particulate matter comes from many sources and varies in size, chemical composition, and other physical and chemical properties depending on the source of the particles and the changes they undergo in the atmosphere. Emissions from engines powered by diesel, gasoline, and jet fuels are major sources of ambient particles. Diesel exhaust particulate matter has been declared a probable human carcinogen by the US Environmental Protection Agency, the International Agency for Research on Cancer, the World Health Organization, and the US National Institute of Occupational Safety and Health. The state of California designated it as a toxic air contaminant. Most health effects research on diesel emissions has focused on their possible contribution to lung cancer. Recently, concerns have also been raised about the potential effect of diesel particulate matter on enhancing human allergic responses and exacerbating asthma. Gaseous pollutants also pose threats to human health, either directly, as with carbon monoxide, or indirectly by the contribution of nitrogen oxides to smog formation.

In the first study described in this report, Dr Alan Gertler and colleagues of the Desert Research Institute in Reno, Nevada, proposed to measure the contribution of diesel and gasoline engine emissions to the ambient mixture of particulate matter and gaseous pollutants. They also planned to identify the number of particles and particle size distribution and to compare their results with those of earlier studies to assess how diesel emissions have changed with improved diesel engine design.

Other components of the exhaust mixture, such as aldehydes, also have been targeted as air toxics because they are highly reactive and, when inhaled, can participate in oxidation and reduction reactions. Many aldehydes are irritants and some, such as formaldehyde, are classified as probable human carcinogens. In the second study described in this report, Dr Daniel Grosjean of DGA, Inc, proposed to identify the concentrations of a large number of carbonyls (aldehydes and ketones) in air samples from urban areas. After the study began, Grosjean proposed to measure carbonyls in the ambient air of two tunnels in addition to urban Los Angeles air. Because both studies present data on pollutants in tunnel air, the HEI Review Committee decided to publish the two reports together.

Summary/Accomplishments (Outputs/Outcomes):

Dr Gertler studied particulate matter emissions in the Tuscarora Mountain Tunnel located on the Pennsylvania Turnpike. Dr Grosjean studied carbonyl emissions in the Tuscarora Mountain Tunnel and in the Caldecott Tunnel in California. The advantages of tunnel studies include measuring emission rates averaged over many vehicles (in contrast to emission rates from dynamometer measurements, which are derived from fewer vehicles), determining the physical and chemical character of emissions under ambient conditions, and in some instances, being able to compare current emissions with past emissions at the same location. Both groups of investigators also measured emissions at times when the proportions of gasoline engine vehicles and diesel engine vehicles differed, allowing them to estimate the differences between emissions from the two sources.


Dr Gertler and colleagues found, as expected, that diesel engines emitted particles at a greater rate per mile than did gasoline engines and that ultrafine particles (less than 0.1 ?m in aerodynamic diameter) dominated the number of particles from both sources. The authors suggest that because gasoline-powered vehicles predominate in the on-road vehicle fleet, their contribution to particle levels in ambient air may exceed that of diesel-powered vehicles. This remains a question for study because the method used to estimate the light-duty vehicles? particulate emissions from the tunnel measurements did not allow a precise determination of their magnitude.

The investigators also reported substantial decreases in diesel emissions of particles, hydrocarbons, carbon monoxide, and carbon dioxide (the latter an indication of improved fuel economy) between their current study and earlier studies. Levels of nitrogen oxides, which are precursors of ground-level ozone, remained essentially unchanged. The authors suggest that newer diesel engines are being operated in a manner to improve fuel economy at the cost of emitting nitrogen oxides.

Dr Grosjean identified about 100 carbonyls in the Tuscarora Mountain and Caldecott Tunnels. Total carbonyl emission factors from diesel-powered trucks were found to be about 4 times those from gasolinepowered cars when both were calculated on a distance-traveled basis. On a fuel-consumed basis, total carbonyl emission factors for diesel trucks were slightly less than for cars. Formaldehyde, acetaldehyde and acetone were the three major carbonyls present. There were distinct differences between emissions of diesel trucks and cars for some carbonyls, such as aromatic carbonyls. Future studies should compare the carbonyl levels reported here with ambient measurements in cities throughout the United States.

Supplemental Keywords:

Air, ambient air quality, air toxics, monitoring, health effects, particulate matter, motor vehicle emissions, diesel exhaust, nitrogen oxides, highway tunnels., RFA, Health, Scientific Discipline, Air, particulate matter, air toxics, Environmental Chemistry, Health Risk Assessment, Epidemiology, Risk Assessments, mobile sources, Biochemistry, ambient air quality, particulates, lung injury, exposure and effects, lung disease, human health effects, inhalability, air pollutants, Highway tunnels, lung, epidemelogy, automotive emissions, emissions measurement, air pollution, environmental health effects, diesel exhaust, emissions, human exposure, Nitric oxide, ambient particle health effects, inhalation, particulate exposure, lung inflammation, inhaled, prolonged exposure, human health

Progress and Final Reports:

Original Abstract
  • 2000
  • 2001
  • 2002
  • 2003

  • Main Center Abstract and Reports:

    R828112    Health Effects Institute (2000 — 2005)

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R828112C042 Does Inhalation of Methanol Vapor Affect Human Neurobehavior?
    R828112C043 Human Responses to Nitrogen Dioxide
    R828112C044 The Role of Inflammation in Ozone-Induced Lung Injury
    R828112C045 How Does Exercise Affect the Dose of Inhaled Air Pollutants?
    R828112C046 How Do Chemicals in Diesel Engine Exhaust Damage DNA?
    R828112C047 Effect of Nitrogen Dioxide on Bacterial Respiratory infection in Mice
    R828112C048 Effects of Ozone Exposure on Airway Epithelium
    R828112C049 Inhalation of Aldehydes and Effects on Breathing
    R828112C050 Does Ozone Cause Precancerous Changes in Cells?
    R828112C051 Effects of Formaldehyde on Human Airway Epithelial Cells Exposed in a Novel Culture System
    R828112C052 Carbon Monoxide and Cardiac Arrhythmias
    R828112C053 Effects of Formaldehyde and Particle-Bound Formaldehyde on Lung Macrophage Functions
    R828112C054 Mechanisms for Protecting Lung Epithelial Cells Against Oxidant Injury
    R828112C055 Relationship of Nitropyrene-Derived DNA Adducts to Carcinogenesis
    R828112C056 Particle Trap Effects on Heavy-Duty Diesel Engine Emissions
    R828112C057 Carbon Monoxide and Atherosclerosis
    R828112C058 Nitrogen Dioxide and Respiratory Illness in Children
    R828112C059 Noninvasive Methods for Measuring Ventilation in Mobile Subjects
    R828112C060 Oxidant Air Pollutants and Lung Cancer: An Animal Model
    R828112C061 Detection of Carcinogen-DNA Adducts: Development of New Methods
    R828112C062 Effects of Carbon Monoxide on Heart Muscle Cells
    R828112C063 Development of Personal Ozone Samplers: Three Approaches
    R828112C064 Development of Biomarkers to Monitor Carcinogen Exposure
    R828112C065 Effects of Prolonged Ozone Inhalation on Collagen Structure and Content in Rat Lungs
    R828112C065II Prolonged Ozone Exposure and the Contractile Properties of Isolated Rat Airways
    R828112C065III Changes in Complex Carbohydrate Content and Structure in Rat Lungs Caused by Prolonged Ozone Inhalation
    R828112C065IV Genetic Control of Connective Tissue Protein Synthesis After Prolonged Ozone Inhalation
    R828112C065V Pulmonary Function Alterations in Rats After Chronic Ozone Inhalation
    R828112C065VII Prolonged Ozone Exposure Leads to Functional and Structural Changes in the Rat Nose
    R828112C065VIII - IX Studies of Changes in Lung Structure and Enzyme Activitiesin Rats After Prolonged Exposure to Ozone
    R828112C065X An Innovative Approach to Analyzing Multiple Experimental Outcomes: A Case Study of Rats Exposed to Ozone
    R828112C065XI The Consequences of Prolonged Inhalation of Ozone on Rats: An Integrative Summary of the Results of Eight Collaborative Studies
    R828112C066 Interactive Effects of Nitropyrenes in Diesel Exhaust
    R828112C067 Detection of Formaldehyde–DNA Adducts: Development of New Methods
    R828112C068I Comparison of the Carcinogenicity of Diesel Exhaust and Carbon Black in Rat Lungs
    R828112C068II An Investigation of DNA Damage in the Lungs of Rats Exposed to Diesel Exhaust
    R828112C068III No Evidence For Genetic Mutations Found In Lung Tumors From Rats Exposed To Diesel Exhaust or Carbon Black
    R828112C069 Noninvasive Determination of Respiratory Ozone Absorption: The Bolus-Response Method
    R828112C070 The Effects of Inhaled Oxidants and Acid Aerosols on Pulmonary Function
    R828112C071 Biochemical Consequences of Ozone Reacting with Membrane Fatty Acids
    R828112C072 DNA Mutations in Rats Treated with a Carcinogen Present in Diesel Exhaust
    R828112C073 Developmental Neurotoxicity of Inhaled Methanol in Rats
    R828112C074 Methanol Distribution in Non Pregnant and Pregnant Rodents
    R828112C075 Is Increased Mortality Associated with Ozone Exposure in Mexico City?
    R828112C076 Effects of Fuel Modification and Emission Control Devices on Heavy-Duty Diesel Engine Emissions
    R828112C077 Metabolic Studies in Monkeys Exposed to Methanol Vapors
    R828112C078 Effects of Ozone on Pulmonary Function and Airway Inflammation in Normal and Potentially Sensitive Human Subjects
    R828112C079 Improvement of a Respiratory Ozone Analyzer
    R828112C080 Mechanism of Oxidative Stress from Low Levels of Carbon Monoxide
    R828112C081 Long-Term Exposure to Ozone: Development of Methods to Estimate Past Exposures and Health Outcomes
    R828112C082 Effects of Ambient Ozone on Healthy, Wheezy, and Asthmatic Children
    R828112C083 Daily Changes in Oxygen Saturation and Pulse Rate Associated with Particulate Air Pollution and Barometric Pressure
    R828112C084 Evaluation of The Potential Health Effects of the Atmospheric Reaction Products of Polycyclic Aromatic Hydrocarbons
    R828112C085 Mechanisms of Response to Ozone Exposure: The Role of Mast Cells in Mice
    R828112C086 Statistical Methods for Epidemiologic Studies of the Health Effects of Air Pollution
    R828112C087 Development of New Methods to Measure Benzene Biomarkers
    R828112C088 Alveolar Changes in Rat Lungs After Long-Term Exposure to Nitric Oxide
    R828112C089 Effects of Prenatal Exposure to Inhaled Methanol on Nonhuman Primates and Their Infant Offspring
    R828112C090 A Pilot Study of Potential Biomarkers of Ozone Exposure
    R828112C091 Effects of Concentrated Ambient Particles on the Cardiac and Pulmonary Systems of Dogs
    R828112C092 Cancer, Mutations, and Adducts in Rats and Mice Exposed to Butadiene and Its Metabolites
    R828112C093 Effects of Concentrated Ambient Particles in Rats and Hamsters: An Exploratory Study
    R828112C094I The National Morbidity, Mortality, and Air Pollution Study: Methods and Methodologic Issues
    R828112C094II The National Morbidity, Mortality, and Air Pollution Study: Morbidity and Mortality from Air Pollution in the United States
    R828112C095 Association of Particulate Matter Components with Daily Mortality and Morbidity in Urban Populations
    R828112C096 Acute Pulmonary Effects of Ultrafine Particles in Rats and Mice
    R828112C097 Identifying Subgroups of the General Population That May Be Susceptible to Short-Term Increases in Particulate Air Pollution
    R828112C098 Daily Mortality and Fine and Ultrafine Particles in Erfurt, Germany
    R828112C099 A Case-Crossover Analysis of Fine Particulate Matter Air Pollution and Out-of-Hospital Sudden Cardiac Arrest
    R828112C100 Effects of Mexico City Air on Rat Nose
    R828112C101 Penetration of Lung Lining and Clearance of Particles Containing Benzo[a]pyrene
    R828112C102 Metabolism of Ether Oxygenates Added to Gasoline
    R828112C103 Characterization and Mechanisms of Chromosomal Alterations Induced by Benzene in Mice and Humans
    R828112C104 Acute Cardiovascular Effects in Rats from Exposure to Urban Ambient Particles
    R828112C105 Genetic Differences in Induction of Acute Lung Injury and Inflammation in Mice
    R828112C106 Effects on Mice of Exposure to Ozone and Ambient Particle Pollution
    R828112C107 Emissions from Diesel and Gasoline Engines Measured in Highway Tunnels
    R828112C108 Case-Cohort Study of Styrene Exposure and Ischemic Heart Disease Investigators
    R828112C110 Effects of Metals Bound to Particulate Matter on Human Lung Epithelial Cells
    R828112C111 Effect of Concentrated Ambient Particulate Matter on Blood Coagulation Parameters in Rats
    R828112C112 Health Effects of Acute Exposure to Air Pollution
    R828112C113 Benzene Metabolism in Rodents at Doses Relevant to Human Exposure from Urban Air
    R828112C114 A Personal Particle Speciation Sampler
    R828112C115 Validation and Evaluation of Biomarkers in Workers Exposed to Benzene in China
    R828112C116 Biomarkers in Czech Workers Exposed to 1,3-Butadiene: A Transitional Epidemiologic Study
    R828112C117 Peroxides and Macrophages in the Toxicity of Fine Particulate Matter in Rats
    R828112C118 Controlled Exposures of Healthy and Asthmatic Volunteers to Concentrated Ambient Particles in Metropolitan Los Angeles
    R828112C119 Manganese Toxicokinetics at the Blood-Brain Barrier
    R828112C120 Effects of Exposure to Concentrated Ambient Particles from Detroit Air on Healthy Rats and Rats with Features of Asthma or Mild Bronchitis
    R828112C121 Field Evaluation of Nanofilm Detectors for Measuring Acidic Particles in Indoor and Outdoor Air
    R828112C123 Time-Series Analysis of Air Pollution and Mortality: A Statistical Review
    R828112C126 Effects of Exposure to Ultrafine Carbon Particles in Healthy Subjects and Subjects with Asthma
    R828112C128 Neurogenic Responses of Rat Lung to Diesel Exhaust
    R828112C130-I Relationships of Indoor, Outdoor, and Personal Air (RIOPA). Part I. Collection Methods and Descriptive Analyses
    R828112C132 An Updated Study of Mortality Among North American Synthetic Rubber Industry Workers