Research

A Visionary Approach to Product Development
Navistar's systematic approach to product development is reflected in the health and safety of our customers and in our products' positive impact on the environment - today and in the future.


Latest Research Research Initiatives Publications & Scholarly Papers Research Programs

Research Initiatives

Topic Details
Impact of New Engine TechnologyAn article developed by Navistar, published in 2009 by the journal Environmental Management, outlines reductions in exhaust emissions achieved through the use of new International® Green Diesel Technology® engines, compared with older engines. In 2011, Navistar published a paper that shows emissions from New Technology Diesel engines are dramatically reduced compared to older diesel engines. In fact, emissions from the newer diesel engines, which are 99.9 percent water vapor and carbon dioxide, are more comparable to emissions from compressed natural gas (CNG) engines).
Health EffectsIn 2011, Dr. Hesterberg and Dr. Bunn co-authored a chapter entitled "Potential Health Effects of Exposure to Diesel Engine Exhausts" which was published in the Praeger Handbook of Environmental Health, Volume III: Water Quality, Air Quality, and Solid Waste Disposal. The chapter reviewed the health studies of diesel exhaust and evaluated human exposure potential, concluding that that there is little or no evidence for a causal relationship between exposure to diesel exhaust and lung cancer in humans and that there is a need for more comprehensive toxicological investigations of New Technology Diesel Exhaust (NTDE) to confirm the toxicological differences between NTDE and Traditional Diesel Exhaust (TDE), as well as to understand how DE health risks compare to those from other common air contaminants.
read more
The review assembled evidence relevant to potential differences in the health risks of NTDE versus TDE, focusing on DEP emissions in order to address the question of the degree to which the prior DE hazard assessments do or do not apply to NTDE. The review concluded that because of the distinct physical and chemical properties of NTDE, findings from the health effects studies conducted on TDE over the last 30 years have little relevance to NTDE, which is more similar to the exhaust from compressed natural gas (CNG) or gasoline engine emissions than to TDE. Furthermore, the review concludes that there is clearly now a greater level of support for the idea that the historical data from animal laboratory and human epidemiological studies of TDE have only limited relevance in assessing the potential health risks of NTDE exposures.

A review being conducted by the Health Effects Institute's Advanced Collaborative Emissions Study (ACES) Advisory Committee promises to provide some of the data needed to better assess the potential carcinogenicity and non-cancer toxicity of NTDE, and the toxicological database.

In 2009, a paper was published in the journal Critical Reviews in Toxicology, which critically reviewed the recent human and toxicological literature on the non-cancer health effects of diesel exhaust and concluded that there is little evidence linking diesel exhaust exposure to any non-cancer health effects.

In 2009, Navistar published an article in the journal Environmental Management, which reviewed the health studies of diesel exhaust and concluded that there was very little evidence linking environmental or occupational diesel exhaust exposures to lung cancer or any other health endpoints examined.

In 2009, an article published by Navistar in the journal Critical Reviews in Toxicology reviewed the human volunteer NO2 exposure studies and concluded that current EPA National Ambient Air Quality Standard (NAAQS) for NO2 is adequate for protecting human health.

In January 2009, a paper entitled "Critical Assessment of Health Studies on Diesel Exhaust" was presented at the Symposium on International Automotive Technology (SIAT) in Pune, India. This paper was later published in the SAE Technical Paper Series.

Through our participation as members of the Health Effects Institute's Advanced Collaborative Emissions Study (ACES) Advisory Committee, we have helped to finalize a research program that will be conducted over the next five to eight years, with final commitments now secured from the U.S. Environmental Protection Agency, the California Air Resources Board, the U.S. Department of Energy, the Engine Manufacturers Association and other industry supporters. The emissions characterization phase of this study was completed in 2008, and the toxicology testing phase was started in 2009.

In 2008, Navistar published an article in the journal Environmental Science and Technology, which provided a detailed characterization of crankcase and exhaust emissions from diesel buses and showed that very little of these emissions were getting into the buses.

In September 2008, a critical assessment of health studies on diesel exhaust was presented at the Medichem Congress in Amsterdam.

An article titled "A Critical Assessment of Studies on the Carcinogenic Potential of Diesel Exhaust" was published in Critical Reviews in Toxicology in 2006. This article reviewed the human epidemiology literature on diesel exhaust and concluded that there is little or no evidence for a causal relationship between exposure to diesel exhaust and lung cancer in humans.

Under the auspices of the Air and Waste Management Association, Navistar's Dr. Thomas Hesterberg organized and chaired a conference on diesel exhaust, in October 2005 in Chicago, with a dual focus on public policy and health studies of diesel exhaust. The conference, which included scientists from government and industry, included an evaluation of studies on new and older diesel technologies, discussions of new studies and upcoming regulations, and a look at the technologies proposed for meeting the new standards.

In 2005, an article titled "Carcinogenicity Studies of Diesel Engine Exhausts in Laboratory Animals: A Summary of Past Studies and a Discussion of Future Research Needs" was published in the journal Critical Reviews in Toxicology. This article showed that diesel exhaust does not cause lung cancer in animals at environmental and occupational exposure levels.

An update on health studies regarding diesel exhaust was published in 2004 in the peer-reviewed journal Inhalation Toxicology
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More Research

Publications & Scholarly Papers

Topic Details
2012Diesel Exhaust Health Effects Research and Regulation: A Historical Overview. (Hesterberg, TW) read more
2012Evaluation of Carcinogenic Hazard of Diesel Engine Exhaust Needs to Consider Revolutionary Changes in Diesel Technology. (McClellan, RO) read more
More Publications & Scholarly Papers

Research Initiatives

Topic Details
Impact of New Engine TechnologyAn article developed by Navistar, published in 2009 by the journal Environmental Management, outlines reductions in exhaust emissions achieved through the use of new International® Green Diesel Technology® engines, compared with older engines. In 2011, Navistar published a paper that shows emissions from New Technology Diesel engines are dramatically reduced compared to older diesel engines. In fact, emissions from the newer diesel engines, which are 99.9 percent water vapor and carbon dioxide, are more comparable to emissions from compressed natural gas (CNG) engines).
Health EffectsIn 2011, Dr. Hesterberg and Dr. Bunn co-authored a chapter entitled "Potential Health Effects of Exposure to Diesel Engine Exhausts" which was published in the Praeger Handbook of Environmental Health, Volume III: Water Quality, Air Quality, and Solid Waste Disposal. The chapter reviewed the health studies of diesel exhaust and evaluated human exposure potential, concluding that that there is little or no evidence for a causal relationship between exposure to diesel exhaust and lung cancer in humans and that there is a need for more comprehensive toxicological investigations of New Technology Diesel Exhaust (NTDE) to confirm the toxicological differences between NTDE and Traditional Diesel Exhaust (TDE), as well as to understand how DE health risks compare to those from other common air contaminants.
read more
The review assembled evidence relevant to potential differences in the health risks of NTDE versus TDE, focusing on DEP emissions in order to address the question of the degree to which the prior DE hazard assessments do or do not apply to NTDE. The review concluded that because of the distinct physical and chemical properties of NTDE, findings from the health effects studies conducted on TDE over the last 30 years have little relevance to NTDE, which is more similar to the exhaust from compressed natural gas (CNG) or gasoline engine emissions than to TDE. Furthermore, the review concludes that there is clearly now a greater level of support for the idea that the historical data from animal laboratory and human epidemiological studies of TDE have only limited relevance in assessing the potential health risks of NTDE exposures.

A review being conducted by the Health Effects Institute's Advanced Collaborative Emissions Study (ACES) Advisory Committee promises to provide some of the data needed to better assess the potential carcinogenicity and non-cancer toxicity of NTDE, and the toxicological database.

In 2009, a paper was published in the journal Critical Reviews in Toxicology, which critically reviewed the recent human and toxicological literature on the non-cancer health effects of diesel exhaust and concluded that there is little evidence linking diesel exhaust exposure to any non-cancer health effects.

In 2009, Navistar published an article in the journal Environmental Management, which reviewed the health studies of diesel exhaust and concluded that there was very little evidence linking environmental or occupational diesel exhaust exposures to lung cancer or any other health endpoints examined.

In 2009, an article published by Navistar in the journal Critical Reviews in Toxicology reviewed the human volunteer NO2 exposure studies and concluded that current EPA National Ambient Air Quality Standard (NAAQS) for NO2 is adequate for protecting human health.

In January 2009, a paper entitled "Critical Assessment of Health Studies on Diesel Exhaust" was presented at the Symposium on International Automotive Technology (SIAT) in Pune, India. This paper was later published in the SAE Technical Paper Series.

Through our participation as members of the Health Effects Institute's Advanced Collaborative Emissions Study (ACES) Advisory Committee, we have helped to finalize a research program that will be conducted over the next five to eight years, with final commitments now secured from the U.S. Environmental Protection Agency, the California Air Resources Board, the U.S. Department of Energy, the Engine Manufacturers Association and other industry supporters. The emissions characterization phase of this study was completed in 2008, and the toxicology testing phase was started in 2009.

In 2008, Navistar published an article in the journal Environmental Science and Technology, which provided a detailed characterization of crankcase and exhaust emissions from diesel buses and showed that very little of these emissions were getting into the buses.

In September 2008, a critical assessment of health studies on diesel exhaust was presented at the Medichem Congress in Amsterdam.

An article titled "A Critical Assessment of Studies on the Carcinogenic Potential of Diesel Exhaust" was published in Critical Reviews in Toxicology in 2006. This article reviewed the human epidemiology literature on diesel exhaust and concluded that there is little or no evidence for a causal relationship between exposure to diesel exhaust and lung cancer in humans.

Under the auspices of the Air and Waste Management Association, Navistar's Dr. Thomas Hesterberg organized and chaired a conference on diesel exhaust, in October 2005 in Chicago, with a dual focus on public policy and health studies of diesel exhaust. The conference, which included scientists from government and industry, included an evaluation of studies on new and older diesel technologies, discussions of new studies and upcoming regulations, and a look at the technologies proposed for meeting the new standards.

In 2005, an article titled "Carcinogenicity Studies of Diesel Engine Exhausts in Laboratory Animals: A Summary of Past Studies and a Discussion of Future Research Needs" was published in the journal Critical Reviews in Toxicology. This article showed that diesel exhaust does not cause lung cancer in animals at environmental and occupational exposure levels.

An update on health studies regarding diesel exhaust was published in 2004 in the peer-reviewed journal Inhalation Toxicology
show less

SustainabilityIn 2010, Navistar published an article describing the company's sustainability program in the Journal of the Air & Waste Management Association, and presented this information at the annual conference of this association. Also in 2010, Navistar published an article describing the energy reduction programs at the company's facilities, and also presented this information at the association's annual meeting.

read more
In 2009, Navistar published an article in Sustainability: Science, Practice, and Policy, which evaluated the criteria for selecting vehicles fueled with diesel or compressed natural gas, and concluded that infrastructure costs and fire and safety concerns are much greater for CNG fuel.

In May 2009, a paper on strategies for sustainability at Navistar was presented at the Practical Sustainability Conference of the Air & Waste Management Association in St. Louis, Mo.
In January 2009, a paper on strategies for sustainability in business was presented at the Symposium on International Automotive Technology (SIAT), in Pune, India. The paper was later published in the SAE Technical Paper Series, 2009.

In September 2008, a paper entitled "Innovation and Occupational Health: Strategies for Sustainability at Navistar," was presented at the Medichem Congress in Amsterdam.

In 2009, Navistar submitted an article to Sustainability: The Journal of Record, which outlined the company's sustainability program.
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Bus StudiesIn 2011, a study titled "Measuring In-Cabin School Bus Tailpipe and Crankcase PM2.5: A New Dual Tracer Method" was published in the journal of the Air & Waste Management Association. This study used a dual tracer method to quantify in-vehicle exposures to vehicle-related emissions and concluded that while crankcase PM concentrations were substantially higher than those of tailpipe exhaust PM, dominant sources of in-cabin PM2.5 concentrations are likely emissions from other vehicles or other sources of carbonaceous material.

read more
In 2009, a study co-authored by the company, on the development and demonstration of a dual intentional tracer method for quantifying in-cabin concentrations of tailpipe and crankcase pm2.5 in school buses, was published in the Journal of the Air & Waste Management Association. In addition, a study co-authored by the company on estimating self-pollution from diesel school buses using three independent methods was published in that same journal.
In 2008, Navistar published an article in Environmental Science and Technology which showed that emissions from vehicles fueled with diesel were comparable to those from compressed natural gas vehicles.

In 2006, the results of the University of Washington school bus exposure study were published in the Journal of the Air and Waste Management Association. These results showed that virtually none of the emissions from the tailpipe were getting into the school buses. Although a small amount of the emissions from the crankcase was getting into the buses, this was very low and similar to background levels of pollutants in the air in the Seattle area. These findings were also presented at a panel session organized by Dr. Thomas Hesterberg at the Air and Waste Management Association's annual conference.

In August 2005, Navistar helped sponsor a school bus exposure study that was part of a larger $3 million asthma study being conducted by the University of Washington in Seattle. In addition to providing some of the funding for this pilot study, Navistar also provided the methodology for specifically measuring potential self-pollution to diesel exhaust and crankcase emissions.

In 2003, Navistar funded a Harvard study which determined that diesel transit buses equipped with particulate filters, like those found in International's Green Diesel Technology® school buses, are more cost efficient and have less health impact than natural gas buses now on the road.

A 2003 study sponsored by Navistar and conducted by California EnSIGHT Inc., an air quality management consulting firm, found that exhaust from a diesel school bus engine adds virtually no diesel particulates to the air inside the bus. A sensitive iridium tracer in the bus diesel fuel determined that the bus's engine contributed less than one percent of the fine particulate matter inside the bus.

In 2003 and 2007, Navistar also sponsored reviews of the methodologies used to conduct school bus in-cabin pollution studies. Theseis reviews concluded that many of the previously conducted school bus studies used methodologies that were inadequate to specifically identify pollution from the bus's tailpipe inside the school bus, and thus brought into question the conclusions of these studies. The specific tracer methodology developed by International's scientists, however, was rated as one of the only ways to specifically measure the amount of the bus's pollution that gets inside the bus.
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Ozone FormationIn 2006, Dr. Hesterberg organized an AWMA panel on the impact of oxides of nitrogen (NOx) levels in cities on the formation of ozone in those cities. The conclusion of this panel was that ozone levels are increased, or remain the same, as NOx levels are reduced in cities throughout the U.S. This research should have important implications for future regulations of NOx emissions from diesel trucks.

Publications & Scholarly Papers

Publication Description
2012Diesel Exhaust Health Effects Research and Regulation: A Historical Overview. (Hesterberg, TW) read more
2012Evaluation of Carcinogenic Hazard of Diesel Engine Exhaust Needs to Consider Revolutionary Changes in Diesel Technology. (McClellan, RO) read more
2012Product stewardship and science: Safe manufacture and use of fiber glass. (Hesterberg, TW) read more
2011Particulate matter in new technology diesel exhaust (NTDE) is quantitatively and qualitatively very different from that found in traditional diesel exhaust (TDE) (Hesterberg, TW) read more
2011Sustainability at Navistar: A model distinguished by sustainable innovation, proactive product stewardship, and sound science (Hesterberg, TW) read more
2011Chrysotile health risk revisited. (Berstein, D) read more
2011Letter to the Editor: Comments on the Diesel Exhaust in Miners Study (Bunn, WB)
2011Letter to the Editor: Comments on the Diesel Exhaust in Miners Study (Borak, J)
2011Measuring in-cabin school bus tailpipe and crankcase PM2.5: A new duel tracer method (Ireson, RG) read more
2011Pulmonary endpoints (lung carcinomas and asbestosis) following inhalation exposure to asbestos (Mossman, BT) read more
2011How to Align Evidence-Based Benefit Design With the Employer Bottom-Line: A Case Study (Bunn, WB)
2011Diesel motor exhaust (DME) and lung cancer -- additional perspectives (Bunn, WB)Diesel motor exhaust (DME) and lung cancer -- additional perspectives (Bunn, WB) read more
2011A Review of Fiber Biopersistence as a Potential Mechanism of Asbestos Tumorigenicity. (Bernstein, D) read more
2011The Mounting Evidence Differentiating the Health Risks of New Technology Diesel Exhaust (NTDE) Versus Traditional Diesel Exhaust (TDE) (Hesterberg, TW) read more
2010What Studies are Appropriate to Use to Estimate Health Impacts from Specific Sources Such as Diesel PM? (Hesterberg, TW) read more
2010What Studies are Appropriate to Use to Estimate Health Impacts from Specific Sources Such as Diesel PM? CARB Symposium: Estimating Premature Deaths from Long-term Exposure to PM2 (Hesterberg, TW)
2010Indirect Costs Associated With Nonadherence to Treatment for Bipolar Disorder (Bagalman, E)
2010Sustainability and Proactive Product Stewardship at Navistar, Both Now and in the Future (Hesterberg, TW) read more
2010Evidence-Based Benefit Design: Toward a Sustainable Health Care Future for Employers (Bunn, WB)
2010Quantification of self-pollution from two diesel school buses using three independent methods (Liu, L-JS) read more
2010Potential Health Effects of Exposure to Diesel Engine Exhausts (Hesterberg, TW) read more
2010Diesel exhaust particulate (DEP) and nanoparticle exposures: What do DEP human clinical studies tell us about potential human health hazards of nanoparticles? (Hesterberg, TW) read more
2009Laboratory Studies of Diesel Exhaust health effects: Implications for near-roadway exposures (Hesterberg, TW) read more
2009Non-cancer health effects of diesel exhaust (DE): A critical assessment of recent human and animal toxicological literature (Hesterberg, TW) read more
2009Critical Assessment of Health Studies on Diesel Exhaust (Hesterberg, TW) read more
2009Relationships among Particle number, surface area, and Respirable Mass Concentrations in Automotive Engine Manufacturing (Heitbrink, WA) read more
2009Critical Review of the Human Data on Short-Term Nitrogen Dioxide (NO2) Exposures: Evidence for NO2 No-Effect Levels (Hesterberg, TW) read more
2009Strategies for Sustainability at Navistar (Hesterberg, TW) read more
2009Best Practices in the care of Type 2 Diabetes: Integrating Clinical Needs with Medical Policy and Practice (Bunn, WB)
2009Strategies for sustainability in business (Bunn, WB)
2009An evaluation of criteria for selecting vehicles fueled with diesel or compressed natural gas (Hesterberg, TW) read more
2008A comparison of emissions from vehicles fueled with diesel or compressed natural gas (Hesterberg, TW) read more
2008Age, overtime, and employee health, safety and productivity outcomes: a case study (Allen, H)
2008Innovation and occupational health. Strategies for sustainability at Navistar (Bunn, WB) read more
2008Validating of Employer-Focused Actuarial Model for Measuring the Economic Burden of Chronic Obstructive Pulmonary Disease (COPD) (Bunn, WB)
2008Risk and burden associated with the acquisition of viral hepatitis A and B in the corporate traveler (Bunn, WB)
2008Comment on the Nanoparticle Conclusions in Cruts et al (Valberg, PA) read more
2008Ultrafine and Respirable Particles in an Automotive Grey Iron Foundry (Evans, DE) read more
2008Detailed characterization and profiles of crankcase and diesel particular matter exhaust emissions using speciated organics (Zielinska, B) read more
2007Control of Silica Exposure in Foundries (Scholz, RC) read more
2007An Expert Review of the Cost-Savings and Benefits with Employee Influenza Vaccination (Bunn, WB)
2007Do Long Workhours Put Employers At Risk? (Allen, H)
2007Employer Initiatives to Support Smoking Cessation: Strategies for Success (Bunn, WB)
2007The Characterization of Very Fine Particles in an Engine Machining and Assembly Facility (Heitbrink, WA)
2007Does Overtime Put Employers At Risk? The Evidence from a U.S. Heavy Manufacturer (Allen, H)
2007A Reality Check on the Risks of Overtime (Allen, H)
2007Employer Efforts to Improve Employee Asthma Outcomes (Bunn, WB)
2006Effect of Smoking Status on Productivity Loss (Bunn, WB)
2006The Mapping of Fine and Ultrafine Particle Concentrations in an Engine Machining and Assembly Facility (Peters, TM) read more
2006Impact of a Musculoskeletal Disability Management Program on Medical Costs and Productivity in a Large Manufacturing Company (Duong, D)
2006Explicit quantification of in-cabin concentrations of school bus exhaust and crankcase emissions using intentional tracers (Ireson, RG) read more
2006Chemical characterization of diesel crankcase and tailpipe PM emissions, including a quantitative deuterated tracer for lubricating oil (Hesterberg, TW)
2006A critical assessment of studies on the carcinogenic potential of diesel exhaust (Hesterberg, TW) read more
2006Use of the Health Plan Employer Data and Information Set for measuring and improving the quality of asthma care (Gelfand, EW)
2006Perspectives on Human Capital and Safety (Slavin, T) read more
2006Comparing three approaches of estimating bus self-pollution - A pilot study (Webber, WL) read more
2006A Focus on the Asthma HEDIS Measure and Its Implications for Clinical Practice (Davies, TJ)
2005Carcinogenicity Studies of Diesel Engine Exhausts in Laboratory Animals: A Summary of Past Studies and a Discussion of Future Research Needs (Hesterberg, TW) read more
2005Testing of fibrous particles: Short-term assays and strategies (Bernstein, DB)
2005The Clinical Management of Asthma: A Focus on the NCQA/HEDIS® Asthma Measure (Bunn, WB)
2005Estimating Quartz Dose-Response (Slavin, TS)
2004Reducing Diesel Engine Emissions Using Catalyzed Diesel Particulate Filter Technology (Bunn, WB) read more
2004A Reevaluation of the Literature Regarding the Health Assessment of Diesel Engine Exhaust (Bunn, WB) read more
2004Occupational medicine: the use of physician assistants and the changing role of the occupational and environmental medicine provider (Bunn, WB)
2004Under Control: Worksite Diabetes Education Targets At-Risk Employees (Bunn, WB)
2004The ITEC Allergy Project: Lessons Learned (Allen, H)

Formalizing Our Development Model

In 2002 our unique approach to product development was embodied in a formal Product Stewardship program, which is led by Dr. Thomas Hesterberg, director of product stewardship and environmental health. Following is a sampling of the program's many achievements.

Topic Details
Work with supplier partners and government regulatorsWhile we are proud of our leadership in product stewardship, we also recognize the supplier partners that work with us to develop environmentally friendly solutions. Our close collaboration with state and federal government agencies, including the U.S. EPA, CARB and DOE, helps to assure that future societies will have a strong foundation for managing health and environmental issues.
Health effects researchIn 2002 Navistar developed a proactive research initiative designed to assess the potential health effects of the new low-emitting diesel technology that has been developed to meet the much more stringent U.S. and California emissions standards. We subsequently secured a broad consensus and support among industry, government agencies and non-government organizations regarding the importance of this health research initiative.

In 2004, through our participation as advisors to the Health Effects Institute’s Advanced Collaborative Emissions Study (ACES) Research Committee, we helped to finalize a specific research program that will be conducted over the next five to eight years, with final commitments now secured from the U.S. Environmental Protection Agency (EPA), the California Air Resources Board (CARB), the U.S. Department of Energy (DOE), the Engine Manufacturers Association and other industry supporters.

Beyond the ACES Research Committee, Navistar representatives have served as advisors on a number of important government and industry science committees, including National Institute for Occupational Safety and Health's (NIOSH) Board of Scientific Counselors, the Health Effects Institute's Emerging Technologies Committee, the EPA’s Mobile Source Air Toxics Committee, the advisory board for the National Environmental Respiratory Center, and the Health Effects and Exposure Committee of the Air and Waste Management Association (AWMA).

We also sponsor research on the health effects of emissions.

International's low-emitting Green Diesel Technology® vehiclesOur vehicles illustrate one key element of our product stewardship: a rigorous approach to risk management. Products are developed to not only meet, but exceed tough government regulations. By setting the bar high, we strengthen our commitment to serve as a provider of environmentally friendly products.