The Effects of a Catalyzed Particulate Filter and Ultra Low Sulfur Fuel on Heavy Duty Diesel Engine Emissions

Thalagavara, Abishek M.; Johnson, John H.; Bagley, Susan T.; Shende, Anand S.

doi:10.4271/2005-01-0473

Cited by 13 publications

(9 citation statements)

References 13 publications

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“… Khalek et al (2011) , as well as other studies (e.g. Biswas et al, 2009a ; Liu et al, 2008 , 2010 ; Thalagavara et al, 2005 ; Tang et al, 2007 ), demonstrate that the EC particles characteristic of TDE are largely eliminated from NTDE. The shift from a dominant insoluble EC fraction to a composition with major soluble sulfate and OC fractions has important toxicological implications, because as discussed later, it is the insoluble EC fraction of DEP that has been linked with tumor formation in rats via a lung overload mechanism.…”

Section: Development Of Diesel Engine Technology and Changes In Diesesupporting

confidence: 63%

Health effects research and regulation of diesel exhaust: an historical overview focused on lung cancer risk

Hesterberg

Long

Bunn

et al. 2012

Inhalation Toxicology

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The mutagenicity of organic solvent extracts from diesel exhaust particulate (DEP), first noted more than 55 years ago, initiated an avalanche of diesel exhaust (DE) health effects research that now totals more than 6000 published studies. Despite an extensive body of results, scientific debate continues regarding the nature of the lung cancer risk posed by inhalation of occupational and environmental DE, with much of the debate focused on DEP. Decades of scientific scrutiny and increasingly stringent regulation have resulted in major advances in diesel engine technologies. The changed particulate matter (PM) emissions in “New Technology Diesel Exhaust (NTDE)” from today's modern low-emission, advanced-technology on-road heavy-duty diesel engines now resemble the PM emissions in contemporary gasoline engine exhaust (GEE) and compressed natural gas engine exhaust more than those in the “traditional diesel exhaust” (TDE) characteristic of older diesel engines. Even with the continued publication of epidemiologic analyses of TDE-exposed populations, this database remains characterized by findings of small increased lung cancer risks and inconsistent evidence of exposure-response trends, both within occupational cohorts and across occupational groups considered to have markedly different exposures (e.g. truckers versus railroad shopworkers versus underground miners). The recently published National Institute for Occupational Safety and Health (NIOSH)-National Cancer Institute (NCI) epidemiologic studies of miners provide some of the strongest findings to date regarding a DE-lung cancer association, but some inconsistent exposure-response findings and possible effects of bias and exposure misclassification raise questions regarding their interpretation. Laboratory animal studies are negative for lung tumors in all species, except for rats under lifetime TDE-exposure conditions with durations and concentrations that lead to'lung overload."The species specificity of the rat lung response to overload, and its occurrence with other particle types, is now well-understood. It is thus generally accepted that the rat bioassay for inhaled particles under conditions of lung overload is not predictive of human lung cancer hazard. Overall, despite an abundance of epidemiologic and experimental data, there remain questions as to whether TDE exposure causes increased lung cancers in humans. An abundance of emissions characterization data, as well as preliminary toxicological data, support NTDE as being toxicologically distinct from TDE. Currently, neither epidemiologic data nor animal bioassay data yet exist that directly bear on NTDE carcinogenic potential. A chronic bioassay of NTDE currently in progress will provide data on whether NTDE poses a carcinogenic hazard, but based on the significant reductions in PM mass emissions and the major changes in PM composition, it has been hypothesized that NTDE has a low carcinogenic potential. When the International Agency for Research on Cancer (IARC) reevaluates DE (along with GEE and ni...

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Section: Development Of Diesel Engine Technology and Changes In Diesesupporting

confidence: 63%

Health effects research and regulation of diesel exhaust: an historical overview focused on lung cancer risk

Hesterberg

Long

Bunn

et al. 2012

Inhalation Toxicology

View full text Add to dashboard Cite

show abstract

“…The sulfate emission rate, however, is controlled by the fuel sulfur level, being more than an order of magnitude lower for the ultra-low sulfur fuel (Thalagavara et al, 2005) as compared to the 375 ppm S fuel (Warner et al, 2003). Looking specifically at the nucleation mode, the catalyzed DPF alters its composition.…”

Section: How Does Exhaust Aftertreatment Affect Pm?mentioning

confidence: 96%

“…While filtering of accumulation mode soot particles may promote a nucleation mode by reducing the available surface area for condensation, catalyzed DPFs are nonetheless observed to reduce semivolatile organic matter mass. Warner, Johnson, Bagley, and Huynh (2003) and Thalagavara, Johnson, Bagley, and Shende (2005) studied the effect of a catalyzed DPF (with 5 and 50 g Pt/f 3 ) on the emissions from a 10.8 L diesel engine (using 375 and 0.6 ppm S fuel) run on modes 8-11 of the EPA 13 mode cycle. Indeed, nucleation mode particle number emissions increased downstream of the DPF; however, Soxhlet extraction and EC/OC analysis of filter-collected PM consistently showed that both solid particle and semivolatile organic mass emissions decreased.…”

Section: How Does Exhaust Aftertreatment Affect Pm?mentioning

confidence: 99%

Chemical characterization of particulate emissions from diesel engines: A review

Maricq

2007

Journal of Aerosol Science

760

122

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“…17 Other studies have also reported similarly high EC and OC reductions across a range of engines, aftertreatment configurations, test cycles, and fuel sulfur content. 25,26,28,37,38 For example, Liu et al 28 observed >99% reductions for both EC and OC in their comprehensive study of emissions of more than 150 organic species from a 2007 engine representative of NTDE versus a 2004 non-retrofit engine (see Table 1 for engine specifications).…”

Section: Major Chemical Speciesmentioning

confidence: 99%

“…25,[38][39][40] This may be due to some aftertreatment configurations not meeting the conditions needed for sulfate nucleation, or it may also be due to differences in experimental factors (e.g., test cycles, temperatures, dilution ratios, residence times, and sampling techniques) between studies. Grose et al 39 and Kittelson et al 40 documented the generation of nucleation-mode sulfate particles during onroad testing of heavy-duty diesel engines equipped with a CRT and operated with fuels containing either 15 or 49 ppm sulfur.…”

Section: Major Chemical Speciesmentioning

confidence: 99%

Particulate Matter in New Technology Diesel Exhaust (NTDE) is Quantitatively and Qualitatively Very Different from that Found in Traditional Diesel Exhaust (TDE)

Hesterberg

Long

Sax

et al. 2011

Journal of the Air & Waste Management Association

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Diesel exhaust (DE) characteristic of pre-1988 engines is classified as a "probable" human carcinogen (Group 2A) by the International Agency for Research on Cancer (IARC), and the U.S. Environmental Protection Agency has classified DE as "likely to be carcinogenic to humans." These classifications were based on the large body of health effect studies conducted on DE over the past 30 or so years. However, increasingly stringent U.S. emissions standards for particulate matter (PM) and nitrogen oxides (NO x ) in diesel exhaust have helped stimulate major technological advances in diesel engine technology and diesel fuel/lubricant composition, resulting in the emergence of what has been termed New Technology Diesel Exhaust, or NTDE. NTDE is defined as DE from post-2006 and older retrofit diesel engines that incorporate a variety of technological advancements, including electronic controls, ultra-low-sulfur diesel fuel, oxidation catalysts, and wall-flow diesel particulate filters (DPFs). As discussed in a prior review (T. W. Environ. Sci. Technol. 2008, 42, 6437-6445), numerous emissions characterization studies have demonstrated marked differences in regulated and unregulated emissions between NTDE and "traditional diesel exhaust" (TDE) from pre-1988 diesel engines. Now there exist even more data demonstrating significant chemical and physical distinctions between the diesel exhaust particulate (DEP) in NTDE versus DEP from pre-2007 diesel technology, and its greater resemblance to particulate emissions from compressed natural gas (CNG) or gasoline engines. Furthermore, preliminary toxicological data suggest that the changes to the physical and chemical composition of NTDE lead to differences in biological responses between NTDE versus TDE exposure. Ongoing studies are expected to address some of the remaining data gaps in the understanding of possible NTDE health effects, but there is now sufficient evidence to conclude that health effects studies of pre-2007 DE likely have little relevance in assessing the potential health risks of NTDE exposures. INTRODUCTIONDiesel-engine exhaust (DE) exposures and health effects have been studied extensively for decades. DE is a source of particulate matter (PM), nitrogen oxides (NO x ), carbon monoxide (CO), and a number of air toxics (e.g., aldehydes,

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The Effects of a Catalyzed Particulate Filter and Ultra Low Sulfur Fuel on Heavy Duty Diesel Engine Emissions

Cited by 13 publications

References 13 publications

Health effects research and regulation of diesel exhaust: an historical overview focused on lung cancer risk

Health effects research and regulation of diesel exhaust: an historical overview focused on lung cancer risk

Chemical characterization of particulate emissions from diesel engines: A review

Particulate Matter in New Technology Diesel Exhaust (NTDE) is Quantitatively and Qualitatively Very Different from that Found in Traditional Diesel Exhaust (TDE)

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