title: Predicting the effects of nanoscale cerium additives in diesel fuel on regional-scale air quality.
abstract: Diesel vehicles are a major source of air pollutant emissions. Fuel additives containing nanoparticulate cerium (nCe) are currently being used in some diesel vehicles to improve fuel efficiency. These fuel additives also reduce fine particulate matter (PM2.5) emissions and alter the emissions of carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbon (HC) species, including several hazardous air pollutants (HAPs). To predict their net effect on regional air quality, we review the emissions literature and develop a multipollutant inventory for a hypothetical scenario in which nCe additives are used in all on-road and nonroad diesel vehicles. We apply the Community Multiscale Air Quality (CMAQ) model to a domain covering the eastern U.S. for a summer and a winter period. Model calculations suggest modest decreases of average PM2.5 concentrations and relatively larger decreases in particulate elemental carbon. The nCe additives also have an effect on 8 h maximum ozone in summer. Variable effects on HAPs are predicted. The total U.S. emissions of fine-particulate cerium are estimated to increase 25-fold and result in elevated levels of airborne cerium (up to 22 ng/m3), which might adversely impact human health and the environment.
authors.affiliation: Atmospheric Modeling and Analysis Division, U.S. Environmental Protection Agency , Research Triangle Park, North Carolina 27711, United States.
authors.forename: Garnet B
authors.initials: GB
authors.lastname: Erdakos
authors.forename: Prakash V
authors.initials: PV
authors.lastname: Bhave
authors.forename: George A
authors.initials: GA
authors.lastname: Pouliot
authors.forename: Heather
authors.initials: H
authors.lastname: Simon
authors.forename: Rohit
authors.initials: R
authors.lastname: Mathur
mesh_terms: D000393:Air Pollutants / Q000032:analysis; D000397:Air Pollution / Q000032:analysis*; D002248:Carbon Monoxide / Q000032:analysis; D002563:Cerium / Q000737:chemistry*; D005742:Gasoline / Q000032:analysis*; D006838:Hydrocarbons / Q000032:analysis; D053758:Nanoparticles / Q000737:chemistry*; D009566:Nitrates / Q000032:analysis; D009573:Nitrites / Q000032:analysis; D009589:Nitrogen Oxides / Q000032:analysis; D010126:Ozone / Q000032:analysis; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis; D014481:United States
chemical_list: D000393:Air Pollutants; D005742:Gasoline; D006838:Hydrocarbons; D009566:Nitrates; D009573:Nitrites; D009589:Nitrogen Oxides; D052638:Particulate Matter; D002563:Cerium; D010126:Ozone; D002248:Carbon Monoxide