title: Health effects of subchronic inhalation exposure to gasoline engine exhaust.
abstract: Gasoline engine emissions are a ubiquitous source of exposure to complex mixtures of particulate matter (PM) and non-PM pollutants; yet their health hazards have received little study in comparison with those of diesel emissions. As a component of the National Environmental Respiratory Center (NERC) multipollutant research program, F344 and SHR rats and A/J, C57BL/6, and BALBc mice were exposed 6 h/day, 7 days/week for 1 week to 6 months to exhaust from 1996 General Motors 4.3-L engines burning national average fuel on a simulated urban operating cycle. Exposure groups included whole exhaust diluted 1:10, 1:15, or 1:90, filtered exhaust at the 1:10 dilution, or clean air controls. Evaluations included organ weight, histopathology, hematology, serum chemistry, bronchoalveolar lavage, cardiac electrophysiology, micronuclei in circulating cells, DNA methylation and oxidative injury, clearance of Pseudomonas aeruginosa from the lung, and development of respiratory allergic responses to ovalbumin. Among the 120 outcome variables, only 20 demonstrated significant exposure effects. Several statistically significant effects appeared isolated and were not supported by related variables. The most coherent and consistent effects were those related to increased red blood cells, interpreted as likely to have resulted from exposure to 13-107 ppm carbon monoxide. Other effects supported by multiple variables included mild lung irritation and depression of oxidant production by alveolar macrophages. The lowest exposure level caused no significant effects. Because only 6 of the 20 significant effects appeared to be substantially reversed by PM filtration, the majority of effects were apparently caused by non-PM components of exhaust.
authors.affiliation: Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Reed
authors.forename: E G
authors.initials: EG
authors.lastname: Barrett
authors.forename: M J
authors.initials: MJ
authors.lastname: Campen
authors.forename: K K
authors.initials: KK
authors.lastname: Divine
authors.forename: A P
authors.initials: AP
authors.lastname: Gigliotti
authors.forename: J D
authors.initials: JD
authors.lastname: McDonald
authors.forename: J C
authors.initials: JC
authors.lastname: Seagrave
authors.forename: J L
authors.initials: JL
authors.lastname: Mauderly
authors.forename: S K
authors.initials: SK
authors.lastname: Seilkop
authors.forename: J A
authors.initials: JA
authors.lastname: Swenberg
mesh_terms: D000818:Animals; D004249:DNA Damage / Q000187:drug effects / Q000502:physiology; D005260:Female; D005742:Gasoline / Q000009:adverse effects*; D006304:Health Status; D019570:Inhalation Exposure / Q000009:adverse effects*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D052638:Particulate Matter / Q000008:administration & dosage / Q000009:adverse effects; D051381:Rats; D011916:Rats, Inbred F344; D011918:Rats, Inbred SHR; D001335:Vehicle Emissions
chemical_list: D005742:Gasoline; D052638:Particulate Matter; D001335:Vehicle Emissions