Sunday, May 15, 2005

Diesel Particulate Matter v. Gasoline Particulate

BrooklynDodger opines that toxicity of vehicle exhaust emissions cruxes energy policy. Transition to light vehicle diesels would dramatically boost CAFE, but is there a health cost? Diesel Particulate Matter is a bad boy, but maybe in comparison only because hazards of gasoline engine emissions have been swept under the rug. Regarding CNG engine emissions, both industry and the environmental community have united behind don't ask, don't tell, don't persue.

Now comes a study from NIOSH Morgantown, which operates across the street from DOE laboratories [courtesy Robert Byrd.] This informs truck driver lung cancer studies; truckers are exposed to highway particulate, which includes both gasoline and diesel emissions. Gasoline emissions are IARC 2B, vs. diesel which is a 2B. These lab data show extracts of the particles are roughly equitoxic; it would be nice to compare the full particle exposure to that of CNG particles.

Acetone extracts of engine exhaust particulate matter (PM) and of vapor-phase semi-volatile organic compounds (SVOCs) collected from diesel and from gasoline engines were assayed for in vitro genotoxic activities. Gasoline and diesel PM were comparably positive mutagens on a mass of PM extract basis with diesel higher on a mileage basis; gasoline SVOC was more active than diesel on an extracted-mass basis, with diesel SVOC more active on a mileage basis. For chromosomal damage diesel PM expressed about one-tenth that of gasoline PM on a mass of extract basis, but was comparably active on a mileage basis; diesel SVOC was inactive. For DNA damage gasoline PM was positive while diesel PM was active at the higher doses; gasoline SVOC was active with toxicity preventing measurement at high doses, while diesel SVOC was inactive at all but the highest dose.


J Environ Monit. 2005 Jan;7(1):60-6. Epub 2004 Dec 8.

In vitro genotoxicity of exhaust emissions of diesel and gasoline engine vehicles operated on a unified driving cycle.

Liu YQ, Keane M, Ensell M, Miller W, Kashon M, Ong TM, Mauderly J, Lawson D, Gautam M, Zielinska B, Whitney K, Eberhardt J, Wallace W.National Institute for Occupational Safety and Health, 1095 Willowdale Rd., Morgantown, WV 26505, USA.

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