Health effects of soy-biodiesel emissions: mutagenicity-emission factors

Inhal Toxicol. 2015;27(11):585-96. doi: 10.3109/08958378.2015.1080771.

Abstract

Context: Soy biodiesel is the predominant biodiesel fuel used in the USA, but only a few, frequently conflicting studies have examined the potential health effects of its emissions.

Objective: We combusted petroleum diesel (B0) and fuels with increasing percentages of soy methyl esters (B20, B50 and B100) and determined the mutagenicity-emission factors expressed as revertants/megajoule of thermal energy consumed (rev/MJ(th)).

Materials and methods: We combusted each fuel in replicate in a small (4.3-kW) diesel engine without emission controls at a constant load, extracted organics from the particles with dichloromethane, determined the percentage of extractable organic material (EOM), and evaluated these extracts for mutagenicity in 16 strains/S9 combinations of Salmonella.

Results: Mutagenic potencies of the EOM did not differ significantly between replicate experiments for B0 and B100 but did for B20 and B50. B0 had the highest rev/MJ(th), and those of B20 and B100 were 50% and ∼85% lower, respectively, in strains that detect mutagenicity due to polycyclic aromatic hydrocarbons (PAHs), nitroarenes, aromatic amines or oxidative mutagens. For all strains, the rev/MJ(th) decreased with increasing biodiesel in the fuel. The emission factor for the 16 EPA Priority PAHs correlated strongly (r(2 )= 0.69) with the mutagenicity-emission factor in strain TA100 + S9, which detects PAHs.

Conclusions: Under a constant load, soy-biodiesel emissions were 50-85% less mutagenic than those of petroleum diesel. Without additional emission controls, petroleum and biodiesel fuels had mutagenicity-emission factors between those of large utility-scale combustors (e.g. natural gas, coal, or oil) and inefficient open-burning (e.g. residential wood fireplaces).

Keywords: Combustion emissions; complex mixtures; mutagenicity.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Air Pollutants / toxicity
  • Animals
  • Biofuels / toxicity*
  • Dose-Response Relationship, Drug
  • Glycine max / toxicity*
  • Mutagens / toxicity*
  • Particulate Matter / toxicity
  • Rats
  • Rats, Sprague-Dawley
  • Salmonella / drug effects*
  • Salmonella / metabolism
  • Vehicle Emissions / toxicity*

Substances

  • Air Pollutants
  • Biofuels
  • Mutagens
  • Particulate Matter
  • Vehicle Emissions