Mutagenic Effects of Emissions from Old and New

Technology Diesel Engines Combusting Biogenic

and Fossil Fuel Qualities

Bünger J1,4, Munack A2,4, Schröder O3, Krahl J3,4

1 Institute for Prevention and Occupational Medicine of the German Social Accident Insurance (IPA),

Ruhr-University Bochum, Germany

2 Thünen Institute of Agricultural Technology, Braunschweig, Germany

3 Coburg University of Applied Sciences and Arts, Coburg, Germany

4 Fuels Joint Research Group, www.fuels-jrg.de

Introduction

Fuels, Engines, Methods

Results

Summary and Conclusions

Outline

2

Introduction

Fuels, Engines, Methods

Results

Summary and Conclusions

Outline

3

Components of Diesel Engine Emissions (DEE)

DEE consist of a complex mixture of compounds.

Several can be hazardous to human health:

• Carbon monoxide (CO)

• Carbon dioxide (CO2)

• Sulfur dioxide (SO2)

• Nitrogen oxides (NOX)

• Hydrocarbons (HC), thereof ca. 2-5%

• Polycyclic aromatic Hydrocarbons (PAH)

• Particles

Source: HEI 1995

Carcinogenicity of DEE

Diesel engine emissions (DEE) are considered to be

carcinogenic on the basis of numerous scientific data:

1. Strong mutagenicity of particle extracts of DEE in the Ames-test

(Huisingh et al. 1978)

2. Lung tumors in rats after inhalation of DEE (Heinrich et al. 1986)

3. Increased lung cancer risk in occupationally DEE-exposed subjects

(IARC 2012)

“In conclusion, the Working Group classified diesel engine exhaust

as “carcinogenic to humans” (Group 1).”

Genotoxicity of diesel engine particles

6

(PAH)

Modified according to HEI 1995

Direct genotoxic mechanism:

Indirect genotoxic mechanism:

PAH: Modes-of-Action

DNA

DNA-Strand Breaks

Mutations

H O

O H

O

B [ a ] P - 7 , 8 - d i h y d r o d i o l - 9 , 1 0 - e p o x i de

Reactive Oxygen Species (ROS)

DNA-Oxidation

Mutations H O

O H

B [ a ] P - 7 , 8 - d i h y d r o d i o l

O

O

B [ a ] P - 7 , 8 - d i o ne

Non substituted PAH

indirectly mutagenic

Substituted PAH

especially Nitro-PAH

directly mutagenic

Carcinogenic Components of DEE

Benzo[a]pyrene

Nitro-benzo[a]pyrene

Often much stronger mutagenic !

Introduction

Fuels, Engines, Methods

Results

Summary and Conclusions

Outline

Data Base

Projects: 23 studies from 1993 until 2012

Engines: 6 passenger cars, Euro 2 - 6;

7 truck engines, Euro 0 – VI;

2 one-cyl.-test engines (Euro 0)

Fuels: DF from gas stations used as reference in all studies

11 fossil (sulfur <2 - 500 ppm, aromates <1 - 37%)

14 biogenic (sulfur <2 ppm, aromates <1%)

Aftertreatment: Diesel Oxidation Catalyst (DOC)

Diesel Particle Filter (DPF)

Selective Catalytic Reduction (SCR)

Emission Test Stand

Sampling Setup for Mutagenicity Testing

(according to VDI-guideline 3872, page 1)

Preparation of Test Solutions

Particle phase

Soxhlet extraction of filters

Dichloromethane (150 mL)

Reduction by evaporation

Drying under a stream of nitrogen.

Condensates

Reduction by evaporation.

Drying under a stream of nitrogen.

Re-dissolution of residues in 4 mL

dimethyl sulfoxide (DMSO)

Bacterial Reverse Mutation Test = Ames-Test (OECD-Guideline 471) Standard test protocol of Maron and Ames (1983) Mutat Res 113: 173-215

Tester strains TA98 and TA100 with and without metabolic

activation by a microsomal rat liver enzyme fraction (S9)

4 concentrations; controls: DMSO (neg.) 3-NBA, 2-AF, MMS (pos.)

Docherty et al. Green Chem., 2006, 8, 560

Introduction

Fuels, Engines, Sampling Methods

Results

Summary and Conclusions

Outline

Mutagenicity of DEP from VO, RME, and high sulfur DF

(Deutz Tractor, EURO 0)

0

250

500

750

1000

1250

1500

DF VO RME

Mu

tati

on

s p

er

Pla

te

TA98 -S9

TA98 +S9

1994

Mutagenicity of DF with high sulfur

and optimization of RME combustion

0

100

200

300

400

500

600

idling 25% load rated power max. torque

Mu

tati

on

s p

er

pla

te

DF without S9

DF with S9

RME without S9

RME with S9

RME opt. without S9

RME opt. with S9

2000

DF RME GTL 1 GTL 20

25

50

75

100

125

150

175

200

225

250

Fuels

Mu

tati

on

s p

er

pla

teMutagenicity of LSDF, RME and Gas to Liquid Fuels (GTL)

2004

0

50

100

150

200

DF JME NExBTL RME

Muta

tions [

-]

-S9

+S9

0

50

100

150

200

DF JME NExBTL RME

Muta

tions [

-]

Mutagenicity of PM-Extracts (left) and Condensates (right)

2008

-10

-5

0

5

10

15

20

25

Mu

tati

on

s p

er

pla

te

DF cold

DF

warm

HVOB7 cold

HVOB7 warm

DF cold

DF warm

HVOB7 cold

HVOB7 warm

DF cold

DF warm

HVOB7 cold

HVOB7 warm

2011

Euro 6 Euro 5 Euro 3

DF RME B 20 GTL 1 GTL 20

25

50

75

100

125

150

175

200

225

250

Fuels

Mu

tati

on

s p

er

pla

te

2004

Mutagenicity of B20 from LSDF and RME

DF RME ULT V-P B20 ULT B20 V-P

0

50

100

150

200

250

300

Fuels

Mu

tati

on

s p

er

pla

teMutagenicity of B20 from Ultimate / V-Power DF and RME

2006

DF B 5 B 10 B 20 B 50 RME 0

10

20

30

40

50

60

70

80

90

100

Fuels

Mu

tati

on

s p

er

pla

teMutagenicity of a Series of Blends from DF and RME

2008

24

Mutagenicity of rapeseed oil (Mercedes Benz OM 906 LA, Euro III, ESC)

DF GTL RME VO 0

200

400

600

TA98-S9

TA98+S9

Mu

tati

on

s

2007

25

VO_mod. DF GTL RME VO

Mu

tati

on

s

0

200

400

600

800

1000

1200

1400

1600

TA98-S9

TA98+S9

Mutagenicity of rapeseed oil with preheating (Mercedes Benz OM 906 LA, Euro III, ESC)

2007

Introduction

Fuels, Engines, Methods

Results

Summary and Conclusions

Outline

Mutagenicity – Reduction in the last 20 years

No significant mutagenicity :

• Cars with Euro 5-standard

• Cars with Euro 6-standard

• Trucks with Euro VI-standard

1993

-199

7

1998

-200

2

2003

-200

7

2008

-201

2

1993

-199

7

1998

-200

2

2003

-200

7

2008

-201

2

0

100

200

300

400

500

Fossil fuels Biogenic fuels

Mu

tati

on

s p

er

L E

xh

au

st

Conclusions

Measuring only regulated compounds is not

sufficient for the estimation of health effects

from diesel engine emissions.

Independent fuel and emission research is needed

for a reliable consumer and worker protection.

Mutagenicity of DEE was lowered to non significant

levels in the last 20 years using the Ames test.

Jürgen Bünger Prof. Dr. Jürgen Bünger, MD

Endowed Chair Experimental Occupational Medicine

Institute for Prevention and Occupational Medicine of the German Social Accident Insurance (IPA)

Institute of the Ruhr-University Bochum

Buerkle-de-la-Camp-Platz 1, 44789 Bochum, Germany

Tel.: 0049 234 3024556

Fax: 0049 234 3024505

http://www.ipa.ruhr-uni-bochum.de/

email: buenger@ipa-dguv.de

Thank you for listening !

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