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Folie 1Vortrag > Autor > Dokumentname > Datum

Combustion Generated Nanoparticles (Soot Precursors): Underrated Species with Potentially High Health Risk

Horst-Henning Grotheer, Tania Gonzalez Baquet, Joachim Happold,Institute of Combustion Technology, DLR Stuttgart

Antonio Borghese, Luciano Speranza, Instituto Motori, CNR, Naples

Christa Baumstark-Khan, Christine E. Hellweg, Institute of Aerospace Medicine, DLR Cologne

Vortrag > Autor > Dokumentname > Datum

Folie 2

road dusttyre attrition

10-4 10-3 10-2 10-1 1 10

0,1 1 10 100 1000 10.000

µm

nm

gas molecules

oil smoke

soot

viruses bacterias

visible light

cement dust

fly ash

particle diameter, Dp

adapted from GSF,Umweltmed. Forsch. Prax. 7, 2002

Matter presently found in the Atmosphere

range of

nanoparticles

Range of PM 10


Folie 3

Nanoparticles – species between gas phase molecules and soot

primarysoot

some PAH exhaustgas components

nano-particles

restructuringrequires t,T

Critical stepin case ofengines

Emission of nanoparticles in addition to soot


Folie 4

Two types of limiting structures

• already in moderately rich flamesΦ ~ 1.1 or larger

• very slow growthemitted in large numbers

• environmental aspect

• only in sooting flamesΦ ~ 2 or larger

• rapid growthrapidly decreasing numbers

• important for soot formation

Giant molecules Molecular crystallites


Folie 5

Mobile setup for flame and engine measurements (Stuttgart)

TOF- mass spectrometer

pump

pump

MCP

reflectron

5x10-6

molecular beam

sampling line

timing electronicsIon optics

data handling

1x10-7

mbarskimmer

pulsed valve

pump pump

quartz tube

photo-ionisation

MS

Inlet system

ArF excimer laser193nm; P < 8mJ/pulse Δt = 10ns; f. = 200 cps


Folie 6

Flame generated particles,C2H2 low pressure flame

Polymer like spectra

Average Δm between hills= mass of single layerΔ = 450u – 500u

Average mass of first„hill“ 900 – 1000u→ double layer.

Interpretation as stacksrather than chains

Note: this type of nanoparticles is found only under sooting conditions


Folie 7

Measurements of combustion generated nanoparticles (<5 nm) behind commercial engines

500 1000 1500 2000 2500 30000

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

18_08_04 Mess 10-12

Rollermessungen IIMit LinseWarm

1400 rpm2500 rpm4000 rpm

Sig

nal (

coun

ts)

Mass (amu)

1300 1350 1400 1450 15000

1000

2000

3000

4000

5000

18_08_04 Mess 10-12

Sign

al (c

ount

s)

Mass (amu)

strong dependence on (idle) engine speed

Common result of TOC analysis:

Some 1012 particles /Ncm3

at the end of the exhaust pipe, very high relative to soot

Investigated:

2 stroke motor scooter4 stroke motor bike (2)gasoline DI research engine (industries)gasoline 4 stroke power generator (2)Diesel power generator

Result of DLR-ME:Toxicity, see below

Scooter


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Transmitter TX

Receiver RXRetro-reflector

Open-Path Ultra-Violet Spectrophotometry, Naples

Optical Extinction of the Atmosphere

1. Confined O2+N22. Ambient AIR


Folie 9

O2 21%O3 102 µg/m3

NO2 130 µg/m3

EC 70 µg/m3

Nitrate 60 µg/m3

Extinction spectrum measured 1m above ground


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0

2

4

6

8

10

12

14

200 220 240 260 280 300 320 340 360 380 400

wavelength , nm

Ke

xt

, 1

/k

m <---- Experimental

<------- Built from Known Species

O2

O3EC

nitrate

NOC

Reconstruction of the Atmospheric Extinction Spectrumincluding the Contribution of NOC = 30 μg / m3

dp= 2 nm ⇒ Number Concentration Np> 109 / cm3


Folie 11

Verdünnungsfaktor

10-4 10-3 10-2 10-1 100

Rel

. Lum

ines

zenz

(Lux

i/Lux

0)

0.0

1.0

2.0

3.0

4.0

5.0

BMW

Rel

. Flu

ores

zenz

(Flu

x/Flu

0)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Verdünnungsfaktor

10-4 10-3 10-2 10-1 100

Rel

. Lum

ines

zenz

(Lux

i/Lux

0)

0.0

1.0

2.0

3.0

4.0

5.0Vespa

Rel

. Flu

ores

zenz

(Flu

x/Flu

0)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

BMW4 stroke engineno catalytic converter

Vespa2 stroke engine

Nanoparticle Samples from Motor BikesSWITCH-Test of DLR-ME using Salmonellae bacterias

In both cases:50% of the bacterias survive@ 2E10 particles/scm(mass of 3000 u assumed)


Folie 12Verdünnungsfaktor10-4 10-3 10-2 10-1 100

Rel

ativ

es Z

ellw

achs

tum

0.0

0.2

0.4

0.6

0.8

1.0Menschliche Lungenzellen A549

Inkubationszeit

30 m

in 1 h

2 h

4 h

24h

30 m

in 1 h

2 h

4 h

24h

30 m

in 1 h

2 h

4 h

24h

Rel

ativ

e G

enex

pres

sion

no

rmal

isie

rt a

uf B

2M-E

xpre

ssio

n

-6

-4

-2

2

4

6

* *1/-1

Inkubationszeit

1 h 2 h 4 h 1 h 2 h 4 h 1 h 2 h 4 h

Rel

ativ

e G

enex

pres

sion

nor

mal

isie

rt a

uf B

2M-E

xpre

ssio

n

-6

-4

-2

2

4

6

* *

** *

-1/1

GADD45beta CDKN1A IL-6 Significance*

Nanoparticle samples from a Propane (C3H8) flameGene expression in human lung cell solutions (DLR-ME)

Inkubationszeit

30 m

in 1 h

2 h

4 h

24h

30 m

in 1 h

2 h

4 h

24h

30 m

in 1 h

2 h

4 h

24h

Rel

ativ

e G

enex

pres

sion

no

rmal

isie

rt a

uf B

2M-E

xpre

ssio

n

-6

-4

-2

2

4

6

*

1/-1

Inkubationszeit

30 m

in1 h2 h4 h30

min1 h2 h4 h

30 m

in1 h2 h4 h

Rel

ativ

e G

enex

pres

sion

norm

alis

iert

auf

B2M

-Exp

ress

ion

-6

-4

-2

2

4

6

**

** *

*

*

*

*

-1/1


Folie 13

Conclusion

Nanoparticles are species between polyaromatics and soot.They can be measured by a variety of methods such as optical UV extinction, mass spectrometry and others.They are predominantly emitted from instationary combustion sources(engines)According to UV extinction measurements they are present in theatmosphere in high numbersExperiments using bacterias and human lung cells indicate a high toxicity(cytotoxicity as well as genotoxicity)In the current EU regulation on PM10 the particle mass is measured. This grossly underrates nanoparticles due to their small masses.

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