Biomonitoring of Air Pollution Exposure and

Pathological Changes in Individuals

Junfeng (Jim) Zhang, PhD

Professor of Global and Environmental Health

Highlights

Exposure Biomarker for diesel nitro-PAHsUrine (CEF published work)

Urine (HEART study)

Hb-adducts of BaP and nitro-PAHs

Biomarkers of physiological response/pathway

MDA

8-OHdG

nitrite

Exposure Biomarker for diesel nitro-PAHs

Urine

Diesel exhaust (DE) is a significant source of air

pollution that has been linked to respiratory and

cardiovascular morbidity and mortality.

Nitro-PAHs have been detected from diesel

exhaust particles, and appear to be a more specific

marker of DE exposure.

Nitro-PAHs, once inhaled, can be partially

metabolized to the corresponding amino-PAHs

and excreted in urine.

Nitroreductase

cytochrome P-450

+

Hydrolysis Hydrolysis

Hemoglobin adducts DNA adducts

1-Nitro-Pyrene 1-Amino-Pyrene

1-Nitroso-Pyrene

Exposure Biomarker for diesel nitro-PAHs

CEF study

• An HPLC-fluorescence system was used to

analyze 1-aminopyrene in human urine

samples collected prior to and during 24 h

following the start of 1 h controlled

exposure to DE (target concentration 300

µg/m3 as PM10) and clean air control.

Exposure Biomarker for diesel nitro-PAHs

Beijing Olympic study

1&2-amino-naphthalene

-40

-20

0

20

40

60

0 1 2 3

Total PAHs

0 1 2 3

B[a]P

0 1 2 3

pyrene

0 1 2 3

EC

0 1 2 3

PN

0 1 2 3

PM2.5

0 1 2 3

O3

0 1 2 3

NO2

Perc

ent changes in 1

&2-A

N

per

IQR

incre

ases in p

ollu

tants

Pollutant * Lag

0 1 2 3

CO

1-amino-pyrene

-40

-20

0

20

40

60

80

Perc

ent changes in 1

-AP

per

IQR

incre

ases in p

ollu

tants

Pollutant * Lag

0 1 2 3

CO

0 1 2 3

NO2

0 1 2 3

O3

0 1 2 3

PM2.5

0 1 2 3

PN

0 1 2 3

EC

0 1 2 3

pyrene

0 1 2 3

B[a]P

0 1 2 3

Total PAHs

1-OH-pyrene

-20

0

20

40

60

Perc

ent changes in 1

-OH

P

per

IQR

incre

ases in p

ollu

tants

Pollutant * Lag

0 1 2 3

CO

0 1 2 3

NO2

0 1 2 3

O3

0 1 2 3

PM2.5

0 1 2 3

PN

0 1 2 3

EC

0 1 2 3

pyrene

0 1 2 3

B[a]P

0 1 2 3

Total PAHs

• The formation of DNA and protein adducts

from benzo[a]pyrene

Exposure Biomarker for diesel nitro-PAHs

Hemoglobin adducts

Biomarkers of physiological response /

pathway

Particulate Matter

Epithelial cells•Mitochondria•NADPH oxidase

Fenton reactions•Transit metals: Fe, Cu, V, Cr, etc

Inflammation•Macrophage cells• iNOS (NO synthase)

DNA oxidation Lipid peroxidation • Oxidation of NO

8-OHdG MDA

ω-6-polyunsaturated acidsDNA repair

RS-NO RS-H

Biomarkers of physiological response / pathway

malondialdehyde (MDA)

Spectrophotometry

(TBARS)

Rapid

Easy

Economical

Less specific

Less sensitive

Less reproducible

HPLC-FL

Specific

Reproducible

Easily available

Require derivatization

GC-MSMS

Specific

Reproducible

Sensitive

Pre-treatment required

On-fibrederivatization

LC-MSMS

Specific

Reproducible

Sensitive

Costly

Derivatizationrequired

• Free MDA VS Total MDA

– Broncho-alveolar lavage fluid (BALF)

– Urine

– Serum

Biomarkers of physiological response / pathway

malondialdehyde (MDA)

y = 0.2053x - 2.2772

R² = 0.7868

0

500

1000

1500

2000

2500

0.0 2000.0 4000.0 6000.0 8000.0 10000.0 12000.0

Fre

e M

DA

(n

M)

Total MDA (nM)

Free and total MDA

Urine

Free and total MDA

Serum

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

Total MDA Free MDA

MD

A c

on

cen

tra

tin

(µ

M)

Asthmatic non-Asthmatic

**

*

Biomarkers of physiological response / pathway

Animal Inhalation Chambers

Flow rate= 35 L/minVelocity= 0.0004 m/sTemp= 24 ± 1 ᵒCLighting= natural day/night cycle

Biomarkers of physiological response / pathway

MDA: Animal Inhalation Chambers

Pregnant rats after

14 day exposure

Pups at 3 or 8 wks

old (male + female)

-15

-10

-5

0

5

10

15

20

25

30

Lag0 Lag1 Lag2 Lag3 Lag4 Lag5 Lag6 Lag0 Lag1 Lag2 Lag3 Lag4 Lag5 Lag6

% changes in EBC MDA associated with IQR increases in

ambient SO2 and PM2.5

SO2 PM2.5

Biomarkers of physiological response / pathway

MDA: Beijing Olympic study

-10

-5

0

5

10

15

20

25

30

35

Lag0 Lag1 Lag2 Lag3 Lag4 Lag5 Lag6 Lag0 Lag1 Lag2 Lag3 Lag4 Lag5 Lag6

% changes in Urine MDA associated with IQR increases in

ambient SO2 and PM2.5

Biomarkers of physiological response / pathway

MDA: Beijing Olympic study

• Analyzing methods

Biomarkers of physiological response / pathway

8-hydroxy-2’-deoxyguanosine (8-OHdG)

LC-MSMS

• Specific

• More sensitive

HPLC-ECD

• Specific

• Sensitive

• Possible interferences from the biological matrix

ELISA

• Easy to perform

• Non-specific

• Lower reproducibility

Ref: Rapid Commun. Mass Spectrom. 2004; 18: 505-510

Biomarkers of physiological response / pathway

Urinary 8-OHdG: Beijing Olympic study

-40

-20

0

20

40

60

80

100

120

Lag0 Lag1 Lag2 Lag3 Lag4 Lag5 Lag6 Lag0 Lag1 Lag2 Lag3 Lag4 Lag5 Lag6

% changes in urine 8-OHdG associated with IQR increases in

ambient SO2 and PM2.5

• HPLC-UV

– Sensitive

– Reproducible

– Easy to perform (no pretreatment required for

exhaled breath condensate and BALF samples)

Biomarkers of physiological response / pathway

Nitrite

-15

-10

-5

0

5

10

15

20

25

30

35

Lag0 Lag1 Lag2 Lag3 Lag4 Lag5 Lag6 Lag0 Lag1 Lag2 Lag3 Lag4 Lag5 Lag6

% changes in EBC Nitrite associated with IQR increases in

ambient SO2 and PM2.5

Biomarkers of physiological response / pathway

Nitrite: Beijing Olympic study

Jake Chung

Mingquan Li

Xiaoxing Cui

Drew Day

Marlyn Duarte

PI: Junfeng (Jim) Zhang

Jicheng Gong

Hailong HanLinchen He