biomonitoring of air pollution exposure and pathological

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